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Urbanecology and environmental planning


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Urbanecology and environmental planning

  2. 2. CONTENTS UNIT I INTRODUCTION  Introduction to Urban Eco-systems.  Basis of environmental science.  Ecology,  Ecosystems,  Habitat,  Structure of the ecosystem,  major ecosystems,  productivity of ecosystemsadaptation.  Flow of energy,  food chain,  ecological pyramids,  predation, regulatory forces.  Components of natural and built environment UNIT II CONCEPTS AND APPROACHES TO ECOLOGICAL PLANNING  Different types of life supporting services provided by the nature.  General concept of urban ecological planning.  Impact of urbanization on nature.  Impact of industrialization on nature.  Resiliency and Biodiversity  resources planning and climate resilient urban development. UNIT III HUMAN INFLUENCE ON ECO-SYSTEM  Examination of critical issues underlying the current and future environmental problems.  Human impact on environment.  Modification of natural environment  Current conditions of natural resources like land,water,air.  Over exploitation of natural resources,agriculture,fishing, mineral resources,energy resource, forest wealth etc. UNIT IV EFFECTS OF GROWING POPULATION ON ECO-SYSTEMS  Population and pollution,  Overcrowding and congestions,  Hygiene and health problems. Sanitation, water supply,solid and fluid waste generation and disposal problem,  Changing climate of the cities-urban heat island,urban flood, etc.  Urban heat island (uhi)  Urban flooding  Energy and human settlement.  Ecological land planning:  Preservation and protection of ecologically sensitive areas,  Rehabilitation of degraded sites,  Development of sites/ land in accordance to their environmental properties. UNIT V GLOBAL ISSUES ON MODERN CITIES  Global environmental problems:  Overview of Government of India’s policies,  United Nations contribution to address these issues.
  3. 3. UNIT I INTRODUCTION Introduction to Urban Eco-systems. Urban ecosystem, any ecological system located within a city or other densely settled area or, in a broader sense, the greater ecological system that makes up an entire metropolitan area. This is the growth in the urban population and the supporting built infrastructure has affected both urban environments and also on areas which surround urban areas. These include semi or 'peri-urban' environments that fringe cities as well as agricultural and natural landscapes. Semi environments can also be called peri-urban. The Structure of Urban Ecosystems Urban ecosystems, like all ecosystems, are composed of biological components (plants, animals, and other forms of life) and physical components (soil, water, air, climate, and topography). In all ecosystems these components interact with one another within a specified area. 1. The physical complex includes buildings, transportation networks, modified surfaces (e.g., parking lots, roofs, and landscaping), and the environmental alterations resulting from human decision making. 2. The physical components of urban ecosystems also include energy use and the import, transformation, and export of materials. Such energy and material transformations involve not only beneficial products (such as transportation and housing) but also pollution, wastes, and excess heat. 3. Urban ecosystems are often warmer than other ecosystems that surround them, have less infiltration of rainwater into the local soil, and show higher rates and amounts of surface runoff after rain and storms. Heavy metals, calcium dust, particulates, and human-made organic compounds(e.g., fertilizers, pesticides, and contaminants from pharmaceutical and personal care products) are also concentrated in cities. 4. The expansion of large urban areas results in the conversion of forests, wetlands, deserts, and other adjacent biomes into areas devoted to residential, industrial, commercial, and transportation uses. 5. Urban animal communities tend to be dominated by medium-size generalists, such as raccoons, coyotes, opossums, skunks, foxes, and other animals capable of surviving across a wide range of environmental conditions. 6. Introduced groups include rodents, earthworms, shade trees, weeds, and insect pests. In addition, animal populations in urban areas sometimes show evidence of genetic differentiation from rural populations of the same species
  4. 4. Basis of environmental science. Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences (including ecology, biology, physics, chemistry, zoology, mineralogy, oceanology, limnology, soil science, geology, atmospheric science, and geodesy) to the study of the environment, and the solution of environmental problems. Environmental science came alive as a substantive, active field of scientific investigation in the 1960s and 1970s driven by (a) the need for a multi-disciplinary approach to analyze complex environmental problems, (b) the arrival of substantive environmental laws requiring specific environmental protocols of investigation and (c) the growing public awareness of a need for action in addressing environmental problems A program that focuses on the application of biological, chemical, and physical principles to the study of the physical environment and the solution of environmental problems, including subjects such as abating or controlling environmental pollution and degradation; the interaction between human society and the natural environment; and natural resources management. Includes instruction in biology, chemistry, physics, geosciences, climatology, statistics, and mathematical modeling. Ecology, 1. Ecology is the scientific analysis and study of interactions among organisms and their environment. 2. It is an interdisciplinary field that includes biology, geography, and Earth science. 3. Ecology includes the study of interactions that organisms have with each other, other organisms, and with abiotic components of their environment. 4. Topics of interest to ecologists include the diversity, distribution, amount (biomass), and number (population) of particular organisms, as well as cooperation and competition between organisms, both within and among ecosystems. Ecologists seek to explain:  Life processes, interactions, and adaptations  The movement of materials and energy through living communities  The successional development of ecosystems  The abundance and distribution of organisms and biodiversity in the context of the environment.
  5. 5. Ecosystems, 1. Ecosystems are composed of dynamically interacting parts including organisms, the communities they make up, and the non-living components of their environment. 2. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and various niche construction activities, regulate the flux of energy and matter through an environment. 3. An ecosystemis a community of living organisms in conjunction with the nonliving components of their environment (things like air, water and mineral soil), interacting as a system. 4. These biotic and abiotic components are regarded as linked together through nutrient cycles and energy flows. 5. As ecosystems are defined by the network of interactions among organisms, and between organisms and their environment, they can be of any size but usually encompass specific, limited spaces. 6. An ecosystem is all the living and nonliving things in a certain area. All the plants and animals, even the microorganisms that live in the soil, are living parts of an ecosystem. Air, water, and rocks are nonliving parts of an ecosystem. Habitat,  A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism.  The term typically refers to the zone in which the organism lives and where it can find food, shelter, protection and mates for reproduction.  It is the natural environment in which an organism lives, or the physical environment that surrounds a species population.  A habitat is made up of physical factors such as soil, moisture, range of temperature, and light intensity as well as biotic factors such as the availability of food and the presence or absence of predators.  A habitat is not necessarily a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, and for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body.  Habitat types include polar, temperate, subtropical and tropical.  The terrestrial vegetation type may be forest, steppe, grassland, semi-arid or desert.  Fresh water habitats include marshes, streams, rivers, lakes, ponds and estuaries, and
  6. 6.  marine habitats include salt marshes, the coast, the intertidal zone, reefs, bays, the open sea, the sea bed, deep water and submarine vents. Habitats change over time.  This may be due to a violent event such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents; or the change may be more gradual over millennia with alterations in the climate, as ice sheets and glaciers advance and retreat, and as different weather patterns bring changes of precipitation and solar radiation.  Other changes come as a direct result of human activities; deforestation, the ploughing of ancient grasslands, the diversion and damming of rivers, the draining of marshland and the dredging of the seabed.  The introduction of alien species can have a devastating effect on native wildlife, through increased predation, through competition for resources or through the introduction of pests and diseases to which the native species have no immunity. Structure of the ecosystem, Each ecosystemhas two main components: (1) Abiotic (2) Biotic (1) Abiotic Components: The non-living factors or the physical environment prevailing in an ecosystem form the abiotic components. They have a strong influence on the structure, distribution, behavior and inter- relationship of organisms. Abiotic components are mainly of two types: (a) Climatic Factors: Which include rain, temperature, light, wind, humidity etc. (b) Edaphic Factors: Which include soil, pH, topography minerals etc.?
  7. 7. (2) Biotic Components: The living organisms including plants, animals and micro-organisms (Bacteria and Fungi) that are present in an ecosystem form the biotic components. On the basis of their role in the ecosystemthe biotic components can be classified into three main groups: (A) Producers (B) Consumers (C) Decomposers or Reducers. (A) Producers: The green plants have chlorophyll with the help of which they trap solar energy and change it into chemical energy of carbohydrates using simple inorganic compounds namely water and carbon dioxide. This process is known as photosynthesis. As the green plants manufacture their own food they are known as Autotrophs (i.e. auto = self, trophos = feeder) The chemical energy stored by the producers is utilised partly by the producers for their own growth and survival and the remaining is stored in the plant parts for their future use. (B) Consumers: The animals lack chlorophyll and are unable to synthesise their own food. Therefore, they depend on the producers for their food. They are known as heterotrophs The consumers are of four types, namely: (a) Primary Consumers or First Order Consumers or Herbivores: These are the animals which feed on plants or the producers. They are called herbivores. Examples are rabbit, deer, goat, cattle etc. (b) Secondary Consumers or Second Order Consumers or Primary Carnivores: The animals which feed on the herbivores are called the primary carnivores. Examples are cats, foxes, snakes etc. (c) Tertiary Consumers or Third Order Consumers: These are the large carnivores which feed on the secondary consumers. Example are Wolves. (d) Quaternary Consumers or Fourth Order Consumers or Omnivores: These are the largest carnivores which feed on the tertiary consumers and are not eaten up by any other animal. Examples are lions and tigers.
  8. 8. (C) Decomposers or Reducers: Bacteria and fungi belong to this category. They breakdown the dead organic materials of producers (plants) and consumers (animals) for their food and release to the environment the simple inorganic and organic substances produced as by-products of their metabolisms.
  9. 9. major ecosystems, Six major ecosystems of the world are as follows: 1. Fresh Water Ecosystem 2. Marine (Ocean) Ecosystem 3. Grassland Ecosystem 4. Forest Ecosystem 5. Desert Ecosystem 6. Cropland Ecosystem. 1. Fresh Water Ecosystem: Fresh water habitats can be divided into two categories: (i) Standing water or lentic (calm)—lake, pond, swamp or bog. (ii) Running water or lotic (washed)—river, spring, stream. 2. Marine (Ocean) Ecosystem: The marine ecosystemis different from fresh water ecosystemmainly because of its salty water and also because: (i) The sea covers 70 per cent of earth’s area, (ii) The sea is deep, (iii) The sea is continuous, and (iv) The sea water is in continuous circulation. 3. Grassland Ecosystem: Grasslands occupy about 19 per cent of the earth’s area, which include tropical and temperate grasslands. In this, the savannah ecosystem is very important. 4. Forest Ecosystem: About 30 per cent of the land area of the earth is under forest cover, but due to man’s intervention this area is gradually becoming smaller. But still forest ecosystem is very important. 5. Desert Ecosystem: Deserts generally occur in regions having less than 25 cms of rainfall and are unevenly distributed. Scarcity of rainfall may be due to: (i) High sub-tropical pressure, as in the Sahara and Australian deserts, (ii) Geographical position in rain shadows, or (iii) High altitude as in Tibetan, Gobi, Bolivia deserts.
  10. 10. There are three life forms of plants that are adapted to deserts: (i) The annuals, which avoid drought by growing only when there is adequate moisture, (ii) The succulents, such as the cacti, which store water, and (iii) The desert shrubs, which have numerous branches and a special root system which help them to adapt to desertic conditions. 6. Cropland Ecosystem: Apart from above mentioned natural ecosystems, there are also man-engineered ecosystems. One such ecosystem is the cropland ecosystem, in which man has developed croplands after considering the soil, climatic and other environmental conditions. These are ecosystems of dominant crop species like wheat, maize, jowar, paddy, sugarcane, cotton, tea, coffee, etc. productivity of ecosystems adaptation.  A terrestrial ecosystemis a type of ecosystem found only on biomes. Six primary terrestrial ecosystems exist: tundra, taiga, temperate deciduous forest, tropical rain forest, grassland and desert.  A community of organisms and their environment that occurs on the land masses of continents and islands. Terrestrial ecosystems are distinguished from aquatic ecosystems by the lower availability of water and the consequent importance of water as a limiting factor. Terrestrial ecosystems are characterized by greater temperature fluctuations on both a diurnaland seasonal basis than occur in aquatic ecosystems in similar climates.  Organisms in terrestrial ecosystems have adaptations that allow them to obtain water when the entire body is no longer bathed in that fluid, means of transporting the water from limited sites of acquisition to the rest of the body, and means of preventing the evaporation of water from body surfaces.  They also have traits that provide body support in the atmosphere, a much less buoyant medium than water, and other traits that render them capable of withstanding the extremes of temperature, wind, and humidity that characterize terrestrial ecosystems. Finally, the organisms in terrestrial ecosystems have evolved many methods of transporting gametes in environments where fluid flow is much less effective as a transport medium. Flow of energy, Ecosystems maintain themselves by cycling energy and nutrients obtained from external sources. At the first trophic level, primary producers (plants, algae, and some bacteria) use solar energy to produce organic plant material through photosynthesis.
  11. 11. Herbivores—animals that feed solely on plants—make up the second trophic level. Predators that eat herbivores comprise the third trophic level; if larger predators are present, they represent still higher trophic levels. Organisms that feed at several trophic levels (for example, grizzly bears that eat berries and salmon) are classified at the highest of the trophic levels at which they feed. Decomposers, which include bacteria, fungi, molds, worms, and insects, break down wastes and dead organisms and return nutrients to the soil. food chain, A food chain is a linear network of links in a food web starting from producer organisms (such as grass or trees which use radiation from the Sun to make their food) and ending at apex predator species (like grizzly bears or killer whales), detritivores (like earthworms or woodlice), or decomposer species (such as fungi or bacteria).
  12. 12. ecological pyramids, An ecological pyramid (also trophic pyramid, eltonian pyramid or sometimes food pyramid) is a graphical representation designed to show the biomass or bio productivity at each trophic level in a given ecosystem. predation, regulatory forces. The word predator often invokes a vision of a fierce and cruel animal the world would be better without. However, predation is a major ecological process controlling both the structure and function of communities. Predation affects the distribution and abundance of species, the strength and direction of energy flow within a system and the diversity and composition of communities. Predators play an essential role in evolution. Traits that decrease the likelihood of being predated and traits that increase the efficacy of the predating are under strong selection. Key Concepts  Predators are animals which actively catch and consume other animals.  Predators may be limited in the type of prey they consume; these limitations may be extrinsic, due to factors such as prey abundance, or they may be intrinsic, where the predators’ physiological, reproductive or ecological requirements result in specialization on certain types of prey.  Predation is a crucial ecological force because it moves energy through the system.
  13. 13.  Mathematical models and empirical research illustrate how predators and their prey coexist and should cycle through time.  Prey species evolve defenses that reduce their vulnerability to predators whereas predators evolve adaptations to counter the defenses of the prey.  Predator–prey interactions structured ancient, fossil ecosystems and played a role in determining the history of life on earth. Components of natural and built environment Natural environment refers to naturally occurring landforms such as mountains, plains, valleys, canyons plateaus and barrier islands, etc... The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species. The concept of the natural environment can be distinguished by components: 1. Complete ecological units that function as natural systems without massive human intervention, including all vegetation, microorganisms, soil, rocks, atmosphere and natural phenomena that occur within their boundaries. 2. Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water, and climate, as well as energy, radiation, electric charge, and magnetism, not originating from human activity. the term built environment, or built world, refers to the man-made surroundings that provide the setting for human activity, ranging in scale from buildings to parks. It has been defined as "the humanitarian-made space in which people live, work, and recreate on a day-to-day basis. The "built environment encompasses places and spaces created or modified by people including buildings, parks, and transportation systems."
  14. 14. UNIT II CONCEPTS AND APPROACHES TO ECOLOGICAL PLANNING Different types of life supporting services provided by the nature. Ecosystem services are the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystems, grassland ecosystems and aquatic ecosystems. Ecosystem services Ecosystem services are the direct and indirect contributions of ecosystems to human well-being. They support directly or indirectly our survival and quality of life. Ecosystem services can be categorized in four main types: Provisioning services are the products obtained from ecosystems such as food, fresh water, wood, fiber, genetic resources and medicines. Regulating services are defined as the benefits obtained from the regulation of ecosystem processes such as climate regulation, natural hazard regulation, water purification and waste management, pollination or pest control. Habitat services highlight the importance of ecosystems to provide habitat for migratory species and to maintain the viability of gene-pools. Cultural services include non-material benefits that people obtain from ecosystems such as spiritual enrichment, intellectual development, recreation and aesthetic values.
  15. 15. Some examples of key services provided by ecosystems are described below: Climate regulation is one of the most important ecosystem services on globally. However, the climate regulating function of peatlands depends on land use and intensification (such as drainage and conversion to agriculture) and is likely to have profound impacts on the soil capacity to store carbon and on carbon emissions (great quantities of carbon are being emitted from drained peatlands). Water purification by ecosystems has a high importance for Europe, because of the heavy pressure on water from a relatively densely populated region. Both vegetation and soil organisms have profound impacts on water movements: vegetation is a major factor in controlling floods, water flows and quality; vegetation cover in upstream watersheds can affect quantity, quality and variability of water supply; soil micro-organisms are important in water purification; and soil invertebrates influence soil structure, decreasing surface runoff. Forests, wetlands and protected areas with dedicated management actions often provide clean water at a much lower cost than man-made substitutes like water treatment plants. Pests and diseases are regulated in ecosystems through the actions of predators and parasites as well as by the defense mechanisms of their prey. One example of these regulating services is provided by insectivorous birds in farms that use most of their land for agriculture. Soil biodiversity is a major factor in soil formation, which supports a range of provisioning services such as food, fiber and fuel provision and is fundamental to soil fertility, being a highly important ecosystem service in Europe. In addition, a diverse soil community will help prevent loss of crops due to soil-borne pest diseases. • purification of air and water. • mitigation of droughts and floods. • generation and preservation of soils and renewal of their fertility. • detoxification and decomposition of wastes. • pollination of crops and natural vegetation. • dispersal of seeds. • cycling and movement of nutrients. • control of the vast majority of potential agricultural pests. • maintenance of biodiversity. • protection of coastal shores from erosion by waves. • protection from the sun’s harmful ultraviolet rays. • partial stabilization of climate. • moderation of weather extremes and their impacts. • provision of aesthetic beauty and intellectual stimulation that lift the human spirit.
  16. 16. General concept of urban ecological planning. The basic principles of construction of ecological city the main building of ecological city following aspects need to follow the principles • the principle of sustainable development; • people-oriented, the principles of harmonious development; • economic, social and ecological benefits of coordinated development principles; • both environmental protection and economic development principles; • local conditions, highlighting the principle driving force of innovation; • according to the development, the principle of overall planning; The basic elements of ecological city construction. Development of a city by the industrial engineering, agricultural engineering, forestry engineering, water conservancy, energy, engineering, tourism, landscape engineering, cultural engineering, environmental engineering, home construction and development capacity building project together. Ecological function zoning of urban economy (1) Human ecological zone, (2) Ecological Agriculture Development Area, (3) Ecological and economic coordination and development zones, (4) Cultivating ecological protection zone, urban ecological problems arising from 1 Urbanization environmental problems caused by lack of awareness. 2 Urban expansion pressures on the environment 3 population growth environmental problems caused by Impact of urbanization on nature. Urbanization is the increase in the proportion of people living in towns and cities. Urbanization occurs because people move from rural areas to urban areas. 1. Impact on atmosphere and climate  Creation of heat island.  Change in air quality.  Change in patterns and precipitation. 1. The creation of heat island Materials like concrete, asphalt, bricks etc absorb and reflect energy differently than vegetation and soil. Cities remain warm in the night when the countryside has already cooled. 2. Changes in Air Quality
  17. 17. Human activities release a wide range of emissions into the environment including carbon dioxide, carbon monoxide, ozone, sulfur oxides, nitrogen oxides, lead, and many other pollutants. 3. Changes in Patterns of Precipitation Cities often receive more rain than the surrounding countryside since dust can provoke the condensation of water vapor into rain droplets. 2. Impact on lithosphere and land resources  Erosion and other changes in land quality.  Pollution. 1. Erosion and other changes in land quality Rapid development can result in very high levels of erosion and sedimentation in river channels. 2. Pollution Pollutants are often dispersed across cities or concentrated in industrial areas or waste sites. Lead- based paint used on roads and highways and on buildings is one such example of a widely dispersed pollutant that found its way into soil. Burying tremendous amounts of waste in the ground at municipal and industrial dumps. 3. Impact on hydrosphere and water resources  Flow of Water into Streams.  Flow of Water through Streams.  Degraded Water Quality. 1. Flow of Water into Streams Natural vegetation and undisturbed soil are replaced with concrete, asphalt, brick, and other impermeable surfaces. This means that, when it rains, water is less likely to be absorbed into the ground and, instead, flows directly into river channels. 2. Flow of Water through Streams Higher, faster peak flows change streams channels that have evolved over centuries under natural conditions. Flooding can be a major problem as cities grow and stream channels attempt to keep up with these changes. 3. Degraded Water Quality The water quality has degraded with time due to urbanization that ultimately leads to increased sedimentation there by also increasing the pollutant in run-off. 4. Impact on biosphere  Modification of Habitats.  Destruction of Habitats.  Creation of New Habitats. 1. Modification of Habitats The fertilizers that spread across lawns finds its way into water channels where it promotes the growth of plants at the expense of fish. The waste dumped into streams lowers oxygen levels during its decay and cause the die-off of plants and animals.
  18. 18. 2. Destruction of Habitats There is also complete eradication of habitats as an outcome of urbanization and native species are pushed out of cities. 3. Creation of New Habitats New habitats are also created for some native and non-native species. Cities also create habitats for some species considered pests, such as pigeons, sparrows, rats, mice, flies and mosquitoes. Urbanization has, for example, eliminated many bat colonies in caves, but has provided sites such as bridges for these species to nest.  Waste are a major problem in large cities.  Air pollution results from overdependence on motorized transport and from burning of coal to supply energy.  Water pollution results from poor sewage facilities and disposal of industrial heavy metals into waterways.  Vast quantities of solid waste are produced in industries.  Traffic congestion and noise pollution are major environmental impacts of large cities. Impact of industrialization on nature. 1. Pollution. Industrialization normally adds to pollution in air, water, soil, due to the waste products it produces. 2. Extraction. Industrialization makes use of resources - raw materials from the land, water, perhaps wood and plants, fossil fuels, etc. This has an effect on the environment, since demand for all these goes up, and more quantities are extracted from the land. 3. Urbanization. Industrialization needs people to work in factories. So, people move from rural/agricultural areas, that are spread out, to industrialized cities, that are concentrated. A higher population puts added pressure on the local environment. 4. Waste material. Industrialization produces a greater amount of waste, both directly as a result of production of goods, as well as the disposal of those goods once their purpose has been served. For example, if a factory makes plastic furniture, it produces waste plastic … and once the plastic furniture is worn, it is added to the rubbish pile too. Resiliency and Biodiversity Ecosystemresilience referstothe capacityof an ecosystemtorecoverfrom disturbance orwithstand ongoingpressures. It isa measure of howwell anecosystemcantolerate disturbancewithoutcollapsingintoadifferent state that is controlledbyadifferentsetof processes.
  19. 19. Resilience isnotabouta single ideal ecological state,butaneverchangingsystemof disturbance and recovery. resources planning and climate resilient urban development.
  20. 20. UNIT III HUMAN INFLUENCE ON ECO-SYSTEM Examination of critical issues underlying the current and future environmental problems. Present and future Environmental Problems  Air Pollution:  Water Pollution:  Soil and Land Pollution:  Climate Change:  Global Warming:  Deforestation:  Increased Carbon Footprint:  Genetic Modification:  Effect on Marine Life:  Public Health Issues:  Overpopulation:  Loss of Biodiversity:  Household and Industrial Waste:  Ozone Layer Depletion:  Mining:  Natural Resource Depletion:  Natural Disasters:  Nuclear Issues:  Loss of Endangered Species:  Acid Rain:  Agricultural Pollution:  Light and Noise Pollution:  Urban Sprawl:  Medical Waste:  Littering and Landfills: Human impact on environment. Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity, and other resources. The term anthropogenic designates an effect or object resulting from human activity. in reference to human influences on climax plant communities. The term is sometimes used in the context of pollution emissions that are produced as a result of human activities but applies broadly to all major human impacts on the environment.  Causes o Technology o Agriculture
  21. 21.  Fishing  Irrigation  Agricultural land loss and soil erosion  Meat production o Introductions and invasive species o Energy industry  Biodiesel  Coal mining and burning  Electricity generation  Nuclear power  Oil and Petroleum industry  Reservoirs  Wind power o Light pollution o Manufactured products  Cleaning agents  Nanotechnology  Leather  Paint  Paper and Plastics  Pesticides, Pharmaceuticals and personal care products o Mining o Transport  Aviation  Roads  Shipping o War  Effects o Biodiversity o Coral reefs o Carbon cycle o Nitrogen cycle o Effects on human health Modification of natural environment The natural environment encompasses all living and non-living things occurring naturally, This environment encompasses the interaction of all living species, climate, weather, and natural resources that affect human survival and economic activity. In contrast to the natural environment is the built environment. In such areas where man has fundamentally transformed landscapes such as urban settings and agricultural land conversion, the natural environment is greatly modified into a simplified human environment. Even acts
  22. 22. which seem less extreme, such as building a mud hut or a photovoltaic system in the desert, modify the natural environment into an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams and the works of Mound-building termites are thought of as natural. Classification: 1 Residential & Commercial Development 1.1 Housing & Urban Areas Human cities, towns, and settlements including non-housing development typically integrated with housing 1.2 Commercial & Industrial Areas Factories and other commercial centers 1.3 Tourism & Recreation Areas Tourism and recreation sites with a substantial footprint 2 Agriculture & Aquaculture Farming and ranching as a result of agricultural expansion and intensification, including silviculture, mariculture and aquaculture 2.1 Annual & Perennial Non-Timber Crops Crops planted for food, fodder, fiber, fuel, or other uses 2.2 Wood & Pulp Plantations Stands of trees planted for timber or fiber outside of natural forests, often with non-native species 2.3 Livestock Farming & Ranching Domestic terrestrial animals raised in one location on farmed or non-local resources (farming); also domestic or semi-domesticated animals allowed to roam in the wild and supported by natural habitats (ranching) 2.4 Marine & Freshwater Aquaculture Aquatic animals raised in one location on farmed or non-local resources; also hatchery fish allowed to roam in the wild 3 Energy Production & Mining 3.1 Oil & Gas Drilling Exploring for, developing, and producing petroleum and other liquid hydrocarbons
  23. 23. 3.2 Mining & Quarrying Exploring for, developing, and producing minerals and rocks 3.3 Renewable Energy Exploring, developing, and producing renewable energy 4 Transportation & Service Corridors 4.1 Roads & Railroads Surface transport on roadways and dedicated tracks 4.2 Utility & Service Lines Transport of energy & resources 4.3 Shipping Lanes Transport on and in freshwater and ocean waterways 4.4 Flight Paths Air and space transport 5 Biological Resource Use 5.1 Hunting & Collecting Terrestrial Animals Killing or trapping terrestrial wild animals or animal products for commercial, recreation, subsistence, research or cultural purposes, or for control/persecution reasons; includes accidental mortality/bycatch 5.2 Gathering Terrestrial Plants Harvesting plants, fungi, and other non-timber/non-animal products for commercial, recreation, subsistence, research or cultural purposes, or for control reasons 5.3 Logging & Wood Harvesting Harvesting trees and other woody vegetation for timber, fiber, or fuel 5.4 Fishing & Harvesting Aquatic Resources Harvesting aquatic wild animals or plants for commercial, recreation, subsistence, research, or cultural purposes, or for control/persecution reasons; includes accidental mortality/bycatch 6 Human Intrusions & Disturbance 6.1 Recreational Activities People spending time in nature or traveling in vehicles outside of established transport corridors, usually for recreational reasons
  24. 24. 6.2 War, Civil Unrest & Military Exercises Actions by formal or paramilitary forces without a permanent footprint 6.3 Work & Other Activities People spending time in or traveling in natural environments for reasons other than recreation, military activities, or research 7 Natural System Modifications 7.1 Fire & Fire Suppression Suppression or increase in fire frequency and/or intensity outside of its natural range of variation 7.2 Dams & Water Management/Use Changing water flow patterns from their natural range of variation either deliberately or as a result of other activities 7.3 Other Ecosystem Modifications Other actions that convert or degrade habitat in service of “managing” natural systems to improve human welfare 8 Invasive & Other Problematic Species & Genes 8.1 Invasive Non-Native/Alien Species Harmful plants, animals, pathogens and other microbes not originally found within the ecosystem(s) in question and directly or indirectly introduced and spread into it by human activities 8.2 Problematic Native Species Harmful plants, animals, or pathogens and other microbes that are originally found within the ecosystem(s) in question, but have become out-of-balance or released directly or indirectly due to human activities 8.3 Introduced Genetic Material Human altered or transported organisms or genes 9 Pollution 9.1 Household Sewage & Urban Waste Water Water-borne sewage and non-point runoff from housing and urban areas that include nutrients, toxic chemicals and/or sediments 9.2 Industrial & Military Effluents Water-borne pollutants from industrial and military sources including mining, energy production, and other resource extraction industries that include nutrients, toxic chemicals and/or sediments
  25. 25. 9.3 Agricultural & Forestry Effluents Water-borne pollutants from agricultural, silvicultural, and aquaculture systems that include nutrients, toxic chemicals and/or sediments including the effects of these pollutants on the site where they are applied 9.4 Garbage & Solid Waste Rubbish and other solid materials including those that entangle wildlife 9.5 Air-Borne Pollutants Atmospheric pollutants from point and nonpoint sources 9.6 Excess Energy Inputs of heat, sound, or light that disturb wildlife or ecosystems 10 Geological Events 10.1 Volcanoes Volcanic events 10.2 Earthquakes/Tsunamis Earthquakes and associated events 10.3 Avalanches/Landslides Avalanches or landslides 11 Climate Change & Severe Weather 11.1 Habitat Shifting & Alteration Major changes in habitat composition and location 11.2 Droughts Periods in which rainfall falls below the normal range of variation 11.3 Temperature Extremes Periods in which temperatures exceed or go below the normal range of variation 11.4 Storms & Flooding Extreme precipitation and/or wind events
  26. 26. Current conditions of natural resources like land, water, air. Water, air, and soil are three natural resources that we cannot live without. WATER Water is one of the most important natural resources Water covers 71% of the Earth's surface. On Earth, 96.5% of the planet's crust water is found in seas and oceans, 1.7% in groundwater, 1.7% in glaciers and the ice caps of Antarctica and Greenland, a small fraction in other large water bodies, 0.001% in the air as vapor, clouds (formed of ice and liquid water suspended in air), and precipitation. Only 2.5% of this water is freshwater, and 98.8% of that water is in ice (excepting ice in clouds) and groundwater. Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's freshwater (0.003%) is contained within biological bodies and manufactured products. Effects on human civilization  Health and pollution  Human uses o Agriculture o For drinking o Washing o Transportation o Chemical uses o Heat exchange o Fire extinction o Recreation o Water industry o Industrial applications o Food processing o Medical use Water pollution The contamination of water bodies such as lakes, rivers, oceans, underground water and seas by harmful substances is known as water pollution. Polluted water becomes unfit for drinking, bathing, washing and irrigation. The major cause of pollution of water is sewage, industrial wastes, pesticides and fertilizers from farming. Garbage dumping can also leak out pollutants into underground water. The major pollutants are usually lead, mercury, fertilizer and pesticide compounds. For example, the major source of pollution of the Ganga River is sewage and industrial wastes from tanning factories.
  27. 27. SOIL Soil provides nutrients, water, oxygen and heat to natural land areas. Understanding the ability and capacity of soil to support an ecosystem plays an important role in land management decisions. Soil Pollution Soil pollution is the contamination of soil due by harmful substances. Polluted soil becomes unfit for growing crops and plants and is usually accompanied by water pollution. The major causes of soil pollution are over irrigation, pesticides, sewage and garbage dumping, deforestation and mining. The most common pollutants are heavy metals like lead and mercury, pesticide compounds, salt and mineral ores. Water and soil pollution usually occur together as polluted water seeps into soil and contaminates it. Pollutants can also leach out from soil into water bodies when it rains. AIR Air is a third critical resource for humans, plants, animals and all other organisms within a natural area. Air must be monitored in order to control and lower pollution levels, control smoke caused by wildland fires, and to monitor air quality. Air pollution It is the pollution of air by harmful gases (sulphur diffarmingoxide, carbon monoxide, carbon dioxide etc.), smoke and dust. The major pollutants are Carbon dioxide, nitrogen dioxide, nitrous oxide, sulphur dioxide, suspended particulate matter and carbon monoxide. Air pollution is usually caused by burning of fossil fuels like petroleum and coal, burning of wood and cow dung cakes in homes, factories, vehicles and power plants. For example, New Delhi is one of the most air polluted cities in the world because of excessive use of fossil fuels by cars and factories. The effects of air pollution that may impair visibility, harm human health, injure trees and other plants, acidify or cause unnatural fertilization of streams and lakes, leach nutrients from soils, and degrade cultural resources, like archeological sites and historical buildings. Forest activities that can affect air quality such as prescribed burning, ski areas, and mining are also monitored to ensure compliance with air regulations for human health and to monitor possible impacts to natural resources.
  28. 28. Over exploitation of natural resources, agriculture, fishing, mineral resources, energy resource, forest wealth etc. Currently, natural resources, such as water and soil, are greatly over-exploited worldwide. Only their sustainable use will secure the foundations of life for future generations. Economic growth and resource consumption must be decoupled. WHY:  Increase in the sophistication of technology enabling natural resources to be extracted quickly and efficiently. E.g., in the past, it could take long hours just to cut down one tree only using saws. Due to increased technology, rates of deforestation have greatly increased  A rapid increase in population that is now increasing gradually. The current number of 7.132 billion humans consume many natural resources.  Cultures of consumerism. Materialistic views lead to the mining of gold and diamonds to produce jewelry, unnecessary commodities for human life or advancement. Consumerism also leads to extraction of resources for the production of commodities necessary for human life but in amounts excessive of what is needed, because people consume more than is necessary or waste what they have.  Excessive demand often leads to conflicts due to intense competition. Organizations such as Global Witness and the United Nations have documented the connection.  Non-equitable distribution of resources. Natural resources are not limitless, and the following consequences can arise from the careless and excessive consumption of these resources:  Deforestation  Desertification  Extinction of species  Forced migration  Soil erosion  Oil depletion  Ozone depletion  Greenhouse gas increase  Extreme energy  Water pollution  Natural hazard/Natural disaster
  29. 29. Over exploitationof agriculture The environmental impact of agriculture involves a variety of factors from the soil, to water, the air, animal and soil variety, people, plants, and the food itself. Some of the environmental issues that are related to agriculture are climate change, deforestation, genetic engineering, irrigation problems, pollutants, soil degradation, and waste.  Land conversion & habitat loss  Wasteful water consumption  Soil erosion and degradation  Pollution  Climate change  Genetic erosion Over exploitationof fishing Overfishing is a form of overexploitation where fish stocks are reduced to below acceptable levels. Overfishing can occur in water bodies of any sizes, such as ponds, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels The exponential growth in human population experienced in last decades has lead to an overexploitation of marine living resources to meet growing demand for food. Worldwide, fishing fleets are two to three times as large as needed to take present day catches of fish and other marine species and as what our oceans can sustainably support. The use of modern techniques to facilitate harvesting, transport and storage has accelerated this trend. Overexploitation do not only affect open ocean or pelagic ecosystems, but also coastal and intertidal areas Over exploitationof mineral resources (a) Mining is hazardous occupation: 1. This occupation involves several health risk dust produced during mining operation are injurious to health and cause lung diseases. 2. Extraction of some toxic or radioactive minerals leads to life threatening hazards. 3. Dynamite explosion during mining is very risky as fumes produced are extremely poisonous. 4. Underground mining is more hazardous than surface mining as there are more chances if accidents like roof falls, flooding and inadequate ventilation etc.
  30. 30. (b) Rapid depletion of high grade minerals: Increasing demand for high grade minerals has compelled miners to carry out more extraction of minerals, which require more energy sources and produce large amount of waste materials. (c) Wastage of upper soil layer and vegetation: Surface mining results in the complete destruction of upper soil layer and vegetation. After extraction, the wastes are dumped in an area which destroys the total surface and vegetation. (d) Environmental problems: Over exploitation of mineral resources resulted in many environmental problems like: 1. Conversion of productive land into mining and industrial areas. 2. Mining and extraction process are one of the sources of air, water and land pollution. 3. Mining involves huge consumption of energy resources like coal, petroleum, natural gas etc. which are in-turn nonrenewable sources of energy. 4. Surface mining directly degrades the fertile soil surface thus effect ecology and climate if that particular area. Over exploitationof energy resource Conventional energy resources include oil, gas, coal, nuclear and hydel power. These conventional energy resources are usually fossil fuels. The exploitation and utilization of these conventional energy resources would lead to increased greenhouse gas emissions and other environmental damage. Over exploitationof forest wealth Forests are overexploited when they are logged at a rate faster than reforestation takes place. Reforestation competes with other land uses such as food production, livestock grazing, and living space for further economic growth. Historically utilization of forest products, including timber and fuel wood, have played a key role in human societies, comparable to the roles of water and cultivable land. Today, developed countries continue to utilize timber for building houses, and wood pulp for paper. In developing countries almost three billion people rely on wood for heating and cooking. Short-term economic gains made by conversion of forest to agriculture, or overexploitation of wood products, typically leads to loss of long-term income and long term biological productivity. West Africa, Madagascar, Southeast Asia and many other regions have experienced lower revenue because of overexploitation and the consequent declining timber harvests.
  31. 31. UNIT IV EFFECTS OF GROWING POPULATION ON ECO-SYSTEMS Population and pollution, Environmental pollution is directly related to population growth. With the rapid increase in population, the environmental pollution is also increasing day by day. The following causes show the relationship between the population growth and the environmental pollution. Industrialisation: To meet the demands of the people’s needs, a large number of industries have been set up. The factories and mills are responsible for increasing the environmental pollution because they do not make necessary arrangements for disposing their wastes which include toxic chemicals and are great hazards for all sorts of life especially human life. Insecticides and Pesticides: To feed increasing population of the world, extensive use of insecticides and pesticides are used in agriculture. Deforestation: Growth of population has increased deforestation which has be posing serious threat to natural vegetation. Population growth are contributing to many serious environmental problems in India. These include pressure on land, land/soil degradation, forests, habitat destruction and loss of biodiversity, changing consumption pattern, rising demand for energy, air pollution, global warming and climate change and water scarcity and water pollution. Overcrowdingand congestions, Overcrowding or crowding refers to the condition where more people are located within a given space than is considered tolerable from a safety and health perspective which will depend on current environment and local cultural norms. Overcrowding may arise temporarily and/or regularly, in the home, public spaces or on public transport. Effects on quality of life due to crowding may be due to increased physical contact, lack of sleep, lack of privacy and poor hygiene practices. Risks due to overcrowding: Physical: Spread of infectious diseases Psychological: Frustration, anxiety Social: Violence
  32. 32. High morbidity and mortality What is Overpopulation? Overpopulation is an undesirable condition where the number of existing human population exceeds the carrying capacity of Earth. Causes of Overpopulation  Decline in the Death Rate:  Better Medical Facilities:  More Hands to Overcome Poverty:  Technological Advancement in Fertility Treatment:  Immigration:  Lack of Family Planning: Effects of Overpopulation  Depletion of Natural Resources:  Degradation of Environment:  Conflicts and Wars:  Rise in Unemployment:  High Cost of Living: Solutions to Overpopulation  Better Education:  Making People Aware of Family Planning:  Tax Benefits or Concessions:  Knowledge of Sex Education: hygiene and health problems. Sanitation, watersupply, solid and fluid waste generation and disposal problem, 1. Many health problems are associated with poor sanitation and waste management, principally caused by contact with human faces. 2. The main types of infectious agent responsible for communicable diseases are bacteria, viruses, protozoa and parasitic worms. 3. The F diagram shows how infectious agents from faces can be ingested by someone who then becomes infected. 4. Poor sanitation and waste management create conditions that may encourage flies and other disease vectors. 5. Good hygiene behavior, especially handwashing with soap at critical times, can significantly reduce health risks. 6. Diseases associated with poor sanitation affect children’s physical development and school attendance. Poor sanitation facilities in schools also affect attendance, especially for girls.
  33. 33. 7. Healthy people are more productive, which brings economic benefits to them and to the wider community. 8. In industry, minimizing the amount of waste can reduce costs throughout the manufacturing process. 9. Environmental impacts of poor sanitation and waste management at a local level include pollution of land and watercourses, the visual impact of litter, and bad odours. At a global level, applying the 3 Rs to solid waste management can reduce energy use which will reduce greenhouse gas emissions. It effects on:  health  education  economic conditions  the environment.  Effects on health: Good sanitation and waste management help to keep people separate from potential sources of pathogens. They reduce the risk of contaminating water supplies with pathogens and discourage the transmission of disease.  Effects on education: Healthy children have fewer days off school through illness. When they are at school, healthy children learn better than sick children. Providing good sanitation facilities encourages children to attend school, particularly girls during their menstrual periods.  Effects on economic conditions: The health benefits promoted by good sanitation and waste make for a more productive community. Less money is spent on healthcare and people lose fewer days off work through caring for the sick.  Effects on the environment: Good sanitation and waste management means that there will be less faces and waste deposited in public places and less pollution of the water and soil. changing climateof the cities-urban heat island, urbanflood, etc. CITIES HAVE THE POWER TO CHANGE THE WORLD. For centuries, cities have been centers of commerce, culture and innovation, and the birthplace for some of humankind’s greatest ideas. At this critical crossroads in time, we need the ideas that cities can create more than ever. BUT CITIES ARE AS VULNERABLE AS THEY ARE POWERFUL.
  34. 34. 70% of cities are already dealing with the effects of climate change, and nearly all are at risk. Over 90% of all urban areas are coastal, putting most cities on Earth at risk of flooding from rising sea levels and powerful storms. CLIMATE CHANGE CAUSES FINANCIAL DAMAGE TOO. The financial effects of climate change can be just as devastating as the physical ones. Unexpected expenditures from storms, flooding, snow removal and drought can lead to major disruptions in business operations and city budgets. URBAN GROWTH SHOWS NO SIGN OF SLOWING. Cities have become awesome in size, and also greenhouse gas emissions. Larger cities have a ravenous appetite for energy, consuming ⅔ of the world's energy and creating over 70% of global CO2 emissions. BUT IN THE HEART OF THE CITY LIES AN OPPORTUNITY URBAN DENSITY PRESENTS A GREENER WAY TO LIVE WHY CITIES CAN BE THE SOLUTION TO CLIMATE CHANGE. City mayors are directly accountable to their constituents for their decisions, and are more nimble than state and national elected officials to take decisive action—often with immediate and impactful results. What our cities do individually and in unison to address climate change can set the agenda for communities and governments everywhere. CITIES ARE OUR FUTURE. We believe that a better global future lies in urban innovation and action. As the majority of future humans will live in cities, it just makes sense that our solution to climate change will reside there too. URBAN HEAT ISLAND (UHI) An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference usually is larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the urban heat island effect is from the modification of land surfaces. Waste heat generated by energy usage is a secondary contributor. As a population center grows, it tends to expand its area and increase its average temperature. The less-used term heat island refers to any area, populated or not, which is consistently hotter than the surrounding area. Monthly rainfall is greater downwind of cities, partially due to the UHI. Increases in heat within urban centers increases the length of growing seasons, and decreases the occurrence of weak tornadoes. The UHI decreases air quality by increasing the production of pollutants such as ozone, and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems. URBANFLOODING Flooding in urban areas can be caused by flash floods, or coastal floods, or river floods, but there is also a specific flood type that is called urban flooding.
  35. 35. Urban flooding is specific in the fact that the cause is a lack of drainage in an urban area. As there is little open soil that can be used for water storage nearly all the precipitation needs to be transport to surface water or the sewage system. High intensity rainfall can cause flooding when the city sewage system and draining canals do not have the necessary capacity to drain away the amounts of rain that are falling. Water may even enter the sewage system in one place and then get deposited somewhere else in the city on the streets. Urban floods are a great disturbance of daily life in the city. Roads can be blocked, people can’t go to work or to schools. The economic damages are high but the number of casualties is usually very limited, because of the nature of the flood. The water slowly rises on the city streets. When the city is on flat terrain the flow speed is low and you can still see people driving through it. The water rises relatively slow and the water level usually does not reach life endangering heights. energy and humansettlement.
  36. 36. Ecological LandPlanning: Competition for land is increasing as demand for multiple land uses and ecosystem services rises. Food security issues, renewable energy and emerging carbon markets are creating pressures for the conversion of agricultural land to other uses, such as reforestation and biofuels. This is occurring in parallel with other growing demands from land systems for urbanization and recreation, mining, food production, and biodiversity conservation. Land use planning can be of use with regard to finding a balance among competing and sometimes contradictory uses, while promoting sustainable land use options. This brief presents evidence of land use planning, spatial planning, territorial (or regional) planning, and ecosystem- based or environmental land use planning as tools that can strengthen land governance, improve economic opportunities based on sustainable management of land resources, and develop land use options that reconcile conservation and development objectives. An environmental policy instrument to regulate land use and productive activities, to protect the environment, promote the conservation and sustainable use of natural resources, considering land use potential and land degradation trends. It is considered the most appropriate policy instrument to harmonize human activities and environmental sustainability in the short, medium and long term. Rural, subnational level Rehabilitation of abandoned agricultural lands, including both afforestation and pasture rehabilitation, together with a succession option (e.g. leaving pastures as natural succession areas) Preservation and protection of ecologicallysensitiveareas, Environmentally sensitive natural features can either enhance or restrict development, depending on the type and extent of the feature. For example, the crest of a hill may provide a view which adds appeal to a site. Construction on the hillside can create the need to mitigate erosion, which can dramatically increase development costs. However, the cost to the community could be the loss of a natural view. On the other hand, using natural features to accent the development can substantially increase the marketability of the project and enhance its value to the developer. Preservation Preservation measures apply to those features which are so sensitive or valued that any alteration may have negative impacts on aesthetics, property, or environmental quality. Development should either be prohibited or restricted to those projects which have only a slight effect on these features. An identified habitat for endangered plants or animals is an example of
  37. 37. lands requiring preservation techniques. In many instances, the value of these features is so great that specific legislation has been enacted for their protection. Integration In areas where the natural features are an integral part of the community's character, but where minor changes only slightly impact the quality of life, integration may provide adequate protection. Integration allows natural features to co-exist with development, yet remain largely undisturbed. The community should carefully monitor land use in areas rich in these features. Rehabilitation of degraded sites, Rehabilitation should Ensure that • Future public health and safety are not compromised • Environmental resources are not subject to physical and chemical deterioration • Post-mining use of the site is beneficial and sustainable in the long term • Adverse socio-economic impacts are minimised • Opportunity is taken to maximise socioeconomic benefits Rehabilitating mines to meet land use objectives: bauxite mining in the jarrah forest of Western Australia Alcoa's recent push for improvement in rehabilitation practices has aimed to increase species richness in rehabilitated areas to the same level as the adjacent forest. In 1992 the species richness in rehabilitated areas was just over 60 percent of the forest average. At the last measurement in areas rehabilitated in 1999, average species richness was 96.8 percent of the forest average. Improvements have come from improved topsoil handling methods, seed collection, treatment and application methods and the planting of nursery-grown recalcitrant species. By and large all monitoring indicates that the rehabilitated areas are developing towards the stated objective. However, given the level of disturbance from the mining activities and the age that the forest will need to reach to fulfil all of its functions, it will take some time to confirm this.
  38. 38. Evolution in revegetation of iron-ore mines in Minas Gerais State, Brazil Developmentof sites/ land in accordanceto their environmentalproperties. • Topography& Landform • Flora& Vegetation • Fauna • Surface Water Hydrology&Groundwater • Soil & Water Contamination  Selecting successful germplasms;  characterizing soil/over-burden and waste/spoils;  restoring land capability;  landscaping and land shaping;  controlling soil erosion;  rainwater harvesting;  soil moisture storage;  profile development;  soil modifications;  creating plant-rooting medium;  planting techniques;  evaluating post-reclamation sustainability.  Stabilizationof surface materialsthroughappropriate landscape reconstruction,  Establishmentof long-term,sustainablevegetationcommunities.
  39. 39. UNIT V GLOBAL ISSUES ON MODERN CITIES Global environmental problems: Environmental Problems Our environment is constantly changing. There is no denying that. However, as our environment changes, so does the need to become increasingly aware of the problems that surround it. 1. Pollution: Pollution of air, water and soil require millions of years to recoup. Industry and motor vehicle exhaust are the number one pollutants. Heavy metals, nitrates and plastic are toxins responsible for pollution. While water pollution is caused by oil spill, acid rain, urban runoff; air pollution is caused by various gases and toxins released by industries and factories and combustion of fossil fuels; soil pollution is majorly caused by industrial waste that deprives soil from essential nutrients. 2. Global Warming: Climate changes like global warming is the result of human practices like emission of Greenhouse gases. Global warming leads to rising temperatures of the oceans and the earth’ surface causing melting of polar ice caps, rise in sea levels and also unnatural patterns of precipitation such as flash floods, excessive snow or desertification. 3. Overpopulation: The population of the planet is reaching unsustainable levels as it faces shortage of resources like water, fuel and food. Population explosion in less developed and developing countries is straining the already scarce resources. Intensive agriculture practiced to produce food damages the environment through use of chemical fertilizer, pesticides and insecticides. Overpopulation is one of the crucial current environmental problem. 4. Natural Resource Depletion: Natural resource depletion is another crucial current environmental problem. Fossil fuel consumption results in emission of Greenhouse gases, which is responsible for global warming and climate change. Globally, people are taking efforts to shift to renewable sources of energy like solar, wind, biogas and geothermal energy. The cost of installing the infrastructure and maintaining these sources has plummeted in the recent years. 5. Waste Disposal: The over consumption of resources and creation of plastics are creating a global crisis of waste disposal. Developed countries are notorious for producing an excessive amount of waste or garbage and dumping their waste in the oceans and, less developed countries. Nuclear waste disposal has tremendous health hazards associated with it. Plastic, fast food, packaging and cheap electronic wastes threaten the wellbeing of humans. Waste disposal is one of urgent current environmental problem. 6. Climate Change: Climate change is yet another environmental problem that has surfaced in last couple of decades. It occurs due to rise in global warming which occurs due to increase in temperature of atmosphere by burning of fossil fuels and release of harmful gases by industries. Climate change has various harmful effects but not limited to melting of polar ice, change in seasons, occurrence of new diseases, frequent occurrence of floods and change in overall weather scenario. 7. Loss of Biodiversity: Human activity is leading to the extinction of species and habitats and and loss of bio-diversity. Eco systems, which took millions of years to perfect, are in danger when any species population is decimating. Balance of natural processes like pollination is
  40. 40. crucial to the survival of the eco-system and human activity threatens the same. Another example is the destruction of coral reefs in the various oceans, which support the rich marine life. 8. Deforestation: Our forests are natural sinks of carbon dioxide and produce fresh oxygen as well as helps in regulating temperature and rainfall. At present forests cover 30% of the land but every year tree cover is lost amounting to the country of Panama due to growing population demand for more food, shelter and cloth. Deforestation simply means clearing of green cover and make that land available for residential, industrial or commercial purpose. 9. Ocean Acidification: It is a direct impact of excessive production of CO2. 25% of CO2 produced by humans. The ocean acidity has increased by the last 250 years but by 2100, it may shoot up by 150%. The main impact is on shellfish and plankton in the same way as human osteoporosis. 10. Ozone Layer Depletion: The ozone layer is an invisible layer of protection around the planet that protects us from the sun’s harmful rays. Depletion of the crucial Ozone layer of the atmosphere is attributed to pollution caused by Chlorine and Bromide found in Chloro-floro carbons (CFC’s). Once these toxic gases reach the upper atmosphere, they cause a hole in the ozone layer, the biggest of which is above the Antarctic. The CFC’s are banned in many industries and consumer products. Ozone layer is valuable because it prevents harmful UV radiation from reaching the earth. This is one of the most important current environmental problem. 11. Acid Rain: Acid rain occurs due to the presence of certain pollutants in the atmosphere. Acid rain can be caused due to combustion of fossil fuels or erupting volcanoes or rotting vegetation which release sulfur dioxide and nitrogen oxides into the atmosphere. Acid rain is a known environmental problem that can have serious effect on human health, wildlife and aquatic species. 12. Water Pollution: Clean drinking water is becoming a rare commodity. Water is becoming an economic and political issue as the human population fights for this resource. One of the options suggested is using the process of desalinization. Industrial development is filling our rivers seas and oceans with toxic pollutants which are a major threat to human health. 13. Urban Sprawl: Urban sprawl refers to migration of population from high density urban areas to low density rural areas which results in spreading of city over more and more rural land. Urban sprawl results in land degradation, increased traffic, environmental issues and health issues. The ever growing demand of land displaces natural environment consisting of flora and fauna instead of being replaced. 14: Public Health Issues: The current environmental problems pose a lot of risk to health of humans, and animals. Dirty water is the biggest health risk of the world and poses threat to the quality of life and public health. Run-off to rivers carries along toxins, chemicals and disease carrying organisms. Pollutants cause respiratory disease like Asthma and cardiac-vascular problems. High temperatures encourage the spread of infectious diseases like Dengue. 15. Genetic Engineering: Genetic modification of food using biotechnology is called genetic engineering. Genetic modification of food results in increased toxins and diseases as genes from an allergic plant can transfer to target plant. Genetically modified crops can cause serious environmental problems as an engineered gene may prove toxic to wildlife. Another drawback is that increased use of toxins to make insect resistant plant can cause resultant organisms to become resistant to antibiotics.
  41. 41. Carbon Rating: The total amount of greenhouse gases produced to directly and indirectly support human activities, usually expressed in equivalent tons of carbon dioxide (CO2). Your carbon footprint is the sum of all emissions of CO2 (carbon dioxide), which were induced by your activities in a given time frame. Usually a carbon footprint is calculated for the time period of a year. Pollution of air, water and land (A, W L ) Pollution is of different types. They are air pollution, water pollution and land pollution. Air pollution Air pollution is the accumulation in the atmosphere of substances that, in sufficient concentrations, endanger human health or produce other measured effects on living matter and other materials. Among the major sources of pollution are power and heat generation, the burning of solid wastes, industrial processes, and, especially, transportation. The six major types of pollutants are carbon monoxide, hydrocarbons, nitrogen oxides, particulates, sulphur dioxide, and photochemical oxidants. Examples of Air Pollution include • Noise Pollution Noise pollution or unwanted sounds that are carried by the air have an irritating and detrimental effect on humans and other animals. Careful planning of streets and buildings in towns and better control over noisy vehicles may add to the control of noise pollution. • Tobacco Pollution Tobacco smoke is one of the major forms of pollution in buildings. It is not only the smoker who is infected, but everyone who inhales the polluted air. There is a very strong connection between smoking and lung cancer. Bronchitis is common among smokers and unborn babies of mothers who smoke also suffer from the harmful effects of smoking. • Exhaust Gases of Vehicles Pollution from exhaust gases of vehicles is responsible for 60% of all air pollution and in cities up to 80%. There is a large variety of harmful chemicals present in these gases, with lead being one of the most dangerous.
  42. 42. • Combustion of Coal The combustion of coal without special precautions can have serious consequences. If winds do not blow away the poisonous gases, they can have fatal effects and may lead to death. • Acid rain Acid rain is the term for pollution caused when sulfur and nitrogen dioxides combine with atmospheric moisture to produce highly acidic rain, snow, hail, or fog. The acid eats into the stone, brick and metal articles and pollutes water sources. Control Measures Although individual people can help to combat air pollution in their own immediate environment, efficient control can be best achieved by legislation. Some commonly enforced control measures include  the establishment of more smokeless zones;  control over the kinds of fuel used in cars, aeroplanes, power stations, etc. Air Pollution affects human beings and other living species in a dangerous way. It makes the living process less happy. Some of the effects are quite definite and judged. But most of them are ill-defined and difficult to conceptualise. Even the scientists themselves disagree on the quantitative effects of pollution on living species. So it is highly desirable that human beings themselves understand the consequences of air pollution and try to prevent air pollution as much as possible. Otherwise the whole civilization will become extinct like the dinosaurs. Land pollution Land pollution is the degradation of the Earth's land surface through misuse of the soil by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban wastes. It includes visible waste and litter as well as pollution of the soil itself. Examples of Land Pollution • Soil Pollution Soil pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests). Litter is waste material dumped in public places such as streets, parks, picnic areas, at bus stops and near shops. • Waste Disposal The accumulation of waste threatens the health of people in residential areas. Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in.
  43. 43. Control Measures The following measures can be used to control land pollution:  Anti-litter campaigns can educate people against littering;  Organic waste can be dumped in places far from residential areas;  Inorganic materials such as metals, glass and plastic, but also paper, can be reclaimed and recycled. Water pollution Water pollution is the introduction into fresh or ocean waters of chemical, physical, or biological material that degrades the quality of the water and affects the organisms living in it. This process ranges from simple addition of dissolved or suspended solids to discharge of the most insidious and persistent toxic pollutants such as pesticides, heavy metals, and nondegradable, bioaccumulative, chemical compounds. Examples of Water Pollution include • Industrial affluents Water is discharged from after having been used in production processes. This waste water may contain acids, alkalis, salts, poisons, oils and in some cases harmful bacteria. • Mining and Agricultural Wastes Mines, especially gold and coal mines are responsible for large quantities of acid water. Agricultural pesticides, fertilisers and herbicides may wash into rivers and stagnant water bodies. • Sewage Disposal and Domestic Wastes Sewage as well as domestic and farm wastes were often allowed to pollute rivers and dams. Control Measures The following measures can be used to stop water pollution:  Every intelligent people should be wise enough not to pollute water in any way;  By research and legislation, the pollution of water bodies, even though not entirely prevented, must be effectively controlled.
  44. 44. Overview ofGovernmentof India’spolicies, ENVIRONMENTAL PROBLEM:NATURE AND DIMENSIONS Environmental problems in India can be classified into two broad categories: a. those arising as negative effects of the very process of development; and b. those arising from conditions of poverty and under-development. The first category has to do with the impact of efforts to achieve rapid economic growth and development and continuing pressures of demand generated by those sections of society who are economically more advanced and impose great strains on the supply of natural resources. Poorly planned developmental projects are also often environmentally destructive. The second category has to do with the impact on the health and integrity of our natural resources (land, soil, water,forests,wildlife, etc.) as a result of poverty and the inadequate availability, for a large section of our population, of the means to fulfill basic human needs (food, fuel, shelter, employment, etc.). Needless to say, the two problems are interrelated. Implementation of the aims and objectives of conservation and sustainable development will require integration and internalization of environmental considerations in the policies and programmes of development in various sectors. Curtailment of consumerism and shift towards use of environment friendly products and processes,and low waste generating technologies through conscious efforts and appropriate economic policies including pricing of natural resources as well as fiscal incentives and disincentives will be the guiding factors for ensuring conservation and sustainable development. For environmental conservation and sustainable development, the steps which need to be taken in some of the key sectors of development activities are outlined in the following sections 1.1 Agriculture: ·  Development of pesticides and insecticides policy for the country;  Development and promotion of methods of sustainable farming, especially organic and natural farming; Promotion of environmentally compatible cropping practices, bio-fertilisers and biopesticides ;  Ensuring land for different uses based upon land capability and land productivity;  Evolving cost effective and efficient methods of water conservation and use; 1.2 Irrigation  Priority to small projects to meet the requirements of irrigation without causing significant alteration in the environmental conditions;  Measures for increasing the efficiency of water-use,water conservation and recycling;  Measures for provision of drainage as an integral component of irrigation projects and to prevent water logging and leaching;  Watershed management through catchment treatment of the drainage areas,  Design and implementation of irrigation projects which are environmentally sustainable, 2 Animal Husbandry  Development of an animal husbandry policy for the country;  Intensification of sterilization programme for containing unsustainable growth in livestock population;  Improvement in genetic variability of indigenous population;
  45. 45.  Distribution of animals like goats under the Integrated Rural Development Programme strictly consistent with the availability of pasture lands to reduce pressure on the lands;  Propagation of wildlife and wildlife resources management on sustainable basis;  Selective breeding of animals used for draught power to conserve fuel; 3 Forestry  Increasing the productivity of forests to meet the essential national needs;  Encouraging efficient utilization of forest produce;  Restriction on diversion of forest lands for non-forest uses and compensatory afforestation in case where diversion is unavoidable;  Afforestation on common lands by the local communities through usufruct-sharing schemes;  Motivation of farmers/land owners to resort to tree farming in similar manner of crop based farming;  Substitution of wood by other materials, alternative sources of energy and fuel efficient stoves; 4 Energy Generation and Use  Environmental impact assessment prior to investment decisions and site selection;  Location of energy generation projects based on environmental considerations including pollution, displacement of people and loss of biodiversity;  Decentralized small projects for meeting the rural energy needs and incentives for use of non- conventional energy sources; 5 Industrial Development  Incentives for environmentally clean technologies, recycling and reuse of wastes and conservation of natural resources;  Fiscal incentives to small-scale industries for pollution control and for reduction of wastes;  While deciding upon sites, priority to compatible industries so that, to the extent possible, wastes from one could be used as raw material for the other and thus the net pollution load is minimized;  Location of industries as per environmental guidelines for sitting of industry; 6 Mining and Quarrying  Mined area rehabilitation and implementation of the environmental management plans concurrently with the on-going mining operations to ensure adequate ecological restoration of the affected areas;  Rehabilitation of the abandoned mined areas in a phased manner so that scarce land resources can be brought back under productive use;  Upgradation and beneficiation of minerals at the source, to the extent possible in order to ensure utilization of low-grade mineral resources and to reduce the cost of transportation, processing and utilization;  Environmentally safe disposal of the by-products of mining;  Restriction on mining and quarrying activities in sensitive areas such as hill slopes, areas of natural springs and areas rich in biological diversity;  Environmental impact assessment prior to selection of sites for mining and quarrying activities.
  46. 46. 6.7 Tourism ·  Promotion of tourism based on careful assessment of the carrying capacity and support facilities such as transport, fuel, water and sanitation;  Development of tourism in harmony with the environmental conditions and without affecting the lifestyles of local people; and,  Restriction on indiscriminate growth of tourism and strict regulation of the tourist activities in sensitive areas such as hill slopes, islands, coastalstretches,National Parks and Sanctuaries. 8 Transportation  Improvement in mass transport system to reduce increasing consumption t of fuel, traffic congestion and pollution;  Improved transport system based on bio-energy and other nonpolluting energy sources;  Rail transport and pipeline transport instead of road transport, where ever possible, by appropriate freight pricing so as to reduce congestion, fuel consumption and environmental hazards;,  Transportation of hazardous substances through pipelines;  Improvement in traffic flow through proper maintenance of roads, updated traffic regulation and strict enforcement of prescribed standards; United Nationscontribution to address these issues. UN Environment's main activities are related to:  climate change;  including the Territorial Approach to Climate Change (TACC);  disasters and conflicts;  ecosystem management;  environmental governance;  environment under review;  harmful substances;  resource efficiency. UN Environment has aided in the formulation of guidelines and treaties on issues such as the international trade in potentially harmful chemicals, transboundary air pollution, and contamination of international waterways. Relevant documents, including scientific papers, are available via the UNEP Document Repository. UN Environment has sponsored the development of solar loan programs, with attractive return rates, to buffer the initial deployment costs and entice consumers to consider and purchase solar PV systems. The most famous example is the solar loan program sponsored by UN Environment helped 100,000 people finance solar power systems in India.[8]Success in India's solar programme has led to similar projects in other parts of the developing world like Tunisia, Morocco, Indonesia and Mexico.