describes how we can use remote sensing for various impacts happening on environment.

1. REPORT OF SURVEY
SHUBHAM SHAMA
14142
CIVIL ENGINEERING DEPARTMENT

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SUBMITTED BY:
Shubham Shama
Roll No. 14142
Branch: Civil
Year/Sem.: 2nd
/ 4th
SUBMITTEDTO:
Er. Sandeep Panchal
ON

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INTRODUCTION
Environmental Impact Assessment (EIA) may be defined as study of effects of any
proposed project, plan or program on the environment. In the present era, rapid
industrialization and urbanization are affecting our environment and atmosphere very
badly. So need of Environmental Impact Assessment is always there to minimize the
harmful effects on environment.
EIA is a procedure used to examine the environmental consequences or impacts, both
beneficial and adverse, of a proposed development project and to ensure that these
effects are taken into account in project design. The EIA is therefore based on predictions.
These impacts can include all relevant aspects of the natural, social, economic and human
environment. The study therefore requires a multi-disciplinary approach and should be
done very early at the feasibility stage of a project. In other words, a project should be
assessed for its environmental feasibility.
There can be several techniques of analyzing Environmental Impact Assessment (EIA)
and one of the modern techniques used for it is Remote Sensing and GIS. Satellite remote
sensing is a powerful and efficient tool to ensure acquisition of images over wide areas in
short time and with great repetition that can be used in environmental impact studies.
Remote sensing can be used in environmental impact assessment, impact caused of urban
development, mining and changes that appeared due to the human factor or natural
factors.

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APPLICATION OF REMOTE SENSING IN
ENVIRONMENTAL IMPACT ASSESSMENT
Geographical Information System (GIS) and Remote Sensing, play an
important role in generating automat spatial datasets and in establishing spatial
relationships.
The Environmental Impact Assessment (EIA), for any project like dam construction on
the Man River, Gujarat, India, was performed using GIS and Remote Sensing software-
Arc/Info and ERDAS Imagine.
Efficient management of irrigation water can be suggested using recent information
of the command area by processing imageries through ERDAS Imagine. The impact of the
dam in terms of catchment area and command area was computed to assess the net
benefit to the society. GIS can also help in the site selection for the rehabilitation and
infrastructure location.
Geospatial technology consists of remote sensing and GIS is an essential component
of the Environmental Impact Assessment (EIA) process, as environmental resources are
directly affected by changes in the shape and extent of the proposed disturbance. With
the use of geo-spatial techniques like remote sensing, Geographical Information Systems
(GIS), and Global Positioning Systems (GPS), EIA has enhanced substantial viewing,
movement, query, and even map-making capabilities.
However, one of the main challenges is to have access to the most up-to-date and
accurate geospatial data and interpretations. With an emphasis on using geospatial data
in particular, the value of the information resource is far higher than is generally available
with text and numeric information. Several specific relevant applications of geospatial
tools to integrate EIA are presented in the context of an Indian scenario.

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Applications have included monitoring of actual resources (air, water, land, etc.),
ground-level ozone, soil erosion, study of sea-level rise due to global warming, change-
detection studies, delineation of ecologically sensitive areas using digital-image analysis
and Geographic Information Systems. This study focuses on the possibility of using a
proposed spatial-decision-support system to conduct EIA, which should make it possible
to upload, evaluate, maintain, and report field and analytical data that have been stored
in a variety of formats.
The EIA is used:
(1) To ensure that local agencies carefully consider significant environmental impacts
arising from projects under agency jurisdiction.
(2)To establish a procedure by which the public is given an opportunity for meaningful
participation in the agency’s consideration of the proposed action.
(3) To provide records for efficient spatial analysis. The EIA was designed to be a detailed
and quantitative investigation which rigorously analyzed the findings of potential
environmental impact of the proposed project and also addressed the public concerns
through the use of remote sensing and GIS technologies.
GEOSPATIAL REQUIREMENTS
The inherent spatial requirements of an EIA that is the need to assess the impact of a
proposed projection spatial analysis provides significant opportunities to apply GIS
analysis for completing the EIA project.
GIS analysis can greatly enhance the evaluation of ElA-required items.
A case study of the use of GIS analysis for land, territorial resources, for example, land use,
infrastructures and analysis of emissions and dispersion modelling system, like
meteorological and air pollution data is also analyzed along with a discussion of the
benefits of novel geomantic applications. Addressing land use and territorial resources
require the quantification of the land to be affected by the project.

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Specifically, morphological and land use analysis requires estimating the acreage of
various types of land use to be impacted. Spatial analysis requires estimating the amount
of available data for EIA. Spatial multi-criteria decision problems typically involve a set of
geographically-defined alternatives or events from which a choice of one or more
alternatives is made with respect to a given set of evaluation criteria.
SPATIAL DECISION SUPPORT SYSTEM
Two considerations are of paramount importance for spatial multi-criteria decision
analysis:
(1) The GIS component such as data acquisition, storage, retrieval, manipulation, and
analysis capability.
(2) The Spatial analysis component such as aggregation of spatial data and decision
makers’ preferences into discrete decision alternatives.
Spatial Decision Support System should be capable of:
1) Providing mechanisms for the input of spatial data.
2) Following representation of the spatial relations and structures.
3) Including the analytical techniques of spatial and geographical analysis
4) Providing output in a variety of spatial forms, including thematic cartography.
SDSS typically have three components:
A database management system and geographical database, a model-based
management system (analytical modelling capabilities and analysis procedures), and a
dialogue generation and management system (a user interface with display and report
generators).

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GIS IN ENVIRONMENTAL IMPACT ASSESSMENT
The development of Geographical Information Systems (GIS) analysis can serve as a
valuable tool for EIA and Spatial Analysis. Geographical Information
System (GIS) are computer systems that can store, integrate, analyze and display spatial
data. The first systems evolved in the late sixties, and by mid-seventies they have been
used for EIA. In 1972 a computerized version of the technique was used for sitting power
lines and roads (Munn, 1975). It is noteworthy that the so called “first GIS” (Canada GIS or
CGIS) was used for EIA in the late 1970s for the preparation of an EIS for a dam on the
river Thames (Griffith, 1980).
GIS offers a special environment for dealing with the spatial properties of a project.
Those special attributes of the GIS are very important for the analysis of environmental
issues, since most of them are spatial by nature, and no other computerized system can
handle them properly.
In recent years two important developments have helped in reduce the complexity of
spatial analysis. In the last decade, due to the evolution of computer technology, and
especially their graphic capabilities,
GISs have become more users friendly and powerful In addition the availability and quality
of digital spatial data sets improved, to the level where they are now adequate for routine
analysis. These two trends make possible the set-up of and use of GIS at lower cost in
terms of time and money than ever before.
However, the use of GIS in EIA process in general ,and for scoping in particular has
been limited, due in part to their cost in terms of time and money relative to the time and
budgets allocated for EIA preparation, and especially for scoping. Surveys use of GIS in
EIA found that while GIS is widely utilized, its use is largely limited to the basic GIS
functions such as map production, classic overlay or buffering.
This utilization does not make use of key advantage of GIS for EIA, its ability to perform
spatial analysis and modelling. Some of the uses of GIS for
EIA are complex modelling representation techniques, repository of data and cumulative
impact assessment. Spatial data analysis of data in GIS systems temporal variations and
change detection analysis, creation of maps of with mandatory buffers.

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Such economies may be of particular relevance for the use of many GIS systems are
insufficiently accurate for legal purposes due to several reasons, such as:
Limitations of the photogrammetric process, errors in the process of digitizing
existing maps, inaccuracies inherent in the maps, maps of different scales, different
levels of cartographic representation and cartographic generalization, and so on. Hence,
the user of GIS for EIA study should be cautions in view of the above limitations. In an
EIA framework, GIS can prove particularly useful for the evaluation of cumulative
impacts. Smit and Spalding stress the potential of GIS for this type of analysis, arising
from the ability to consider the spatial component and to allow the analysis of the
temporal evolution.
DIFFERENT TYPE OF SENSORS USED FOR
ENVIRONMENTAL IMPACT ASSESSMENT
Remote sensing instruments are of two primary types—active and passive.
Active sensors, provide their own source of energy to illuminate the objects they observe.
An active sensor emits radiation in the direction of the target to be investigated. The
sensor then detects and measures the radiation that is reflected or back scattered from
the target.
Passive sensors, on the other hand, detect natural energy (radiation) that is emitted or
reflected by the object or scene being observed. Reflected sunlight is the most common
source of radiation measured by passive sensors.
TYPE OF ACTIVE SENSORS
The majority of active sensors operate in the microwave portion of the electromagnetic
spectrum, which makes them able to penetrate the atmosphere under most conditions.
An active technique views the target from either end of a baseline of known length. The

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change in apparent view direction (parallax) is related to the absolute distance between
the instrument and target.
Laser altimeter— an instrument that uses a lidar to measure the height of the platform
(spacecraft or aircraft) above the surface. The height of the platform with respect to the
mean Earth’s surface is used to determine the topography of the underlying surface.
Lidar— A light detection and ranging sensor that uses a laser (light amplification by
stimulated emission of radiation) radar to transmit a light pulse and a receiver with
sensitive detectors to measure the backscattered or reflected light. Distance to the object
is determined by recording the time between transmitted and backscattered pulses and
by using the speed of light to calculate the distance traveled.
Radar— an active radio detection and ranging sensor that provides its own source of
electromagnetic energy .An active radar sensor, whether airborne or space borne, emits
microwave radiation in a series of pulses from an antenna. When the energy reaches the
target, some of the energy is reflected back toward the sensor. This backscattered
microwave radiation is detected, measured, and timed. The time required for the energy
to travel to the target and return back to the sensor determines the distance or range to
the target. By recording the range and magnitude of the energy reflected from all targets
as the system passes by, a two-dimensional image of the surface can be produced.
Ranging Instrument— a device that measures the distance between the instrument and
a target object. Radars and altimeters work by determining the time a transmitted pulse
(microwaves or light) takes to reflect from a target and return to the instrument. Another
technique employs identical microwave instruments on a pair of platforms. Signals are
transmitted from each instrument to the other, with the distance between the two
determined from the difference between the received signal phase and transmitted
(reference) phase. These are examples of active techniques. An active technique views the
target from either end of a baseline of known length. The change in apparent view
direction (parallax) is related to the absolute distance between the instrument and target.
TYPE OF PASSIVE SENSORS
Passive sensors include different types of radiometers and spectrometers. Most passive
systems used in remote sensing applications operate in the visible, infrared, thermal

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infrared, and microwave portions of the electromagnetic spectrum. Passive remote
sensors include the following:
Accelerometer— an instrument that measures acceleration (change in velocity per unit
time). There are two general types of accelerometers. One measures translational
accelerations (changes in linear motions in one or more dimensions), and the other
measures angular accelerations (changes in rotation rate per unit time).
Hyper spectral radiometer—anadvanced multispectral sensor that detects hundreds of
very narrow spectral bands throughout the visible, near-infrared, and mid-infrared
portions of the electromagnetic spectrum. This sensor’s very high spectral resolution
facilitates fine discrimination between different targets based on their spectral response
in each of the narrow bands.
Imaging radiometer—A radiometer that has a scanning capability to provide a two-
dimensional array of pixels from which an image may be produced. Scanning can be
performed mechanically or electronically by using an array of detectors.
Radiometer—an instrument that quantitatively measures the intensity of
electromagnetic radiation in some bands within the spectrum. Usually, a radiometer is
further identified by the portion of the spectrum it covers; for example, visible, infrared,
or microwave.
Sounder—an instrument that measures vertical distributions of atmospheric parameters
such as temperature, pressure, and composition from multispectral information.
CONCLUSION
To understand the consequences of human actions and natural phenomena on the
environment there are needed data acquired in real-time that are the basis of modelling
various environmental impacts. Satellite remote sensing is an excellent tool for this
purpose using images with different spatial, spectral and radiometric resolution
depending on purpose.

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Using satellite images in environmental impact assessment has the following
advantages:
recorded area is large, they capture the overall characteristics, they can be retrieved
at any time of day (radar records), they cover areas inaccessible or hostile to humans, they
highlight the unusual features of phenomena or registered details, information obtained
is uniform throughout the area, data are obtained with high repetitivity and there can be
identified the phenomena rapidly evolving in time, data are obtained in real time, there
can be made thematic selections and classifications, records are made as needed in
different parts of the electromagnetic spectrum in various forms (analogue, digital, radar,
lidar).
REFERENCES
1. Dr. B.C. PunmiaSurveyingvol.2
2. Internetsources:
 Earth Data NASA UserGovt. resources
 NewsletterEnvironmental ImpactAssessment
 Wikipedia
 Youarticle.com/environmentalimpactassessment