For a new better version of this tutorial see my Google Slides with embedded videos.
https://docs.google.com/presentation/d/1MftEOT3uvYpCVwUaLMhsesm5Que-Kr7GQRV4pKZ2SNQ/edit?usp=sharing
This is a 2016 tutorial on how to do watershed delineation using ArcMap 10. It is an open education resource. Please let me know if you find it useful or see something that could be improved. Feel free to use it for teaching Geographic Information Science.
This document describes the process of conducting watershed analysis in ArcGIS. It involves creating a digital elevation model (DEM), then generating flow direction, flow accumulation, and stream network rasters from the DEM. Sinks in the DEM are identified and filled. The stream network is converted to stream links and assigned stream orders. Finally, watersheds are delineated by pouring points using the stream links raster. The overall process allows for comprehensive watershed analysis and delineation of drainage basins.
The document discusses the raster data model. The key points are:
- Raster data is represented as a grid of cells (pixels) organized into rows and columns. Each cell contains a value representing information.
- Common raster data types include satellite imagery, digital elevation models, and scanned maps.
- Raster data has advantages for modeling and analysis but disadvantages for representing linear features and conforming to cartographic standards due to resolution issues.
For a new better version of this tutorial see my Google Slides with embedded videos.
https://docs.google.com/presentation/d/1MftEOT3uvYpCVwUaLMhsesm5Que-Kr7GQRV4pKZ2SNQ/edit?usp=sharing
This is a 2019 tutorial on how to do watershed delineation using ArcMap 10. It is an open education resource. Please let me know if you find it useful or see something that could be improved. Feel free to use it for teaching Geographic Information Science.
Digital Elevation Model (DEM) is the digital representation of the land surface elevation with respect to any reference datum. DEM is frequently used to refer to any digital representation of a topographic surface. DEM is the simplest form of digital representation of topography. GIS applications depend mainly on DEMs, today.
Iirs overview -Remote sensing and GIS application in Water Resources ManagementTushar Dholakia
Remote sensing and GIS application in Water Resources Management- By S.P. Aggarval spa@iirs.gov.in Indian Institute of Remote sensing ISRO, Department of space, Dehradun
This presentation is about the raster and vector data in GIS which is important and costly as well, through the presentation we will learn about both type of data.
This document provides an overview of ArcGIS and its components. It discusses how data are stored in ArcGIS using different data models over time, including coverages, shapefiles, and geodatabases. It describes the main ArcGIS applications - ArcMap for viewing and editing data, ArcCatalog for data management, and ArcToolbox for geoprocessing tools. It also outlines some key ArcGIS extensions for spatial, geostatistical, and 3D analysis.
The document discusses vector data models in GIS. Vector data models represent geographic features using points, lines, and polygons. The two main types of vector data models are the spaghetti model and the TIN (triangulated irregular network) model. The spaghetti model stores vector data as strings of coordinate pairs without any topological relationships, while the TIN model creates a network of triangles to store topological relationships between features. Vector data models are useful for storing data with discrete boundaries but are more complex for analysis compared to raster data models.
This document describes the process of conducting watershed analysis in ArcGIS. It involves creating a digital elevation model (DEM), then generating flow direction, flow accumulation, and stream network rasters from the DEM. Sinks in the DEM are identified and filled. The stream network is converted to stream links and assigned stream orders. Finally, watersheds are delineated by pouring points using the stream links raster. The overall process allows for comprehensive watershed analysis and delineation of drainage basins.
The document discusses the raster data model. The key points are:
- Raster data is represented as a grid of cells (pixels) organized into rows and columns. Each cell contains a value representing information.
- Common raster data types include satellite imagery, digital elevation models, and scanned maps.
- Raster data has advantages for modeling and analysis but disadvantages for representing linear features and conforming to cartographic standards due to resolution issues.
For a new better version of this tutorial see my Google Slides with embedded videos.
https://docs.google.com/presentation/d/1MftEOT3uvYpCVwUaLMhsesm5Que-Kr7GQRV4pKZ2SNQ/edit?usp=sharing
This is a 2019 tutorial on how to do watershed delineation using ArcMap 10. It is an open education resource. Please let me know if you find it useful or see something that could be improved. Feel free to use it for teaching Geographic Information Science.
Digital Elevation Model (DEM) is the digital representation of the land surface elevation with respect to any reference datum. DEM is frequently used to refer to any digital representation of a topographic surface. DEM is the simplest form of digital representation of topography. GIS applications depend mainly on DEMs, today.
Iirs overview -Remote sensing and GIS application in Water Resources ManagementTushar Dholakia
Remote sensing and GIS application in Water Resources Management- By S.P. Aggarval spa@iirs.gov.in Indian Institute of Remote sensing ISRO, Department of space, Dehradun
This presentation is about the raster and vector data in GIS which is important and costly as well, through the presentation we will learn about both type of data.
This document provides an overview of ArcGIS and its components. It discusses how data are stored in ArcGIS using different data models over time, including coverages, shapefiles, and geodatabases. It describes the main ArcGIS applications - ArcMap for viewing and editing data, ArcCatalog for data management, and ArcToolbox for geoprocessing tools. It also outlines some key ArcGIS extensions for spatial, geostatistical, and 3D analysis.
The document discusses vector data models in GIS. Vector data models represent geographic features using points, lines, and polygons. The two main types of vector data models are the spaghetti model and the TIN (triangulated irregular network) model. The spaghetti model stores vector data as strings of coordinate pairs without any topological relationships, while the TIN model creates a network of triangles to store topological relationships between features. Vector data models are useful for storing data with discrete boundaries but are more complex for analysis compared to raster data models.
The document provides an introduction to ArcGIS. It outlines that it will discuss what GIS is, how geographic data is represented in GIS, how data is stored in ArcGIS, GIS maps, GIS analysis processes, what ArcGIS is, and planning a GIS project. It then proceeds to define GIS, explain how geographic data is modeled in vector and raster formats, describe how data is organized and stored in an ArcGIS geodatabase, discuss GIS mapping and visualization, and overview spatial analysis tools in ArcGIS.
Digital elevation models (DEMs) can be used to delineate watersheds through a multi-step hydrologic modeling process. The DEM is first used to determine flow direction from each cell based on steepest downhill slope. Flow accumulation is then calculated to identify streams above a threshold. Stream networks and outlets are identified and used to delineate watershed polygons for each outlet. Vector conversion and post-processing steps such as dissolving spurious polygons and merging watersheds produce the final watershed delineation.
This document discusses flood mapping and summarizes the key inputs and processes. It notes that more accurate flood maps are needed and describes using precipitation data, rainfall-runoff models, hydraulic models, and terrain data to create flood maps. Issues with importing data and a lack of ArcGIS 10 support are mentioned. Future work on real-time flood mapping by interpolating water surface elevations from stage data is also discussed.
This document defines and describes Digital Elevation Models (DEMs). It discusses that DEMs are 3D representations of land surface elevation from various data sources. There are two main types of DEMs - raster and vector (TIN). Data can be captured through remote sensing, photogrammetry, or land surveys. Free global DEMs are available from sources like SRTM, ASTER, and ALOS. DEMs have many applications including terrain analysis, hydrology, mapping, and more.
The document discusses structures for data compression. It begins by introducing general compression concepts like lossless versus lossy compression. It then distinguishes between vector and raster data, describing how each is structured and stored. For vectors, it discusses storing points and lines more efficiently. For rasters, it explains how resolution affects file size and covers storage methods like tiles. Overall, the document provides an overview of data compression techniques for different data types.
This document provides an overview of a course on applying remote sensing and geographical information systems in civil engineering. The course consists of lectures and seminars covering topics in remote sensing and GIS. For remote sensing, lectures will discuss principles, sensors, data processing, platforms, image processing software, and microwave sensing. For GIS, lectures will cover concepts, data structures, software tools like ArcGIS, spatial queries, and applications in hydrological modeling. The goal of the course is to provide students with an understanding of remote sensing and GIS and their integration, and to learn basic skills in working with related data and software.
Image classification, remote sensing, P K MANIP.K. Mani
Image classification involves using spectral bands of images to separate landscape features into categories. Pixels with similar spectral signatures are clustered and classified using techniques like maximum likelihood classification. This results in a classified image map where each pixel is assigned a land cover class. However, classified maps have errors, so accuracy assessment is important to estimate the map's accuracy. Supervised classification involves using training areas of known land cover to develop spectral signatures for classification, while unsupervised classification clusters pixels without prior class definitions.
The document discusses the key components of a geographic information system (GIS). It describes the main components as hardware, software, data, people, procedures, and networks. It provides details on each component, including how hardware is used to capture, store and display spatial data; common GIS software and their functions; different types of spatial and attribute data; and how procedures and methods ensure quality. Topological relationships and database models used in GIS are also overviewed.
Spatial analysis & interpolation in ARC GISKU Leuven
In ArcGIS, a data model describes the thematic layers used in the applications (for example, hamburger stands, roads, and counties); their spatial representation (for example, point, line, or polygon); their attributes; their integrity rules and relationships (for example, counties must nest within states).
The document discusses various methods of georeferencing, which is assigning accurate locations to spatial information. The most comprehensive method is using latitude and longitude, which defines locations based on angles from the equator and Greenwich Meridian. However, the Earth's curved surface poses issues for technologies that work with flat maps and data. Therefore, map projections are used to translate locations on the spherical Earth onto flat planes or surfaces, though all projections introduce some distortion. Common projections include cylindrical, conic, and the Universal Transverse Mercator system.
This document discusses the key functions of a geographic information system (GIS). It explains that a GIS allows users to capture, store, query, analyze, display and output geographic data. It describes the vector and raster data models used to store spatial data. The document also outlines the three main views of a GIS - the geovisualization view which includes maps, the geodata view which is the spatial database, and the geoprocessing view which involves tools to transform and derive new information from existing datasets. Finally, it discusses some key concepts for GIS maps including layers, features, attributes, and scale.
it is highly useful for geography students in the field of remote sensing and it is in very simple and explanatory for the purpose of simplification with relevant images in this ppt.
GIS.INTRODUCTION TO GIS PACKAGES &GEOGRAPHIIC ANALYSISTessaRaju
A geographic information system (GIS) allows users to integrate and analyze spatial data from a variety of sources through mapping and visualization. GIS provides tools to gather, store, retrieve, analyze and output geographic data. Spatial analysis techniques in GIS, such as buffering, proximity analysis and overlay analysis, enable users to model and understand relationships within and between spatial datasets to gain insights and solve problems.
This document discusses the history and recent advances in hydrologic modeling. It begins with definitions of hydrology and applications of hydrologic models such as water resources planning. It then discusses the historical development of early component models in the 1900s and the creation of integrated watershed models starting in the 1960s. Recent advances include the use of remote sensing, GIS, and handling spatial and temporal variability. The future outlook emphasizes increasing model complexity through linking with other domains and improving reliability.
This document discusses inverse distance weighting (IDW) interpolation, which is a technique used to estimate unknown values between known data points. IDW assumes that points closer to one another are more alike than distant points. The interpolated value is a weighted average of known points, with the weights being inversely proportional to the distances. This allows for the creation of continuous surfaces like elevation or temperature from point data. A case study examines the relationship between weekly rainfall patterns and dengue outbreaks in Sri Lanka using IDW and GIS tools to model spatial and temporal associations and identify potential risk areas.
The document discusses the application of remote sensing and geographical information systems (GIS) in civil engineering. It provides definitions of remote sensing as remotely sensing objects on Earth and GIS as a system to capture, store, analyze and present geographically referenced data. The document outlines some basic concepts of GIS including its origins from technologies like computer-aided cartography and databases. It also discusses data types in GIS like spatial data, attributes and different data models. Common software, functional elements and applications of GIS in areas like facilities management and environmental planning are summarized as well.
This document discusses key concepts related to data in GIS systems. It describes the different types of spatial and attribute data as well as vector and raster data formats. It explains how data is organized into layers and how those layers can be queried and overlaid to integrate information from different sources and analyze spatial patterns in the data.
This presentation discusses scales used in photographs. It explains that scale is the ratio of an object's size in a photo to its actual size on the ground. Scale can be expressed through a unit equivalent, representative fraction, or ratio. Knowing the camera focal length and aircraft altitude allows one to determine the scale of a vertical photograph. The presentation was given by Mr. Amol V. Ghogare of SRES, SCOE, Kopargaon on the topic of scales used in photographs.
Spatial interpolation techniques are used to estimate values at unsampled locations based on known sample points. There are two main types of interpolation methods: global methods which apply a single mathematical function to all points, and local methods which apply functions to subsets of points. Specific interpolation methods covered include Thiessen polygons, triangulated irregular networks, spatial moving average, trend surfaces, inverse distance weighting, and Kriging. Kriging is similar to inverse distance weighting but uses minimum variance to calculate weights.
Nicanor Perlas is a presidential candidate in the Philippines who has a plan to improve watershed management in the country. His plan is to view development through the lens of bioregions defined by watersheds. He wants to ensure every community has access to clean water by partnering with organizations to build water systems. Key aspects of his plan include improving water resource management, conducting conferences on water issues, assessing freshwater intrusion, protecting lakes, and preventing activities like logging that damage watersheds.
The document summarizes a study that delineated the Bark River Watershed using DEMs with different spatial resolutions (30m, 10m, 5ft) and compared the results to the actual watershed boundaries from the USGS. The 30m DEM was found to have the most accurate representation of the watershed area, being only 2.36% larger than the USGS measurement. While the 10m DEM was also similar, the 5ft DEM incorrectly cut off around half of the total watershed area due to lack of data and road crossings. The study aims to determine the best DEM resolution for accurate watershed delineation.
The document provides an introduction to ArcGIS. It outlines that it will discuss what GIS is, how geographic data is represented in GIS, how data is stored in ArcGIS, GIS maps, GIS analysis processes, what ArcGIS is, and planning a GIS project. It then proceeds to define GIS, explain how geographic data is modeled in vector and raster formats, describe how data is organized and stored in an ArcGIS geodatabase, discuss GIS mapping and visualization, and overview spatial analysis tools in ArcGIS.
Digital elevation models (DEMs) can be used to delineate watersheds through a multi-step hydrologic modeling process. The DEM is first used to determine flow direction from each cell based on steepest downhill slope. Flow accumulation is then calculated to identify streams above a threshold. Stream networks and outlets are identified and used to delineate watershed polygons for each outlet. Vector conversion and post-processing steps such as dissolving spurious polygons and merging watersheds produce the final watershed delineation.
This document discusses flood mapping and summarizes the key inputs and processes. It notes that more accurate flood maps are needed and describes using precipitation data, rainfall-runoff models, hydraulic models, and terrain data to create flood maps. Issues with importing data and a lack of ArcGIS 10 support are mentioned. Future work on real-time flood mapping by interpolating water surface elevations from stage data is also discussed.
This document defines and describes Digital Elevation Models (DEMs). It discusses that DEMs are 3D representations of land surface elevation from various data sources. There are two main types of DEMs - raster and vector (TIN). Data can be captured through remote sensing, photogrammetry, or land surveys. Free global DEMs are available from sources like SRTM, ASTER, and ALOS. DEMs have many applications including terrain analysis, hydrology, mapping, and more.
The document discusses structures for data compression. It begins by introducing general compression concepts like lossless versus lossy compression. It then distinguishes between vector and raster data, describing how each is structured and stored. For vectors, it discusses storing points and lines more efficiently. For rasters, it explains how resolution affects file size and covers storage methods like tiles. Overall, the document provides an overview of data compression techniques for different data types.
This document provides an overview of a course on applying remote sensing and geographical information systems in civil engineering. The course consists of lectures and seminars covering topics in remote sensing and GIS. For remote sensing, lectures will discuss principles, sensors, data processing, platforms, image processing software, and microwave sensing. For GIS, lectures will cover concepts, data structures, software tools like ArcGIS, spatial queries, and applications in hydrological modeling. The goal of the course is to provide students with an understanding of remote sensing and GIS and their integration, and to learn basic skills in working with related data and software.
Image classification, remote sensing, P K MANIP.K. Mani
Image classification involves using spectral bands of images to separate landscape features into categories. Pixels with similar spectral signatures are clustered and classified using techniques like maximum likelihood classification. This results in a classified image map where each pixel is assigned a land cover class. However, classified maps have errors, so accuracy assessment is important to estimate the map's accuracy. Supervised classification involves using training areas of known land cover to develop spectral signatures for classification, while unsupervised classification clusters pixels without prior class definitions.
The document discusses the key components of a geographic information system (GIS). It describes the main components as hardware, software, data, people, procedures, and networks. It provides details on each component, including how hardware is used to capture, store and display spatial data; common GIS software and their functions; different types of spatial and attribute data; and how procedures and methods ensure quality. Topological relationships and database models used in GIS are also overviewed.
Spatial analysis & interpolation in ARC GISKU Leuven
In ArcGIS, a data model describes the thematic layers used in the applications (for example, hamburger stands, roads, and counties); their spatial representation (for example, point, line, or polygon); their attributes; their integrity rules and relationships (for example, counties must nest within states).
The document discusses various methods of georeferencing, which is assigning accurate locations to spatial information. The most comprehensive method is using latitude and longitude, which defines locations based on angles from the equator and Greenwich Meridian. However, the Earth's curved surface poses issues for technologies that work with flat maps and data. Therefore, map projections are used to translate locations on the spherical Earth onto flat planes or surfaces, though all projections introduce some distortion. Common projections include cylindrical, conic, and the Universal Transverse Mercator system.
This document discusses the key functions of a geographic information system (GIS). It explains that a GIS allows users to capture, store, query, analyze, display and output geographic data. It describes the vector and raster data models used to store spatial data. The document also outlines the three main views of a GIS - the geovisualization view which includes maps, the geodata view which is the spatial database, and the geoprocessing view which involves tools to transform and derive new information from existing datasets. Finally, it discusses some key concepts for GIS maps including layers, features, attributes, and scale.
it is highly useful for geography students in the field of remote sensing and it is in very simple and explanatory for the purpose of simplification with relevant images in this ppt.
GIS.INTRODUCTION TO GIS PACKAGES &GEOGRAPHIIC ANALYSISTessaRaju
A geographic information system (GIS) allows users to integrate and analyze spatial data from a variety of sources through mapping and visualization. GIS provides tools to gather, store, retrieve, analyze and output geographic data. Spatial analysis techniques in GIS, such as buffering, proximity analysis and overlay analysis, enable users to model and understand relationships within and between spatial datasets to gain insights and solve problems.
This document discusses the history and recent advances in hydrologic modeling. It begins with definitions of hydrology and applications of hydrologic models such as water resources planning. It then discusses the historical development of early component models in the 1900s and the creation of integrated watershed models starting in the 1960s. Recent advances include the use of remote sensing, GIS, and handling spatial and temporal variability. The future outlook emphasizes increasing model complexity through linking with other domains and improving reliability.
This document discusses inverse distance weighting (IDW) interpolation, which is a technique used to estimate unknown values between known data points. IDW assumes that points closer to one another are more alike than distant points. The interpolated value is a weighted average of known points, with the weights being inversely proportional to the distances. This allows for the creation of continuous surfaces like elevation or temperature from point data. A case study examines the relationship between weekly rainfall patterns and dengue outbreaks in Sri Lanka using IDW and GIS tools to model spatial and temporal associations and identify potential risk areas.
The document discusses the application of remote sensing and geographical information systems (GIS) in civil engineering. It provides definitions of remote sensing as remotely sensing objects on Earth and GIS as a system to capture, store, analyze and present geographically referenced data. The document outlines some basic concepts of GIS including its origins from technologies like computer-aided cartography and databases. It also discusses data types in GIS like spatial data, attributes and different data models. Common software, functional elements and applications of GIS in areas like facilities management and environmental planning are summarized as well.
This document discusses key concepts related to data in GIS systems. It describes the different types of spatial and attribute data as well as vector and raster data formats. It explains how data is organized into layers and how those layers can be queried and overlaid to integrate information from different sources and analyze spatial patterns in the data.
This presentation discusses scales used in photographs. It explains that scale is the ratio of an object's size in a photo to its actual size on the ground. Scale can be expressed through a unit equivalent, representative fraction, or ratio. Knowing the camera focal length and aircraft altitude allows one to determine the scale of a vertical photograph. The presentation was given by Mr. Amol V. Ghogare of SRES, SCOE, Kopargaon on the topic of scales used in photographs.
Spatial interpolation techniques are used to estimate values at unsampled locations based on known sample points. There are two main types of interpolation methods: global methods which apply a single mathematical function to all points, and local methods which apply functions to subsets of points. Specific interpolation methods covered include Thiessen polygons, triangulated irregular networks, spatial moving average, trend surfaces, inverse distance weighting, and Kriging. Kriging is similar to inverse distance weighting but uses minimum variance to calculate weights.
Nicanor Perlas is a presidential candidate in the Philippines who has a plan to improve watershed management in the country. His plan is to view development through the lens of bioregions defined by watersheds. He wants to ensure every community has access to clean water by partnering with organizations to build water systems. Key aspects of his plan include improving water resource management, conducting conferences on water issues, assessing freshwater intrusion, protecting lakes, and preventing activities like logging that damage watersheds.
The document summarizes a study that delineated the Bark River Watershed using DEMs with different spatial resolutions (30m, 10m, 5ft) and compared the results to the actual watershed boundaries from the USGS. The 30m DEM was found to have the most accurate representation of the watershed area, being only 2.36% larger than the USGS measurement. While the 10m DEM was also similar, the 5ft DEM incorrectly cut off around half of the total watershed area due to lack of data and road crossings. The study aims to determine the best DEM resolution for accurate watershed delineation.
Soil degradation occurs through two main processes: erosion by water and wind, which removes solid material; and leaching, which removes soluble matter. Erosion involves mobilization, transport, and deposition of solids, while leaching involves solubilization, transport, and precipitation/fixation of dissolved components through physicochemical and biological processes like hydration and hydrolysis. Models like the Universal Soil Loss Equation are used to estimate soil degradation from erosion and leaching over large areas based on local measurements and factors such as climate, landscape, soil type, and land use. Soil losses at one site result in deposition elsewhere through aquatic, wind, or precipitation transport.
This mid-term presentation summarizes a master's thesis on modeling soil erosion in the Kankai Mai watershed in Nepal using the Universal Soil Loss Equation (USLE) model. Key points include:
1) The USLE model was implemented in ArcGIS to estimate soil loss rates across the watershed using factors like rainfall, soil type, slope, land use, and management practices.
2) Model parameters were calibrated and validated against observed sediment data, achieving R2 values over 0.7.
3) Results show the average annual sediment yield for the watershed is 21.94 tons/hectare and ranges from 18.04 to 25.07 tons/hectare in different
Watershed Science - The Upper Grand RiverDerek Moy
Watershed Science - The Upper Grand River, by David P. Lusch, PhD, GISP of Remote Sensing & GIS Research and Outreach Services (RS&GIS), Michigan State University. Presented as part of a Watershed Management Short Course, March 2007.
This document summarizes a presentation about the BC Open Textbook Project. The project aims to connect the expertise, programs and resources of BC post-secondary institutions under a collaborative framework. It has three phases: 1) Launch open textbooks in high-enrollment subjects, 2) Adapt existing open textbooks to the BC context, and 3) Create new open textbooks from scratch. The project expects to improve access to education by reducing student costs and improve learning outcomes. It also enables faculty collaboration on open educational resources.
Soil Erosion for Vishwamitri River watershed using RS and GISvishvam Pancholi
1) This document summarizes a study of soil erosion in the Vishwamitri River watershed using the Universal Soil Loss Equation (USLE).
2) The USLE factors of rainfall (R), soil erodibility (K), slope length and steepness (LS), crop management (C), and supporting practices (P) were calculated for four sub-watersheds using GIS and remote sensing data.
3) The results showed that two of the sub-watersheds (SW1 and SW2) have very severe soil erosion rates of over 97 and 129 tons/ha/year respectively, and should be prioritized for soil conservation measures.
hydro chapter_11_hydrology_by louy al hami Louy Alhamy
The document discusses key concepts in hydrology including the hydrologic cycle, precipitation measurement methods, watershed characteristics, the watershed response in the form of hydrographs, unit hydrographs, and methods to develop synthetic hydrographs for ungauged watersheds. Specifically, it covers the hydrologic cycle, precipitation measurement including arithmetic mean, Thiessen polygon, and isohyetal methods. It also discusses watershed characteristics, the watershed response in the form of hydrographs, and the development of unit hydrographs and their use in developing synthetic hydrographs for ungauged watersheds using the principles of superposition and linearity.
sciencepowerpoint.com delivers a four part 2150+ slide PowerPoint slideshow becomes the roadmap for an amazing and interactive science experience. Complete with bundled homework package, many built-in quizzes, hands-on activities with directions, unit notes, answer keys, video links, rubrics, review games, and much more.
This unit aligns with the Next Generation Science Standards and Common Core Standards for ELA and Literacy in Science and Technical Subjects. See preview for more information.
Areas of Focus within The Rivers Unit -Watersheds, Rivers of the United States, Sections of a River, Parts of River (Vocabulary), Stream Order, Erosion and Deposition, Water Quality, Chemical Properties of Water, Bio-Indicators of Water Quality (EPT richness), Physical Properties of Water Quality, Rivers and Flooding, Factors that Control Flooding, Types of Flooding, Tsunami's, Wetlands, Flood Prevention, Levees, Dams and Ecosystem, Importance of Dams, Impacts of Dams, Hydropower, Parts of Dam, Salmon (Life Cycle), Systems of Help Salmon, Fish (General), Layering in a Lake, Lake Turnover, Nutrients and Lakes.
Teaching Duration = 4+ Weeks + PowerPoint Review Games
Ryan Murphy M.Ed
www.sciencepowerpoint.com
APPLICATIONS OF REMOTE SENSING AND GIS IN WATERSHED MANAGEMENTSriram Chakravarthy
This document discusses watershed management and the role of remote sensing and GIS applications. It begins with defining a watershed and the watershed approach. It then discusses watershed characterization, prioritization, development activities, and monitoring. Remote sensing provides synoptic data to map natural resources within watersheds. GIS is used to integrate spatial data for watershed delineation and analysis. The goal of watershed management is sustainable development through activities like water conservation, afforestation, and improving livelihoods.
Water resources are sources of water that are useful or potentially useful for various human uses like agriculture, industry, households, recreation, and the environment. However, only 3% of the water on Earth is fresh water, with over two-thirds frozen in glaciers and polar ice caps. Fresh water supplies are dwindling as demand rises with population growth. Conservation efforts aim to ensure future availability, conserve energy used in water distribution, and preserve freshwater habitats. Common conservation strategies include public education, tiered water pricing, and outdoor use restrictions. The Water Code of the Philippines governs water use and ownership with the objectives of establishing principles for appropriate development and conservation of water resources.
CHARACTERISTICS OF WATERSHED: size, shape; physiography, slope, climate, drainage, land use, vegetation, geology and soils, hydrology and hydrogeology, socio-economic characteristics, basic data on watersheds.
This document provides an overview of watershed management and development. It defines a watershed and explains their importance for sustaining life. Watershed management aims to manipulate natural, agricultural, and human resources within a watershed to provide desired resources suitably. The objectives are to protect and improve land and water resources. Key perspectives include hydrological, environmental, socio-economic, financial, and administrative aspects. Approaches involve people's participation and a hierarchical organizational structure. Geological aspects that influence watersheds like soil, water, natural hazards are also described.
The document describes a case study where an instructor taught students online using open educational resources after their university closed due to protests. Surveys found that students were generally satisfied with the online learning experience, though some noted drawbacks like lack of collaboration and slower pace. While openness could increase, the study showed that the instructor's role is vital for student performance and blogs can encourage active learning and community when used for education.
This document discusses GIS tools and techniques for watershed analysis including DEM, fill sinks, flow direction, flow accumulation, conditional elevation, stream ordering, snapping pour points, watershed delineation, basin delineation, and calculating flow length. Key steps are opening a DEM, preprocessing the DEM with fill and flow tools, defining streams and pour points, delineating watersheds, and calculating attributes like flow length. The overall goal is to use GIS to analyze watersheds, drainage patterns, and water flow across landscapes.
How to empower community by using GIS lecture 2wang yaohui
The document provides instructions for completing a GIS project using ArcGIS software. It outlines 4 steps: 1) Identifying project objectives which in this case is siting a wastewater treatment plant. 2) Creating a project database by assembling data layers and defining their coordinate systems. 3) Analyzing the data using tools in ArcToolbox to apply criteria to potential sites. 4) Presenting results to stakeholders like a city council. It then gives examples of using ArcCatalog to organize data and ArcToolbox tools to manage data formats and projections as part of completing the project.
The Matsu Project - Open Source Software for Processing Satellite Imagery DataRobert Grossman
The Matsu Project is an Open Cloud Consortium project that is developing open source software for processing satellite imagery data using Hadoop, OpenStack and R.
Jim Gray presented on his work with large databases and grid computing. He discussed two major projects - TerraServer and SkyServer/World Wide Telescope. TerraServer is a photo database of the United States containing over 15 TB of imagery data accessed through an SQL database. SkyServer is a database of astronomical data containing images and attributes of celestial objects from surveys like SDSS. Gray discussed lessons learned from building and managing these large databases, and future plans to build databases from inexpensive disk bricks. He advocated for grid computing through web services as a way to federate and access distributed data sources on the internet.
This document discusses using LiDAR data to map hydrologic features on timberlands owned by Plum Creek Timber Company in Essex County, Vermont. The goals are to locate hydrologic features like streams more accurately than the company's current data by processing LiDAR point cloud data. Key steps discussed include acquiring LiDAR data for the study area, performing QA/QC on the data, creating terrain and hydrologic digital elevation models (DEMs) from the LiDAR point clouds, and comparing the results to the company's existing hydrology data to improve accuracy.
Using Deep Learning to Derive 3D Cities from Satellite ImageryAstraea, Inc.
Detection and reconstruction of 3D buildings in urban areas has been a hot topic of research due to its many applications, including 3D population density studies, emergency planning, and building value estimation. Standard approaches to extract building footprint and measure building height rely on either aerial or space borne point cloud data, which in many areas is unavailable. In contrast, high resolution satellite imagery has become more readily available in recent years, and could provide enough information to estimate a building’s height. Recent successes of deep learning on semantic segmentation have shown that convolutional neural networks can be effective tools at extracting 2D building footprints. Using a digital surface model derived using FOSS and LiDAR data as ground truth, this study goes a step further by employing state of the art deep learning architectures such as U-net to infer both building footprints and estimated building heights in one pass from a single satellite image. This application of open deep learning frameworks can bring the benefits of 3D cities to a larger portion of the world.
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That is a lot of connected data, graphs are truly everywhere. Companies are finding that graph database technology is helping them make sense of their big data.
Objectivity’s Nick Quinn, Chief Architect of InfiniteGraph, shows us just how popular graph databases have become and where they are being used, as well as showing us the ins and outs.
Do you want to build technology that does great things with big data? You might want to find out what your colleagues are Tweeting about, make recommendations for apps, music or other retail that result in higher purchase rates, discover hidden connections between new and recorded medical research data, or maybe even leverage intel across government agencies to catch the bad guys.
All this is possible with a graph database.
1) Postgres and PostGIS have been used at EDINA for over 8 years to power major geospatial services like Digimap.
2) It is used for data storage, mapping, spatial indexing, querying, and data downloads. Postgres allows EDINA to handle large amounts of geospatial data and large user bases.
3) EDINA finds Postgres reliable, performant, scalable, and standards-compliant with good support tools. It will continue being the core database for EDINA's geoservices.
This slide will provide an overview of current functionality, techniques, and tips for visualization and query of HDF and netCDF data in ArcGIS, as well as future plans. Hierarchical Data Format (HDF) and netCDF (network Common Data Form) are two widely used data formats for storing and manipulating scientific data. The NetCDF format also supports temporal data by using multidimensional arrays. The basic structure of data in this format and how to work with it will be covered in the context of standardized data structures and conventions. This slide will demonstrate the tools and techniques for ingesting HDF and netCDF data efficiently in ArcGIS, as well as some common workflows to employ the visualization capabilities of ArcGIS for effective animation and analysis of your data.
This document discusses using ESRI ArcGIS tools to perform geoscience analysis and visualization. It provides examples of using ArcMap, extensions like Spatial Analyst and 3D Analyst, and web services to [1] model simple surface and thickness trends, [2] compare ESRI tools to other gridding and contouring tools, and [3] demonstrate workflows for thickness mapping and contouring. The document concludes that ArcGIS tools can provide initial analysis and integration with other datasets but are not a replacement for specialized reservoir modeling packages.
Accumulo Summit 2016: GeoMesa: Using Accumulo for Optimized Spatio-Temporal P...Accumulo Summit
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– Speaker –
Dr. James Hughes
Mathematician, Commonwealth Computer Research, Inc (CCRi)
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— More Information —
For more information see http://www.accumulosummit.com/
This document describes the DA_MAP project, which aims to create a desktop application for METOC (meteorology and oceanography) data analysis and modeling. The application will integrate data access, visualization, and analysis tools to allow users to more easily find, access, and analyze diverse METOC data. Key aspects of the project include using Java and XML technologies, providing search and query of metadata stored in XML format, and including interactive visualization and analysis modules. Screenshots show examples of the data registration, search and query, and analysis modules with features like model output overlays, time series plots, and difference maps.
Modelling complex geometry structures using SAP2000 APIValerio Stuart
This document discusses modelling complex geometry structures using computational tools. It describes various complex geometries used in architecture like shells, helicoids and catenoids. It then discusses using Rhinoceros and Grasshopper to model these and exporting models to SAP2000 for structural analysis. It also describes using SAP2000's API to directly model geometries without intermediate files. A case study is presented on modelling the Kresge Auditorium using the API to define nodes, elements, loads and material properties in an .s2k file for analysis in SAP2000. The API approach is said to allow customized modelling procedures tailored for specific projects without intermediate files.
This document discusses various sources for map data and adding maps to websites. It outlines sources for commercial map data like Ordnance Survey and Navteq, as well as open data sources like OpenStreetMap, Natural Earth, and downloadable UK base maps. The document also discusses creating your own map data by tracing out-of-copyright maps or converting GPS tracks. Additional non-map data sources mentioned include patterns, icons, and tools for warping and rectifying scanned maps. The last section briefly discusses sourcing maps from Google, Bing, and OpenStreetMap for websites.
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This document discusses scaling topological data analysis (TDA) using the Mapper algorithm to analyze large datasets. It introduces Mapper and its computational bottlenecks. It then describes Betti Mapper, the authors' open-source scalable implementation of Mapper on Spark that achieves an 8-11x performance improvement over a naive version. Betti Mapper uses locality-sensitive hashing to bin data points and compute topological networks on prototype points to analyze large datasets enterprise-scale.
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Content in the Living Atlas of the World isn’t just for making web maps—it includes ready-to-use data that can be used for analysis in the ArcGIS Platform. The Living Atlas includes hundreds of image services you can use in ArcGIS Desktop and Pro as inputs to geoprocessing tools. That means no downloading, no data preparation, and huge time savings. Image services work so well in ArcGIS, you will be challenged to find how they differ from the raster datasets on your hard drive. With a focus on Pro, this session teaches you about the keys to success when performing analysis with Living Atlas image services.
Similar to Watershed Delineation Using ArcMap (20)
Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
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This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
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advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
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significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
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like India, rapid population growth and the emphasis on extensive resource exploitation can lead
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providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
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Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
Communicating effectively and consistently with students can help them feel at ease during their learning experience and provide the instructor with a communication trail to track the course's progress. This workshop will take you through constructing an engaging course container to facilitate effective communication.
2. What is This?
Watershed Delineation by Arthur Gill Green is licensed under a Creative Commons Attribution-
ShareAlike 4.0 International License.
Based on a work at http://greengeographer.com/.
• An open training module for learning
Geographic Information Science as applied to
watershed delineation.
• It was developed for students at UBC.
• It uses data from the USGS (SRTM) and
software from ESRI (ArcMap 10.3).
3. Why Do This Training?
It’s free and you will learn how to:
• Get SRTM 1 Arc-Second (30 meter resolution) for
free to make Digital Elevation Models (DEM).
• Merge raster grids into mosaics.
• Derive streams, stream orders, basins, and specific
watersheds from the data.
• Convert raster grids into vector features.
• Calculate area and length.
• Create and analyze evidence for responding to
geographic questions.
4. Research Question
While working in Cameroon on a transboundary
international conservation area near Tchabal
Mbabo, we wondered…
5. Does the Faro River basin cross the international
border between Cameroon and Nigeria?
If it does, this is one reason to explore setting up a
transboundary international conservation area or
international watershed co-management plan.
6. Where are Tchabal Mbabo &
the Faro River?
• This photo is from the Tchabal Mbabo cliffs
looking down into the Faro River basin.
• This is a remote region, located in the west of the
Adamaoua Province of Cameroon. Livelihoods
are based around herding.
• The rapid drop of the cliffs provide many
microclimates and are home to rare Afromontane
and Sudano-Guinean flora and fauna. For
example, Prunus africana is one rare species
here.
Click below to see
the region on OSM.
7.
8. What You Need
• Software: ArcMap 10.3.
• A license to use Spatial Analyst.
• Access to the internet.
• 3-4 hours (depending on the size of the data
you download and your computer’s processing
abilities it could be even longer – so choose a
small area).
9. Outline
1. Get Data
2. Set Work Environment
3. Mosaic Rasters (put them together)
4. Find Sinks and Fill Sinks (create a depressionless DEM)
5. Flow Direction
6. Flow Accumulation
7. Basins and Watersheds
8. Stream Network
9. Converting to Polygons and Cleaning Up
10. Comparing Basin to Watersheds
11. Answering the Research Question
11. Get Data
• We will use SRTM (Shuttle Radar Topographic
Mission) 1 Arc-Second Global elevation data
(~30 meter resolution) from the USGS and
NASA. Collected Feb. 2000.
• Get an account at:
http://earthexplorer.usgs.gov/
• I use data from the border of Cameroon and
Nigeria to look at where the Faro River is
located.
https://en.wikipedia.org/wiki/Faro_River
• You can select your own region. Make sure
to only take 1-2 SRTM image areas or your
computer may take a very long time to
process the data.
Source:
http://www2.jpl.nasa.gov/srtm/mis
sion.htm
12. • This is the http://earthexplorer.usgs.gov/ interface.
• Sign up for a free account.
• Once you have a free account, you can search for data
from any part of the world or manually outline your area of
interest (AOI).
13. • I manually outlined my area of interest using the above
points.
• Once you have outlined your area of interest, you can
move on to searching the types of data available. We are
going to search for SRTM.
14. • After outlining your area
of interest (AOI), move
on to the Data Sets tab.
• Type in “srtm” and you
should see SRTM 1 Arc-
Second Global.
• Select that, then click on
Results.
15. • You can show the SRTM image footprints by using the buttons on the
left.
• We see there are two SRTM images that fall within my AOI.
• I will have to download both of them and mosaic (merge) them into a
new raster.
• You can display metadata (SRTM files were collected in 2000 but
published in 2014). You can do individual or bulk downloads.
17. Product Specifications (some metadata)
Projection Geographic
Horizontal Datum WGS84
Vertical Datum EGM96 (Earth Gravitational Model
1996) ellipsoid
Vertical Units Meters
Spatial Resolution 1 arc-second for global coverage
(~30 meters)
3 arc-seconds for global coverage
(~90 meters)
Raster Size 1 degree tiles
C-band Wavelength 5.6 cm
Projection is geographic, so we will need to reproject to do
measurements (area, length) in meters.
19. Download Data
• Earth Explorer offers SRTM data as:
• Digital Terrain Elevation Data (DTED)
• Band interleaved by line (BIL) (a binary raster format)
• Georeferenced Tagged Image File Format (tif, tiff,
GeoTIFF)
• Any of these formats will work for this exercise.
• I downloaded the GeoTIFF.
• You should make a project directory (such as
“C:/WATERSHED/DATA”) and move/unzip the files
into that directory.
https://lta.cr.usgs.gov/SRTM1Arc
21. Map Document Settings
• Create a new mxd document in the same folder as
your data. Call it “watershed.mxd”
• Enable Spatial Analyst tools Customize > Extensions >
Spatial Analyst. Search the Hydrology toolbox.
• Set Map Document Properties
22. Geoprocessing Settings
• Create a new file geodatabase in your DATA directory using
ArcCatalogue. You can name it what you want.
• Go to Geoprocessing > Environment and enter the following
settings.
23. Load Data and Check
Properties
• Load your geodatabase and images into the
mxd.
• Check your data properties.
• I have 1 band and 16 Bit pixel depth. None of
the data values are negative so, I can use a 16
Bit Unsigned when I mosaic rasters in the next
step.
29. 4. Find Sinks &
Fill Sinks
(Creating a depressionless DEM)
30. Find Sinks
• Sinks are a common problem in DEM. “A sink is a cell or set of
spatially connected cells whose flow direction cannot be assigned
one of the eight valid values in a flow direction raster.”
• Sinks are often data aberrations and they will impact and possibly
ruin models of flow direction…. Yet, to find sinks we need to first
do a flow direction analysis which assigns cell values that reflect
flow direction.
Flow Direction Results, Source:
http://desktop.arcgis.com/en/arcmap/latest/tools/spatial-analyst-
toolbox/how-flow-direction-works.htm
Up to 4.7% of the cells in a 30 meter DEM
might be sinks.
Tarboton, D. G., R. L. Bras, and I. Rodriguez–
Iturbe. 1991. "On the Extraction of Channel
Networks from Digital Elevation
Data." Hydrological Processes 5: 81–100.
http://dx.doi.org/10.1002/hyp.3360050107
31. Flow Direction to Find Sinks
Sinks are assigned a value of the sum of
their possible directions. You can see
below that the results do not give the
actual flow direction grid that we want,
they give us a raster with values 1-255.
We can use this to identify sinks.
32. I zoomed into a small AOI. These
dots are all sinks and peaks in the
data that we need to fix. Notice how
an apparent stream bed has a
number of low and high values.
33. Fill
• We need to run Fill on the original mosaic
raster. Then we will run the Flow Direction
again.
• Fill will create a depressionless DEM.
35. Flow Direction
• Now we can do a flow direction analysis on a
depressionless DEM. (Notice the difference in our results
now versus using the uncorrected data previously!)
• We can include a drop raster that models drops in elevation
too.
39. Flow Accumulation
• Now that we know flow direction we can do a
number of additional analyses.
• Flow Accumulation counts the number of cells
that flow into a particular cell.
40. Flow Accumulation
• Deriving streams from flow accumulation requires examining your
data and that you make a threshold decision.
• Here I have made two classes of the flow accumulation grid, as a
result any cells with more than 5000 cells flowing into them will be
recognized as part of the stream network.
44. Basins and Watersheds
• There is a function (Basin) that will
automatically calculate the basins in your data
set using flow direction.
• There is a way for us to choose to model
specific watersheds by establishing pour points
and looking at flow accumulation.
• Let’s look at how to do both of these and then
compare our results. Watersheds will take
longer, so let’s start by making basins.
46. Watersheds
• Pour points are outlets of the watershed that
you are interested in mapping.
• You can upload a predetermined set of pour
points (based on known locations) or you can
establish your own set of points.
• You will first need to create an empty shapefile
(or geodatabase feature class) for your points.
You can do this in ArcCatalogue. Call the new
layer “pourpoints”.
47. Watersheds
• When creating the new
feature class, create a
field called UNIQUEID
using Short Integer Data
Type.
• This will be used to
identify watersheds.
48. Pour Points
• Load the new layer
you created.
• Start editing the file.
• You may need to
open the Create
Features window to
make the points.
49. • Add points to
your new feature
class as close as
possible to the
stream network.
• Assign an
“uniqueid”
number to each
point.
• Save your edits
and stop editing
when done.
50. • Snap pour points to the highest
point of flow accumulation near
them.
• Snap to Pour Point will do this
and it will convert the points to a
new raster grid.
• Try several snap distances to
avoid having all points go the
same location (snap distance to
large) or miss the stream network
completely (snap distance too
small).
• We have a geographic coordinate
system so the distance is
measured in decimal degrees (1
decimal degree is ~111 km at the
equator but changes further from
the equator).
51. • Snap pour point distance has big
impacts on watershed generation.
• Distance 5 (~555km) led all my
points to be collapsed to one point.
• Distance 0 (no movement) led me
to have one good watershed and
one poor watershed.
• Distance 0.005 (roughly 555
meters) allowed me snap my points
to the highest flow cells and keep
three watersheds.
52. Original vector pour points (yellow) shown next to the
new raster pour points snapped to the highest flow
accumulation point within roughly 555 meters.
53. Generate Watershed
Using the three different snap pour
points rasters to generate
watersheds, I found that the 555
meters snap measurement gave the
best results.
54. Erroneous watershed generated
when Snap Distance = 0 km
Only one
watershed
generated
when Snap
Distance =
555km
Three watersheds
generated when
snap distance =
555 meters
56. Creating a Stream Network
• In order to get our raster streams into a vector
format and to perform some other analysis, we
need to make a raster that only shows our
streams.
• We will use Raster Calculator (located in the
toolbox Spatial Analyst > Map Algebra).
• Use the formula on the following slide to
generate a new raster with only the streams
represented.
57. This creates a new raster “streams” wherein all cells that
had the flow accumulation value greater than 5000 will
be given the value “1” and all other cells no value.
59. • We can perform Stream Link (to assign unique
values to branches of the stream network).
• Also, look at stream order using Shreve or
Strahler approaches.
60. • Shreve adds cumulatively
saying that 1+1=2, 2+3=5,
and 2+2=4.
• Strahler says that when
order 1+1=2 and that 2+3 =
3 and that 2+2=3.
• This makes a big difference
in the number of orders!
61. We can now convert these ordered steams to a vector
(polyline) feature using Stream to Feature.
This gives us a feature
class that includes
attributes for the nodes
and the order (“grid code”)
as well as the length (but
in decimal degrees, so we
need to fix that).
62. Projections and
Calculating Length
• We need to project our data into a projected
coordinate system in order to accurately
measure length and areas.
• There are two ways to do this calculation:
• Project our data into a new feature class in a
geodatabase (automatically will calculate length
and are in meters).
• Project our data into a shapefile, add data fields,
and calculate geometry for the new fields.
63. Projections
• First find a projected coordinate system that is
appropriate.
• For my data I used UTM Zone 33N (which
covers the majority of my region).
• I add the EPSG number to the file name to
identify the projection. The EPSG for UTM
Zone 33N is 32633.
• You can reproject direcly to a feature class
(gdb) or a shapefile.
64. You can also project directly to a
feature class in your geodatabase.
Or use Feature Class to Feature
Class to send the shapefile to your
geodatabase.
Project to a shapefile:
No geographic transformation is
needed as I am using the same
datum.
66. Calculating Length (shapefile)
Add a new field, right click on the field and choose Calculate Geometry,
Now you should see the calculation in your attribute table.
67. You can now change the Symbology (try line width
and/or colors) on your new vector stream network
to visually represent the stream orders, section
length, or other attributes.
69. Basin to Polygon
• Open up the Basin raster attribute table and
sort by count.
• By selecting the row you will be able to visually
identify and select the basin near your
watershed.
70. Basin to Polygon
• The only function you need now is Raster to
Polygon.
• If you don’t select parts of the raster, then you
can get all the basin polygons using the above
function.
72. Watersheds to Polygon
• Like Basins, we use Raster to Polygon.
• Yet, something funny happens… Open the
attribute table to see.
73. Watersheds to Polygon
• We now have five watersheds because in
converting the raster to a polygon, some cells were
cut off and formed new features.
• Select one of the areas with small or no
Shape_Area (again this is in decimal degree
because we have not projected our data yet).
• Zoom to the selected area (this is an option in the
menu).
74. Watersheds to Polygon
Here we see the original
raster watershed below the
vector watershed.
We have two options, delete
the hanging area or merge
the features.
Given the small size, I simply
deleted the small polygon
features in the table (you may
need to turn on editing).
I then projected (EPSG
32633) the feature class in
the geodatabase. I now have
my three watersheds and the
measurement of area in
meters.
79. We can compare our basin to
our watersheds and rivers.
• When we decided to locate pour points, we ended
up not capturing the entire basin and even
including part of another basin.
• This could impact field decisions.
• For example, if we were collecting flow information
with monitors located in the field we might decide
to change the location of our pour points
(monitors) to more accurately represent the entire
basin and maybe even capture 1-2 more basins
with the same amount of monitors.
81. Does the basin or any small
watershed cross international
borders?
82. Does the basin or any small
watershed cross international
borders?
• Yes, the basin appears to cross the border, it is largely in
Cameroon with small parts of it in Nigeria.
• As well there were other basins that, appeared to cross the
border (largely in Nigeria with small parts in Cameroon).
• We could continue on with this analysis identifying and
quantifying the overlap of basins throughout this region.
• Given our findings, we might suggest that the basin and
watersheds overlapping the border are reasons to explore
an international conservation area or an international
agreement on watershed management.
83. Looking Back
You now know how to:
• Get SRTM 1 Arc-Second (30 meter resolution) for free.
• Merge raster grids into mosaics.
• Derive streams, stream orders, basins, and specific
watersheds from the data.
• Convert raster grids into vector features.
• Calculate area and length.
• Create and analyze evidence for responding to geographic
questions.
More information about this region can be found from organizations
such as BirdLife International:
http://www.birdlife.org/datazone/sitefactsheet.php?id=6112
84. End
Did you find an error?
Could something be more clearly explained?
Did you adopt and adapt these materials?
Let me know at arthur.green@mail.mcgill.ca
Watershed Delineation by Arthur Gill Green is licensed under a Creative Commons Attribution-
ShareAlike 4.0 International License.
Based on a work at http://greengeographer.com/.