Objectives
The course provides the student with a broad overview of the GIS tools for the study and evaluation of water resources. At the end of the course, the student will have the abilities to:
- Know the open source GIS software environment.
- Use specialized complements for spatial analysis.
- Represent spatial information in a thematic map.
- Perform spatial interpolations and contour lines.
- Use satellite images in hydrological studies.
- Determine watersheds and their study parameters.
Course content
The course consists of a total of 20 hours. The sessions consist of a theoretical introduction plus a practical part. The development of the theory and applications of this course is shown below grouped by session:
Session 1
Theoretical Part
- Introduction to Geographic Information Systems (GIS).
- Components and functions of the SIG.
- Projections and coordinate systems.
- Types of vector and raster information.
- Introduction to QGIS.
Practical part
- Familiarization with the QGIS environment.
- Generation of vector data (points, lines and polygons).
- Assignment of coordinate systems.
- Topological edition: Generation of topologically correct polygons (perfectly adjacent).
- Generation of spatial queries (Query).
- Style application of vector and raster files.
Edition mode of vector files:
- Add / remove part
- Reshape spatial objects
- Scroll curve
- Divide objects
- Merge objects
- Node tools
- Preparation of maps with grids, legend and scale.
Georeferencing images in QGIS:
- Application of projection systems to a file and a project
- Georeferencing maps in jpg or .tif format
- Georeferencing satellite images
Session 2
Practical part
- Download satellite images from the NASA Echo Reverb server.
- Modification of ASTER DEM images (joining, cutting and reprojecting).
- Creation and edition of vector layers for modification of rasters.
- Import delimited text as a point layer.
Geoprocessing tools to obtain basic parameters of one:
- Manual delineation of watersheds in QGIS.
- Automatic delineation of watersheds with Saga Gis and QGIS.
- Identification of the surface flow network
- Obtaining elevation level curves
- Obtaining slope rasters, orientation rasters, hillshade rasters, relief rasters and basin scab index
- Conversion of raster file to vector.
Obtaining properties of the raster layer:
- Determination of the histogram
- Determination of the average height, area and perimeter of the basin
- Determination of the average slope of the basin
Obtaining properties of the vector layer:
- Basic spatial statistics of the water network
- Determination of spatial attribute calculations
Selection tools:
- Selection by location
- Conversion, filtering and annexing of basin attributes
Labeling of watershed elements:
Labeling with graduated symbols
Creation of expression for subbasin labeling
Session 3
Practical part
- Determination of the Normalized Difference Vegetation Index (NDVI) with raster calculator
- Modification of the NDVI raster:
- Obtaining contour lines
- Filtering of spatial data by threshold
- Simplifying contour lines
- Obtaining nodes of the contour lines
- Extraction of the elevation of the nodes
- Obtaining a simplified superficial flow network and obtaining its nodes.
- Multilevel Interpolation B-Spline of the water table in Saga Gis with wetlands interpreted from the NDVI and points of the network of simplified superficial flow.
- 3D visualization of rasters in Saga GIS.
- Modification of water table:
- Trimming of the water table to the extension of the basin
- Correction of the water table at points where the interpolation is greater than the surface elevation
- Generation of cross sections with surface elevation and water table.
Session 4
Theoretical part
The water cycle in Andean basins.
Practical part
- Obtaining centroid coordinates, maximum height and minimum height of the basin.
- Capture of coordinates of a point in different projection systems (tool: Capture coordinates).
- LocClim configuration for the choice of meteorological stations to be used.
- Obtaining precipitation data and potential evapotranspiration of the valley bottom and valley top with the LocClim 1.1 software
Manipulation of data obtained from LocClim:
- Obtaining water surplus from precipitation data and potential evapotranspiration.
- Determination of precipitation regression lines, potential evapotranspiration and water surplus with elevation.
- Generation of precipitation rasters, potential evapotranspiration and water surplus from the elevation raster.
- Contour lines generation of main components of the water cycle.
Methodology
Here are some details of each methodology:
- Manuals and files for the exercises will be delivered.
- The course will be developed by videos on private web platform.
- There is online support for questions regarding the exercises developed in the course.
- Digital certificate available at the end of the course.
- Video of the classes will be available for 2 months.
- To receive the digital certificate you must submit the exercises after 1 month.
