How to explore hydrological analyses using SAGA GIS?

How to explore hydrological analyses using SAGA GIS?

This Wiki has been produced for the GEOM 4008 – Advanced Topics in Geographic Information Systems class at Carleton University for the purposes of exploring and describing the methods of Hydrological Analyses using FOSS4G, in specific SAGA GIS.

How to assess flow over a landscape in Saga?

There is a variety of way to assess flow over a landscape in SAGA. this example allows you to interactively initiate points of flow over corrected (Sink Filled) elevation data. Geoprocessing>Terrain Analysis>Hydrology>Flow Accumulation>Downslope Area (Interactive)

How are hydrologic models used in the USGS?

USGS models are widely used to predict responses of hydrologic systems to changing stresses, such as increases in precipitation or ground-water pumping rates, as well as to predict the fate and movement of solutes and contaminants in water.

Is there a cost to use SAGA GIS?

SAGA GIS also comes at no cost for the user because it is a Free Open Source Software for Geospatial analysis (FOSS4G).

How to calculate Dem in hydrological analysis QGIS?

Select the DEM in the Elevation field, and leave the default values for the rest of parameters. Some algorithms calculate many layers, but the Catchment Area one is the only one we will be using. You can get rid of the other ones if you want. The rendering of the layer is not very informative.

How is the watersheds basins algorithm used in QGIS?

Now, we will use the Watersheds basins algorithm to delineate the subbasins corresponding to that channel network, using as outlet points all the junctions in it. Here is how you have to set the corresponding parameters dialog.

Why is catchment area not evenly distributed in QGIS?

To know why, you can have a look at the histogram and you will see that values are not evenly distributed (there are a few cells with very high value, those corresponding to the channel network). Calculating the logarithm of the catchment area value yields a layer that conveys much more information (you can do it using the raster calculator).