Watershed model setup

Watershed model setup

Conventional Method:

You will need the following layers to make the conventional model within arcgis:

1. Rain Gage shapefile
2. Temperature gage shapefile(if your area has snow)

Rain Gage shapefile:

                                   This file contains georeferenced location of automatic rain gauge or automatic weather stations or both. It looks like this in our example:

AWS Stations for Tehri Catchment

The green dots represent the automatic weather stations. In our case the temperature and rain gage are same because we are using Automatic Weather Stations.

By using this we can obtain the metrological model (Thiessen polygon) as shown below which will be useful to determine the gage weights for particular area of catchment and analysis of rainfall data to convert into flow(inflow/outflow)

Thiessen Polygon for Tehri Catchment

Discharge sites which will provide us observed data for calibration and validation of model are also geo referenced in Arc GIS.

Gage and Discharge Stations for Tehri Catchment

Modern Method: 

                              Modern method is the era of grids. In this data is in the form of grid whether it's temperature, precipitation, canopy etc. For this you need your catchment to be gridded. With the available resolution of grids with you you can choose the size of pixels. In our case I have chosen 10km*10km. My grid cell file looks like this.

Grid Cell file for Tehri Catchment