How to use gis to calculate rainwater harvesting area

Isohyet method and Tai Sen polygon method.

Tai Sen polygon method is relatively simple. A Tai Sen polygon is generated by a rainfall station, and the rainfall value of this station is assigned to this polygon, and the rainfall value of this station is taken as the rainfall value of the whole basin (region).

Isorainfall method is a kind of rainfall distribution map that is often seen in weather forecast. Its principle is a bit like contour line. Through the interpolation analysis of a series of stations, the spatial distribution law is obtained.