Abstract

Rainfall Analyst: An ArcGIS tool for deriving spatially distributed rainfall
Track: Water Resources
Authors: Nasser Alsaaran

Hydrologic modeling requires spatially distributed rainfall data at given spatial and temporal scales. Such data are usually obtained by spatial interpolation of point data measured at sparse irregular stations. Performance of spatial interpolators depends on density of rainfall recording stations and their spatial configuration, and topography. The best spatial interpolator for a given situation is not a priori known but has to be inferred from the data by means of cross-validation. A script ArcGIS tool was developed to: (i) find the most accurate spatial interpolator using cross-validation technique; (ii) grid rainfall at a given spatial resolution using the most accurate spatial interpolator; (iii) compute areal rainfall and append it to the attribute table of the study area feature class. The required inputs are: (i) a polygon feature class for the study area; and (ii) a point feature class for rainfall stations with an attribute table containing rainfall field.