Relating point to area average rainfall in semiarid West Africa and the implications for rainfall estimates derived from satellite data

Abstract

In the Republic of Niger, rainfall was as well or better correlated over small distances as rainfall in other semiarid climates. A regression model was developed to specify the systematic correction required, when a raingage measurement is used to represent an area average rainfall and to quantify the errors involved. It was found that in this particular climate large point measurements are not representative of even small areas and need to be reduced by a factor which depends on the size of the area. The effect of satellite location errors on the correct pairing of point measurements and pixel estimates are discussed. -from Authors