Optimization of rain gauge network using multi-criteria decision analysis and entropy approaches: case of Tekeze River basin, northwestern Ethiopia

Abstract

Rainfall is an important hydro-meteorological variable that has various applications in water resource planning and development. Adequate rain gauge network gives immediate and precise rainfall data that are crucial for effective and economical water resource management. This study describes a multi-criteria decision analysis (MCDA) in combination with kriging and entropy methods to optimize rain gauge networks in the Tekeze River basin, northwestern Ethiopia. The Tekeze River basin is a trans-boundary river basin in the northwestern part of Ethiopia having a drainage area 86 510 km2. The MCDA was used for selecting suitable locations for additional rain gauges in the basin. The kriging and entropy methods were used to determine the optimal number of rain gauge stations in the basin. Initial analysis showed that the existing 63 rain gauge stations in the basin are not adequate and result in about 12% rainfall estimation error. Optimization of rain gauge network in the Tekeze River basin resulted in 216 additional gauging stations. The total optimal number of rain gauges for the Tekeze River would thus be 279. The results of the study revealed that the combined use of the MCDA, kriging, and entropy methods is useful to optimize the spatial distribution and number of rain gauge stations in a basin.