Evaluation of Thornthwaite's method to establishing a water balance in hyper-arid lands

Abstract

The valley of Oued-Souf, located in the North East of the Algerian Sahara, characterized by an hyper arid climate, marked by a mild and dry winter and a very hot summer, with an average annual temperature of 23° C, translating into an excessive evaporation. The region suffers too much from the problem of rising groundwater which is the result of water excess (or hydromorphy). However, the most previous hydrological studies have shown that the water balance of the region is deficient. These observations lead us to evaluate the climatic parameters of the region and to examine the water balance established by Thornthwaite method. We have found that the soil storage capacity is not taken into account by application of this method which leads to an underestimation of the water balance, so as a mismanagement of water resources theoretically and practically.