GLOBAL AND DISTRIBUTED MODELLING OF RUNOFF IN NORTHERN ALGERIA

摘要

This paper describes a new methodology for estimating monthly runoff discharge in nongauged watersheds with areas less than 1500 km~2 in Northern Algeria by using global and distributed models. The global model, which is based upon simplified assumptions such as linearity and constancy of the production and transfer functions, is calibrated on 136 gauging stations. Inputs are monthly rainfall data maps established from 887 raingauges and monthly averaged values of evapotranspiration. In the distributed model, each watershed is discretized into elementary areas considered to be elementary watersheds. The results represent the quantity of runoff within an area for a specified month, and the sum of runoff for all areas within a specified watershed represents the runoff for the specified watershed for the same month. Results are successfully validated.