A methodology for the evaluation of global warming impact on soil moisture and runoff

This paper presents a numerical evaluation of the variability of soil moisture and direct surface runoff due to global warming. An analytical model of the soil moisture balance based on our previous work is used to evaluate the probability distribution of the soil moisture concentration and resulting surface runoff. The input of hydroclimatic values is based on the approach suggested by C. W. Richardson in 1981. Our results show that not only the mean of the distribution of both soil moisture and runoff change, as expected, but that the variability of the values around the means also changes. The results of our research have immediate applications on the planning of reservoir operation for irrigation demands and evaluation of the change in surface runoff expected due to global warming.