ملخص
Abstract
this study aims to investigate the hydrological cycle at wadi Zaghadnah basin in Tarhuna in terms of (rainfall-surface run-off-evaporation-infiltration) and estimation of the quantity of surface water , and to predict the maximum flood can happen in order to reduce hazardous to houses and farms that are found on my profile of the valley was the use of a series of years of readings rainfall and results have indicated to the fact that annual average rainfall was (238) mm, via using (Isohyetal method).The quantity of water which is supposed to be reserved in the dam was (1.94) million cubic meters. As for rain test, it was found that it is random and non-coherent. Having studied rain-wave relation through application of modelprediction statistical, it was deduced that it is not reliable to depend-upon in forecasting the expected rain. Results have indicated that total evaporation average to (2324.5)mm via using (CROPWAT) and average annual infiltration is (2065.17)mm, and post application of some statistic equations like probability log-Pearson Type ׀׀׀distribution and Gumbels distribution-plotting (25-50-100-1000), maximum possible amount (via using the aforesaid three methods) was found, but due to silt and likely erosion of soils as a result of flooding, silt amounts in Dom lake was estimated by using calculative equations was (5622)m³/year.