Spatial and Temporal Variability of Rainfall and Its Impact on the Formation of the Hydrographic Network: An Analytical Study of Wadis and Springs in Northwestern Libya

Abstract

This study aims to analyze the spatial and temporal variability of rainfall in northwestern Libya and to demonstrate its role in shaping the hydrographic network, represented by wadis and springs. The study adopts a descriptive-analytical approach, employing cartographic and statistical analysis of data from meteorological stations and available hydrological data. Temporally, the study covers the period from 1979 to 2023, while thematically it is confined to analyzing the relationship between rainfall and the characteristics of the hydrographic network, considering topography, geology, and soil permeability as mediating factors in this relationship.

The preliminary findings indicate a clear spatial variation in rainfall: rates are higher along the coast and in the northern highlands of the Western Mountain (Jabal al-Gharbi), particularly in Gharyan and Tripoli, then decrease toward the south and southwest, reaching Nalut and Ghadames. Precipitation is also concentrated in the autumn and winter seasons, which is reflected in increased wadi flow during this period and a higher probability of flash floods in basins with steep slopes and limited soil permeability. The study shows that both traditional and modern water-harvesting techniques represent an important option for reducing water loss, enhancing groundwater recharge, and mitigating flood hazards.