Estimation of nutrient fluxes from the flooding of the Wadi Gaza catchment into the Mediterranean Sea

Abstract

The coastal catchment of Wadi Gaza is the main surface water basin that flows down to Gaza coastal plain zone and drains into the Mediterranean Sea. The modeling-based assessment of the hydrological system is an essential endeavor for managing water resources and ensuring water security for the transnationally shared Wadi Gaza basin and defining water resources rights. The hydrological simulation of the basin was performed using the SWAT model from 1984 to 2020. The outputs of the simulation refer to an average discharge that varies between zero in the summer months and about 15 m3/s in the winter with a maximum recorded discharge of about 130 m3/s. The sediments and nutrient transport indicate to valuable quantities might reach the downstream area of the wadi Gaza stream where on average about 3,673, 177, and 62 tons per month of sediments, total nitrogen (TN), and total phosphorus (TP), respectively, are received at the downstream point. Through the rainy seasons, for the nitrogen sources, the average monthly contents were 4, 13, and 1 ton for nitrate (NO3).