The impact of climate change and soil salinity in irrigation water demand on the Gaza Strip

Abstract

The presented work analyzes the potential impacts of the temperature, precipitation changes and water salinity on agricultural water demand. The study was carried out on five representative orchard crops (olive, palm, grapes, citrus and guava) that cover around 83% of the orchard farms in Gaza Strip. To achieve this goal, CropWat modeling software version 8.0 is used to calculate the reference evapotranspiration rate and crop water requirement under different temperature and precipitation scenarios. Furthermore, a survey was conducted to evaluate the farmers' current irrigation practices and the impact of water salinity on leaching requirements and production yield. The increased temperatures by 1 or 2 °C caused an increase of the annual average evapotranspiration by 45 and 91 mm relative to the current climate condition and leading to increase of irrigation requirements by 3.28 and 6.68%, respectively. Leaching requirements do not exceed 15% for electrical conductivity (EC) value less than 2 dS/m, while it begins to increase for the EC value between 3 and 4 dS/m and account for 114, 89 and 36% for grape, citrus and guava. Generally, the impact of salinity increase on irrigation requirements is much higher than the impact of evapotranspiration increase due to the temperature increase by 2 °C and 10% precipitation reduction.