The Potential of Remote Sensing Data for Water Budget Evaluation in Arid Areas of Sinai, Egypt

Abstract

Water scarcity is a growing concern in arid and semi-arid regions of the world, locations where groundwater is the main source of freshwater. In order to preserve local water budgets, it is critical that accurate climatic data be acquired. Unfortunately, the majority of these arid regions feature a very limited number of rain gauges, reducing the reliability of the data produced. The present study offers a series of steps for overcoming the issue of data scarcity. Once resolved, this could then promote greatly needed hydrological studies on topics such as the spatiotemporal distribution of rainfall, the mitigation of flash floods hazards, or the minimization of soil erosion. These studies would be directly applicable to the study site, which was the eastern side of the Gulf of Suez in the Sinai Peninsula in Egypt. Data collected by Landsat5 and Landsat8 during the years 2000, 2010, and 2019 were downloaded from Google Earth Engine in order to determine changes in land cover and land use. This allowed the author to answer three main questions: Is the area under study active or dormant? Was there a change in the rate of water consumption over time? If so, was this change in consumption positive or negative? Following the acquisition of land cover and land use data, the spatiotemporal distribution of rainfall at the study site was analyzed using two types of remote sensors, the TRMM(3B42V7) and the GPM(IMERG). The performances of each were compared to determine the optimal type for utilization in this study. A final step included the use of DEM file and GPM(IMERG) data to identify the most suitable locations for a new network of rain gauges. Results suggested that, during the period of 2000 to 2019, there was an increase in both vegetation and land development in the areas tested. They further indicated an increase in the rate of water consumption. Data acquired via both remote sensors during light intensity precipitation events produced significant conclusions. However, data recorded during heavy intensity events was not able to achieve this, irrespective of the type of sensor used. Overall, GPM(IMERG) data produced results closer to those of the limited rain gauge records. It was therefore selected for use with the SRTM90×90m DEM file, which aided the author in identifying 31 new locations for rain gauges, together able to produce more accurate and reliable information on the climate at the test site in the future. The conclusions reached by this study recommend the installation of the abovementioned rain gauge network, allowing the community to properly assess proposed water management procedures (including withdrawal portions and expansion rates in existing settlements) as well as to develop improved warning systems for flash flood hazards.