جيومورفومناخية المناطق الجافة وأثرها على حصاد المياه : دراسة نموذجية على إقليم الفاشر-غرب السودان

الملخص EN

This study took with climatic geomorphology in dry environments and its impact on water harvesting, using the locality of Al-Fashir as the model for this study.

It mainly aimed at studying the geomorphological features and processes and the role of climate elements in these dry environments, evaluating their impact on water harvesting projects in the region, and verifying the validity of the topography and surface features of those projects, especially dams and excavations.

The study used several methods, including: the historical and quantitative mathematical method, the analytical and explanatory method, and the causal method to the use of (ARC GIS 10.5) and (ARC HYDRO 10.4) software in analyzing satellite visual images and making hydrological derivations.

In addition to the (SPSS) program for data analysis and presentation, in addition to the use of some morph-climatic equations to extract the values of wind and water erosion, in addition to field work and on-site investigation.

Thus, the study reached several results, the most important of which are: that the study area with a dry environment is active in the physical weathering processes in general, where the daily and annual range is large and the intensity of heat during the day and its coldness during the night, as it is exposed to high wind erosion, its value reached (180) according to the Chapel equation The presumption of erosion, which led to the burial of dams, pits and natural pits.

It also clarified that the siltation process had negatively affected water harvesting technologies, as about 43.7% of the storage capacity of excavations was buried, while dams are the most affected by the silting and collapse processes, as they lost about 79.9% of their storage capacity.

Earth's surface in choosing dam sites.

A study also proved that only 3.2% of the study area represents a typical area for harvesting runoff water, taking into account the high temperatures in the summer and during the day and the increase in the amount of evaporation, while 49.6% of it represents a suitable medium area, while 47.2% of the total area represents an area Not suitable for harvesting.

The research came out with several recommendations, the most important of which are: the need to pay attention to the preliminary studies of the topography and geomorphology of the area to be activated, as well as taking into account the climate factors, in addition to conducting biological (ecological) treatments to stop the processes of weathering and erosion of all kinds, especially wind and water and sediment influx towards dams and excavations in addition to the natural deposits as well as the need to pay attention and strive hard to Removing siltation and sediments from reservoirs and pits, and the need to establish several sedimentation basins on the main streams leading to the dams to reduce the amount of silt deposits that reach the reservoirs and activate periodic maintenance.

As well as stopping work on the maintenance or rehabilitation of dams, which the study proved to be affected by the steep slope process and the unsuitability of their surface for the water harvesting process, and the search for other alternative sites that are more suitable for the construction of dams in terms of their topography, hydrology and geomorphology, in addition to taking into account the climatic factors in the region