Morphometric, Meteorological, and Hydrologic Characteristics Integration for Rainwater Harvesting Potential Assessment in Southeast Beni Suef (Egypt)

Abstract

In arid areas, the forecast of runoff is problematic for ungauged basins. The peak discharge of flashfloods and rainwater harvesting (RWH) was assessed by the integration of GIS, the RS tool and hydrologic modeling. This approach is still under further improvement to fully understand flashflood and rainwater harvesting potentialities. Different morphometric parameters are extracted and evaluated; they show the most hazardous sub-basins. Vulnerability potential to flooding is high relative to steep slopes, high drainage density, and low stream sinuosity. Using hydrologic modeling, lag time, concentration time, peak discharge rates, runoff volume, rainfall, and total losses are calculated for different return periods. The hydrologic model shows high rainfall rates, and steep slopes are present in the southeastern part of the study area. Low rainfall rates, moderate–high runoff, and gentle slopes are found in the central and downstream parts, which are suitable sites for rainwater harvesting. An analytic hierarchy process is utilized for mapping the best sites to RWH. These criteria use land-cover, average annual max 24 h rainfall, slope, stream order, and lineaments density. About 4% of the basin area has very high potentialities for RWH, while 59% of the basin area has high suitability for RWH. Ten low dam sites are proposed to impact flooding vulnerability and increase rainwater-harvesting potentialities.

Integrated Hydrological Modeling for Watershed Analysis, Flood Prediction, and Mitigation Using Meteorological and Morphometric Data, SCS-CN, HEC-HMS/RAS, and QGIS

“…In small catchments where overland flow is essential, the basin slope is crucial. Under such circumstances, a steeper catchment slope leads to a higher peak discharge [60,61]. The drainage densities of the studied sub-basins range from 0.01 to 1.53 and 0.09 to 2.69 km/km 2 for Wadi An-Nawayah and Al-Rashrash, respectively.…”

“…Water resources in Egypt face significant pressure owing to population growth. Consequently, flood mitigation measures are essential not only for protection but also for the sustainable utilization of this freshwater resource [60,68]. Based on the findings of this modeling on the potential for flash flooding, implementation of mitigation measures for flash flood control are strongly recommended to mitigate potential flash flood hazards in the study areas.…”

“…This limits the rate of infiltration and increases runoff, resulting in increased flooding. Consequently, heavy rainstorms can cause rapid and significant peak floods [60].…”