Hydrologie : recherche actuelle

This study aims to model and combine the eco-hydrological components to evaluate its impact on the potential water flow of selected catchment in eastern Sudan. Spatial variability of landcover types and magnitudes was assessed using landsat and sentinel 2 imageries for years 1996, 2011 and 2018, topographic and soil type factors were used to assess the potentiality for runoff at sub catchment level using CN approach. Rainfall records, CN map and one gauge readings for stream discharge were used to simulate the hydrograph using 10 years return period and assess volumetric flow at sub-catchment level.

Evaluation of the potentiality of the area for high runoff and prediction of water quantity produced by the catchment is crucial for dry lands in Africa generally and in Sudan. Land cover changes show the dominance of agricultural lands and reduction in natural vegetation through the studied periods in addition to soil and topography factors, curve number was generated and reflect high potentiality for generating runoff. Hydrograph analysis was generated and the runoff peak by means of volume and time during the storm event was generated. The studies demonstrate this approach that could be used for promising areas for water management and planning purposes.

The relationship between rainfall-runoff is a complex hydrological process that requires technical-based approaches to investigate and understand the interaction of the hydrological variables. A calibrated rainfall simulator was developed to produce storms at seven (7) predetermined Rainfall Intensities (RIs) over two (2) Runoff Plots (RP). The Runoff Plot (RPA) is 0.72 m2 and RPB is 0.5 m2 was each inserted 0.3 m into the bare sandy loam. The results of the experimentation showed the first Rainfall Simulation Attempt (RSA) of RI value of 10.8 mm/hr was totally lost to infiltration without generation of surface runoff from the two runoff catchment plots. Subsequently, the RSA generated varying Surface Runoff Intensities (SRI) and with RPB producing higher SRI and volume compared to large catchment plots (RPA). Conversely, the relationship of rainfall-runoff showed co-linearity between the simulated rainfall and generated surface flow RPA and RPB with the determinant of coefficients of 0.9926 and 0.9942 at P<0.05. Therefore, the study’s finding is useful to develop a rainfall-runoff model under different runoff catchment areas for constructing Integrated Water Management Schemes (IWMS), hydraulic structures, and irrigation scheduling.