## 4 Results and Discussion
### Prioritization Assessment of Sub-Catchments Based on Combined Values  
Watershed prioritization due to morphometric evidence can successfully identify sub-catchments that are at high level of risk for soil erosion process. No single morphometric characteristic can sufficiently describe the susceptibility of sub-catchments to erosion. This limitation arises from the complex nature of soil erosion, which is influenced by a variety of significant factors, including land use, geological features, climatic conditions, and management practices. Therefore, a more holistic measure of a watershed's vulnerability to erosion is represented by the combined value of multiple morphometric attributes. As indicated by the authors in Refs. [15; 24; 40], it is computed by summing the numerical results of several morphometric factors and ranking them in order of relative relevance. Though the overall compound values technique can be applied to assign soil erosion risk, it is important to ask how well the watershed's future tackling soil erosion rates are predicted [43]. In the current study, and due to their compound value, the Wadi Haly catchment is divided into the following three priority categories: high (\(\leq\)7.3), moderate (7.9-9.2), and low (\(\geq\)9.3) (Figure 8). This classification could be adapted differently from catchment to another. For example, the authors in Ref. [40] categorized Dabus catchment in Ethiopia into very high, high, moderate, and low soil erosion priority classes due to compound values such as low (\(\geq\)7.51), moderate (7.5-6.51), high (6.51-6.5), and high (\(\leq\)5.5). Additionally, the authors in Ref. [64] divided the Didessa sub-watershed and Jema sub-watershed into the following three priority categories: high rates, medium rates, and low rates, based on extracted compound values of less than 2.55, 2.55 to 3.55, and more than 3.55. In the Wadi Haly catchment, Sub-C 7 has the highest compound value at 10.3 (Figure 8). Figure 7: Rank maps of the relief morphometric parameters and their priority classes, R, Sb, Rr, Rn, MRn, and Gc indicate basin relief, basin slope, relief ratio, ruggedness number, Melton ruggedness number, and channel gradient, respectively. The findings of this study reveal that four specific sub-watersheds, sub-catchments 1, 11, 12, and 13, have been marked for high priority levels due to their pronounced steepness, considerable relief, low vegetation cover, reduced infiltration capacity, and substantial runoff levels, which increase the soil erosion risk and underscore the urgent need for effective water and soil conservation interventions. These areas are crucial to local ecosystems and agriculture, where the soil health directly influences crop yields and overall ecosystem stability. Immediate actions are essential, including practices like contour bunding, river tracking, grass water-passes, in addition to guilty control structures which are designed to slow water flow, mitigate gully erosion, and enhance sediment retention, thereby fostering a more stable soil structure. Beyond controlling erosion, these techniques also improve water quality by filtering sediments and pollutants before they enter water bodies and help maintain hydrological cycles to ensure water availability for agricultural and ecological needs [65]. To address the adverse effects of soil erosion further, implementing agricultural strategies such as strip cropping and mixed cropping is necessary; these practices protect the soil from direct rainfall impact and improve soil structure and fertility through crop diversity, enhancing the resilience of agricultural systems against climatic variations and reducing dependency on chemical fertilizers. This study's final map categorizes sub-catchments 2, 4, 5, 6, and 14 as moderate-priority, while sub-catchments 3, 8, 9, 10, and 15 fall into the low-priority category, allowing for targeted resource allocation based on specific vulnerabilities and potential impacts (Figure 9).