Abstract
Precipitation is one of the most significant variables with an impact on the environment, agriculture, as well as the design of any hydraulic infrastructures. The rainfall analysis predicts the highest, average, and minimal values of rainfall that are expected in certain catchments for return periods. The long-term variability of rainfall over the Arbaat watershed was studied at the various stations in a duration (day, month, and year) from 1942 to 2010 rainfall runoff using the Isohyetal Map of the area besides using different plotting position formulae of rainfall ratios. This statistical analysis will offer valuable data for water resource planners for Port Sudan, farmers, and Red Sea Water Corporations engineers (RSSWC) to evaluate the availability of water and create the storage accordingly. From the rainfall-depth analysis outcomes, the rainfall pattern was found to be irregular. Although the historical data was used, the meteorological observation of Suakin, Sinkat, and Arbaat stations was stopped from work. However, Port Sudan station gave reliable results without resorting to precipitation data measured by the satellites. Besides, the outcomes of this study can provide rational guidelines and policy concerning water resources to preserve the health of several ecosystems in the regions of under study.