Rainfall – Runoff Relationship in ALHWAIZ Basin

River flows depend on precipitation in their catchments, where the flow is highly correlated with precipitation, among many climatic and geographic factors. The relationship between precipitation and runoff is of great importance in estimating flow changes in The HWAIZ basin that is located between The-Zrod and The-Gelani basins. The Al-HWAIZ Dam was built on the HWAIZ River with storage capacity of 16.5 MCM. The purpose of this study is to find a relationship between rainfall and runoff in The HWAIZ basin. This study depended on statistical analysis of rainfall and runoff data, and the analytical study of the annual rainfall data (1959-2011), to guess the trend of rainfall and its future changes and forecasting changes in the HWAIZ river flows. The study showed that the runoff coefficient values ranged between (0.007-0.66). A mathematical relationship was established that allows to estimate flow based on measured or predicted precipitation values, as well as appraise missing or lacking data with accepted level of accuracy.

Rainfall – Runoff Relationship in Alsafarqieh Watershed

The Alsafarqieh watershed is located on the western slopes of the coastal mountain range, Its area is 132.58 km2, It forms a part of the Alros river basin, The river starts at a height of 1200 m, A group of tributaries meet and form the Alros River, which flows into the Mediterranean Sea. Salaheddin Dam was constructed to store 10 MCM on the riverbed at the intersection of the Qurdaha River with the Shehada River. The study aims to determine the rainfall- runoff relationship in The Alsafarqieh watershed. The solution depends on the statistical analysis of precipitation and runoff data. Then the study found the mean annual precipitation is 159.6 MCM/year, and the mean annual flow into the Salaheddin lake was 9.4 MCM during the study period (2010-2012), so the runoff coefficient is 0.06. This indicates a significant water loss. A mathematical equation to predict the runoff quantities depending on the values of precipitation, has been concluded. This is important to study water projects for water storage and flood prevention.