تقدير خط السيول شرقي مدينة مكة المكرمة باستخدام تقنتي الاستشعار عن بعد و نظم المعلومات الجغرافية

الملخص EN

The area located eastern of The Holy City of Makkah is considered as a strategic and an attractive site for human investments including government projects, residential zoned area, cultivated lands, and many other activities.

The area embraces the sacred site of Arafat where two million people are gathered every year, the main campus of Umm Al-Qura University (UQU), Alhosainiah town and villages.

The area is considered to be at risk from flooding by 18 wadis which are the tributaries of Naaman and Oranah vallies.

The loading of all tributaries converge in Alabediah where UQU resides.

In this study, geographic information system and remote sensing techniques were utilized to compute the discharge coefficient and peak, and numbers of morphometric and hydrologic variables in order to assess flood risks.

It is concluded that the study area is at risk of flood due to several factors contribute to the surface imperviousness such as geologic structure, slope, and the scarcity of vegetation cover, which as a whole generate high value of the discharge and flood coefficients, particularly in the southwestern part of the study area where is most of the human activities are clustered.

In addition to the mentioned factors, some more factors were examined and found contributing to flood hazards such as the length of stream particularly first order streams, stream frequency, the average length of runoff, peak discharge particularly in Wadi Naaman watershed, and poor watershed management.

Several recommendations were suggested for better flood management in the area of study.