Dam breach analysis and flood hazard assessment : case study : Jebal Aulia Dam-White Nile

العناوين الأخرى

تحليل انهيار السد و تقييم خطر الفيضان : دراسة الحالة : سد جبل أولياء-النيل الأبيض

مقدم أطروحة جامعية

Muhammad, Sadiq Ahmad

مشرف أطروحة جامعية

Ibrahim, Yusuf Ahmad

الجامعة

جامعة أم درمان الإسلامية

الكلية

كرسي اليونسكو للمياه

دولة الجامعة

السودان

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2009

الملخص الإنجليزي

The purpose of this study is to develop a hydraulic analysis through computer modeling to evaluate the impact of dam breach on downstream land use.

The methodology of this research comprise of 3 phase, namely ; Literature study phase, Data collection phase and Modeling phase.

Information about Jebal Aulia dam and reservoir characteristics were obtained from Jebal Aulia Dam Directory, 90 m resolution digital elevation model DEM and satellite images were used to describe Land use, soil cover and topography for lower White Nile area.

Excel spreadsheet is developed to predict the breach size, shape and formation time using four empirical methods namely: Froehlich (1995), MacDonald and Langridge-Monopolis (1984), Von Thun and Gillette (1990) and U.

S.

A.

Bureau of Reclamation (1982), combined procedure that utilized Level Pool method and Fread (1988) were employed to estimate the reservoir outflow hydrograph as effected by dam breach.

One-dimensional unsteady flow simulation using HEC-RAS is performed to route the resulted breach outflow hydrograph through Jebal Aulia downstream valley, the analysis described in this research focused on the impact of two failure scenarios ; these are: overtopping failure and normal reservoir pool or sunny day failure. Froehlich’s relation appears to be the best predictor of breach width (Br) in the case of Jebal Aulia Dam.

(Br = 615.54 m for overtopping breach and Br = 478.28 m for sunny day breach), while Reclamation method produce the worst case of predicted time of failure.

(0.40 hours for sunny day and 0.50 hours for overtopping scenario). Results of breach outflow computations showed that sunny day failure produced 21,944.00 m3 / s peak discharge and time required to emptying of the reservoir is more than 2 days, while in overtopping failure produced 42,016.6 m3 / s peak discharge and the time required for emptying of reservoir is more than 2.5 days.

Results obtained from HEC-RAS model for dam breach scenarios were included water surface elevation profiles, routing of breach outflow hydrographs, flood wave attenuation and Inundation maps, HEC-RAS results shown a significant propagation of dam break flood wave through the downstream valley with wide inundation for overtopping failure comparatively with sunny day.

التخصصات الرئيسية

علوم الأرض و المياه و البيئة

الموضوعات

• الفيضانات
• السدود
• السودان
• النيل الأبيض(ولاية)

عدد الصفحات

144

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-382614