Subagadis, Yohannes Hagos (2009) Stochastic Simulation of Streamflow and Hydrologic Drought Analysis (Case Study: Upper Blue Nile Basin). Masters thesis, Addis Ababa University.
![[img]](http://thesisbank.jhia.ac.ke/style/images/fileicons/application_pdf.png) |
PDF (Stochastic Simulation of Streamflow and Hydrologic Drought Analysis (Case Study: Upper Blue Nile Basin).)
Yohannes Hagos(1).pdf - Accepted Version Restricted to Repository staff only Download (1MB) | Request a copy |
Abstract
This thesis is concerned with the problem of stochastic simulation of streamflow and hydrological drought analysis in the upper Blue Nile basin ( Abbay).Thirteen stations with long record period ranging from 35 to 45 years were used for the analysis. Two sets of time series models named PARMA (p,q) and Thomas-Fiering were tested and inter-compared for the stochastic simulation of monthly streamflow , and a suitable model were selected. PARMA models of low order are found to be most appropriate for all stations than Thomas – Fiering model. The performance of the model ranges from R 2 value of 0.893 at Gilgel Abbay near Merawi station to 0.33 at Abbay near Bahirdar station. The Thomas-Fiering model gives similar results; its R 2 values ranging from 0.87 at Gilgel Abbay near Merawi station to 0.32 at Abbay near Bahirdar station. But both models did not give acceptable results for the gauging station at Abbay near Bahirdar .In general, best fit PARMA (p,q) models was found to perform better in most of the gauging stations than Thomas-Fiering model considered in this study. Therefore, long sequence of synthetic flow used for drought analysis in the study were generated using PARMA (p,q) model. Hydrological drought parameters namely, drought duration (D) and drought severity (S) were derived and analyzed from historic and long sequence of synthetically generated data at Gilgel Abbay near Merawi and Guder near Guder stations. The threshold method has been used to identify drought parameters in the streamflow series. Both drought severity and duration were found independent without a trace of trend within it. Accordingly the important drought characteristics were determined and the suitable probability distribution for each parameter was arrived at after studying different probability models. The use of the probability curves thus derived has been also illustrated. It can be concluded that the duration and severity of drought in the basin doesn’t show any trend of increasing or decreasing. However, in the event of other circumstances like climate change, the trend may evolve differently. Future studies may investigate the impact of climate change in the severity and duration of drought.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Civil Engineering |
| Subjects: | T Technology > TA Engineering (General). Civil engineering (General) T Technology > TC Hydraulic engineering. Ocean engineering T Technology > TD Environmental technology. Sanitary engineering |
| Divisions: | Africana |
| Depositing User: | Andriamparany Edilbert RANOARIVONY |
| Date Deposited: | 04 Oct 2018 08:33 |
| Last Modified: | 04 Oct 2018 08:33 |
| URI: | http://thesisbank.jhia.ac.ke/id/eprint/6696 |
Actions (login required)
 |
View Item |