Risk-based reservoir operation under drought conditions

Türkeri, Mustafa Kemal
This study introduces a practical drought risk assessment methodology for reservoirs and hydraulic structures, which can be used in basin drought risk management. Reservoir operation study is used as a main tool in the risk assessment methodology. The methodology developed in this study contains a probabilistic deficiency analysis approach for reservoir inflows. Different scenarios are developed which include hydrological deficiencies for various return periods. Developed scenarios are also modified for climate change by utilizing trend slope. In addition, past hydrological drought events are also evaluated in order to compare probabilistic scenarios with historical drought events. The probabilistic scenarios and reservoir operation studies are modeled by using Water Evaluation and Planning (WEAP) software of Stockholm Environment Institute (SEI). In the discussion part, the vulnerability status of reservoirs is determined by evaluating the reservoir behaviors under drought conditions and supply insufficiencies obtained with operation studies. By utilizing determined vulnerabilities, operation strategies to mitigate hydrological drought impacts are determined. The developed methodology is tested successfully on a reservoir system which includes three dams and one diversion weir located in Sivas, Turkey. A catastrophic drought event with 100-years return period was assessed and a future operation plan was recommended for the hydraulic structures located in the case study area. With the application of recommended operation strategies, it is determined that Sivas Province and Hafik District will have sufficient municipal water until 2050 even if a catastrophic drought occurs in the study area, provided that there is no change in the conditions considered in this study.


Understanding Drought with Copula Functions: Case Study for Konya Province
Evkaya, Ömer Ozan; Yozgatlıgil, Ceylan; Kestel, Sevtap Ayşe (null; 2018-10-07)
Drought is one of the most drastic and complex natural phenomenon in the world, a major reason for undesired agricultural, economic and environmental damages. For this reason, the objective identification of drought and its characteristics deserve more detailed models. Most of the studies in the literature related to drought monitoring and analysis are based on special widespread quantitative drought indices. On the other hand, the generated drought indices have been derived using only one drought related p...
Drought Forecasting with Time Series and Machine Learning Approaches
Evkaya, Ömer Ozan; Yozgatlıgil, Ceylan; Kestel, Sevtap Ayşe (null; 2017-12-08)
As a main reason of undesired agricultural, economic and environmental damages, drought is one of the most important stochastic natural hazard having certain features. In order to manage the impacts of drought, more than 100 drought indices have been proposed for both monitoring and forecasting purposes [1], [3]. For different types of droughts, these indices have been used to understand the effects of dry periods including meteorological, agricultural and hydrological droughts in many distinct locations. I...
Conditional Copula-Based Spatial-Temporal Drought Characteristics Analysis-A Case Study over Turkey
Afshar, Mahdı Hesamı ; Yılmaz, Mustafa Tuğrul (2016-10-01)
In this study, commonly used copula functions belonging to Archimedean and Elliptical families are fitted to the univariate cumulative distribution functions (CDF) of the drought characteristics duration (LD), average severity (S), and average areal extent (A) of droughts obtained using standardized precipitation index (SPI) between 1960 and 2013 over Ankara, Turkey. Probabilistic modeling of drought characteristics with seven different fitted copula functions and their comparisons with independently estima...
Ersoy, Nuri Erhan; Yılmaz, Mustafa Tuğrul; Department of Civil Engineering (2022-3-11)
Analyzing the effects of drought and making accurate predictions for the future under changing climate conditions are of great importance in the agricultural, drinking water, industrial and ecosystem policies to be determined. The climate projection simulations generated over CORDEX domains are one the most popular datasets used today in climate change related studies. In this study impact of climate change over the variability of drought characteristics over 25 basins of Turkey were investigated using clim...
Adjusting SPI for crop specific agricultural drought
YILDIRAK, ŞAHAP KASIRGA; Kestel, Sevtap Ayşe (2015-12-01)
Standardized Precipitation Index (SPI) is one of the most used drought monitoring tools. It is easy to compute as it only needs cumulative precipitation amount for an input. However, it is more of a meteorological drought index rather than an agricultural one. In this study, we reconstruct SPI for monitoring a specific crop by calibrating the cut-off values that separates drought classes. For this purpose, two objectives to optimize are obtained: area under receiver operating characteristics (ROC) curve and...
Citation Formats
M. K. Türkeri, “Risk-based reservoir operation under drought conditions,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Civil Engineering., Middle East Technical University, 2019.