Comparison of Different Techniques about Reservoir Capacity Calculation at Sami Soydam Sandalcık Dam

Abstract

Reservoirs are designed to provide the balance between the flow brought by the river which is high variable in time and volume of water. The storage required on a river to meet a specific demand depends basically on three factors; the magnitude and the variability of the river, the size of the demand and the degree of reliability of this demand being met.  Several procedures have been proposed to estimate storage requirements. Critical period methods are those in which required reservoir capacity is equated to the difference between the water released from an initially full reservoir and the inflows for periods of low flow. In the presented study reservoir capacity-yield-reliability relationships are investigated for a single reservoir named Sami Soydam Sandalcik Dam. For this purpose, six design techniques (Mass Curve, Residual Mass Curve, Moran Probability Matrix Method, Hardison's method and Minimum flow approach) are used in determining reservoir capacity, monthly and annual mean flow data observed for a period between 1962-2013, of EIE-811 Sucati Flow Gauging Station on Dalaman River in West Mediterranean Basin in Turkey are used as case study. For 0% probability of failure, the highest reservoir capacity resulted for methods Mass Curve, Residual Mass Curve and Minimum flow approach at the range between 814.22 to 852.74*10 6 m 3 for draft equal 60% and at the range between 2043.4 to 2145.74*10 6 m 3 for draft equal 80% by using the monthly data. On the other hand when high value of probability of failure (5% and 10%) are used for estimation, the reservoir capacity values were resulted at the range between 612.36 to 1154.74*10 6 m 3 for draft equal 60% and at the range between 1443.42 to 2165.13*10 6 m 3 for draft equal 80% for Hardison's method. By using Moran Probability Matrix method, the reservoir capacity resulted 1280*10 6 m 3 and the interval was divided to 140*10 6 m 3 for annual data 52 years.