Modifying Ritchie equation for estimation of reference evapotranspiration at coastal regions of Anatolia

Evapotranspiration (ET) is of great importance in many disciplines, including irrigation system design, irrigation scheduling and hydrologic and drainage studies. A large number of more or less empirical methods have been developed to estimate the evapotranspiration from different climatic variables. The Food and Agriculture Organization (FAO) rates the Penman- Monteith equation as the major model for estimation of reference (grass) evapotranspiration (ET0) because of the fact that it gives more accurate and consistent results as compared to the other empirical models. However, the main disadvantage of this method is that it cannot be used when the sufficient data are not available. The FAO-56 PM equation requires quite a few independent variables such as solar radiation, air temperature, wind speed, and relative humidity in predicting ET0. Worldwide, the weather stations measuring all these variables are few as the majority measure air temperature only. Therefore, for regions which may not be measuring all these meteorological variables, the temperature based models like Ritchie, Hargreaves-Samani and Thornthwaite equations is necessarily used instead of the FAO-56 PM equation. In this study, the Ritchie equation is applied on the measured data recorded at 158 stations at the Coastal are of Turkey (Mediterranean, Aegean, Marmara and Black Sea regions of Anatolia), and the monthly ET0 values computed by it are observed to be smaller than those given by the Penman-Monteith equation. Next, average values for the coefficients of the Ritchie equation, which are constants originally developed in [6], are recomputed using the ET0 values given by the FAO-56 PM equation at all weather stations in coastal regions of Anatolia (Turkey). The Ritchie equation modified in such manner is observed to yield greater determination coefficients (R2), smaller root mean square errors (MSE), and smaller mean absolute relative errors (MARE) as compared to the original versions of Ritchie equation suggested by [6]. It is concluded that for estimation of reference evapotranspiration at coastal regions of Anatolia where the meteorological measurements are scarce, the modified Ritchie equation can be easily used for estimating the ET0 values

Evaluation of some groundwater quality parameters using geostatistics in the urban coastal aquifer of Bosaso plain, Somalia

Groundwater is a major drinking water resource in arid coastal regions. The groundwater quality of Bosaso city experienced degradation due to rapid urbanization and industrialization. This study was carried out to delineate the spatial distribution of groundwater quality parameters and evaluate groundwater suitability for drinking and irrigation uses. The groundwater samples were collected from Bosaso Plain to determine the pH, electrical conductivity (EC), total dissolved solids (TDS), and sodium and chloride concentrations. To categorize water quality for irrigation purposes, sodium adsorption ratio (SAR) was calculated. Ordinary kriging procedure was performed in order to map the spatial distribution of groundwater quality parameters. The interpretation of laboratory analysis results revealed that the most of groundwater wells in the study area is unsafe for drinking purposes due to high salinity, except for the central area (Biyo Kulule). In terms of irrigation uses, the minor area may be under the risk of alkalinity or sodium hazard. However, all groundwater supply points are not suitable for irrigation due to the salinization risk and can be only used to irrigate high salt-tolerant crops. The final maps show that the groundwater quality decreases from southeast to the north of the plain. This indicates that the groundwater is probably subjected to the seawater intrusion. In this regard, the implementation of a groundwater monitoring program is necessary to achieve concrete results. Nevertheless, the most suitable groundwater quality is found to be at the central part of the Bosaso plain

Chance-constrained linear programming method in determining the reservoir storage capacity and operation policy

İlk planlama aşamasında rezervuar depolama kapasitesi tayini ve işletme politikasının belirlenmesi için Doğrusal Karar Kuralı yardımı ile Şans Kısıtlı Doğrusal Programlama yöntemi 1969 dan beri kullanılmaktadır. Yöntemin iki geliştirilmiş önerimi vardır ve her ikisi için de doğrudan çözüm yöntemleri literatürde verilmiştir. Çalışmada yöntemin ilk öneriminin çözümü için Simpleks formülasyonu yapılmış ve her iki önerim için gerek doğrudan çözüm, gerekse Simpleks yöntemiyle çözüm için bir bilgisayar programı geliştirilmiştir. Program Seyhan havzasındaki muhtelif barajlara uygulanarak sonuçlar diğer yöntemlerle de karşılaştırmıştır.Chance-Constrained Linear Programming method with the Linear Decision Rule (LDR) has been used for estimating the capacity and operation policy of a reservoir since 1969. Two version of the methods and their algorithm for direct solutions have been given in the references. In this study, a computer program was developed for the method. The program can solve the problem by both the direct and simplex methods. This computer model was applied to several reservoirs in the Seyhan Basin and the results obtained were compared to other widely used methods solutions

Çoklu baraj sistemlerinin enerji optimizasyonu için geliştirilmiş etkin bir artırımlı dinamik programlama modeli ve Aşağı Seyhan Havzası'na uygulanması

TEZ1371Tez (Doktora) -- Çukurova Üniversitesi, Adana, 1993.Kaynakça (s. 97-99) var.xi, 101 s. : hrt. ; 30 cm.

Seyhan ve Ceyhan yağış alanlarındaki akarsular üzerinde mevcut ve muhtemel barajların hacim-verim ilişkilerinin belirlenmesi

TEZ300Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 1986.Kaynakça (s. 114-117) var.ix, 117 s. ; 30 cm.

Change-constrained linear programming method for determination of operation policy and storage capacity of reservoirs

Barajların depolama hacimleri; yapının ekonomisi, işletme politikaları ve kazanılacak net faydayla doğrudan ilişkili olması nedeni ile büyük önem arz etmektedir. Bu çalışmada rezervuar işletmesi ve tasarımında, Doğrusal Karar Kuralı yardımı ile şans Kısıtlı Doğrusal programlama yönteminin litaretürlerdeki iki geliştirilmiş öneriminden yararlanılmış ve Doğrusal Karar Kuralı' nın yeni önerimini kullanan genel amaçlı TURBO PASCAL dilinde bir bilgisayar programı geliştirilmiştir. Bu program Aşağı Seyhan Havzasındaki mevcut ve Planlanan altı baraja uygulanmış, sonuçlar litaretürde önerilen diğer çözüm yöntemlerinin sonuçları ile karşılaştırılmıştır.The storage capacity of a reservoir is a very important peculiarity of it as it directly affects 1. the overall economy of the structure, 2. the operation policies, and 3. the net benefits to be obtained. In this study, a computer program was developed in TURBO PASCAL programming language using chance constrained Linear programming with the Linear Decision Rule. The program was applied to six reservoirs in the lower Seyhan Basin with the historical and the generated flows and the storage capacities and the operation policies, were determined. The results obtained were compared to some other recognized methods

Multi-stage flood routing for gated reservoirs and conjunctive optimization of hydroelectricity income with flood losses

A six-stage operation policy for routing of flood hydrographs of return periods from 1.01 year up to the Probable Maximum Flood (PMF) for any dam having a gated spillway is proposed. The gate opening rules are determined depending on the recent pool level. Regardless of the size and timing of any incoming floods, the fixed rules of the six-stage operation policy will provide optimum routing for all, which are classified into six different groups based on their return periods. 10-, 100-, 1000-, 10 000- 100 000-year floods, and PMF are the upper limits for the six groups. Next, an Incremental Dynamic Programming programme is developed to optimize both the firm and secondary energies of hydroelectric generation at monthly periods. First, the six-stage flood routing programme is applied sequentially to three dams, all on the Seyhan River in Turkey, for 18 combinations resulting from different active storages, and optimum flood operation policies for all three dams for all Is combinations are determined. Second, the Dynamic Programming programme is applied to these three darns, and optimum hydroelectricity generation policies for an 18 combinations are computed. Finally, the optimum active and flood retention storages for the three darns are determined so as to maximize the net probability-weighted present worth of hydroelectricity benefits minus flood damage costs