Optimal Planning and Operation of Multiaquifer System

Three ground-water management models were developed to determine the optimal planning and operating policies of a multiaquifer system in eastern Saudi Arabia for an eight-year planning period. The modeled system, which consisted of the Alat, Khobar, and Umm Er Radhuma aquifers, was represented by a three-dimensional simulation model included in linear and quadratic optimization models using response functions. Yearly optimal pumping policies were determined for 52 well fields under three management objectives that maximized agricultural water withdrawals and minimized total drawdowns, and pumping costs subject to constraints related to the system's response equations, demand requirements, drawdown limitations, and discharge bounds. Multiobjective analyses were conducted to develop trade-off curves relating increased agricultural water production to drawdown, aquifer dewatering, and pumping costs. Modeling results show the agricultural water production could be increased by almost two and a half times without causing dewatering. Optimal pumping schedules differed, depending upon the type of objective function employed. The best option appears to be the one in which extensive water transport is allowed between municipal wel

Sustainable development and management of an aquifer system in western Turkey

This study presents the establishment of sustainable development and management policies for the Kucuk Menderes River Basin aquifer system in western Turkey. Geological, hydrogeological, and geophysical data are used conjunctively to define various hydrogeological units and their geometry. Distributions of hydraulic-parameter values and recharge are estimated by geostatistical methods and hydrologic simulations, respectively. A finite-difference groundwater flow model is used to represent the unconfined flow in the aquifer system. The model has been calibrated under steady state and transient conditions. The resulting model was used to test seven management scenarios for a planning period of 21 years to determine the so-called safe yield and sustainable yield of the aquifer system and to investigate the potential impacts of four planned surface water reservoirs on groundwater resources in the basin. The results demonstrate that the continuation of the present pumping rates exceeds both the safe yield and the sustainable yield of the aquifer system. Consequently, the growing need for irrigation water should be met by the construction of the planned surface water reservoirs and the implementation of efficient water management policies and plans

Assessing the impact of climate change on Mogan and Eymir Lakes' levels in Central Turkey

Global warming is likely to have significant effect on the hydrological cycle. Some parts of the world may see significant reductions in precipitation or major alterations in the timing of wet and dry seasons. Climate change is one of the serious pressures facing water resources and their management over the next few years and decades. As part of the southern belt of Mediterranean Europe, Turkey is highly vulnerable to anticipated climate change impacts. The changes in global climate will seriously affect inland freshwater ecosystems and coastal lakes. Mogan and Eymir Lakes located in Central Turkey are shallow lakes that may be impacted significantly by climate change. The interaction between the lakes and groundwater system has been modelled in order to analyse the response of lake levels to climate change over a planning period of 96 years, beginning from October 2004 and ending in September 2100. The impacts of the emission scenarios of A2 and B1 of the Intergovernmental Panel on Climate Change (IPCC) on lake levels have been analyzed with the help of the lake-aquifer simulation model. The fluctuations in lake levels due to climate change scenarios are compared with the results of a scenario generated by the assumption of the continuation of the average recharge and discharge conditions observed for 1999 and 2004. The results show that very small, but long-term changes to precipitation and temperature have the potential to cause significant declines in lake levels and temporary drying of the lakes in the long-term. The impact of climate change on lake levels will depend on how these water resources are managed in the future

Çok katlı akifer sistemlerinde kapasitenin optimum genişletilmesi

TÜBİTAK TBAG Proje30.11.1992Çok katlı akifer sistemlerinde optimum kapasite genişletme politikasını belirleyen üç model geliştirilmiştir. Bu sistemlerdeki üç boyutlu yeraltısuyu akım karakteristikleri, optimizasyon modellerinin kısıtlamalar seti içinde, düşüm-tepki matrisi yaklaşımı kullanılarak düşünülmüştür. Birinci model kuyu sahalarındaki toplam düşüm değerlerini ve yeni kuyu sahalarının geliştirilmesi ve suyun talep merkezine transferi için gereken boru hattı inşa (sabit yatırım) maliyetlerini en aza indirmektedir. Diğer iki model, mevcut kuyu sahaların işletme, yeni kuyu sahalarının açılma ve işletme, ve boru hattı inşa maliyetlerini en aza indirmektedir. Tüm modellerin kısıtlamalar seti yıllık su talepleri, sistemin tepki denklemleri, düşüm-pompaj limitleri ve diğer çeşitli hidrojeolojik, ekonomik ve teknik koşullardan oluşmuştur. Çok amaçlı sistemler için geliştirilen diğer bir model bir taraftan toplam düşüm ve sabit yatırım maliyetlerini en aza indirirken diğer taraftan toplam verimi artırmaktadır; böylelikle çelişkili ve ekonomik değerlerle ölçülemeyen amaçlar arasındaki optimum değiş-tokuş ilişkisinin belirlenmesine olanak sağlamaktadır. Tüm modeller 0/1 karma tam sayılı modeller olup iki-katlı prototip bir sisteme üç değişik su talebi için uygulanmıştır. Model sonuçlarının su talepleri, iskonto oranları ve sistem parametrelerindeki değişikliklere karşı duyarlılık analizleri çalışılmıştır. Birinci model toplam minimum düşüm verirken, ikinci ve üçüncü modeller toplam minimum maliyet vermektedir; böylelikle karar vericilerin sistemin genişletilme ve işletilme amaçlarına göre modellerden uygun olanı seçebilmeleri için olanak sağlanmıştır. Bilgi işlem gereksinimleri yönünden ele alındığında, birinci model uzun planlama dönemlerini kapsayan kapasite genişletme problemleri için daha uygundur. ikinci ve üçüncü modellerin amaç fonksiyonlarındaki eğriselliği kaldırmak için kullanılan doğrusallaştırma yaklaşımları çok etkin olup, gerçek ve görünür pompaj maliyetleri arasındaki farklar çok azdır

Laboratory determination of multicomponent effective diffusion coefficients for heavy metals in a compacted clay

Diffusion and sorption of heavy-metal ions (Cd, Cr, Cu, Fe, K, Mn, Ni, Plb, and Zn) through an Ankara clay liner were studied experimentally. The Ankara clay consists of calcite, quartz, smectite and illite, and is a highly plastic inorganic clay with optimum weight water content of 32% and corresponding dry density of 1.413 g/cm(3). U nder optimum compaction conditions, effective porosity (volumetric water content) and hydraulic conductivity in the material were determined as 0.45 and 1.3 to 2.6x10(-9) cm/s, respectively. The Ankara clay adsorbed Cd, Cr, Cu, Fe, K, Mn, Ni, Pb. and Zn metals, but desorbed Ca, Mg and Na metals for the solution concentration range used. Sorption isotherms of these ions were experimentally established. Effective diffusion coefficients of Cd. Cl. Cr, Cu, Fe, K. Mn, Ni, Pb, and Zn metals, determined through column experiments are, respectively, 2.5, 9.5, 2.2, 2.9, 2.2, 7.9, 3.1, 1.6, 3.2 and 2.5 (x10(-6)) cm(2)/s. The tortuosity factor of non-reactive chloride is approximately 0.47. The factor changes between 0.34 and 0.45 for the other ions. The results show that diffusion is the dominant mass transport mechanism in an Ankara clay liner. Due to sorption processes, transported heavy metals studied in this research will be significantly attenuated in the liner. Because diffusion and sorption processes depend on solution composition, mass transport determinations in clay liners require case studies using multicomponent systems similar to those presented in this study

Assessment of Open Pit Dewatering Requirements and Pit Lake Formation for the KA +/- AYladag Gold Mine, UAYak, Turkey

The KA +/- AYladag gold mine (UAYak, Turkey) has operated since 2006 and is projected to close by 2030, leaving a large open pit. We quantified dewatering requirements during the operational period, predicted pit lake formation during the post-closure period, and assessed the likely impacts on groundwater resources. Groundwater inflow into the pit during 17 years of mining was calculated using analytical and numerical models. The analytical model yielded lower inflow rates because it does not account for groundwater that will be released from storage. Post-closure, pit lake water balance calculations show that the system will reach equilibrium 585 years after dewatering ceases and that lake levels will stabilize at 816 m above sea level (masl). Further analysis indicated that 830 masl is a critical level, below which the pit will behave as a sink; above that, it will be a flowthrough system that could possibly affect downgradient groundwater quality

Optimal Ground Water Pollution Plume Containment with Fixed Charges

Six ground-water management models were developed and compared to identify the best management alternative for the containment of a ground-water pollution plume in a hypothetical aquifer that is used for freshwater supply The proposed models are formulated as quadratic programming, linear programming, and mixed-integer programming models. Management models are grouped into two on the basis of treatment cost consideration. The optimal solutions of the models are compared and evaluated on the basis of total costs associated with the remediation system design. Sensitivity of the model solutions to variations in unit pumping and treatment costs are analyzed. The results of the models are quite different in regard to the number of potential interception wells completed, their pumping rates, resulting operation, and capital investment costs. Results show that considerable amounts of savings may be achieved through application of the mixed-integer programming models explicitly considering each of the cost components. Therefore, in remediation system designs that require installation of interception wells, ground-water managers should take into account the fixed charges incurred for each well that is introduced in the mathematical model