Bu çalışmada Güneydoğu Anadolu Projesinin bir parçası olan Fırat Nehrinin Kollarından biri üzerindeki Büyükcırcıp Yeraltısuyu Besleme barajının 100-Yıllık taşkın ve ortalama yllık akımlara göre modellemesi yapılmıştır. Barajda yağışlı mevsimlerdeki yüzeysel akışlardan toplanan suların ne kadarının hangi sürede yeraltına boşaldığı HYDRUS-1D programı yardımıyla yapılan modelle belirlenmeye çalışılmıştır. Modelleme sonucunda reservuar tabanındaki 15-m kalınlığındaki alüvyon tabakanın sızmayı zorlaştrdığı, bunu hızlandıröak için bu tabakada enjeksiyon kuyuları açılarak sızmanın hızlandırılabilecği önerilmiştir.
The purpose of this
research is estimation of duration and amount of infiltration from the dam
reservoir of Büyük Cırcıp groundwater recharge dam by Hydrus-1D model. Büyük
Cırcıp groundwater recharge dam is one of the element of the southeastern
Anatolian project in Turkey located on one of minor watercourse of great
Euphrates River. The collected flood waters from rainy season (from October to
May) are controlled by this small dam with 1.75 hm3 storage volume.
The recharge dam reservoir bed has 15 meters thick alluvium layer overlain a
permeable limestone. Groundwater depth under the reservoir is about 55 meters.
The water seepage in this groundwater recharge dam is considered mainly vertical
in the z-direction, therefore HYDRUS-1D software is suitable for modeling such
1-D infiltration. HYDRUS-1D, one of the most widely used models, can model water
flow and solutes transport through the variable saturation media. The model
uses finite element method for solving the Richards flow equation and contaminant
transport equation. In this study, the model was used to calculate amount and duration
of infiltration effectively under two cases: 1) 100-years flood and 2) annual
flow. Results show that the time to fill up the dam depends on the hydrograph characteristics
while the time to empty is related to the hydrogeological character of the
reservoir bed alluvium. A sensitivity analysis for hydraulic conductivity of
the alluvium was performed using the model. According to the results, technical
recommendations were suggested to improve the efficiency by implementing a
group of recharge wells to accelerate water infiltration through 15-m thick alluvium
layer under the reservoir that has low permeability. The annual potential
groundwater recharge for the basin was reported 97 hm3/year,
however, this study shows that the infiltrated water into the ground through
Büyük Cırcıp dam is about 10 hm3/year, which is one of 13 dam
projects are planned to be implemented by GAP.