Faculty of New Sciences and Technologies, University of Tehran Iranian journal of Ecohydrology 2423-6098 6 1 2019 03 21 Determination the Capture Zone of Wells by using Meshless Local Petrov-Galerkin Numerical Model in Confined Aquifer in Unsteady State (Case study: Birjand Aquifer) Determination the Capture Zone of Wells by using Meshless Local Petrov-Galerkin Numerical Model in Confined Aquifer in Unsteady State (Case study: Birjand Aquifer) 239 255 70301 10.22059/ije.2019.271425.1004 FA Ali Mohtashami PhD Student of Civil Engineering, Nikbakht Faculty of engineering, University of Sistan and Baluchestan, Zahedan, Iran Seyed Arman Hashemi Monfared Associate Professor of Civil Engineering, Nikbakht Faculty of engineering, University of Sistan and Baluchestan, Zahedan, Iran Gholamreza Azizyan Associate Professor of Civil Engineering, Nikbakht Faculty of engineering, University of Sistan and Baluchestan, Zahedan, Iran Abolfazl Akbarpour Associate Professor of Civil Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran Journal Article 2018 09 22 In this study, for the first time, the capture zone is determined and depicted in two confined and unconfined aquifers using a numerical method. The engaged numerical method is meshless local Petrov-Galerkin which is not used in this field and in this application. The confined aquifer has regular geometry with 4 extraction wells. After simulating the groundwater flow, capture zones of wells is depicted in 1-month, 1-year, 2-year and 5-year time periods. Then the effect of both hydraulic conductivity and storage coefficients is evaluated in order to see the changes in shape and development of capture zone. The results indicated that by passing the time the area and width of the capture zone get greater, in other words, when number -1 well is in extraction by itself, in the second year the width of the capture zone is 2.82m and in the fifth year, it is 5.8m. Also with increasing hydraulic conductivity and storage coefficients, the area and width of capture zone get smaller on the other hand the number of nodes which is located in capture zones is reduced. In another example, a capture zone depicted for a real aquifer. Birjand aquifer which is located in South Khorasan province has an unconfined type. Head is simulated and the results are compared with observation data. The RMSE errors for steady and unsteady condition are 0.483 and 0.757 respectively. This aquifer has 190 extraction wells. Two wells are chosen as a sample. Then capture zone for these wells is determined and depicted. The results show that extension of this region in a real aquifer is more influenced by hydraulic conductivity coefficient. In this study, for the first time, the capture zone is determined and depicted in two confined and unconfined aquifers using a numerical method. The engaged numerical method is meshless local Petrov-Galerkin which is not used in this field and in this application. The confined aquifer has regular geometry with 4 extraction wells. After simulating the groundwater flow, capture zones of wells is depicted in 1-month, 1-year, 2-year and 5-year time periods. Then the effect of both hydraulic conductivity and storage coefficients is evaluated in order to see the changes in shape and development of capture zone. The results indicated that by passing the time the area and width of the capture zone get greater, in other words, when number -1 well is in extraction by itself, in the second year the width of the capture zone is 2.82m and in the fifth year, it is 5.8m. Also with increasing hydraulic conductivity and storage coefficients, the area and width of capture zone get smaller on the other hand the number of nodes which is located in capture zones is reduced. In another example, a capture zone depicted for a real aquifer. Birjand aquifer which is located in South Khorasan province has an unconfined type. Head is simulated and the results are compared with observation data. The RMSE errors for steady and unsteady condition are 0.483 and 0.757 respectively. This aquifer has 190 extraction wells. Two wells are chosen as a sample. Then capture zone for these wells is determined and depicted. The results show that extension of this region in a real aquifer is more influenced by hydraulic conductivity coefficient. https://ije.ut.ac.ir/article_70301_30cb747295390571100be52ba4f24c42.pdf