آرشیو

آرشیو شماره ها:
۴۶

چکیده

برداشت بی رویه از سفره های آب زیرزمینی در کشور سبب افت شدید سطح ایستابی آبخوان و از بین رفتن لایه های آبدار زمین گردیده است. در این پژوهش به منظور بررسی وضعیت تراز آب زیرزمینی حوضه آبریز پریشان ، واقع در استان فارس در رابطه با برداشت بی رویه آب های زیرزمینی از داده های 33 حلقه چاه پیزومتری در بازه زمانی (2008- 2020) با استفاده از مدل Modflow شبیه سازی انجام گرفت. هم چنین نتایج حاصل از محاسبه بیلان آبی تعداد960 حلقه چاه بهره برداری در حوضه حاکی از آن است که میزان13 متر کاهش سطح تراز آب زیرزمینی در سطح حوضه پریشان اتفاق افتاده است و جمعا میزان 42.4 میلیون مترمکعب آب از ذخیره ثابت آبخوان در بازه 10 ساله کاسته شده است. با توجه به نقشه های درون یابی تهیه شده بیشترین میزان افت آب زیرزمینی مربوط به مناطق پریشان و فامور اتفاق افتاده است. از این رو با آمار سازمان آب منطقه ای فارس مبنی بر وجود چاه هایی با آبدهی بالا در این مناطق هماهنگی دارد. با استناد به نقشه های تهیه شده از آبخوان پریشان با توجه به آبرفتی بودن سفره آب زیرزمینی اثر افت سطح آب را می توان با فاصله مکانی کم مشاهده کرد. از سوی دیگر در نقشه های میان یابی ضریب پارامتر هدایت هیدرولیکی بیان کننده این است که میزان افت تراز آبخوان در مناطق پریشان و ملااره، فامور دارای بیشترین مقدار می باشد که با 11درصد خطای نسبی مؤید مدل سازی مناسب است.

Investigation of groundwater level and simulation of forecast scenarios in Parishan catchment

Extended Abstract Introduction Groundwater is the most important source of water in many parts of the world, used in drinking water, agriculture, industry and related ecosystems. However, the lack of control over human activities and climate change can lead to the destruction of these valuable resources. Accordingly, in this study, the groundwater level of Parishan catchment in Fars province in the period 2008 to 2019 in relation to groundwater abstraction has been investigated and using Madflu modeling in different scenarios to reduce the level of aquifer for future years. Predict for different areas of this basin in order to show different degrees of crisis in different parts of the basin. Methodology Parishan Lake catchment area is one of the semi-enclosed cups in Fars province (Kazerun city) between the eastern longitude of "251-52" to "501-43" and the northern latitude of "25.22" to "29.27". This basin leads from the north to the Kazerun basin, from the east to the Boram basin, from the south and west to the Jarreh and Baladeh basins. The area of this basin is 225 square kilometers, of which 40 percent (90 square kilometers) is covered with heights and 60 percent (135 square kilometers) is covered with plains and lakes. The maximum altitude of Parishan Basin is 1800 meters and the minimum altitude is 855 meters above sea level, and these altitudes extend from northwest to southeast. Results and Discussion In the present study, data and information from the study area such as exploitation and observation wells data including data related to 25 exploration wells and 960 exploitation wells were collected from Fars Water Resources Management Organization (Fars Water Organization Statistics, 1398). After collecting the required data, the conceptual model of the area was determined as a geometric form and based on the parameters that have the greatest impact on the aquifer. Then other characteristics of the aquifer such as permeable and non-permeable boundaries were determined using lithological properties parameters, geological characteristics and characteristics of boundary formations in the region as well as inlet and outlet flow to boundary cells in the range. And Natrova was prepared in the aquifer and by preparing intermediate maps, the amount of groundwater reduction in different parts of the zoning basin and the extent of expansion of critical areas were determined. Madflow is a physical, three-dimensional model capable of stable and unstable simulations of free-pressed and free-pressed aquifers. The Madflu model solves the equation governing groundwater flow based on the finite difference method. In this regard, Marvdasht aquifer is networked into smaller cells, assuming that the characteristics of the aquifer are uniform in each cell. According to the law of mass conservation and groundwater movement, the equation governing groundwater flow is obtained as a second-order partial differential equation. This equation is given as (Equation 1) in unstable, inhomogeneous and three-dimensional conditions.

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