Abstract

Over the last several decades, increased groundwater usage by agriculture with a consequence of groundwater resource depletion has motivated the discussion of sustainability of groundwater resource. In this study, to investigate the impacts of agricultural best management practices (BMPs) on groundwater level, two kinds of conservation practices and five scenarios of tail water recovery pond and crop rotation were simulated by various groundwater recharge and pumping plans in Soil and Water Assessment Tool (SWAT) and MODFLOW models in an agriculture watershed in Mississippi, U.S.. The calibrated and validated ground water model indicated coefficient of determination (R²) of 0.81 and Nash–Sutcliffe model efficiency coefficient (NSE) of 0.79 respectively. The results from this study showed that the groundwater recharge changed with irrigation plans and surface hydrological impact of management practices. In addition, it determined that tail water recovery pond could help mitigate groundwater depletion. The groundwater recharge due to continuous corn crop scenario was 7% higher in average than that of the continuous soybean. Non-growing season groundwater recharge may be critical for groundwater recovery. The average groundwater level was increased continuous corn scenario by 15%, continuous soybean by 13%, and corn-soybean by 14% as compare to the baseline scenario with rice planted. Results of this study can be helpful for planning on how various BMPs impact on groundwater.

中文翻译：

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在分水岭规模上评估农业保护实践对地下水位的影响

摘要

在过去的几十年中，由于地下水资源枯竭，农业对地下水的使用量增加，引发了对地下水资源可持续性的讨论。在这项研究中，为了调查农业最佳管理实践（BMP）对地下水位的影响，通过土壤和水评估中的各种地下水补给和抽水计划，模拟了两种养护实践以及尾水回收池和作物轮作的五个方案。美国密西西比州一个农业流域中的工具（SWAT）和MODFLOW模型。经校准和验证的地下水模型指示测定系数（R ²）分别为0.81和纳什-萨特克利夫模型效率系数（NSE）为0.79。这项研究的结果表明，地下水补给量随着灌溉计划和管理实践的地表水文影响而变化。此外，它确定了尾水回收池可以帮助减轻地下水的消耗。由于连续种植玉米，地下水补给量平均比连续大豆高7％。非生长季节的地下水补给对于地下水的回收可能至关重要。与种植水稻的基准情景相比，平均地下水水平使连续玉米情景增加了15％，连续大豆情景增加了13％，玉米大豆情景增加了14％。这项研究的结果有助于规划各种BMP对地下水的影响。