Assessing agriculture conservation practice impacts on groundwater levels at watershed scale

Abstract

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

Citation

Ni, Xiaojing; Parajuli, Prem B.; Ouyang, Ying. 2020. Assessing agriculture conservation practice impacts on groundwater levels at watershed scale. Water Resources Management. 34(4): 1553-1566. https://doi.org/10.1007/s11269-020-02526-3.