Management of water resources is essential to maintain sustainable agricultural productivity and preserve groundwater and surface ecosystems. The long-term sustainability of these systems depends on the understanding of complex surface-groundwater flow interactions at different temporal and spatial scales, and the impacts of agricultural practices on water use. To support these efforts, an integrated AnnAGNPS-MODFLOW modeling technology is proposed and evaluated. It combines the capability of the AnnAGNPS model to detailed characterization of farming practices with groundwater flow estimation tools of the MODFLOW model. The AnnAGNPS-MODFLOW model was evaluated in Upper Sunflower River watershed at the Lower Mississippi River Alluvial Plain. The integrated modeling technology in conjunction with observed values of streamflow at the outlet and well water levels were used to estimate irrigation strategies with application rates varying in time and space at field scale. Utilization of improved irrigation characterization have provided evidence of the sensitivity of streamflow and groundwater levels to irrigation strategies. Simulation results indicate that a reduction of irrigation application rates by 20–40% can impact aquifer long-term water levels. This finding supports the need to investigate more efficient irrigation strategies to promote the aquifer sustainable use. The proposed technology provides a management tool critical to understanding and evaluating the impact of agricultural practices, irrigation, and aquifer recharge strategies that are important to sustaining water resources in irrigated agricultural watersheds.

水资源管理对于维持可持续农业生产力和保护地下水和地表生态系统至关重要。这些系统的长期可持续性取决于对不同时间和空间尺度上复杂地表地下水流动相互作用的理解，以及农业实践对用水的影响。为了支持这些努力，提出并评估了一种集成的 AnnAGNPS-MODFLOW 建模技术。它将 AnnAGNPS 模型的功能与 MODFLOW 模型的地下水流量估算工具结合起来，以详细描述农业实践。AnnAGNPS-MODFLOW 模型在密西西比河下游冲积平原的上游向日葵河流域进行了评估。这综合建模技术与出口流量和井水位的观测值相结合，用于估计灌溉策略，在田间尺度上随时间和空间变化而变化。利用改进的灌溉特性提供了河流流量和地下水位对灌溉策略敏感性的证据。模拟结果表明，灌溉施用量减少 20-40% 会影响含水层长期水位。这一发现支持研究更有效的灌溉策略以促进含水层可持续利用的必要性。拟议的技术提供了一种管理工具，对于理解和评估农业实践、灌溉和含水层补给策略的影响至关重要，这些策略对于维持灌溉农业流域的水资源很重要。