Baseflow is an essential water resource because it is the groundwater discharged to streams and represents long-term storage. Understanding its future changes is a major concern for water supply and ecosystem health. This study examines the impacts of climate and agriculture on monthly baseflow in the U.S. Midwest through the end of the 21st century. We use a statistical approach to evaluate three scenarios. The first scenario is based on downscaled and bias corrected global climate model (GCM) outputs and the representative concentration pathway (RCP) 8.5, and agriculture is held constant (and equal to the mean from 2013 to 2019). In the next two scenarios, climate is held constant (2010–2019) to isolate the impact of agriculture on baseflow. In terms of agricultural changes, we consider scenarios representative of either increases or decreases with respect to the production of corn and soybeans. Changes in the climate system point to increases in baseflow that are likely a result of increased precipitation and antecedent wetness. Seasonally, warmer temperature in the winter and spring (i.e., February to July) is expected to cause increasing trends in baseflow. Changes in land use showed that agriculture would either mitigate the impact of climate change or possibly amplify it. Expanding corn and soybean areas would increase baseflow in the Corn Belt region. On the other hand, converting land back to perennial vegetation would decrease baseflow throughout the entire year. Despite its simplicity, this study can provide basic information to understand where to expect adverse effects on baseflow and thus improve land management practices in those areas.

中文翻译：

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美国中西部每月基流的预计变化

基流是一种重要的水资源，因为它是排放到溪流中的地下水，代表着长期储存。了解其未来的变化是供水和生态系统健康的一个主要问题。本研究考察了气候和农业对美国中西部到 21 世纪末月基流的影响。我们使用统计方法来评估三种情况。第一种情景基于缩小和偏差校正的全球气候模型 (GCM) 输出和代表性浓度路径 (RCP) 8.5，农业保持不变（等于 2013 年至 2019 年的平均值）。在接下来的两个情景中，气候保持不变（2010-2019 年）以隔离农业对基流的影响。在农业变化方面，我们考虑代表玉米和大豆产量增加或减少的情景。气候系统的变化表明基流增加，这可能是降水增加和前期湿度增加的结果。季节性地，预计冬季和春季（即 2 月至 7 月）温度升高会导致基流增加。土地利用的变化表明，农业要么减轻气候变化的影响，要么可能放大气候变化的影响。扩大玉米和大豆种植面积将增加玉米带地区的基流。另一方面，将土地转换回多年生植被会降低全年的基流。尽管它简单，