School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, Hubei 430079, China.
Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD 20742, USA.
Environ Res. 2019 Apr;171:193-203. doi: 10.1016/j.envres.2019.01.004. Epub 2019 Jan 4.
Climate change impacts all water sources, including high quality groundwater that supplies agricultural irrigation in many regions of the United States. This study assessed groundwater level changes in the U.S. Mid-Atlantic region with a focus on cultivated areas. Trends of groundwater level were estimated using linear regression, and examined for shallow, medium, and deep depths across physiographic regions of Mid-Atlantic. A hotspot analysis was conducted to identify spatial clusters of wells with rising or declining groundwater levels. In addition, differences in the percentage of cultivated area with declining groundwater between cultivated land categories was examined at the county level. From 2002-2016, the Mid-Atlantic region had an overall decline in groundwater level (0.06 m/yr, 95% CI: 0.03, 0.09) although groundwater changes varied by physiographic regions. The Coastal Plain physiographic region was dominated by declining groundwater wells (48%) and had the most significant groundwater level declines (0.23 m/yr, 95% CI: 0.19, 0.26). Significant groundwater level rises were detected in Southern Virginia adjacent to the Chesapeake Bay (0.92 m/yr on average), which could be due to the cessation of groundwater withdrawal from one of the region's largest groundwater users. In the Mid-Atlantic region, shallow groundwater was found to have slight rising trends (0.08 m, p < 0.05) while deeper groundwater showed distinctive declining trends (1.36 m, p < 0.05) between 2002 and 2016. There were significantly more cultivated areas with declining groundwater levels (88% vs. 35%, p < 0.05) in counties with high percentages of cropland (> 50%) compared to areas covered by less cropland. As climate and human pressures increase, it will be critical to identify and evaluate alternative water sources, such as reclaimed water, to sustain agricultural production and protect groundwater resources.
气候变化影响所有水源，包括为美国许多地区农业灌溉提供的高质量地下水。本研究评估了美国大西洋中部地区的地下水水位变化，重点关注耕作区。使用线性回归估算地下水水位趋势，并在大西洋中部各地貌区检查浅层、中层和深层的地下水水位趋势。进行热点分析以识别地下水水位上升或下降的井的空间集群。此外，还在县一级检查了不同耕作土地类别中地下水水位下降的耕作面积百分比差异。2002-2016 年期间，尽管地下水变化因地貌区而异，但大西洋中部地区的地下水总体呈下降趋势（0.06m/yr，95%CI：0.03，0.09）。沿海平原地貌区以地下水水位下降的水井为主（48%），地下水水位下降幅度最大（0.23m/yr，95%CI：0.19，0.26）。在切萨皮克湾附近的弗吉尼亚州南部发现了显著的地下水水位上升（平均每年 0.92m/yr），这可能是由于该地区最大的地下水用户之一停止了地下水开采。在大西洋中部地区，浅层地下水有略微上升的趋势（0.08m，p<0.05），而深层地下水在 2002 年至 2016 年间表现出明显的下降趋势（1.36m，p<0.05）。在高耕地比例（>50%）的县，与耕地面积较少的地区相比，有更多的耕作区地下水水位下降（88%比 35%，p<0.05）。随着气候和人为压力的增加，确定和评估替代水源（如再生水）以维持农业生产和保护地下水资源将至关重要。
