Land subsidence caused by groundwater extraction in California’s San Joaquin Valley has been occurring for many decades. In situ monitoring of subsidence in this large geographic area has historically been limited. The California Department of Water Resources (CDWR) sought the National Aeronautics and Space Administration’s assistance for satellite- and aircraft-based synthetic aperture radar interferometry (InSAR) monitoring of subsidence during the 2012–2016 drought. InSAR was successful in cost-effectively providing first-ever synoptic measurement of land subsidence over the entire San Joaquin Valley. The purpose of the monitoring was screening or hotspot detection of impact areas affecting critical water infrastructure. Long-term cumulative land subsidence has substantially reduced the conveyance capacity of sections of major valley canals and the monitoring revealed that subsidence rates observed during the drought ranked with maximum historically observed rates, highlighting risks to water infrastructure. InSAR also identified new and rapidly emerging hotspots adjacent to critical water infrastructure. The success of the InSAR monitoring for drought response resulted in CDWR’s decision to subsequently provide InSAR data as technical assistance to local agencies required to comply with recent state groundwater management legislation.

中文翻译：

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InSAR 在监测地面沉降以支持加利福尼亚州圣华金河谷的水资源管理方面的价值

加利福尼亚州圣华金河谷地下水开采造成的地面沉降已经发生了几十年。在历史上，对这个大地理区域的沉降进行现场监测是有限的。加州水资源部 (CDWR) 寻求美国国家航空航天局的帮助，以利用基于卫星和飞机的合成孔径雷达干涉测量法 (InSAR) 监测 2012-2016 年干旱期间的沉降情况。InSAR 成功地以具有成本效益的方式首次对整个圣华金河谷的地面沉降进行了天气测量。监测的目的是筛选或热点检测影响关键水基础设施的影响区域。长期累积的地面沉降大大降低了主要河谷运河部分的输送能力，监测显示，干旱期间观察到的沉降率是历史上观测到的最大沉降率，突出了水利基础设施面临的风险。InSAR 还确定了与关键水利基础设施相邻的新的和迅速出现的热点。InSAR 干旱响应监测的成功导致 CDWR 决定随后将 InSAR 数据作为技术援助提供给当地机构，这些机构需要遵守最近的州地下水管理立法。InSAR 还确定了与关键水利基础设施相邻的新的和迅速出现的热点。InSAR 干旱响应监测的成功导致 CDWR 决定随后将 InSAR 数据作为技术援助提供给当地机构，这些机构需要遵守最近的州地下水管理立法。InSAR 还确定了与关键水利基础设施相邻的新的和迅速出现的热点。InSAR 干旱响应监测的成功导致 CDWR 决定随后将 InSAR 数据作为技术援助提供给当地机构，这些机构需要遵守最近的州地下水管理立法。