Development of an Integrated Superconducting Gravity Meter Sensor System for Subsurface Water Storage

这项拨款支持现场超导重力仪（FSG）的采购、开发和测试，作为一种超灵敏系统，用于监测长时间（数月）无人值守部署期间地下水储存的波动和趋势。FSG将由商用超导重力仪（GWR, Inc.）建造，该重力仪不需要补充液氦，并集成了气象传感器（气压、温度、湿度、降水）、现场封闭和适当的纪念碑，并部署在德克萨斯州和亚利桑那州的两个试验点（通过亚利桑那大学的子奖），代表不同的含水层类型。纪念碑的设计将允许重新占用这些遗址。在这些地点的观测经验将有助于了解部署传感器系统的适当环境和采样要求（重力观测的最短持续时间、横向非均质性的空间采样和数据处理方法）。的吉尼斯世界纪录。在实验室测试中，超导重力仪的灵敏度为地球磁场的100亿分之一。如果在现场可以实现类似的测量灵敏度，并对仪器地点的大气压力和湿度、土壤湿度、温度和垂直位移的任何变化进行适当的校正，那么PI希望在特征良好的地点检测下伏地下水位高度的厘米级变化，并结合其他独立的水文测量，应该能够分离非饱和带和饱和带之间的储水成分。估算含水层参数，如比产量，并改进水文过程的量化，包括入渗、蒸散发和补给。＊＊＊

0345864WilsonThis grant supports acquisition, development and testing of a field superconducting gravity-meter (FSG) as an ultra-sensitive system for monitoring fluctuations and trends in subsurface water storage over long (months) unattended deployment periods. The FSG will be constructed from a commercially available superconducting gravimeter (GWR, Inc.) that does not require liquid Helium replenishment and integrated with meteorological sensors (barometric pressure, temperature, humidity, precipitation), a field enclosure and appropriate monumentation and deployed at two test sites in Texas and Arizona (through a subaward to the Univ. of Arizona) representing varying aquifer types. The monument design will allow for re-occupation of the sites. Observational experience at these sites will lead to understanding of appropriate environments for deploying the sensor system and sampling requirements (minimum duration of gravity observations, spatial sampling of lateral heterogeneity, and data processing methods). The GWR. Inc. superconducting gravimeter has a stated sensitivity of 1 part in 10 billion of the Earth's field in laboratory tests. If similar measurement sensitivity can be achieved in the field and with appropriate corrections for atmospheric pressure and humidity, soil moisture, temperature and any changes in vertical displacement at the instrument site, the PI's hope to detect cm-level changes in the underlying water table height and together with other independent hydrological measurements at well characterized sites, should be able to separation of water storage components between unsaturated and saturated zones, estimate aquifer parameters such as specific yield, and improve quantification of hydrologic processes, including infiltration, evapotranspiration, and recharge. ***