Collaborative Research: GPS-based terrestrial water storage anomalies during hydrologic extremes: linking hydrologic process, solid-earth response, and monitoring networks

GSTDTAP

项目编号	1521127
	Collaborative Research: GPS-based terrestrial water storage anomalies during hydrologic extremes: linking hydrologic process, solid-earth response, and monitoring networks
	Adrian Borsa
主持机构	University of California-San Diego Scripps Inst of Oceanography
项目开始年	2015
	2015-07-01
项目结束日期	2018-06-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	70168(USD)
国家	美国
语种	英语
英文摘要	Terrestrial water storage (TWS) is the total amount of water stored as soil moisture, groundwater, snow, in surface water bodies, and in the biosphere. Variations in TWS reflect the watershed-scale response to changes, such as drought and groundwater pumping. Observations of TWS are needed to study the water cycle and its role on the Earth, but existing tools for monitoring TWS variations are not satisfactory. Recently, global positioning system (GPS) observations of the height of the land surface have been used to quantify TWS variations. However, errors in TWS estimated from GPS data have not been quantified. This research has three components to study how GPS observations can be used to monitor TWS. First, the resolution and accuracy of TWS variations estimated from GPS land surface heights will be quantified by combining hydrologic data and a model of how the Earth deforms. Second, GPS data from several thousand stations will be used to estimate TWS variations across the continental United States for the past decade and forward in time. Third, a comparison will be made between existing TWS estimates and estimates based on GPS observations. The expected outcomes of this project will advance the start-of-the-art in TWS monitoring by evaluating the magnitude and sources of errors in GPS-based TWS data. This is a necessary step towards applying these data to a range of wide hydrologic applications, including estimates of soil water volumes and groundwater recharge, the effects of drought, and subsidence caused by changes in groundwater storage. Observations of TWS anomalies are critical for understanding how the hydrologic cycle responds to forcing such as drought. Existing tools for monitoring TWS anomalies are not optimal for many hydrologic applications. Recently, GPS observations of land surface vertical displacement have been used in novel ways to quantify the spatial and temporal variations of TWS anomalies associated with groundwater mining, seasonal snowpack, and drought. These results suggest that GPS-based records of displacement could greatly enhance monitoring of the terrestrial water cycle. However, none of the studies to date have quantified the errors in TWS anomalies estimated from GPS observations. The research plan has three components designed to assess how GPS observations can best be used to monitor TWS. First, the resolution and accuracy of TWS anomalies estimated from GPS vertical position data will be quantified by combining hydrologic loading data and models of the Earth's elastic response. Second, vertical position data from several thousand stations will be used to estimate TWS anomalies and associated errors across the continental United States, retrospectively for the past decade and forward in time. Third, a comparison will be made between existing TWS anomaly products and the product based on GPS positions. Differences will be related to hydrologic processes through analyses of in situ hydrologic observations of groundwater, soil moisture, and snow water equivalent. The expected outcomes of this project will advance the start-of-the-art in TWS monitoring by evaluating how errors in GPS-based TWS anomalies are related to interactions between hydrologic process, the solid earth response, and the monitoring network at the continental scale. This is a necessary step towards applying these data to a range of hydrologic applications.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/68149
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Adrian Borsa.Collaborative Research: GPS-based terrestrial water storage anomalies during hydrologic extremes: linking hydrologic process, solid-earth response, and monitoring networks.2015.