Title: Use of Remotely Sensed Data for Improved Quantification of Evapotranspiration for Water Management in Nebraska
Project Type: Research
Start Date: 03/06/2006
End Date: 02/28/2007
Congressional District: First
Focus Categories: Water Use, Water Quantity, Hydrology
Keywords: evapotranspiration, consumptive water use, water resources management, surface energy balance, remote sensing
Principal Investigators: Irmak, Ayse; Hu, Qi Steven (University of Nebraska - Lincoln); Irmak, Suat (University of Nebraska - Lincoln); Martin, Derrel L.; Meyer, George; Rundquist, Donald C.; Verma, Shashi
Federal Funds: $ 20,000
Non-Federal Matching Funds: $ 40,086
Abstract: Irrigation provides an important degree of stability and sustainability of crop production and enhances the economy of Nebraska, representing an annual income for the state of about $9 billion. In the Central Plains of the United States, at least 90%, or more, of the precipitation is returned back to the atmosphere by evapotranspiration (ET) (USGS, 1997). Thus, accurate estimation of ET is one of the key elements for better managing water resources management. Particularly, in the context of crop production in irrigated agriculture such as a) scheduling of irrigation, b) evaluation of the effects of changing land use on water yields, c) environmental assessment by developing best management practices for surface and groundwater quality protection, d) predicting the status of the soil water supplies and their allocation and efficient use and e) quantifying water use by different vegetation surfaces over large areas. Better allocation and management of the region's water resources will ultimately affect the economics of the region and will in meeting stream requirements for water compacts and endangered species.
Practical, reliable and cost-efficient techniques are needed for quantification of ET to enhance efficient use of water resources and protect water quality in the region. Most field measurements are indirect and based on equations and assumptions. In addition, in spite of the elegance and theoretical attractions of these techniques for measuring ET, their practical use over large vegetation surfaces is limited. Therefore, our objective is to conduct an applied scientific research for satellite-derived estimates of evapotranspiration in conjunction with the surface energy balance algorithm for land at different scales in Nebraska. There is a need in Nebraska to study and implement such technique for quantification and mapping water use by different vegetation surfaces for estimating hydrological balances over large areas more economically.
Progress/Completion Report, PDF