Water Resources Research Act Program

Details for Project ID 2010ND214B

Reference Evapotranspiration and Actual Evapotranspiration Measurements in ND

Institute: North Dakota
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-28
Total Federal Funds: $6,000 Total Non-Federal Funds: $12,001

Principal Investigators: Xinhua Jia

Abstract: Evapotranspiration (ET) is one of the most important components in the hydrologic cycle. Almost all research related to water resources management require a good understanding on ET, or accurate ET measurement. However, ET is the hydrologic component most difficult to measure. However, the Eddy Covariance (EC) method measures the surface fluxes using precise and high speed instrument at a frequency of 10-20 Hz. It is superior to the lysimeter and Soil Water Balance (SWB) approaches because it measures the ET above crop canopy and accounts for the heterogeneity at the land surface. It also measures the ET without interfering with different water management practices, such as elevated water table and subsurface drainage (SSD) conditions. The SSD has been in practice in United States for more than a century. Its use in the Red River Basin (RRB) started relatively in recent years, 1993. It is widely used in the southeastern and central eastern part of North Dakota due to its wet climate. The quality and quantity of water in the Red River is influenced by the SSD. Therefore, a study of the potential impact of SSD on Red River is underway. Research proposed here is part of the comprehensive study. The ET of both the drained and undrained fields needs to be compared to understand the surface and subsurface hydrology of the field. This project proposes to measure ET using the EC method both in the undrained and the SSD fields and also compare them with reference ET estimated using ASCE/EWRI 2005 method.