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United States Department of Agriculture

Agricultural Research Service

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Research Project: Resilience and Vulnerability of Beef Cattle Production in the Southern Great Plains under Changing Climate, Land Use and Markets

Location: Soil and Water Management Research

Project Number: 3090-13000-014-31
Project Type: General Cooperative Agreement

Start Date: Sep 01, 2013
End Date: Aug 31, 2014

Objective:
Derive daily, seasonal, and monthly water consumption by vegetation (agricultural and range land) in Southern Great Plains from MODIS data using Surface Energy Balance System (SEBS); and Develop evaporation and transpiration components of the crop water use using the Two Source Model (TSM) for selected locations using Landsat TM/ETM+ data.

Approach:
Surface Energy Balance System (SEBS) will be used for mapping ET with a daily, monthly, and seasonal time-step with both MODIS (250-1000 m) and Landsat 5 TM (30-120 m) satellite data. Remote sensing database will be screened to remove images with cloud cover. We will use MODIS and Landsat TM/ETM+ data acquired during 2000-2009 for estimating daily, monthly, and seasonal ET maps. MODIS images will be used for mapping ET for the entire study area. However, the Landsat TM data will be used for locations where high resolution ET data is needed for site-specific full life cycle analysis. We will use weather and reference ET data from the Texas High Plains ET (TXHPET) network for the Texas High Plains, University of Oklahoma’s Mesonet data for Oklahoma, and ozNET ET data for Kansas portion of the Southern Great Plains. Selection of the reference ET stations will be based on the quality of the data and locations. Two Source Model (TSM) model will be applied on the Landsat data to derive evaporation and transpiration maps separately. Since ground observations (lysimetric measurements) of ET for assessing the accuracy are available only for the Texas High Plains, vigorous accuracy assessment of ET maps will be done for that region only. For Oklahoma and Kansas regions of the Southern High Plains, SEBS-based ET maps as observations in evaluating TSM-based evaporation and transpiration maps. MODIS-based ET maps will be evaluated using the Landsat-based ET maps as high-resolution Landsat data mostly likely to yield relatively accurate ET maps. SEBS and TSM will be evaluated by comparing daily ET against lysimetric measurements.

Last Modified: 10/25/2014
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