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United States Department of Agriculture

Agricultural Research Service

Title: Spatial and Temporal Dynamics of Vegetation in the San Pedro River Basin Area

Authors
item Qi, Jiaguo - MICHIGAN STATE UNIVERSITY
item Marsett, Robin - USDA-ARS TUCSON AZ
item Moran, Mary
item Goodrich, David - USDA-ARS TUCSON AZ
item Heilman, Phil - USDA-ARS TUCSON AZ
item Kerr, Y - CESBIO TOULOUSE FRANCE
item Dediu, G - CESBIO TOULOUSE FRANCE
item Chehbouni, A - ORSTOM/MADES/IRD MEXICO

Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 14, 2000
Publication Date: N/A

Interpretive Summary: The San Pedro River basin in the arid and semiarid southwestern United States is an important ecosystem. The basin contains more than 80% of the wildlife habitats found in the southwestern United States. Significant change in basin-wide vegetation communities has resulted from climate change, which includes reduced precipitation; and human induced change, which includes such factors as agriculture, population growth, and fire suppression. Changes in vegetation patterns also have affected the water supply of the river. This is due to the critical role vegetation plays in using water from the river and soils and its effect on rainfall runoff. Therefore, there is an increasing interest in knowing how much green vegetation is present at any time of the year in this region and its changes in space and time. In this study, we developed a remote sensing technique to use satellite images to map the density of green vegetation cover. This technique can provide an easy, simple, and accurate technique to examine the health of plants or natural grasses in arid and semiarid regions. The results not only will provide a timely assessment of surface physical conditions but also a way of estimating green vegetation density for water studies in this region. The results from this research will provide farm and rangeland managers a convenient way to monitor crop and vegetation densities over large areas using satellite data.

Technical Abstract: The San Pedro River originates in northern Mexico near the city of Canenea and extends to its confluence with the Gila River in the southwestern United States near Winkelman, Arizona. The basin contains more than 80% of the wildlife habitats found in the southwestern United States. Significant change in the spatial and temporal dynamics in basin- wide vegetation communities has resulted from climate change, which includes reduced precipitation; and human induced change, which includes such factors as agriculture, population growth, and fire suppression. Changes in vegetation patterns also have affected the water supply of the river. This impact is due to the critical role vegetation plays in transpiring water from river and soils and its effect on runoff. Therefore, there is increasing interest in mapping the vegetation dynamics and their spatial distribution. In this study, we developed a new technique to use remote sensing imagery to quantify these spatial and temporal dynamics. Imagery from Landsat TM, SPOT 4 VEGETATION, and aircraft based sensors was used to estimate the total amount of green vegetation cover and green leaf area index of the San Pedro River riparian corridor and the San Pedro River basin. The remotely estimated measurements were compared with in-situ measurements and suggested that remote sensing imagery can provide an accurate estimate of vegetation dynamics of this region.

Last Modified: 12/28/2014
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