Hydrological impacts of mesquite encroachment in the upper San Pedro watershed |
| |
| Institution: | 1. Geos Institute, Ashland, OR, USA;2. Fenner School of Environment and Society, The Australian National University, Canberra, Australia;3. John Muir Project of Earth Island Institute, Berkeley, CA, USA;4. Consulting Forester, Rockville, MD, USA;1. University of Guilan, Rasht, Iran;2. Department of Soil Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran;3. Department of Irrigation Eng., Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran;4. Faculty of Environmental Sciences, Environmental Future Centre, Griffith University, Nathan, Queensland 4111, Australia;1. Área de Botánica, Departamento de Ciencias Agroforestales, EiFAB, Campus Duques de Soria, Universidad de Valladolid, 42004 Soria, Spain;2. Facultad de Ciencias Forestales y Recursos Naturales, Laboratorio de Dendrocronología y Cambio Global, Universidad Austral de Chile, Valdivia, Chile;3. Center for Climate and Resilience Research (CR2), Santiago, Chile;4. Instituto de Ciencias de la Tierra, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile |
| |
| Abstract: | Over the past century, mesquite trees (Prosopis spp.) have exhibited substantial increase in abundance throughout areas in the American Southwest that were once dominated by desert grassland. To assess hydrological consequences of mesquite encroachment, the Soil and Water Assessment Tool (SWAT) was applied to simulate progressive mesquite encroachments in the upper San Pedro watershed (U.S./Mexico). The simulated average annual basin evapotranspiration (ET) increases with mesquite encroachment, leading to the decrease of annual water yield and percolation by 9.8% and 9.7%, respectively. Substantial increase of ET (up to 19.19 mm) and decrease of percolation, and surface runoff (to ?12.90 and ?3.20 mm, respectively) were observed in the southeast, middle-west, and northern subwatersheds of the basin and the most significant decrease of surface runoff (around ?35.8%) was simulated during the wet period. In addition, a non-linear hydrological response relative to mesquite encroachment was observed, i.e. hydrological processes changed markedly until a certain amount (approximately 40%) of grassland was removed, indicating that the strongest increase of ET occurred in the earliest stages of encroachment. Consequently, changes in vegetation physiognomy, such as mesquite encroachment, have broad implications for landuse management especially in regard to reliable water supplies in arid and semi-arid environments. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
