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Streamflow Response to Precipitation Measurement Uncertainty and Land-use Changes in Northwestern Mexico

出版	Duke University, 2007
URL	http://books.google.com.hk/books?id=yzLttgAACAAJ&hl=&source=gbs_api

註釋Water resources in an arid to semiarid basin such as the Yaqui River basin are crucial for human development in the region. Located in southwestern North America, the Yaqui River Basin (YRB) receives 80% of the annual precipitation during the summer due to the influence of the North American monsoon. At the same time, 90% of the water resources in the region are used by agriculture, with streamflow as the main supplier. Therefore, the effect of precipitation on streamflow becomes one of the most important components of the regional hydrological cycle and its accurate measurement is necessary for better prediction and improved water resources management practices. Six precipitation datasets (rain gauge-, model and data assimilation-, and merged-based products) are used to force the Variable Infiltration Capacity (VIC) model to assess the discrepancy between the precipitation measurements and its propagation to streamflow simulations. Based on the coefficient of variation, results show that the discrepancy in precipitation forcing data propagates to produce a discrepancy in streamflow that is 1.8 times the discrepancy in precipitation. Interannual variability in the propagation of discrepancy is more prominent than the intraseasonal variability, showing a higher propagation of discrepancy during La Nina years. The streamflow sensitivity to land-use changes is also evaluated under the influence of multi-scale climatic regimes. Land-use changes increase streamflow generation in areas currently dominated by woodland, while in areas dominated by grassland and shrub, there is a reduction in the streamflow generation. Overall the land-use sensitivity experiments show that the Angostura sub-basin is more sensitive to land-use changes during non-monsoon months and La Nina years than its counterparts. The Paso Nacori sub-basin is more sensitive during monsoon months and El Nino years. In both sub-basins, the warm and cold phases of the Pacific Decadal Oscillation (PDO) show similar sensitivities. The Oviachi sub-basin experiences higher sensitivity during the monsoon months, El Nino years, and cold PDO.