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It is now common knowledge that many water resources stresses relate to access to water within a basin. Yi River Basin, a typical river basin characterized by intensive agricultural processes, significant population growth, and water management, has been undergoing grave water problems. In this paper, the long-term trend of precipitation and streamflow in Yi River Basin, from 1964 to 2010, was investigated via Mann-Kendall test. The change point occurred in the year 1965 dividing the long-term series into two periods. Climate elasticity method and linear regression method were implemented to quantify the impact of precipitation and human activities on runoff and presented basically consistent results of the percentage change in an annual runoff for the postchange period. The results reveal that the decline of annual runoff in postchange period is mainly attributed to precipitation variability of 53.66–58.25% and human activities of 46.34–41.74%, as estimated by climate elasticity method and linear regression method, respectively. This study detected the changes in the precipitation-streamflow relationship and investigated the possible causes in the Yi River, which will be helpful for providing a reference for the management of regional water resources. [ABSTRACT FROM AUTHOR]

Meteorological drought can evolve into all aspects of hydrologic system such as soil layer, groundwater, and river discharge, leading to agricultural drought, groundwater drought, and streamflow drought, respectively. How does it propagate? Is there any strong relationship between meteorological drought and others? These issues need further understanding regarding different climate regions. In this paper, monthly SRI and SPEI at different timescales during 1976 and 2005 were utilized to understand how streamflow drought responded to meteorological drought in Xiangjiang river basin, a semihumid basin of Central China. Impressive findings included that strong correlations between SRI and SPEI were found. SPEI of 2-month timescale behaved best when correlating with SRI (R=0.79). Longer timescales of SPEI seemed not to be useful for streamflow drought identification. At seasonal scale, higher correlation coefficients were obtained during dry season, whereas lower coefficients were found in wet season. The maximum R reached up to 0.89 in November at 2-month timescale. Besides, robust response relation between streamflow drought and meteorological drought was also found. The average response rate (Rr) was considerably high (75.4%), with the maximum obtained at 2-month timescale (Rr=82.9%). Meanwhile, important seasonal difference of response rate has also been pointed out. [ABSTRACT FROM AUTHOR]