Quantifying the magnitude of the impact of human activities on runoff consumption in the midstream of Shiyang River, China

The runoff of some rivers in the world especially in the arid and semi-arid regions has decreased remarkably due to climate change and intensive human activities with the development of society and economy. The midstream of Shiyang River, as the study area, is affected by human activities more and more remarkably. From the angle of runoff consumption and relativistic consumption rate, this paper analyzes the characteristics of annual mountainous runoff and runoff consumption in the past 50 years, and obtains the significant inflection point (1975) of runoff under the influence of human activities in the midstream of Shiyang River. The runoff consumption of the last 50 years is divided into three stages, which improves the current study. By the analysis of measured and original quantity of the inflows and consumption, this paper obtains the effect magnitude of the inflows and human activities on runoff consumption, and concludes the respective runoff consumption contribution from both natural and human activities from 1956-2009.