Research on Water Resources and Eco-environment Safety in Heihe River Basin

After analyzing the hydrological data for 58 years in Heihe river basin it was found that the regional water resources was relatively stable due to the replenishment of glacial melt-water. The ratio of the biggest annual runoff to the smallest one was 2∶1, and the average water resources was 32\^31×10~(8) m~(3)\5a~(-1). The average per capita water reached (1 689) m~(3)\5a~(-1), which was within the world-accepted safety range of (1 000)～(1 700) m~(3)\5a~(-1). But among the water resources there are 7\^5×10~(8) m~(3)\5a~(-1) should be used for ecological consumption. With consideration to the characteristics of water resources being retransformed and reused for many times, and the water-saving measures being adopted in the whole river basin, the water resources was still within safety range. According to water resource status, land developmental scale and the eco-environmental situation, the threshold safety line of natural runoff resources in the study river basin is defined as 32\^31×10~(8) m~(3)\5a~(-1); and the safety cordon is 28×10~(8) m~(3)\5a~(-1).