变化环境下渭河流域水资源演变规律分析

Evolution Law of Water Resources in Weihe River Basin Based on Dualistic Water Resources Evolution Model

渭河是黄河最大的支流，它是黄河中下游主要洪水来源区之一，也是黄河主要的产沙区之一。伴随气候变化、人类对水资源的开发利用活动加剧、大规模水土保持工程建设以及其他人类活动影响．渭河流域水资源的演变规律发生很大的变化。本文基于水资源二元演化模型研究了渭河流域的水资源演变规律，分析的水资源演变规律不仅包括狭义水资源。还包括广义水资源。本文所指的狭义水资源就是传统的水资源，即地表、地下水资源；广义水资源不仅包括狭义水资源，还包括直接为人类和生态系统所利用的降水。对1956-2000年渭河流域水资源演变过程进行了模拟．模拟结果表明．主要受降水减少和人类活动影响，1980-2000年地表水资源比1956-1979年衰减了7.3％，不重复地下水资源增加了20．2％．狭义水资源量减少了2．1％，直接为人类和生态系统所利用的降水减少了1．9％，广义水资源减少2．0％。考虑社会经济用水变化和土地利用变化，本文还预测了2020年水资源的演变趋势。经预测，2020年地表水资源量为81．6亿m63,比2000年少3．20亿m^3；不重复地下水资源量为24．62亿m^3，比2000年少0．28亿m^3；狭义水资源总量为106．21亿m^3，比2000年少3．48亿m^3；直接为人类和生态系统所利用的降水为487．16亿m^3，比2000年多3．05亿m^3；广义水资源量为593．37亿m^3，比2000年少0．43亿m^3。

The Weihe River Basin is the largest subbasin of the Yellow River Basin. It is one of the three main flood sources of the middle and lower reaches of the Yellow River and one of main sources of sand in the Yellow River. The water resources in the Weihe River Basin have changed a lot because of climate change, water resources exploitation, conservation of water and soil and other human activities. This paper studied the evolution law of water resources in the Weihe River Basin based on a dualistic water resources evolution model. The dualistic model couples a distributed hydrology model to simulating the natural water cycle process with a water resources allocation model simulating the artificial water cycle processes. This paper not only analyzed the evolution law of the specialized water resources, but also discussed the evolution law of the generalized water resources. The total of the surface water resources and ground water resources is the traditional water resources, namely, specialized water resources. The total of the specialized water resources and the precipitation directly utilized by human or ecological system is called the generalized water resources. A simulation of water cycle in the Weihe River Basin from 1956 to 2000 was performed. The result shows that, comparing the water resources from 1980 to 2000 with those from 1956 to 1979, the surface water resources decreased by 7.3%, the ground water resources not overlapping with the surface water resources increased by 20.2%, the specialized water resources decreased by 2.1%, the precipitation directly used by human and ecological system decreased by 1.9%, the general water resources decreased by 2.0%. As well as water resources at present, water resources in the future was evaluated based on WEP-L taking account of water use change and land use change. The volume of surface water resources in 2020 was predicted to be 8.160×10^9m^3, 0.320×10^9m^3 less than that in 2000. The volume of ground water resources in 2020 was predicted to be 5.563×10^9m^3, 0.463×10^9m^3 more than that in 2000. The volume of ground water resources not overlapped with surface water in 2020 was predicted to be 2.462×10^9m^3, 0.028×10^9m^3 less than that in 2000. The volume of specialized water resources in 2020 was predicted to be 10.621×10^9m^3, 0.348×10^9m^3 less than that in 2000. The volume of precipitation directly utilized by human and ecological system in 2020 was predicted to be 48.716×10^9m^3, 0.305×10^9m^3 more than that in 2000. The volume of generalized water resources in 2020 was predicted to be 59.337×10^9m^3, 0.0430×10^9m^3 less than that in 2000.