Study On Ecological Water Use In Haihe Basin

The study of ecological water use is one of important research subjects that interrelated with ecology, hydrology and water resources. With economic development and water resources crisis intensification, the total amount of water resources decreased and this also caused a great deal of problems in water resources management and utilization. To meet economic development demands, such as urban water supply, irrigation and industrial development, large-scale direct abstraction of water from natural ecosystem has induced the reduction and degradation of the river and other ecosystems' goods and services. The purpose of the study of ecological water use is to estimate the amount of water for ecosystems to maintain their healthy and normal function, and through which to achieve ecology sustainable development and economic sustainable development.Haihe basin, one of Chinese seven large basins, was sited at North China Plain, which is the politic and economic center in China and has advantages for industry and agriculture development. But the ecological and environmental problems in Haihe basin are very serious since 1970's. The forest retrogresses, desertification, water environment degradation was arisen particularly because lack of ecological water. In this paper, Haihe basin was chosen as the case study area. From the aspect of ecosystem, the concept and estimate methods were studied in this paper.Ecological water use refers to water resources demand for maintaining the special structure, process and services of ecosystems. The main part of ecological water use is ecosystem, which contains the water resources for maintain ecosystem structure and the water resources for maintain ecosystem process and services. The former refers to vegetation restoration, wetland reconstruction and urban greenbelt water use and so on. The latter refers to the water resources requirements for transportation of soil and salt, supplement groundwater, dilution pollution and river self-purification.The results were showed as follows: In natural vegetation ecosystems, forestecological water use is 210.9 108 m3, but that don't account available water resources. River ecological water use is 40.1 108 m3, which accounts 15.2% of the annual average water resources 263.9 l08m3(according to 1956-1984 data).Wetland ecological water use is 38.13 108m3, accounting 14.4%; Urban ecological water use is 10.83 108m3,accounting 4.1%. The proportion of these three parts added up to 33.7%. Based on the near and long term ecology restoration target, this paper preestimated the amount of ecological water use in 2010 and 2030.The results showed that river ecosystem ecological water use in 2010 and 2030 is 46 l08m3 and 53.7 l08m3,respectively. And that of wetland is 44.04 l08m3 and 51.03 l08m3, respectively. That of urban ecosystem is 14.59 108m3 and 18.92 l08m3, respectively.On the basis of the analysis of the water resources utiliziation and shortage in Haihe Basin, suggestions and measures to ensure ecological water use and promote the sustainable development are also discussed in this paper.