摘要
In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.
In recent years, wetland ecological water requirements （EWRs） have been estimated by using hydrological and functional approaches, but those approaches have not yet been integrated for a whole ecosystem. This paper presents a new method for calculating wetland EWRs, which is based on the response of habitats to water level, and determines water level threshold through the functional integrity of habitats. Results show that in the Huanghe （Yellow） River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7. One of the dominant plants in the delta, Phragmites australis, tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity. The minimum, optimum and maximum EWRs for the Huanghe River Delta are 9.42× 10^6 m^3, 15.56× 10^6 m^3 and 24.12×10^6 m^3 with water levels of 5.0 m, 5.2 m and 5.5 m, corresponding to functional integrity indices of 0.70, 0.84 and 0.72, respectively. A wetland restoration program has been performed, which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta＇s former wetland area.
基金
Under the auspices of Major State Basic Research Development Program of China (No. 2006CB403303)
National Natural Science Foundation of China (No. U0833002,40571149)
Scientific Research Foundation of Beijing Normal University (No. 2009SD-24)
关键词
黄河三角洲
生态需水
湿地功能
生境
基础
估算
中国
三角洲地区
water level-habitat response
functional integrity
ecological water requirements
wetland
Huanghe River Delta
