检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:李景宜[1]
机构地区:[1]兰州大学资源与环境学院西部环境教育部重点实验室
出 处:《地理科学》2007年第3期371-375,共5页Scientia Geographica Sinica
基 金:国家自然科学基金项目(40501077);陕西省社会科学基金(06E016Z)项目资助
摘 要:运用统计计算和RS/GIS方法,分析渭河下游湿地环境的水文特性、水污染特征、土地利用/覆被状况及其演变特征等湿地环境风险因素,结论为:①渭河下游水沙量年际变化大、年内水沙量分配不均,且呈现减少趋势;汛期黄河洪水倒灌渭河,降低了由于水沙供给变化而导致的湿地水文环境风险度;②湿地水环境日趋恶化的变化趋势降低了湿地的生态净化功能,增加了湿地水环境风险度;③1989~2000年渭河下游新增湿地12.76km^2,年均增长率2.70%;湿地裸地化和盐碱化形势严峻;④以加强湿地保护立法、完善流域水污染治理、重建河岸植被带、强化湿地管理等重点措施确保湿地环境安全和湿地资源的可持续利用。By statistical computation and RS/GIS method, the environmental risk factors, including hydrological characteristics of wetland, water pollution, land-use/cover and their evolution in lower reaches of the Weihe River, were analyzed. The results are as follows. ( 1 ) The quantities of the water and sand are changing dramatically in recent years, and their distribution with the decreasing tendency are not even. In flood season water from the Yellow River flows backward to the Weihe River, which relieves the threat resulted from the decreasing of water and sand supply, and reduces the risk for wetland brought by the changing mentioned above. (2) The degeneration of the hydrological environment of wetland lowers its purification capability, and increases its hydrological environment risk. (3) From 1989 to 2000, in the lower reaches of the Weihe River, the area of the wetland increasesd 12.96 km^2 with an annual increase rate of 2.7%, and there were 2.002km^2 and 0.94km^2 of wetland become bare and saline land, respectively. In addition, 0.03 km^2 wetland was occupied by urban construction. (4) By some measures, such as strengthening lawmaking, fathering water pollution, reconstructing vegetation and enhancing management, environment safety and resources sustainable use will be come tuer.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.112