黄河流域湿地格局特征、控制因素与保护

准确掌握流域湿地资源的数量和分布, 是流域湿地评价、修复与保护决策的前提。利用“北京一号”小卫星数据对黄河流域2006年湿地格局现状进行了监测, 在GIS技术支持下对流域湿地资源分布的影响控制因素进行了分析, 进而结合不同流域分区水资源条件, 对流域湿地保护策略进行了探讨。研究表明, 2006年黄河流域湿地总面积为25134km²,其中, 河流、湖泊、沼泽、滨海、人工湿地面积分别占该流域湿地总面积的36.2%、8.0%、45.0%、3.9%、6.9%.受气候及水资源支撑条件的影响, 黄河流域重要湿地集中分布在源区高寒沼泽湿地、上游河湖湿地、中下游河道湿地以及河口三角洲湿地。流域天然湿地分布受气候影响显着, 随着气候干燥度的增加, 湿地率呈明显递减趋势。研究认为, 黄河流域大部分地区属于半干旱区, 水资源条件先天不足, 必须充分考虑流域和区域水资源的支撑能力和干扰影响, 在流域层面和河流生态系统的尺度上统筹考虑, 构建科学合理的流域湿地保护框架体系。

Monitoring wetlands pattern in the Yellow River Basin for water resources management using Beijing-1 images

Wetlands provide a host of goods and services,including water quality maintenance,agricultural production,fisheries,and recreation.However,they are also under an increasing threat in many parts of the world.Inventory and monitoring of wetlands is fundamental to conservation efforts.At watershed scale,a credible quantitative inventory of wetland resources can support baseline assessment of the status of watershed wetland resources,and monitoring of long term trends in ecological characteristics of wetlands.In this paper,Beijing-1 micro-satellite remote sensing data of 2006 were used to investigate the wetlands distribution in the Yellow River Basin(YRB).Results showed that the total wetland area is 2513481 ha.Palustrine and riverine wetlands comprise the bulk of the basin wetlands,accounting for 45.0% and 36.2%,respectively.The wetlands are mainly distributed in the plateau valley of the source area,river floodplains in the middle and lower reaches and the coastal wetlands in the Yellow River Delta.For lacustrine and riverine wetlands,physiognomy is the main factor affecting the wetland formation,while climate,represented by the ratio of dryness to wetness,has direct relation with local hydrological conditions,and is more important in influencing palustrine wetlands pattern.Since most part of the basin belongs to arid and semi-arid climate,most wetlands,except those in the source area,mainly depend on the Yellow River supply since local precipitation can only partly satisfy the ecological water requirement.In addition,conflicts for water resources arise not only between wetlands and life and production,but also in different parts of the basin,for example,the upper and lower reaches.It is concluded that management of the limited water resources should involve rational allocation of water resources.For the basin managers,it is very important to realize the ecological values of different wetlands.Considering the water resources availability in the future,wetlands in each subregion should be given different priorities for restoration and conservation.