Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water reso...Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.展开更多
基金supported by the Open Research Fund Program of State key Laboratory of Hydroscience and Engineering, Tsinghua University (sklhse-2013-A-03)the National Natural Science Foundation of China (50879041)
文摘Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.
文摘在国家复苏河湖生态环境的要求下,分析京津冀平原区长序列水面面积变化特征及变化原因,有助于科学制定区域生态补水量及预测补水效果。研究通过3期土地利用数据融合确定了京津冀平原区的水域面积,基于GEE(Google Earth Engine)云平台提取了1985—2020年京津冀平原区长序列水面面积,并分析了水域面积填充率及水面面积演变原因。结果表明,京津冀平原区水面面积呈增加趋势,与1985年相比,2020年中部平原区水域面积填充率由3.6%增加到18.5%,滨海平原区水域面积填充率由30%增加到45%;生态补水是河湖水面面积增加的主要原因,2020年较2001年中部平原区水面面积增加了176 km 2,本地和南水北调生态补水的贡献占到84%。进一步以河湖复苏为目标,从水域面积填充率的角度设置了不同情景,分别估算了不同情景下的河湖生态需水量,为未来生态补水计划提供参考。研究成果系统分析了京津冀平原区水面现状及生态补水的效果,对京津冀平原区开展合理河湖复苏措施具有重要意义。
