In arid regions, large-scale water diversion from rivers leads to significant changes in river flow regimes, which may have large impacts on ecological water uses of river-dependent ecosystems, such as river, lake, we...In arid regions, large-scale water diversion from rivers leads to significant changes in river flow regimes, which may have large impacts on ecological water uses of river-dependent ecosystems, such as river, lake, wetland, and riparian ecosystems. To assess the integrated impact of water diversion on ecological water uses, we proposed a hierarchy evaluation model composed of four layers representing the evaluation goal, sub-areas of the influenced region, evaluation criteria, and water diversion schemes, respectively. The evaluation criteria for different types of ecological water uses were proposed, and the analytical hierarchy process was used for the integrated assessment. For a river ecosystem, the percentage of mean annual flow was used to define the grade of environmental flow. For a lake ecosystem, water recharge to the lake to compensate the lake water losses was used to assess the ecological water use of a lake. The flooding level of the wetland and the groundwater level in the riparian plain were used to assess the wetland and riparian ecological water uses, respectively. The proposed model was applied to a basin in northern Xinjiang in northwest China, where both water diversion and inter-basin water transfer projects were planned to be carried out. Based on assessment results for the whole study area and two sub-areas, an appropriate scheme was recommended from four planning schemes. With the recommended scheme, ecological water uses of the influenced ecosystems can be maintained at an acceptable level. Meanwhile, economical water requirements can be met to a great extent.展开更多
From the perspective of adaption to local conditions, the paper had analyzed that it had emphasized visual perception, plane design and grade while functionality, vertical space and applicability of residential enviro...From the perspective of adaption to local conditions, the paper had analyzed that it had emphasized visual perception, plane design and grade while functionality, vertical space and applicability of residential environmental landscapes were neglected. Landscapes in ecologically livable environment were characterized by pretty natural environment, safe and spacious activity place, gentle and harmonious communication space, heavy cultural characteristic, and distinctive landscape feature. It had put forward design ideas for ecologically livable environment covering humanity, integrity, diversity and culture. The design thoughts were adjusting to local conditions, respecting the site, inheriting the spirit of place, conducting reasonable layout, rationally utilizing water, constructing harmonious plants community, creating comfortable activity place, highlighting theme, and manifesting culture. Ecological and livable concept should be integrated into landscape design. It was regarded that green and ecological landscape design was the key for urban environment reconstruction and the responsibility of each designer.展开更多
为探究南水北调中线工程蓄水后新水域环境对鱼类群落的影响,采用eDNA宏条形码技术(environmental DNA metabarcoding)首次对密云水库鱼类群落结构及多样性的时空变化特征进行了分析,并结合生态位宽度Shannon-Winner(B_(i))和重叠Pianka...为探究南水北调中线工程蓄水后新水域环境对鱼类群落的影响,采用eDNA宏条形码技术(environmental DNA metabarcoding)首次对密云水库鱼类群落结构及多样性的时空变化特征进行了分析,并结合生态位宽度Shannon-Winner(B_(i))和重叠Pianka指数(Q_(ik))研究了鱼类种群间的相互作用、共生共存及生态位分化的响应过程。结果表明:本次调查密云水库共检出86个鱼类物种eDNA信息,隶属14目21科68属,有3个鱼类eDNA信息仅注释到科、属级分类水平;鱼类主要栖息于水库底层(61.63%),以肉食性(43.02%)和杂食性(26.74%)摄食类型为主;PCoA分析显示,密云水库各采样点鱼类群落结构无显著性差异(P>0.05),Alpha多样性各项指数也无显著性差异(P>0.05);主要鱼类生态位宽度为1.15~9.25,均为中生态和广生态位种,其中,生态位重叠指数Q_(ik)>0.6的种对有517对,约占总种对数的14.15%;与历史资料相比,鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)、鲫(Carassius auratus)、鲂(Megalobrama terminalis)和鲤(Cyprinus carpio)等增殖放流鱼类仍为水库主要经济鱼类。研究表明,蓄水后营底栖、以肉食性和草食性为主要生活策略的水库鱼类对环境的适应能力较弱,且彼此之间竞争明显。展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50879041)
文摘In arid regions, large-scale water diversion from rivers leads to significant changes in river flow regimes, which may have large impacts on ecological water uses of river-dependent ecosystems, such as river, lake, wetland, and riparian ecosystems. To assess the integrated impact of water diversion on ecological water uses, we proposed a hierarchy evaluation model composed of four layers representing the evaluation goal, sub-areas of the influenced region, evaluation criteria, and water diversion schemes, respectively. The evaluation criteria for different types of ecological water uses were proposed, and the analytical hierarchy process was used for the integrated assessment. For a river ecosystem, the percentage of mean annual flow was used to define the grade of environmental flow. For a lake ecosystem, water recharge to the lake to compensate the lake water losses was used to assess the ecological water use of a lake. The flooding level of the wetland and the groundwater level in the riparian plain were used to assess the wetland and riparian ecological water uses, respectively. The proposed model was applied to a basin in northern Xinjiang in northwest China, where both water diversion and inter-basin water transfer projects were planned to be carried out. Based on assessment results for the whole study area and two sub-areas, an appropriate scheme was recommended from four planning schemes. With the recommended scheme, ecological water uses of the influenced ecosystems can be maintained at an acceptable level. Meanwhile, economical water requirements can be met to a great extent.
基金Supported by Natural Science Project of Tianjin City(08JCYBJC05100)~~
文摘From the perspective of adaption to local conditions, the paper had analyzed that it had emphasized visual perception, plane design and grade while functionality, vertical space and applicability of residential environmental landscapes were neglected. Landscapes in ecologically livable environment were characterized by pretty natural environment, safe and spacious activity place, gentle and harmonious communication space, heavy cultural characteristic, and distinctive landscape feature. It had put forward design ideas for ecologically livable environment covering humanity, integrity, diversity and culture. The design thoughts were adjusting to local conditions, respecting the site, inheriting the spirit of place, conducting reasonable layout, rationally utilizing water, constructing harmonious plants community, creating comfortable activity place, highlighting theme, and manifesting culture. Ecological and livable concept should be integrated into landscape design. It was regarded that green and ecological landscape design was the key for urban environment reconstruction and the responsibility of each designer.
