In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well...In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.展开更多
Projection Pursuit (PP) model is a technique of falling high dimension. Real coding based on Accelerating Genetic Algorithm (RAGA) is a method of optimum. Through combining the PP model and RAGA, the paper applies the...Projection Pursuit (PP) model is a technique of falling high dimension. Real coding based on Accelerating Genetic Algorithm (RAGA) is a method of optimum. Through combining the PP model and RAGA, the paper applies the model in the water environment quality evaluation. The writer takes the water quality evaluated indexes of each sample as projection direction and turns high dimension data into low dimension projection value. Thus, the writer achieves on evaluating the grade of water samples and its optimum order. Based on this, the writer overcomes the jamming of weights calculated on fuzzy synthesize judge and gray system valuation. The paper can provide a new thought for water environment quality evaluation and other falling high dimension and optimum issue.展开更多
1. PREFACE Lingdingyang is a trumpet estuary. It accepts the runoff of the Dongjiang River, the Beijiang River, the Zhengjiang River and the Liusihe River. It also accepts a part of the runoff of the Xijiang River. It...1. PREFACE Lingdingyang is a trumpet estuary. It accepts the runoff of the Dongjiang River, the Beijiang River, the Zhengjiang River and the Liusihe River. It also accepts a part of the runoff of the Xijiang River. Its mean year runoff is 1.742×10" M^3. In resent ten years, industry and agriculture are developing rapidly in Guangzhou City, Dongguan City, Zhongshan City, Shunde County, Panyu County. Lingdingyang’s pollution is increesing. Water quality of lingdingyang is steadily deteriorated. In order to investigate the situation of water environment of Lingdingyang, we study its static environmental capacity of nitrogen and phosphorus. LANDSAT imageries are used in the study. The concentrations of nitrogen and phosphorous is detected by convention method.展开更多
Erosion and transport of soil has worldwide implications for agriculture, landscape stability, climate, natural hazards, and clean, renewable resources of water and air. Assured access to clean water and a healthy and...Erosion and transport of soil has worldwide implications for agriculture, landscape stability, climate, natural hazards, and clean, renewable resources of water and air. Assured access to clean water and a healthy and safe environment requires an ethic of conservation and protection. The minimum scale in which these principles apply successfully is basin wide. These are the fundamental concerns of the Sino-US Centers for Soil and Water Conservation and Environmental Protection.展开更多
The East African Rift extending across Djibouti, Ethiopia and Kenya is characterized by low level of economic development,high level of poverty,increasing population,scarce natural resources(land,water, and environmen...The East African Rift extending across Djibouti, Ethiopia and Kenya is characterized by low level of economic development,high level of poverty,increasing population,scarce natural resources(land,water, and environment),complex and rich ecosystems, increasing desertification and degrading biodiversity, underdeveloped regional trade and market,water resources mainly stored in groundwater and展开更多
Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain env...Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain environment contamination factors in some areas seriously exceeded the standard value and led to the whole water quality at the third class level.The measurements should be taken to promote the sustainable development of breeding area in Shuidong Bay.展开更多
通过探讨变化环境下水-生态-能源-粮食(Water-Ecology-Energy-Food,WEEF)纽带关系的演化规律,旨在解决实现全球可持续发展目标(Sustainable Development Goals,SDGs)面临的资源安全、生态保护及绿色经济转型中的关键技术问题,为经济社...通过探讨变化环境下水-生态-能源-粮食(Water-Ecology-Energy-Food,WEEF)纽带关系的演化规律,旨在解决实现全球可持续发展目标(Sustainable Development Goals,SDGs)面临的资源安全、生态保护及绿色经济转型中的关键技术问题,为经济社会绿色可持续发展提供理论支撑。系统分析了国内外WEEF纽带关系的最新研究动态,解析了变化环境对WEEF纽带关系的影响机理,构建了影响定量解析体系,从技术方案、政策体系、系统措施等方面提出了变化环境下WEEF纽带关系协同保障策略。系统揭示了变化环境下WEEF纽带关系的耦合机制,在此基础上提出了系统性的协同保障对策,可为提升资源利用效率、推动生态保护修复及促进经济社会高质量发展提供科学依据。展开更多
水源涵养服务供需安全是保障区域水资源可持续利用和维护生态平衡的重要支撑。基于土壤和水评估工具(Soil and Water Assessment Tool,SWAT)测算新安江上游水源涵养服务供需指数,采用Theil-Sen Median趋势分析、标准差椭圆、探索性空间...水源涵养服务供需安全是保障区域水资源可持续利用和维护生态平衡的重要支撑。基于土壤和水评估工具(Soil and Water Assessment Tool,SWAT)测算新安江上游水源涵养服务供需指数,采用Theil-Sen Median趋势分析、标准差椭圆、探索性空间数据分析方法揭示其时空演变规律,耦合最优参数地理探测器和时空地理加权回归模型,分析新安江上游水源涵养服务供需指数存在时空差异的原因。结果显示:(1)在2002—2020年,新安江上游水源涵养服务供需指数呈螺旋上升趋势,其中极显著上升区域约占1.36%。(2)新安江上游水源涵养服务供需指数的标准差椭圆分布主要走向为“东北—西南”,全局呈逐渐加强的正相关性。(3)人口密度、坡向、土壤含水量分别是人类活动、下垫面、水文气象维度中对新安江上游水源涵养服务供需指数驱动力最强的因子。(4)人口密度对新安江上游各子流域水源涵养服务供需指数的驱动作用始终为负,坡向的驱动作用主要为负,土壤含水量的驱动作用始终为正。研究可为制定流域尺度的水土保持和水资源管理策略提供理论参考。展开更多
文摘In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang River. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang River will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.
文摘Projection Pursuit (PP) model is a technique of falling high dimension. Real coding based on Accelerating Genetic Algorithm (RAGA) is a method of optimum. Through combining the PP model and RAGA, the paper applies the model in the water environment quality evaluation. The writer takes the water quality evaluated indexes of each sample as projection direction and turns high dimension data into low dimension projection value. Thus, the writer achieves on evaluating the grade of water samples and its optimum order. Based on this, the writer overcomes the jamming of weights calculated on fuzzy synthesize judge and gray system valuation. The paper can provide a new thought for water environment quality evaluation and other falling high dimension and optimum issue.
文摘1. PREFACE Lingdingyang is a trumpet estuary. It accepts the runoff of the Dongjiang River, the Beijiang River, the Zhengjiang River and the Liusihe River. It also accepts a part of the runoff of the Xijiang River. Its mean year runoff is 1.742×10" M^3. In resent ten years, industry and agriculture are developing rapidly in Guangzhou City, Dongguan City, Zhongshan City, Shunde County, Panyu County. Lingdingyang’s pollution is increesing. Water quality of lingdingyang is steadily deteriorated. In order to investigate the situation of water environment of Lingdingyang, we study its static environmental capacity of nitrogen and phosphorus. LANDSAT imageries are used in the study. The concentrations of nitrogen and phosphorous is detected by convention method.
文摘Erosion and transport of soil has worldwide implications for agriculture, landscape stability, climate, natural hazards, and clean, renewable resources of water and air. Assured access to clean water and a healthy and safe environment requires an ethic of conservation and protection. The minimum scale in which these principles apply successfully is basin wide. These are the fundamental concerns of the Sino-US Centers for Soil and Water Conservation and Environmental Protection.
文摘The East African Rift extending across Djibouti, Ethiopia and Kenya is characterized by low level of economic development,high level of poverty,increasing population,scarce natural resources(land,water, and environment),complex and rich ecosystems, increasing desertification and degrading biodiversity, underdeveloped regional trade and market,water resources mainly stored in groundwater and
基金Supported by China Postdoctoral Science Foundation (20090460873)
文摘Fuzzy comprehensive evaluation method was used to develop a standard model to analyze and evaluate nearness degree of water environment quality at breeding area of Shuidong Bay in China.Results showed that certain environment contamination factors in some areas seriously exceeded the standard value and led to the whole water quality at the third class level.The measurements should be taken to promote the sustainable development of breeding area in Shuidong Bay.
文摘通过探讨变化环境下水-生态-能源-粮食(Water-Ecology-Energy-Food,WEEF)纽带关系的演化规律,旨在解决实现全球可持续发展目标(Sustainable Development Goals,SDGs)面临的资源安全、生态保护及绿色经济转型中的关键技术问题,为经济社会绿色可持续发展提供理论支撑。系统分析了国内外WEEF纽带关系的最新研究动态,解析了变化环境对WEEF纽带关系的影响机理,构建了影响定量解析体系,从技术方案、政策体系、系统措施等方面提出了变化环境下WEEF纽带关系协同保障策略。系统揭示了变化环境下WEEF纽带关系的耦合机制,在此基础上提出了系统性的协同保障对策,可为提升资源利用效率、推动生态保护修复及促进经济社会高质量发展提供科学依据。
文摘水源涵养服务供需安全是保障区域水资源可持续利用和维护生态平衡的重要支撑。基于土壤和水评估工具(Soil and Water Assessment Tool,SWAT)测算新安江上游水源涵养服务供需指数,采用Theil-Sen Median趋势分析、标准差椭圆、探索性空间数据分析方法揭示其时空演变规律,耦合最优参数地理探测器和时空地理加权回归模型,分析新安江上游水源涵养服务供需指数存在时空差异的原因。结果显示:(1)在2002—2020年,新安江上游水源涵养服务供需指数呈螺旋上升趋势,其中极显著上升区域约占1.36%。(2)新安江上游水源涵养服务供需指数的标准差椭圆分布主要走向为“东北—西南”,全局呈逐渐加强的正相关性。(3)人口密度、坡向、土壤含水量分别是人类活动、下垫面、水文气象维度中对新安江上游水源涵养服务供需指数驱动力最强的因子。(4)人口密度对新安江上游各子流域水源涵养服务供需指数的驱动作用始终为负,坡向的驱动作用主要为负,土壤含水量的驱动作用始终为正。研究可为制定流域尺度的水土保持和水资源管理策略提供理论参考。
