River classification has emerged as a major application of environmental science, which can overcome the deficcts of tradition- al methods in focusing on the single objective of maintaining specified, valued features ...River classification has emerged as a major application of environmental science, which can overcome the deficcts of tradition- al methods in focusing on the single objective of maintaining specified, valued features of ecosystems. However, current ef- forts to classify rivers by hydrologic processes may result in a growing temptation to ignore ecological variability across basins Thus, an eco-functional classification is proposed for river management in the Pearl River Basin. This method riews ecological functions as fundamental characteristics of riverine systems and provides a framework for dividing a basin iato eco-specific categories according to the heterogeneity of the primary ecological functions. In addition, we proposed specific environmental flow methodologies corresponding to three typical river reaches of the basin by perceiving the key attributes of flow variability In the upstream region of the West River, flow velocity and wetted perimeter are considered as the key attributes of maintain- ing fish habitat; in a small-sized mountainous tributary of the North river, we choose water surface area to maintain the conti- nuity and biodiversity of the river; while for the aspect of river landscape in the midstream reach of the East R vet, water level is crucial for maintaining the aesthetic value. This research highlights the ecologically relevant heterogeneity that occurs within and among regions of a basin, and is expected to contribute to a simpler and more comprehensive river manage：nent.展开更多
Water is a critical natural resource upon which all social and economic activities and ecosystem functions depend. With a surprising social and economic development in the past decades, water has become an important c...Water is a critical natural resource upon which all social and economic activities and ecosystem functions depend. With a surprising social and economic development in the past decades, water has become an important constraint for China's sustainable development, and a matter concerning economic security, ecological security and national security of the country. Understanding the changes of water resources is greatly helpful in analyzing the impacts of climatic change, formulating plans for utilization and protection of water resources, and making water resource decisions. Based on China's national water resources assessment, the Mann-Kendall's test, and Morlet wavelet, we analyzed the changing trends and periods of China's renewable water resources during 1956–2010. The results as following:(1) There is no significant change trend of water resources on the countrywide scale during the period 1956–2010, the total water resources show a slight increasing trend, and the national annual average water resources during the period 1991–2010 increased by 1% relative to that of the period 1961–1990.(2) The changes of water resources in different level-I water resource regions vary significantly. Annual average water resources of the Haihe River and Yellow River regions in the northern China decreased 19% and 17% respectively in the past 20 years. Water resource increased in Southern and Northwestern rivers regions, particularly in the Northwest rivers region, with the increasing amplitude by nearly 10% in the past 20 years.(3) The inter-annual variation of national water resource became larger in the past 20 years, as compared with that of the period 1961–1990. The coefficients of water resource variation increased in Northwestern and Southwestern rivers regions, while the inter-annual variation tended to decrease in the Haihe and the Yellow River regions where significant decline of water resources happened.(4) A 14-year quasi-periodicity of the national water resource variation was detected, overlapping with various periodicities of water resources of different level-I water resource regions. Remarkable uniformity exists between the first or secondary primary periodicity of water resource variation in adjacent level-I water resource regions.展开更多
Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various d...Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various dynamic flows and ecological functions of river-lake interconnected relationships. We then propose a novel method for the health assessment of river systems based on interconnected water system networks. In a healthy river system there is ＂material and energy exchange＂ and it is the first and foremost relationship of material and energy exchange between rivers and lakes. There are unobstructed various ＂flows＂ between rivers and lakes including material flows （water, dissolved substances, sediments, organisms and contaminants）, energy flows （water levels, flow and flow velocity）, information flows （information generated with water flows, organisms and human activities） and value flows （shipping, power generation, drinking and irrigation）. Under the influences of na- ture and human activity, various flows are connected by river-lake interconnection to carry material and energy exchange between rivers and lakes to achieve river-lake interactions. The material and energy exchange between rivers and lakes become one of the approaches and the direct driving forces of changes in river-lake interconnected relationships. The benignant changes in river-lake interconnected relationship tend to be in relatively steady state and in ideal dynamic balance.展开更多
基金supported by the Surface Project of the National Natural Science Foundation of China(Grant No.51379150)Key Project of the National Natural Science Foundation of China(Grant No.51439006)
文摘River classification has emerged as a major application of environmental science, which can overcome the deficcts of tradition- al methods in focusing on the single objective of maintaining specified, valued features of ecosystems. However, current ef- forts to classify rivers by hydrologic processes may result in a growing temptation to ignore ecological variability across basins Thus, an eco-functional classification is proposed for river management in the Pearl River Basin. This method riews ecological functions as fundamental characteristics of riverine systems and provides a framework for dividing a basin iato eco-specific categories according to the heterogeneity of the primary ecological functions. In addition, we proposed specific environmental flow methodologies corresponding to three typical river reaches of the basin by perceiving the key attributes of flow variability In the upstream region of the West River, flow velocity and wetted perimeter are considered as the key attributes of maintain- ing fish habitat; in a small-sized mountainous tributary of the North river, we choose water surface area to maintain the conti- nuity and biodiversity of the river; while for the aspect of river landscape in the midstream reach of the East R vet, water level is crucial for maintaining the aesthetic value. This research highlights the ecologically relevant heterogeneity that occurs within and among regions of a basin, and is expected to contribute to a simpler and more comprehensive river manage：nent.
基金funded by the National Basic Research Program of China (Grant No. 2010CB428406)the External Cooperation Program of the Chinese Academy of Sciences (Grant No. GJHZ1016)
文摘Water is a critical natural resource upon which all social and economic activities and ecosystem functions depend. With a surprising social and economic development in the past decades, water has become an important constraint for China's sustainable development, and a matter concerning economic security, ecological security and national security of the country. Understanding the changes of water resources is greatly helpful in analyzing the impacts of climatic change, formulating plans for utilization and protection of water resources, and making water resource decisions. Based on China's national water resources assessment, the Mann-Kendall's test, and Morlet wavelet, we analyzed the changing trends and periods of China's renewable water resources during 1956–2010. The results as following:(1) There is no significant change trend of water resources on the countrywide scale during the period 1956–2010, the total water resources show a slight increasing trend, and the national annual average water resources during the period 1991–2010 increased by 1% relative to that of the period 1961–1990.(2) The changes of water resources in different level-I water resource regions vary significantly. Annual average water resources of the Haihe River and Yellow River regions in the northern China decreased 19% and 17% respectively in the past 20 years. Water resource increased in Southern and Northwestern rivers regions, particularly in the Northwest rivers region, with the increasing amplitude by nearly 10% in the past 20 years.(3) The inter-annual variation of national water resource became larger in the past 20 years, as compared with that of the period 1961–1990. The coefficients of water resource variation increased in Northwestern and Southwestern rivers regions, while the inter-annual variation tended to decrease in the Haihe and the Yellow River regions where significant decline of water resources happened.(4) A 14-year quasi-periodicity of the national water resource variation was detected, overlapping with various periodicities of water resources of different level-I water resource regions. Remarkable uniformity exists between the first or secondary primary periodicity of water resource variation in adjacent level-I water resource regions.
基金National Natural Science Foundation of China(41361003)Science and Technology Project in Jiangxi Province Department of Education(GJJ14733)
文摘Interconnected river system networks is a national water conservancy strategy in China and focus of research. Here we discuss the classification system, material and energy exchange between rivers and lakes, various dynamic flows and ecological functions of river-lake interconnected relationships. We then propose a novel method for the health assessment of river systems based on interconnected water system networks. In a healthy river system there is ＂material and energy exchange＂ and it is the first and foremost relationship of material and energy exchange between rivers and lakes. There are unobstructed various ＂flows＂ between rivers and lakes including material flows （water, dissolved substances, sediments, organisms and contaminants）, energy flows （water levels, flow and flow velocity）, information flows （information generated with water flows, organisms and human activities） and value flows （shipping, power generation, drinking and irrigation）. Under the influences of na- ture and human activity, various flows are connected by river-lake interconnection to carry material and energy exchange between rivers and lakes to achieve river-lake interactions. The material and energy exchange between rivers and lakes become one of the approaches and the direct driving forces of changes in river-lake interconnected relationships. The benignant changes in river-lake interconnected relationship tend to be in relatively steady state and in ideal dynamic balance.
