Runoff coefficients of the source regions of the Huanghe River in 1956-2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which ...Runoff coefficients of the source regions of the Huanghe River in 1956-2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had attracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient （R/P）, baseflow coefficient （Br/P） and direct runoff coefficient （Dr/P） were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients （including Dr/P, Br/P and R/P）. The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual precipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is -3.9℃, temperature is the main factor influencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/P was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area between Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients become insignificant.展开更多
[Objective] To study the characteristics and effects of inorganic nitrogen in east water-source and inflow rivers of Chaohu Lake. [Method] The speciation and distribution characteristics of dissolvable inorganic nitro...[Objective] To study the characteristics and effects of inorganic nitrogen in east water-source and inflow rivers of Chaohu Lake. [Method] The speciation and distribution characteristics of dissolvable inorganic nitrogen （DIN） in east water-source and inflow rivers of Chaohu Lake were investigated, and their effects on water qual- ity were examined. [Result] The concentrations of NH3-N and NO2--N were the high in flood season, and low in non-flood season, while the concentration of NO3--N pre- sented the opposite trend; the concentration of NO3--N was the highest in Shuangqiao estuary, where the pollution was the worst. DIN in Zhegao estuary and Xiaozhegao estuary was mainly caused by domestic sewage and industrial wastewaters; surface runoff and pollution from ships contribute the most to the DIN content in Shuangqiao estuary. [Conclusion] This study provided basic data and theoretical basis for the control and management of eutrophication in Chaohu Lake.展开更多
The main goal of this study was to assess the long-term impacts of global warming perturbation on water resources of the Kaidu River Basin in Northwest China. Temperature, precipitation and hydrology data during the p...The main goal of this study was to assess the long-term impacts of global warming perturbation on water resources of the Kaidu River Basin in Northwest China. Temperature, precipitation and hydrology data during the past 29 years from 1979 to 2007 were collected and analyzed using parametric and non-parametric methods, the connection between temperature and precipitation by the combination of grey correlation analysis method and the hypothesis testing for trend of climate change. The results show a high increase in temperature in the study area as well as an extreme and highly variable hydrological regime in this region, where flash floods can exceed the total runoff from a sequence of years. These variations may be due to the geographical location of the Kaidu River Basin in arid zone. It also reveals that precipitation has a much greater impact on stream flow than that of temperature. The development of new approaches was proposed as responses to climate change in this arid region.展开更多
Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious society.As mountain eco...Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious society.As mountain ecosystems play a key role in water resources conservation of mountain rivers,and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution,partition theory can be applied to the water resources conservation of mountain river.This theory observes the following partition principles:regional relativity,spatial continuity,integralcounty,meeting management needs,hierarchical principle,and comparability principle.And it lays equal emphasis on both water resources conservation and environmental protection,on both water quality conservation and water quantity protection,on the combination of water features,water cycle and water pollution.In the partition methods,index method and map superposition method will be applied in region partition.The example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers,and it provides a platform for future study in water resources conservation.展开更多
Major elements and carbon isotopes of dissolved inorganic carbon(DIC)have been measured in the waters of Changbaishan mountain,a volcanic area in northeastern China,between June and September 2016 to decipher the orig...Major elements and carbon isotopes of dissolved inorganic carbon(DIC)have been measured in the waters of Changbaishan mountain,a volcanic area in northeastern China,between June and September 2016 to decipher the origin of the CO_2 involved in chemical weathering reactions.Spatial variations of major elements ratios measured in water samples can be explained by a change of the chemical composition of the volcanic rocks between the volcanic cone(trachytes)and the basaltic shield as evidenced by the variations in the composition of these rocks.Hence,DIC results from the neutralization of CO_2 by silicate rocks.DIC concentrations vary from 0.3 to 2.5 mmol/L and carbon isotopic compositions of DIC measured in rivers vary from-14.2‰to 3.5‰.At a first order,the DIC transported by rivers is derived from the chemical weathering’s consumption of CO_2 with a magmatic origin,enriched in^(13)C(-5%)and biogenic soil CO_2 with lower isotopic compositions.The highest δ^(13)C values likely result from C isotopes fractionation during CO_2 degassing in rivers.A mass balance based on carbon isotopes suggest that the contribution of magmatic CO_2 varied from less than 20%to more than 70%.Uncertainties in this calculation associated with CO_2 degassing in rivers are difficult to quantify,and the consequence of CO_2 degassing would be an overestimation of the contribution of DIC derived from the neutralization of magmatic CO_2 by silicate rocks.展开更多
This paper has examined how the resources of the White Volta River are enhancing food availability for riparian communities in northern Ghana despite climate change and its associated effects on food security. Using p...This paper has examined how the resources of the White Volta River are enhancing food availability for riparian communities in northern Ghana despite climate change and its associated effects on food security. Using participatory methods such as focus group discussions and interviews, data was collected from households and institutions in three riparian communities. The result of the study indicates that, all things been equal, cultivation of food crops along the river bank in the rainy season gives significantly high yields as compared to yields from farms farthest from the river under rain fed agriculture. Higher organic content and moisture retention capacity of river bank soils explains the yield differential and adaptability to climate change. In addition, farmers now irrigate cereal crops which were hitherto, reserved for only rainy season production. However, inappropriate irrigation practices are accelerating erosion and sedimentation of the river and thus, threaten the sustainability of agriculture and food security in the White Volta Basin. The paper therefore, recommends the adoption of IWRM （integrated water resources management） and the participation of local communities, Government and Civil Society organisations for sustaining the productive capacity of the White Volta Basin for enabling adaptation of agriculture to climate change in the riparian communities of the basin.展开更多
基金Under the auspices of the Major State Basic Research Development Program of China (No. G19990436-01)the Na-tional Natural Science Foundation of China (No. 40471127)
文摘Runoff coefficients of the source regions of the Huanghe River in 1956-2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had attracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient （R/P）, baseflow coefficient （Br/P） and direct runoff coefficient （Dr/P） were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients （including Dr/P, Br/P and R/P）. The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual precipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is -3.9℃, temperature is the main factor influencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/P was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area between Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients become insignificant.
基金Supported by the Special Fund for the Control and Management of Chaohu Lake of the National Key Technology R&D Program,China(2008ZX07103-005)the Special Fund for the Control and Management of Huaihe River of the National Key Technology R&D Program,China(2008ZX07010-004)+1 种基金National Natural Science Foundation of China(40073030,40972092,41172121)the Natural Science Foundation of Anhui Province,China(090413083)~~
文摘[Objective] To study the characteristics and effects of inorganic nitrogen in east water-source and inflow rivers of Chaohu Lake. [Method] The speciation and distribution characteristics of dissolvable inorganic nitrogen （DIN） in east water-source and inflow rivers of Chaohu Lake were investigated, and their effects on water qual- ity were examined. [Result] The concentrations of NH3-N and NO2--N were the high in flood season, and low in non-flood season, while the concentration of NO3--N pre- sented the opposite trend; the concentration of NO3--N was the highest in Shuangqiao estuary, where the pollution was the worst. DIN in Zhegao estuary and Xiaozhegao estuary was mainly caused by domestic sewage and industrial wastewaters; surface runoff and pollution from ships contribute the most to the DIN content in Shuangqiao estuary. [Conclusion] This study provided basic data and theoretical basis for the control and management of eutrophication in Chaohu Lake.
基金supported by the State Key Development Program for Basic Research of China (973 program (Grant No. 2010CB951002)the Natural Sciences Foundation of China (Grant No. 40871027)+1 种基金the Project from Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone (Grant No. XJYS0907-2011-03)the Knowledge Innovation project of Chinese Academy of Science (KZCX2-YW-334) for financial supports
文摘The main goal of this study was to assess the long-term impacts of global warming perturbation on water resources of the Kaidu River Basin in Northwest China. Temperature, precipitation and hydrology data during the past 29 years from 1979 to 2007 were collected and analyzed using parametric and non-parametric methods, the connection between temperature and precipitation by the combination of grey correlation analysis method and the hypothesis testing for trend of climate change. The results show a high increase in temperature in the study area as well as an extreme and highly variable hydrological regime in this region, where flash floods can exceed the total runoff from a sequence of years. These variations may be due to the geographical location of the Kaidu River Basin in arid zone. It also reveals that precipitation has a much greater impact on stream flow than that of temperature. The development of new approaches was proposed as responses to climate change in this arid region.
基金supported by National Natural Science Foundation of China(Grant No.40730634)State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Project(Grant No.SKLGP2009z006)
文摘Presently concepts and methods related to water resources conservation of mountain rivers are seriously insufficient,and its level is far from being adaptable to the development of a harmonious society.As mountain ecosystems play a key role in water resources conservation of mountain rivers,and the characteristics of mountain ecosystems and hydrologic features of mountain river follow strong temporal and spatial distribution,partition theory can be applied to the water resources conservation of mountain river.This theory observes the following partition principles:regional relativity,spatial continuity,integralcounty,meeting management needs,hierarchical principle,and comparability principle.And it lays equal emphasis on both water resources conservation and environmental protection,on both water quality conservation and water quantity protection,on the combination of water features,water cycle and water pollution.In the partition methods,index method and map superposition method will be applied in region partition.The example of region partition of water resources conservation in the upper reaches of the Yangtze River shows that the partition theory is practicable in water resources conservation of mountain rivers,and it provides a platform for future study in water resources conservation.
基金supported by the National Natural Science Foundation of China through Grant No.41473023
文摘Major elements and carbon isotopes of dissolved inorganic carbon(DIC)have been measured in the waters of Changbaishan mountain,a volcanic area in northeastern China,between June and September 2016 to decipher the origin of the CO_2 involved in chemical weathering reactions.Spatial variations of major elements ratios measured in water samples can be explained by a change of the chemical composition of the volcanic rocks between the volcanic cone(trachytes)and the basaltic shield as evidenced by the variations in the composition of these rocks.Hence,DIC results from the neutralization of CO_2 by silicate rocks.DIC concentrations vary from 0.3 to 2.5 mmol/L and carbon isotopic compositions of DIC measured in rivers vary from-14.2‰to 3.5‰.At a first order,the DIC transported by rivers is derived from the chemical weathering’s consumption of CO_2 with a magmatic origin,enriched in^(13)C(-5%)and biogenic soil CO_2 with lower isotopic compositions.The highest δ^(13)C values likely result from C isotopes fractionation during CO_2 degassing in rivers.A mass balance based on carbon isotopes suggest that the contribution of magmatic CO_2 varied from less than 20%to more than 70%.Uncertainties in this calculation associated with CO_2 degassing in rivers are difficult to quantify,and the consequence of CO_2 degassing would be an overestimation of the contribution of DIC derived from the neutralization of magmatic CO_2 by silicate rocks.
文摘This paper has examined how the resources of the White Volta River are enhancing food availability for riparian communities in northern Ghana despite climate change and its associated effects on food security. Using participatory methods such as focus group discussions and interviews, data was collected from households and institutions in three riparian communities. The result of the study indicates that, all things been equal, cultivation of food crops along the river bank in the rainy season gives significantly high yields as compared to yields from farms farthest from the river under rain fed agriculture. Higher organic content and moisture retention capacity of river bank soils explains the yield differential and adaptability to climate change. In addition, farmers now irrigate cereal crops which were hitherto, reserved for only rainy season production. However, inappropriate irrigation practices are accelerating erosion and sedimentation of the river and thus, threaten the sustainability of agriculture and food security in the White Volta Basin. The paper therefore, recommends the adoption of IWRM （integrated water resources management） and the participation of local communities, Government and Civil Society organisations for sustaining the productive capacity of the White Volta Basin for enabling adaptation of agriculture to climate change in the riparian communities of the basin.
