Since 2001, the French and Chinese researchers have done a cooperative research on the comparison of integrated development of large fiver basins. The Yangtze River was chosen as a crux of this research and linked wit...Since 2001, the French and Chinese researchers have done a cooperative research on the comparison of integrated development of large fiver basins. The Yangtze River was chosen as a crux of this research and linked with other older river experiments like the Rhone, the Nile and the Mississippi. This research includes not only the environmental issues but also economic and social issues. One special issue journal has been published in French for our research results. Other two collective and comparative books in French and Chinese will be finished at the end of this year. In the future, the comparison should be widened to Italy （the Po）, Egypt （the Nile development planning） and the United States （the Mississippi Basin） and we would like to enlarge our research group and want to link up different teams and research projects, in order to get a global understanding of large fiver regions phenomenon.展开更多
Based on the sedimentary study, the present paper discusses the occurrence of large Ordos depositional basin during Early-Middle Jurassic including the present Ordos basin and Ningwu and Datong districts in Shanxi. Pa...Based on the sedimentary study, the present paper discusses the occurrence of large Ordos depositional basin during Early-Middle Jurassic including the present Ordos basin and Ningwu and Datong districts in Shanxi. Paleogeography of the original large Ordos basin was reconstructed and expounded in terms of the four deposition stages. The study on sediment filling in the basin reveales the episodic tectonic activity of downwarping, uplifting and redownwarping and the migration of depocenters, and interpretes the tectonic setting for basin formation and evolution.展开更多
Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,ir...Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.展开更多
Although permafrost degradation contributes significantly to hydrological change in cold regions, gaps remain in our understanding of streamflow variation induced by degrading permafrost in different river basins. We ...Although permafrost degradation contributes significantly to hydrological change in cold regions, gaps remain in our understanding of streamflow variation induced by degrading permafrost in different river basins. We therefore used a deep learning model to simulate the long-term(≥ 30 years) monthly streamflow at 60 hydrological stations along the Lena River, the third longest circum-Arctic river. Analyzing the effects of precipitation, temperature, and thaw depth on streamflow variation throughout the Lena River Basin, we identified two feedback patterns relating streamflow to warming permafrost, observed in areas of continuous and discontinuous permafrost. In northern plain regions with continuous permafrost, 94% of stations presented an increasing trend in annual streamflow from the 1900s to the 2010s due to permafrost degradation. The enhanced streamflow was mainly due to increased meltwater in the flood season. In southern regions covered by both continuous and discontinuous permafrost, approximately 38% of stations exhibited a declining trend in annual streamflow in response to permafrost degradation, with a high proportion(61%) located in mountain regions(elevation ≥ 500 m). The decline is attributed to the enhanced infiltration capacity of thawing frozen layers within discontinuous permafrost regions. Our study provides new insights into the mechanisms behind permafrost degradation-induced streamflow variation and highlights the importance of formulating tailored strategies for sustainable river management in cold regions experiencing climate change.展开更多
文摘Since 2001, the French and Chinese researchers have done a cooperative research on the comparison of integrated development of large fiver basins. The Yangtze River was chosen as a crux of this research and linked with other older river experiments like the Rhone, the Nile and the Mississippi. This research includes not only the environmental issues but also economic and social issues. One special issue journal has been published in French for our research results. Other two collective and comparative books in French and Chinese will be finished at the end of this year. In the future, the comparison should be widened to Italy （the Po）, Egypt （the Nile development planning） and the United States （the Mississippi Basin） and we would like to enlarge our research group and want to link up different teams and research projects, in order to get a global understanding of large fiver regions phenomenon.
文摘Based on the sedimentary study, the present paper discusses the occurrence of large Ordos depositional basin during Early-Middle Jurassic including the present Ordos basin and Ningwu and Datong districts in Shanxi. Paleogeography of the original large Ordos basin was reconstructed and expounded in terms of the four deposition stages. The study on sediment filling in the basin reveales the episodic tectonic activity of downwarping, uplifting and redownwarping and the migration of depocenters, and interpretes the tectonic setting for basin formation and evolution.
基金support for this research is provided by the International Partnership Project of the Chinese Academy of Sciences, "The Basic Research for Water Issues of Inland River Basin in Arid Region" (CXTD-Z2005-2)Scherer Endowment Fund of Western Michigan University Department of Geography
文摘Water shortage is a chronic problem in arid Northwest China.The rapid population growth and expanding urbanization as well as potential climate change impacts are likely to worsen the situation,threatening domestic,irrigation,and industrial supplies and even the survival of the ecosystems in Northwest China.This paper describes the preliminary work of adapting the Distributed Large Basin Runoff Model(DLBRM) to the Heihe watershed(the second largest inland river in arid Northwestern China,with a drainage area of 128,000 km2) for understanding distribution of glacial-snow melt,groundwater,surface runoff,and evapotranspi-ration,and for assessing hydrological impacts of climate change and glacial recession on water supply in the middle and lower reaches of the watershed.Preliminary simulation results show that the Qilian Mountain in the upper reach area produces most runoff in the Heihe watershed.The simulated daily river flows during the period of 1990-2000 indicate that the Heihe River dis-charges about 1×109 m3 of water from the middle reach(at Zhengyixia Station) to lower reach,with surface runoff and interflow contributing 51 and 49 percent respectively.The sandy lower soil zone in the middle reach has the highest evapotranspiration rate and also contributes nearly half of the river flow.Work underway focuses on the DLBRM model improvement and incorporation of the climate change and management scenarios to the hydrological simulations in the watershed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 52109075, U2243201, and 92047303)Open Fund Research at the State Key Laboratory of Hydraulics and Mountain River Engineering (Grant No. SKHL2220)。
文摘Although permafrost degradation contributes significantly to hydrological change in cold regions, gaps remain in our understanding of streamflow variation induced by degrading permafrost in different river basins. We therefore used a deep learning model to simulate the long-term(≥ 30 years) monthly streamflow at 60 hydrological stations along the Lena River, the third longest circum-Arctic river. Analyzing the effects of precipitation, temperature, and thaw depth on streamflow variation throughout the Lena River Basin, we identified two feedback patterns relating streamflow to warming permafrost, observed in areas of continuous and discontinuous permafrost. In northern plain regions with continuous permafrost, 94% of stations presented an increasing trend in annual streamflow from the 1900s to the 2010s due to permafrost degradation. The enhanced streamflow was mainly due to increased meltwater in the flood season. In southern regions covered by both continuous and discontinuous permafrost, approximately 38% of stations exhibited a declining trend in annual streamflow in response to permafrost degradation, with a high proportion(61%) located in mountain regions(elevation ≥ 500 m). The decline is attributed to the enhanced infiltration capacity of thawing frozen layers within discontinuous permafrost regions. Our study provides new insights into the mechanisms behind permafrost degradation-induced streamflow variation and highlights the importance of formulating tailored strategies for sustainable river management in cold regions experiencing climate change.
