Since the 1990s, the Yellow River stream has been temporarily interrupted for several years, which affects the development of society, the economy and human life, limits the economic potential of the drainage areas, a...Since the 1990s, the Yellow River stream has been temporarily interrupted for several years, which affects the development of society, the economy and human life, limits the economic potential of the drainage areas, and especially causes great harm to regions on the lower reaches. Based on the analysis of the relationship between the development of society and economy and water scarcity, the author thinks it is necessary to optimize and adjust the industrial structure that has extravagantly consumed enormous amounts of water, and to develop ecological agriculture, industry and tourism which are balanced with the ecological environment. Finally, the author puts forward several pieces of advice and countermeasures about how to build the economic systems by which water can be used economically.展开更多
We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area. Nitrogen inputs in the bu...We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area. Nitrogen inputs in the budget included N from synthetic fertilizer, biological fixation by leguminous and other crops, wet/dry atmospheric deposition, excreta from humans and animals, and crop residues. The total N input was estimated to be 17.6 Tg, of which 20% or 3.5 Tg N was transported into waterbodies. Of the total N transported into waterbodies, the largest proportion was N from animal waste (26%), followed by N from atmospheric wet/dry deposition (25%), synthetic fertilizer N (17%), N in sewage wastes (17%), N in human waste from rural areas (6%) and industrial wastewater N (9%). We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins, from upstream to downstream: the Tongtian River drainage area (TTD, the headwater drainage area, 138 000 l^n2, less disturbed by human activities); the Jinsha River drainage area (JSD, 347 000 km2, less disturbed by human activities, approx. 3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD, 520 500 krn2, large-scale human disturbance, about 2 000 km upstream of the Changjiang estuary); and the Yichang-Datong drainage area (YDD, 699 900 km^2, large-scale httman disturbance, approx. 620 km upstream of the Changjiang estuary). The average N input into waterbodies was 2.3, 7.3, 24.1, and 28.2 kg N/ha in the TTD, JSD, PYD, and YDD sub-basins, respectively, suggesting an increase of N-components of more than 10 times from upstream to downstream areas.展开更多
In this study,SRTM DEM data and ASTER GDEM data were used as the basic topographic data,and Arc Hydro Tools was utilized for extension module so as to study on extracting digital drainage network of watershed based on...In this study,SRTM DEM data and ASTER GDEM data were used as the basic topographic data,and Arc Hydro Tools was utilized for extension module so as to study on extracting digital drainage network of watershed based on surface runoff model,as well as to compare the two extracted results.The result showed that through the introduction of drainage density parameter to determine the river drainage area threshold,the both extracted drainages showed the goodness-of-fit with the factual drainage network on 1∶250 000 scale topographic map,and the extracted digital river could be used in practical operation of the risk assessment model of mountain torrents disaster in Liaohe basin.展开更多
Conversion relationships between the river and groundwater in the Yellow River drainage area are studied in this paper based on the geologic and physiognomy conditions and the data of the groundwater regime, isotope, ...Conversion relationships between the river and groundwater in the Yellow River drainage area are studied in this paper based on the geologic and physiognomy conditions and the data of the groundwater regime, isotope, groundwater flow field and field survey. Then eight recharge and discharge modes on the relationships are put forward and the hydraulic characteristics of the modes are analysed, which provides a scientific basis for quantitatively simulating and assessing the conversion relationships, maintenance mechanism of the Yellow River and the regeneration ability of the groundwater in the area.展开更多
文摘Since the 1990s, the Yellow River stream has been temporarily interrupted for several years, which affects the development of society, the economy and human life, limits the economic potential of the drainage areas, and especially causes great harm to regions on the lower reaches. Based on the analysis of the relationship between the development of society and economy and water scarcity, the author thinks it is necessary to optimize and adjust the industrial structure that has extravagantly consumed enormous amounts of water, and to develop ecological agriculture, industry and tourism which are balanced with the ecological environment. Finally, the author puts forward several pieces of advice and countermeasures about how to build the economic systems by which water can be used economically.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-Q07-02)the National Basic Research Program of China (973Program)(No.2010CB428706)+1 种基金the Fund for Creative Research Groups of NSFC(No.41121064)the National Natural Science Foundation of China (No.41106090)
文摘We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area. Nitrogen inputs in the budget included N from synthetic fertilizer, biological fixation by leguminous and other crops, wet/dry atmospheric deposition, excreta from humans and animals, and crop residues. The total N input was estimated to be 17.6 Tg, of which 20% or 3.5 Tg N was transported into waterbodies. Of the total N transported into waterbodies, the largest proportion was N from animal waste (26%), followed by N from atmospheric wet/dry deposition (25%), synthetic fertilizer N (17%), N in sewage wastes (17%), N in human waste from rural areas (6%) and industrial wastewater N (9%). We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins, from upstream to downstream: the Tongtian River drainage area (TTD, the headwater drainage area, 138 000 l^n2, less disturbed by human activities); the Jinsha River drainage area (JSD, 347 000 km2, less disturbed by human activities, approx. 3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD, 520 500 krn2, large-scale human disturbance, about 2 000 km upstream of the Changjiang estuary); and the Yichang-Datong drainage area (YDD, 699 900 km^2, large-scale httman disturbance, approx. 620 km upstream of the Changjiang estuary). The average N input into waterbodies was 2.3, 7.3, 24.1, and 28.2 kg N/ha in the TTD, JSD, PYD, and YDD sub-basins, respectively, suggesting an increase of N-components of more than 10 times from upstream to downstream areas.
基金Supported by National Science and Technology Support Project(2008BAK49B07)~~
文摘In this study,SRTM DEM data and ASTER GDEM data were used as the basic topographic data,and Arc Hydro Tools was utilized for extension module so as to study on extracting digital drainage network of watershed based on surface runoff model,as well as to compare the two extracted results.The result showed that through the introduction of drainage density parameter to determine the river drainage area threshold,the both extracted drainages showed the goodness-of-fit with the factual drainage network on 1∶250 000 scale topographic map,and the extracted digital river could be used in practical operation of the risk assessment model of mountain torrents disaster in Liaohe basin.
文摘Conversion relationships between the river and groundwater in the Yellow River drainage area are studied in this paper based on the geologic and physiognomy conditions and the data of the groundwater regime, isotope, groundwater flow field and field survey. Then eight recharge and discharge modes on the relationships are put forward and the hydraulic characteristics of the modes are analysed, which provides a scientific basis for quantitatively simulating and assessing the conversion relationships, maintenance mechanism of the Yellow River and the regeneration ability of the groundwater in the area.