Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance o...Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year (2003), the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.展开更多
Long-term temperature variability has significant effects on runoff into the upper reaches of inland rivers. This paper developed a tree-ring chronology of Qilian juniper (Sabina przewalskii Kom.) from the upper tree-...Long-term temperature variability has significant effects on runoff into the upper reaches of inland rivers. This paper developed a tree-ring chronology of Qilian juniper (Sabina przewalskii Kom.) from the upper tree-line of the middle Qilian Mountains within the upper reaches of Heihe River Basin, Northwest China for a long-term reconstruction of temperature at the study site. In this paper, tree-ring chronology was used to examine climate-growth associations considering local climate data obtained from Qilian Meteorological Station. The results showed that temperatures correlated extremely well with standardized growth indices of trees (r=0.564, P<0.001). Tree-ring chronology was highest correlated with annual mean temperature (r=0.641, P<0.0001). Annual mean temperature which spans the period of 1445–2011 was reconstructed and explained 57.8% of the inter-annual to decadal temperature variance at the regional scale for the period 1961–2011. Spatial correlation patterns revealed that reconstructed temperature data and gridded temperature data had a significant correlation on a regional scale, indicating that the reconstruction represents climatic variations for an extended area surrounding the sampling sites. Analysis of the temperature reconstruction indicated that major cold periods occurred during the periods of 1450s–1480s, 1590s–1770s, 1810s–1890s, 1920s–1940s, and 1960s–1970s. Warm intervals occurred during 1490s–1580s, 1780s–1800s, 1900s–1910s, 1950s, and 1980s to present. The coldest 100-year and decadal periods occurred from 1490s–1580s and 1780s–1800s, respectively, while the warmest 100 years within the studied time period was the 20<sup>th</sup> century. Colder events and intervals coincided with wet or moist conditions in and near the study region. The reconstructed temperature agreed well with other temperature series reconstructed across the surrounding areas, demonstrating that this reconstructed temperature could be used to evaluate regional climate change. Compared to the tree-ring reconstructed temperature from nearby regions and records of glacier fluctuations from the surrounding high mountains, this reconstruction was reliable, and could aid in the evaluation of regional climate variability. Spectral analyses suggested that the reconstructed annual mean temperature variation may be related to large-scale atmospheric–oceanic variability such as the solar activity, Pacific Decadal Oscillation (PDO) and El Ni?o–Southern Oscillation (ENSO).展开更多
Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases...Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases, irrigated agriculture is the primary consumer of water, but water shortages resulting from dramatically growing human needs have become a bottleneck for regional sustainable development, making effective management of the limited available water critical. Effective strategies must be formulated to increase agricultural productivity while reducing its environmental impacts. To support the development of such strategies, water use patterns were analyzed during the 2007 and 2008 growing seasons, from May to early October, to identify opportunities for improving water management using the Mold- en-Sakthivadivel water-accounting method, which combines groundwater and surface water into a single domain and can provide a good estimate of the uses, depletion, and productivity of water in a water basin context. The study area lies in Linze County, Gansu Province, China. In the study area, the inflow water resources consist of irrigation, precipita- tion, and soil water, which accounted for 89.3%, 8.9%, and 1.8% of the total in 2007, and 89.3%, 4.8%, and 5.9% in 2008, respectively. The irrigation depends heavily on groundwater, which accounted for 82.1% and 83.6% of the total irrigation water in 2007 and 2008, respectively. In 2007 and 2008, deep percolation accounted for 50.1% and 47.9% of the water outflow, respectively, with corresponding depleted fractions of 0.51 and 0.55, respectively. For the irrigation district as a whole, the water productivity was only 1.37 CNY/m^3. To significantly increase crop water productivity and prevent depletion of the region's groundwater aquifer, it will be necessary to reduce the amount of water used for ir- rigation. Several water-saving agricultural practices are discussed and recommended.展开更多
Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert...Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response char-acteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed: (1) From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller. (2) In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar. (3) Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and re-search regarding sand-dust weather mechanisms.展开更多
Eight Mesozoic sub-volcanic and intrusive rocks in the Lishui Basin have been selected for zircon U-Pb dating and Lu-Hf isotopic analysis. The Laohutou, Datongshan,Daweizhuang, Yeshanao, Yanwaqiao, Xibeishan, Changsha...Eight Mesozoic sub-volcanic and intrusive rocks in the Lishui Basin have been selected for zircon U-Pb dating and Lu-Hf isotopic analysis. The Laohutou, Datongshan,Daweizhuang, Yeshanao, Yanwaqiao, Xibeishan, Changshantou and Jianshan porphyrites yield concordant early Cretaceous ages of 130.5 ± 1.6 Ma, 136.0 ± 3.4 Ma, 132.7 ±2.7 Ma, 127.0 ± 1.9 Ma, 129.4 ± 1.7 Ma, 133.2 ± 2.1 Ma,131.1 ± 2.3 Ma and 127.4 ± 1.8 Ma, respectively. Zircon eHf(t) values for these rocks range from-3.54 to-9.11, mostly between-3.54 and-5.93, suggesting sources similar to those for coeval igneous rocks in other volcanic basins along the middle and lower reaches of Yangtze River. Considering the geochemical characteristics of coeval magmatic rocks in the middle and lower reaches of Yangtze River and its adjacent areas, this paper proposes a model of slab rollback to explain the Mesozoic magmatism in the east-central part of China continent. In the middle-late Jurassic to early Cretaceous(170–135 Ma), the Pacific plate started to subduct beneath the Eurasian continent, producing a compressive tectonic setting,and magmatism progressed from coast to the inland. The magmas of this period were derived mostly from partial melting of ancient crust. After *135 Ma, the subduction weakened, and the rollback of the subducted Pacific plate produced an extensional environment. This led to the formation of volcanic basins, the partial melting of enriched mantle sources and less ancient crust, and the intrusion of voluminous intermediate-mafic igneous rocks.展开更多
On the basis of the present research progress of ecological agriculture,we take Minle County and Linze County located in the middle reaches of Heihe River as the typical research units.Based on the rural social and ec...On the basis of the present research progress of ecological agriculture,we take Minle County and Linze County located in the middle reaches of Heihe River as the typical research units.Based on the rural social and economic data during the period of 2000-2010,theory and method of mathematical statistics are used to establish the measure theory and model of agro-eco-economic system harmony coefficient,including efficacy function,function of harmony coefficient,harmony coefficient and level of harmony coefficient.Based on the actual situation of research region,evaluation indicator system of agro-eco-economic system is established and measurement is carried out.Results show that the regional agro-eco-economic system in research region was in a serious imbalance in 2000-2013.The harmony coefficient of Minle showed a slight rise from 2000 to 2004,and then presented a fluctuating decline.Its rank of harmony coefficient experienced serious imbalance-extreme imbalance-moderate imbalance-low imbalance-serious imbalance-high imbalance.At the same time,the similar tendency happened in Linze County.The measuring results of subsystem in 2000-2013 further indicated that except that the harmony coefficient of economic subsystem in Minle County and Linze County was moderate and high,the ecological subsystem was at Level II and Level III,and social subsystem was at Level IV and Level III,in high and low imbalance status.Finally,several recommendations were put forward for optimizing agro-eco-economic system.展开更多
基金This work was supported by the Knowledge Innovation Program from the Cold and Add Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences (CACX2003102)the Chinese Academy of Sciences (KZCX 1 - 10-03-01)the National Natural Science Foundation of China (40401012).
文摘Based on the data for meteorology, hydrology, soil, planting, vegetation, and socio-economic development of the irrigation region in the middle reaches of the Heihe River basin, Northwest China, the model of balance of water supply and demand in the region was established, and the security of water resource was assessed, from which the results that the effects of unified management of water resources in the Heihe River basin between Gansu Province and Inner Mongolia on regional hydrology are significant with a decrease in water supply diverted from Heihe River and an increase in groundwater extracted. In addition, it was found that the groundwater level has been steadily decreasing due to over pumping and decrease in recharges. In present year (2003), the volume of potential groundwater in the irrigation districts is far small because of the groundwater overdraft; even in the particular regions, there is no availability of groundwater resources for use. By 2003, water supply is not sufficient to meet the water demand in the different irrigation districts, the sustainable development and utilization of water resources are not secured, and the water supply crisis occurs in Pingchuan irrigation district. Achieving water security for the sustainable development of society, agriculture, economy, industry, and livelihoods while maintaining or improving the abilities of the management and planning of water resources, determining of the reasonable percentage between water supply and groundwater utilization and water saving in agricultural irrigation are taken into account. If this does not occur, it is feared that the present performance of water development and planning may further aggravate the problem of scarcities of water resources and further damage the fragile ecological system.
基金supported by the National Natural Science Foundation of China(91025002,30970492)the National Key Technology Research&Development Program(2012BAC08B05)the Key Project of the Chinese Academy of Sciences(KZZD-EW-04-05)
文摘Long-term temperature variability has significant effects on runoff into the upper reaches of inland rivers. This paper developed a tree-ring chronology of Qilian juniper (Sabina przewalskii Kom.) from the upper tree-line of the middle Qilian Mountains within the upper reaches of Heihe River Basin, Northwest China for a long-term reconstruction of temperature at the study site. In this paper, tree-ring chronology was used to examine climate-growth associations considering local climate data obtained from Qilian Meteorological Station. The results showed that temperatures correlated extremely well with standardized growth indices of trees (r=0.564, P<0.001). Tree-ring chronology was highest correlated with annual mean temperature (r=0.641, P<0.0001). Annual mean temperature which spans the period of 1445–2011 was reconstructed and explained 57.8% of the inter-annual to decadal temperature variance at the regional scale for the period 1961–2011. Spatial correlation patterns revealed that reconstructed temperature data and gridded temperature data had a significant correlation on a regional scale, indicating that the reconstruction represents climatic variations for an extended area surrounding the sampling sites. Analysis of the temperature reconstruction indicated that major cold periods occurred during the periods of 1450s–1480s, 1590s–1770s, 1810s–1890s, 1920s–1940s, and 1960s–1970s. Warm intervals occurred during 1490s–1580s, 1780s–1800s, 1900s–1910s, 1950s, and 1980s to present. The coldest 100-year and decadal periods occurred from 1490s–1580s and 1780s–1800s, respectively, while the warmest 100 years within the studied time period was the 20<sup>th</sup> century. Colder events and intervals coincided with wet or moist conditions in and near the study region. The reconstructed temperature agreed well with other temperature series reconstructed across the surrounding areas, demonstrating that this reconstructed temperature could be used to evaluate regional climate change. Compared to the tree-ring reconstructed temperature from nearby regions and records of glacier fluctuations from the surrounding high mountains, this reconstruction was reliable, and could aid in the evaluation of regional climate variability. Spectral analyses suggested that the reconstructed annual mean temperature variation may be related to large-scale atmospheric–oceanic variability such as the solar activity, Pacific Decadal Oscillation (PDO) and El Ni?o–Southern Oscillation (ENSO).
基金funded by the National Natural Science Foundation of China (Project 40771079 and 41471024)
文摘Oases in arid northwestern China play a significant role in the region's economic stability and development. Overex- ploitation of the region's water resources has led to serious environmental consequences. In oases, irrigated agriculture is the primary consumer of water, but water shortages resulting from dramatically growing human needs have become a bottleneck for regional sustainable development, making effective management of the limited available water critical. Effective strategies must be formulated to increase agricultural productivity while reducing its environmental impacts. To support the development of such strategies, water use patterns were analyzed during the 2007 and 2008 growing seasons, from May to early October, to identify opportunities for improving water management using the Mold- en-Sakthivadivel water-accounting method, which combines groundwater and surface water into a single domain and can provide a good estimate of the uses, depletion, and productivity of water in a water basin context. The study area lies in Linze County, Gansu Province, China. In the study area, the inflow water resources consist of irrigation, precipita- tion, and soil water, which accounted for 89.3%, 8.9%, and 1.8% of the total in 2007, and 89.3%, 4.8%, and 5.9% in 2008, respectively. The irrigation depends heavily on groundwater, which accounted for 82.1% and 83.6% of the total irrigation water in 2007 and 2008, respectively. In 2007 and 2008, deep percolation accounted for 50.1% and 47.9% of the water outflow, respectively, with corresponding depleted fractions of 0.51 and 0.55, respectively. For the irrigation district as a whole, the water productivity was only 1.37 CNY/m^3. To significantly increase crop water productivity and prevent depletion of the region's groundwater aquifer, it will be necessary to reduce the amount of water used for ir- rigation. Several water-saving agricultural practices are discussed and recommended.
基金supported by the Science and Technology Innovation Service Platform of Qilian mountains in Gansu Province (No. 144JTCG254)the Innovation Groups of Basic Research of Gansu Province (No. 145RJIG337)the National Natural Science Foundation of China (No. 41461004)
文摘Sand-dust weather has become an international social-environmental issue of common concern, and constitutes a serious threat to human lives and economic development. In order to explore the responses of natural desert sand and dust to the dynamics of water in desertification, we extracted long-term monitoring data related to precipitation, soil water, groundwater, and sand-dust weather. These data originated from the test stations for desertification control in desert areas of the middle reaches of the Heihe River. We used an algorithm of characteristic parameters, correlations, and multiple regression analysis to establish a regression model for the duration of sand-dust weather. The response char-acteristics of the natural desert sand and dust and changes of the water inter-annual and annual variance were also examined. Our results showed: (1) From 2006 to 2014 the frequency, duration, and volatility trends of sand-dust weather obviously increased, but the change amplitudes of precipitation, soil water, and groundwater level grew smaller. (2) In the vegetative growth seasons from March to November, the annual variance rates of the soil moisture content in each of four studied layers of soil samples were similar, and the changes in the frequency and duration of sand-dust weather were similar. (3) Our new regression equation for the duration of sand-dust weather passed the R test, F test, and t test. By this regression model we could predict the duration of sand-dust weather with an accuracy of 42.9%. This study can thus provide technological support and reference data for water resource management and re-search regarding sand-dust weather mechanisms.
基金supported by National Natural Science Foundation of China (41102123, 41330208)a Grant (1212011120864) from China Geological Survey
文摘Eight Mesozoic sub-volcanic and intrusive rocks in the Lishui Basin have been selected for zircon U-Pb dating and Lu-Hf isotopic analysis. The Laohutou, Datongshan,Daweizhuang, Yeshanao, Yanwaqiao, Xibeishan, Changshantou and Jianshan porphyrites yield concordant early Cretaceous ages of 130.5 ± 1.6 Ma, 136.0 ± 3.4 Ma, 132.7 ±2.7 Ma, 127.0 ± 1.9 Ma, 129.4 ± 1.7 Ma, 133.2 ± 2.1 Ma,131.1 ± 2.3 Ma and 127.4 ± 1.8 Ma, respectively. Zircon eHf(t) values for these rocks range from-3.54 to-9.11, mostly between-3.54 and-5.93, suggesting sources similar to those for coeval igneous rocks in other volcanic basins along the middle and lower reaches of Yangtze River. Considering the geochemical characteristics of coeval magmatic rocks in the middle and lower reaches of Yangtze River and its adjacent areas, this paper proposes a model of slab rollback to explain the Mesozoic magmatism in the east-central part of China continent. In the middle-late Jurassic to early Cretaceous(170–135 Ma), the Pacific plate started to subduct beneath the Eurasian continent, producing a compressive tectonic setting,and magmatism progressed from coast to the inland. The magmas of this period were derived mostly from partial melting of ancient crust. After *135 Ma, the subduction weakened, and the rollback of the subducted Pacific plate produced an extensional environment. This led to the formation of volcanic basins, the partial melting of enriched mantle sources and less ancient crust, and the intrusion of voluminous intermediate-mafic igneous rocks.
基金Supported by General Project of National Social Science Foundation(15BMZ058)
文摘On the basis of the present research progress of ecological agriculture,we take Minle County and Linze County located in the middle reaches of Heihe River as the typical research units.Based on the rural social and economic data during the period of 2000-2010,theory and method of mathematical statistics are used to establish the measure theory and model of agro-eco-economic system harmony coefficient,including efficacy function,function of harmony coefficient,harmony coefficient and level of harmony coefficient.Based on the actual situation of research region,evaluation indicator system of agro-eco-economic system is established and measurement is carried out.Results show that the regional agro-eco-economic system in research region was in a serious imbalance in 2000-2013.The harmony coefficient of Minle showed a slight rise from 2000 to 2004,and then presented a fluctuating decline.Its rank of harmony coefficient experienced serious imbalance-extreme imbalance-moderate imbalance-low imbalance-serious imbalance-high imbalance.At the same time,the similar tendency happened in Linze County.The measuring results of subsystem in 2000-2013 further indicated that except that the harmony coefficient of economic subsystem in Minle County and Linze County was moderate and high,the ecological subsystem was at Level II and Level III,and social subsystem was at Level IV and Level III,in high and low imbalance status.Finally,several recommendations were put forward for optimizing agro-eco-economic system.