The distribution of stable isotopes and ions in precipitation in the Shule River Basin, northwestern China, were investigated to understand the regional water cycle and precipitation input to groundwater recharge. The...The distribution of stable isotopes and ions in precipitation in the Shule River Basin, northwestern China, were investigated to understand the regional water cycle and precipitation input to groundwater recharge. The study found that the mean annual concentrations of Ca2＋, Na＋, SO42-, CI-, Mg2＋, NO3-, and K＋ in the basin were lower than those in other arid areas of northwestern China. The average concentrations of ions in the lower reaches of the Shule River were higher than those in the upper reaches. The results showed that the main ionic concentrations decreased with the increase of precipitation amount, indicating that heavy precipitation cannot only wash crustal aerosols out of the atmosphere, but also create a dilution effect. CI- and Na＋ in precipitation had a strong and positive correlation, suggesting a common origin for the two ions. However, the excess of Na＋, combined with non-marine SO42- and NO3-, indicated that some ions were contributed by terrestrial origins. In the extremely arid regions of northwestern China, the evaporation process obviously changes the original relationship between δ2H and δ18O in precipitation, and leads to dexcess values 〈8‰. δ18O and temperature were significantly correlated, suggested that temperature strongly affected the characteristics of isotopes in the study area. The δ18O value indicates a dominant effect of westerly air masses and southwest monsoon in warm months, and the integrated influence of westerly and Siberian-Mongolian polar air masses in cold months. The d-excess values were generally lower in warm months than those in cold months, indicating that post-condensation processes played a significant role in the water cycle. The results provide reliable precipitation input information that can be used in future groundwater recharge calculations in the study area.展开更多
Based on Investigation and Assessment on Rational Exploitation and Utilization of Groundwater Resources in Typical Areas of the Hexi Corridor, the thesis studies on groundwater and environmental problems arising from ...Based on Investigation and Assessment on Rational Exploitation and Utilization of Groundwater Resources in Typical Areas of the Hexi Corridor, the thesis studies on groundwater and environmental problems arising from the large-scale agricultural development projects in Shule River Basin. The thesis analyzes problems in exploiting and utilizing water resources, defines the function zoning of groundwater resources in key areas and evaluates them. Finally, the thesis uses three-dimensional unsteady flow simulation and regional social and economic development plan to study on the allocation of groundwater in Shule River Basin. A proposal for rational allocation of Shule River Basin water resources has been put forward.展开更多
Global ecosystems and public health have been greatly impacted by the accumulation of heavy metal(loid)s in water.Source-specific risk apportionment is needed to prevent and manage potential groundwater contamination ...Global ecosystems and public health have been greatly impacted by the accumulation of heavy metal(loid)s in water.Source-specific risk apportionment is needed to prevent and manage potential groundwater contamination with heavy metal(loid)s.The heavy metal(loid)s contamination status,water quality,ecological risk,and health risk apportionment of the Shule River Basin groundwater are poorly understood.Therefore,field sampling was performed to explore the water quality and risk of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China.A total of 96 samples were collected from the study area to acquire data for water quality and heavy metal(loid)s risk.There was noticeable accumulation of ferrum in the groundwater of the Shule River Basin.The levels of pollution were considered to be moderately low,as evaluated by the degree of contamination,heavy metal evaluation index,heavy metal pollution index,and Nemerow pollution index.The ecological risks were also low.However,an assessment of the water quality index revealed that only 58.34%of the groundwater samples had good water quality.The absolute principal component scores-multiple linear regression model was more suited for this study area than the positive matrix factorization model.There were no obvious noncarcinogenic or carcinogenic concerns for all types of receptors according to the values of the total hazard index and total carcinogenic risk.The human activities and the initial geological environment factor(65.85%)was the major source of noncarcinogenic risk(residential children:87.56%;residential adults:87.52%;recreational children:86.77%;and recreational adults:85.42%),while the industrial activity factor(16.36%)was the major source of carcinogenic risk(residential receptors:87.96%;and recreational receptors:68.73%).These findings provide fundamental and crucial information for reducing the health issues caused by heavy metal(loid)s contamination of groundwater in arid areas.展开更多
通过改进的光能利用率CASA模型估算2001—2010年间疏勒河流域陆地生态系统的净第一性生产力(NPP),采用线性趋势分析、变异系数和Hurst指数等方法,分析了NPP的时空变化特征及其与气候因子的相关性。结果表明:1疏勒河流域NPP的空间分布具...通过改进的光能利用率CASA模型估算2001—2010年间疏勒河流域陆地生态系统的净第一性生产力(NPP),采用线性趋势分析、变异系数和Hurst指数等方法,分析了NPP的时空变化特征及其与气候因子的相关性。结果表明:1疏勒河流域NPP的空间分布具有明显差异,空间上呈现西北低、东南高的趋势,且具有较明显的经向"条带"分布特征,2001—2010年,NPP平均值为102.26 g C m^(-2)a^(-1)。22001—2010年,疏勒河流域NPP总体呈增长趋势,年际波动较大,NPP明显增加的区域占总面积25.15%,明显减小的区域约占11.93%。3Hurst指数分析显示,疏勒河流域NPP变化的同向特征强于反向特征,其中持续改善地区占总面积的78.3%,21.7%的区域将由改善转为退化。4在年尺度上,降水是植被NPP变化的主要影响因素,NPP与降水呈弱的正相关关系,与温度相关性不显著;在月尺度上,温度是NPP变化的主要控制因子。疏勒河流域NPP对气候因子不存在明显的时滞和累积效应。展开更多
基金supported by the National Natural Science Foundation of China(41271039)the Open Foundation of Key Laboratory of Western China’s Environmental System(Ministry of Education)Lanzhou University and the Fundamental Research Funds for the Central Universities(lzujbky-2015-bt01)
文摘The distribution of stable isotopes and ions in precipitation in the Shule River Basin, northwestern China, were investigated to understand the regional water cycle and precipitation input to groundwater recharge. The study found that the mean annual concentrations of Ca2＋, Na＋, SO42-, CI-, Mg2＋, NO3-, and K＋ in the basin were lower than those in other arid areas of northwestern China. The average concentrations of ions in the lower reaches of the Shule River were higher than those in the upper reaches. The results showed that the main ionic concentrations decreased with the increase of precipitation amount, indicating that heavy precipitation cannot only wash crustal aerosols out of the atmosphere, but also create a dilution effect. CI- and Na＋ in precipitation had a strong and positive correlation, suggesting a common origin for the two ions. However, the excess of Na＋, combined with non-marine SO42- and NO3-, indicated that some ions were contributed by terrestrial origins. In the extremely arid regions of northwestern China, the evaporation process obviously changes the original relationship between δ2H and δ18O in precipitation, and leads to dexcess values 〈8‰. δ18O and temperature were significantly correlated, suggested that temperature strongly affected the characteristics of isotopes in the study area. The δ18O value indicates a dominant effect of westerly air masses and southwest monsoon in warm months, and the integrated influence of westerly and Siberian-Mongolian polar air masses in cold months. The d-excess values were generally lower in warm months than those in cold months, indicating that post-condensation processes played a significant role in the water cycle. The results provide reliable precipitation input information that can be used in future groundwater recharge calculations in the study area.
基金the project Survey and Assessment of Water Resources Exploitation and Utilization in Characteristic Areas of the Hexi Corridor
文摘Based on Investigation and Assessment on Rational Exploitation and Utilization of Groundwater Resources in Typical Areas of the Hexi Corridor, the thesis studies on groundwater and environmental problems arising from the large-scale agricultural development projects in Shule River Basin. The thesis analyzes problems in exploiting and utilizing water resources, defines the function zoning of groundwater resources in key areas and evaluates them. Finally, the thesis uses three-dimensional unsteady flow simulation and regional social and economic development plan to study on the allocation of groundwater in Shule River Basin. A proposal for rational allocation of Shule River Basin water resources has been put forward.
基金This work was supported by the Kunlun Talent Action Plan of Qinghai Province(E140 WX42)National Natural Science Foundation of China(52179026)Strategy for Water Resource Security in Yellow River Sources。
文摘Global ecosystems and public health have been greatly impacted by the accumulation of heavy metal(loid)s in water.Source-specific risk apportionment is needed to prevent and manage potential groundwater contamination with heavy metal(loid)s.The heavy metal(loid)s contamination status,water quality,ecological risk,and health risk apportionment of the Shule River Basin groundwater are poorly understood.Therefore,field sampling was performed to explore the water quality and risk of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China.A total of 96 samples were collected from the study area to acquire data for water quality and heavy metal(loid)s risk.There was noticeable accumulation of ferrum in the groundwater of the Shule River Basin.The levels of pollution were considered to be moderately low,as evaluated by the degree of contamination,heavy metal evaluation index,heavy metal pollution index,and Nemerow pollution index.The ecological risks were also low.However,an assessment of the water quality index revealed that only 58.34%of the groundwater samples had good water quality.The absolute principal component scores-multiple linear regression model was more suited for this study area than the positive matrix factorization model.There were no obvious noncarcinogenic or carcinogenic concerns for all types of receptors according to the values of the total hazard index and total carcinogenic risk.The human activities and the initial geological environment factor(65.85%)was the major source of noncarcinogenic risk(residential children:87.56%;residential adults:87.52%;recreational children:86.77%;and recreational adults:85.42%),while the industrial activity factor(16.36%)was the major source of carcinogenic risk(residential receptors:87.96%;and recreational receptors:68.73%).These findings provide fundamental and crucial information for reducing the health issues caused by heavy metal(loid)s contamination of groundwater in arid areas.
文摘通过改进的光能利用率CASA模型估算2001—2010年间疏勒河流域陆地生态系统的净第一性生产力(NPP),采用线性趋势分析、变异系数和Hurst指数等方法,分析了NPP的时空变化特征及其与气候因子的相关性。结果表明:1疏勒河流域NPP的空间分布具有明显差异,空间上呈现西北低、东南高的趋势,且具有较明显的经向"条带"分布特征,2001—2010年,NPP平均值为102.26 g C m^(-2)a^(-1)。22001—2010年,疏勒河流域NPP总体呈增长趋势,年际波动较大,NPP明显增加的区域占总面积25.15%,明显减小的区域约占11.93%。3Hurst指数分析显示,疏勒河流域NPP变化的同向特征强于反向特征,其中持续改善地区占总面积的78.3%,21.7%的区域将由改善转为退化。4在年尺度上,降水是植被NPP变化的主要影响因素,NPP与降水呈弱的正相关关系,与温度相关性不显著;在月尺度上,温度是NPP变化的主要控制因子。疏勒河流域NPP对气候因子不存在明显的时滞和累积效应。
