The establishment of reliable age in the lake sediment profile mainly depends on the AMS 14C dating technique.However,the presence of the 14C lake reservoir effects(LREs)restricted for using radiocarbon dating in lake...The establishment of reliable age in the lake sediment profile mainly depends on the AMS 14C dating technique.However,the presence of the 14C lake reservoir effects(LREs)restricted for using radiocarbon dating in lake sediment,especially in dry and cold areas with a scarce plant cover in the Qinghai-Tibet Plateau.Hence,the discussion of influence factors of LREs is crucial.This paper selected 15 lakes(17 sediment and 3 plant samples)in the Qinghai-Tibet Plateau to examine the distribution characteristics of the modern LREs and their main influencing factors.In our study area,14 lakes were all affected by the LREs.The minimum 14C year is 5900 a BP towards the deep water area,whereas the maximum 14C year is up to 7185 a BP in the margins of Lake Heihai.The maximum 14C year is up to 7750 a BP,and the minimum 14C year is present-day carbon in the 15 lakes.One further study indicated that the LRE differences in individual lake are mostly owing to the contribution of exogenous carbonate.The results displayed that the LREs tended to increase with the increase of the salinity,moreover,the LREs of saltwater lakes or salt lakes were significantly larger than freshwater lakes due to the possible supply of old total dissolved inorganic carbon with a long residence time in the lakes.Moreover,the contribution of calcite played a significant role on the LREs.Additionally,the LREs differences are affected by the source of organic matter.The lake with groundwater supply shows large LRE due to likely being influenced by crustal and ancient CO_(2) uprising.展开更多
The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial ...The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial reservoir with seasonally anoxic hypolimnion. Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments. In the anoxic season, Fe2+ and Mn2+, formed by biological oxidation, would diffuse up to overlying waters from sedlments. However, the concentration of Fe2+ increased later and decreased earlier than that of Mn2+. Generally, sulfate reduction occurred at 6 cm below the sediment-water interface. Whereas, in the anoxic season, the reduction reached upper sediments, inhibiting the release of Fe2+. The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction Of the sulphur system.展开更多
Eco-compensation is an environmental economic instrument for internalization of external cost. Returning farmland to lake is one of the important parts of restoring wetland ecosystem function in the Yangtze River Vall...Eco-compensation is an environmental economic instrument for internalization of external cost. Returning farmland to lake is one of the important parts of restoring wetland ecosystem function in the Yangtze River Valley of China. Whether the project of lake recovery can be successful depends on the compensation to the farmers who have lost their original benefits and contributed to the wetland ecosystem recovery by returning farmland to lake. Aiming at the wetland recovery of the Dongting Lake, the practical implementation of pro- grams of the lake recovery and flood control in this area has been challenged by the heavy task of population resettlement, so it is an ideal area for case studies to reach the academic objectives proposed as the above. Based on field survey and experimentation, this research evaluated the benefit losses of the resettled farmers and the increased values of ecosystem service functions caused by wetland recovery, and furthermore, the value of eco-compensation for relocated farmers was calculated by considering the combination of the farmers＇ compensation appeal. The value of eco-compensation for relocated farmers in the Dongting Lake area was 6084.5 yuan per household by synthetic analysis of the effects on wetland ecosystem restoration. Moreover, this article took Dongting Lake area as a case to study and explore the basic issues of the eco-compensation by returning farmland to lake, that was who should pay, who should be paid, how much the payment was and what the payment means was, which sought the mechanisms of wetland restoration eco-compensation and prompted the people＇s enthusiasms for ecological restoration.展开更多
A model involving the relationship between non conservative matter (COD) and main range factors(loading, water stage) and strength factor (temperature) in a shallow lake has been established on the basis of less chan...A model involving the relationship between non conservative matter (COD) and main range factors(loading, water stage) and strength factor (temperature) in a shallow lake has been established on the basis of less change of water stage area curve in certain extent, broader distribution in pollution sources and more homogeneous in quantity of heat. The effects of COD inflow and /or outflow, and hydro meterological factors upon COD content in Lake Taihu were calculated and simulated under the actual situation of the loadings and regimen. The results simulated by using the model are in better agreement with the observed field data. The error of the model was also discussed.展开更多
基金The work was supported by a grant from Research Fund for the Doctoral Program of Higher Education of East China University of Technology(DHBK2019012)Key Laboratory for Digital Land and Resources of Jiangxi Province,East China University of Technology(DLLJ202018)Key Research and Development Program of Jiangxi Province(20181BBG70037).
文摘The establishment of reliable age in the lake sediment profile mainly depends on the AMS 14C dating technique.However,the presence of the 14C lake reservoir effects(LREs)restricted for using radiocarbon dating in lake sediment,especially in dry and cold areas with a scarce plant cover in the Qinghai-Tibet Plateau.Hence,the discussion of influence factors of LREs is crucial.This paper selected 15 lakes(17 sediment and 3 plant samples)in the Qinghai-Tibet Plateau to examine the distribution characteristics of the modern LREs and their main influencing factors.In our study area,14 lakes were all affected by the LREs.The minimum 14C year is 5900 a BP towards the deep water area,whereas the maximum 14C year is up to 7185 a BP in the margins of Lake Heihai.The maximum 14C year is up to 7750 a BP,and the minimum 14C year is present-day carbon in the 15 lakes.One further study indicated that the LRE differences in individual lake are mostly owing to the contribution of exogenous carbonate.The results displayed that the LREs tended to increase with the increase of the salinity,moreover,the LREs of saltwater lakes or salt lakes were significantly larger than freshwater lakes due to the possible supply of old total dissolved inorganic carbon with a long residence time in the lakes.Moreover,the contribution of calcite played a significant role on the LREs.Additionally,the LREs differences are affected by the source of organic matter.The lake with groundwater supply shows large LRE due to likely being influenced by crustal and ancient CO_(2) uprising.
文摘The redox cycle of iron and manganese is a major geochemical process at the boundary layers of lake sediments. Lake Aha, which lies in the suburbs of Guiyang City,Guizhou Province, China, is a medium-sized artificial reservoir with seasonally anoxic hypolimnion. Long-term sedimentary accumulation of iron and manganese resulted in their enrichment in the upper sediments. In the anoxic season, Fe2+ and Mn2+, formed by biological oxidation, would diffuse up to overlying waters from sedlments. However, the concentration of Fe2+ increased later and decreased earlier than that of Mn2+. Generally, sulfate reduction occurred at 6 cm below the sediment-water interface. Whereas, in the anoxic season, the reduction reached upper sediments, inhibiting the release of Fe2+. The Fe concentration of anoxic water is quickly decreased from high to low as a result of reduction Of the sulphur system.
基金Social Science Foundation of Hunan Province, No.09YBA003 Science ＆ Technology Research Project of Hunan Province, No.2009JT3005+2 种基金 Knowledge Innovation Project of CAS, No.KZCX2-SW-415 Foundation of Key Laboratory for Agro-ecological Processes in Subtropical Region Wetland Project of WWF
文摘Eco-compensation is an environmental economic instrument for internalization of external cost. Returning farmland to lake is one of the important parts of restoring wetland ecosystem function in the Yangtze River Valley of China. Whether the project of lake recovery can be successful depends on the compensation to the farmers who have lost their original benefits and contributed to the wetland ecosystem recovery by returning farmland to lake. Aiming at the wetland recovery of the Dongting Lake, the practical implementation of pro- grams of the lake recovery and flood control in this area has been challenged by the heavy task of population resettlement, so it is an ideal area for case studies to reach the academic objectives proposed as the above. Based on field survey and experimentation, this research evaluated the benefit losses of the resettled farmers and the increased values of ecosystem service functions caused by wetland recovery, and furthermore, the value of eco-compensation for relocated farmers was calculated by considering the combination of the farmers＇ compensation appeal. The value of eco-compensation for relocated farmers in the Dongting Lake area was 6084.5 yuan per household by synthetic analysis of the effects on wetland ecosystem restoration. Moreover, this article took Dongting Lake area as a case to study and explore the basic issues of the eco-compensation by returning farmland to lake, that was who should pay, who should be paid, how much the payment was and what the payment means was, which sought the mechanisms of wetland restoration eco-compensation and prompted the people＇s enthusiasms for ecological restoration.
文摘A model involving the relationship between non conservative matter (COD) and main range factors(loading, water stage) and strength factor (temperature) in a shallow lake has been established on the basis of less change of water stage area curve in certain extent, broader distribution in pollution sources and more homogeneous in quantity of heat. The effects of COD inflow and /or outflow, and hydro meterological factors upon COD content in Lake Taihu were calculated and simulated under the actual situation of the loadings and regimen. The results simulated by using the model are in better agreement with the observed field data. The error of the model was also discussed.
