Expanding or shrinking of lakes, especially in the closed basin, directly reflects the balance situation of water\|heat regime in the catchment. Fluctuations of the water\|level can be used as an indicator of climatic...Expanding or shrinking of lakes, especially in the closed basin, directly reflects the balance situation of water\|heat regime in the catchment. Fluctuations of the water\|level can be used as an indicator of climatic and environmental changes. Authors have investigated many lakes in West China in recent years, including lakes in the Tibet Plateau and in the arid area in the northwest China. We found that all lakes have been in shrinkage, some of them were changed into swamp and some dried dramatically up, which caused the abrupt change of the lake environment. This change led the grassland to be retrogression and desertification, and made the eco\|environment deterioration in West China.The Xingcuo Lake, in the height of 3425m ASL with 29km\+2 drainage area, located in the Zoige Basin, Northeastern Tibet Plateau, had changed into swamp in the area of 2km\+2 , and the vast area of peripheral marsh changed into grassland by the years of 1990. But the topographic map in the scale of 1/100000 and aerial photography surveyed at the end of 1960’s show clearly that this lake was in the area of 3 3km\+2 and surrounded by vast area of marshland. In the north central part of the Tibet Plateau, the Gourencuo Lake, in the height of 4650m ASL, was in the area of 23 5km\+2 with the average water depth of 1 3m in 1990. Then a dramatic change had been appearing in the recent years. When authors went there again in 1998,they found that the lake dried fully up. A thin salt crystal layer with saturated brine covered the flat central lake floor. This means that at least 30×10 6 m 3 water volume stored in the lake had been lost by the evaporation in 8 years, and many sand dunes had been formed. This abrupt change of lake environment could be recognized as the result of natural process or climate warming because of no human activity there.展开更多
Tibet Plateau has uplifted greatly in the Late Cenozoic era (Li Jijun et al., 1979; Sun Honglie, 1996; Shi Yafeng et al., 1998). The uplift will unquestionably influence the environment and climate of the plateau in t...Tibet Plateau has uplifted greatly in the Late Cenozoic era (Li Jijun et al., 1979; Sun Honglie, 1996; Shi Yafeng et al., 1998). The uplift will unquestionably influence the environment and climate of the plateau in the same time (such as resulting in the decrease of temperature) and leave some footprint on the contemporary sediments on or around the plateau. So, there must be some persistence component in the environmental and climatic evolution reflected by the geochemical information in the contemporary sediments. TS95, namely Tianshuihai Lake core is at the south frank of West Kunlun Mountain of Tibet Plateau and is suitable for the investigation of the persistence component. Using R/S analysis, Zhou Houyun et al. (1999) have previously calculated the Hurst index H of the three ferric indexes, FeO, Fe\-2O\-3 and ratio of FeO/ Fe\-2O\-3, from TS95. It is found that all these indexes satisfy Hurst law and they all are greater than 0 5, which means that there are some long run dependencies\|persistence component in the climatic and environmental evolution around Tianshuihai Lake area. This is in accordance with previous work by Yu Suhua et al. (1996). In this paper, the authors use the same method to do some R/S analysis on the other two climatic proxies of TS95, δ 13 C and δ 18 O, which are more suitable than the three ferric indexes to be climatic and environmental proxies. It is found that both the δ 13 C and δ 18 O satisfy Hurst law very well with H δ 13 C =0 875 and H δ 18 O =894, which suggests stronger persistence than the three ferric indexes.展开更多
Environmental magnetic research on beaches and shoreline processes is limited.Therefore,we carried out environmental magnetic studies on the heavy mineral-enriched,dark-reddish sands on Cedar Beach of western Lake Eri...Environmental magnetic research on beaches and shoreline processes is limited.Therefore,we carried out environmental magnetic studies on the heavy mineral-enriched,dark-reddish sands on Cedar Beach of western Lake Erie(41.68°N,82.40°W).Magnetite has been identified as the dominant magnetic mineral of these sands.This study reveals a spatial variation in concentration of magnetite particles,distribution of展开更多
The urban lake ecosystem has the characteristics of long-term,complex and comprehensive in its ecological restoration process because it is related to social and economic activities at multiple levels.Located in Hangz...The urban lake ecosystem has the characteristics of long-term,complex and comprehensive in its ecological restoration process because it is related to social and economic activities at multiple levels.Located in Hangzhou City,China,the West Lake is a national-level scenic spot and a world heritage cultural landscape.It provides key ecosystem services for the city and has a significant impact on the urban ecological environment and the well-being of citizens.The West Lake has undergone an 1800-year governance process in history,realizing the harmonious coexistence with Hangzhou City.Since modern times,due to the rapid development of urbanization and industrialization,the water quality of the West Lake and its freshwater ecosystem have been greatly damaged.Since 2002,Hangzhou City has achieved the overall restoration of the West Lake ecosystem through a series of measures,such as water diversion projects,dredging projects,and the West Lake comprehensive protection project,and the water environment and lakeshore landscape have been greatly improved.This study analyzed the restoration technology of the West Lake ecosystem from two scales of the watershed and the site and discussed the water ecological governance system of the West Lake in the past 20 years.Through thedata analyses of the West Lake land use,vegetation,TP,TN,NH_(3)-N,COD_(Mn) and other multi-environmental factors,the results showed that the water quality,transparency and eutrophication of the West Lake had been greatly improved.At the same time,the application of large-scale restoration methods and technologies also required long-term observation,and attention should be paid to the proliferation of alien species and the loss of heritage value,so as to further avoid potential ecological risks caused by ecological restoration.展开更多
文摘Expanding or shrinking of lakes, especially in the closed basin, directly reflects the balance situation of water\|heat regime in the catchment. Fluctuations of the water\|level can be used as an indicator of climatic and environmental changes. Authors have investigated many lakes in West China in recent years, including lakes in the Tibet Plateau and in the arid area in the northwest China. We found that all lakes have been in shrinkage, some of them were changed into swamp and some dried dramatically up, which caused the abrupt change of the lake environment. This change led the grassland to be retrogression and desertification, and made the eco\|environment deterioration in West China.The Xingcuo Lake, in the height of 3425m ASL with 29km\+2 drainage area, located in the Zoige Basin, Northeastern Tibet Plateau, had changed into swamp in the area of 2km\+2 , and the vast area of peripheral marsh changed into grassland by the years of 1990. But the topographic map in the scale of 1/100000 and aerial photography surveyed at the end of 1960’s show clearly that this lake was in the area of 3 3km\+2 and surrounded by vast area of marshland. In the north central part of the Tibet Plateau, the Gourencuo Lake, in the height of 4650m ASL, was in the area of 23 5km\+2 with the average water depth of 1 3m in 1990. Then a dramatic change had been appearing in the recent years. When authors went there again in 1998,they found that the lake dried fully up. A thin salt crystal layer with saturated brine covered the flat central lake floor. This means that at least 30×10 6 m 3 water volume stored in the lake had been lost by the evaporation in 8 years, and many sand dunes had been formed. This abrupt change of lake environment could be recognized as the result of natural process or climate warming because of no human activity there.
文摘Tibet Plateau has uplifted greatly in the Late Cenozoic era (Li Jijun et al., 1979; Sun Honglie, 1996; Shi Yafeng et al., 1998). The uplift will unquestionably influence the environment and climate of the plateau in the same time (such as resulting in the decrease of temperature) and leave some footprint on the contemporary sediments on or around the plateau. So, there must be some persistence component in the environmental and climatic evolution reflected by the geochemical information in the contemporary sediments. TS95, namely Tianshuihai Lake core is at the south frank of West Kunlun Mountain of Tibet Plateau and is suitable for the investigation of the persistence component. Using R/S analysis, Zhou Houyun et al. (1999) have previously calculated the Hurst index H of the three ferric indexes, FeO, Fe\-2O\-3 and ratio of FeO/ Fe\-2O\-3, from TS95. It is found that all these indexes satisfy Hurst law and they all are greater than 0 5, which means that there are some long run dependencies\|persistence component in the climatic and environmental evolution around Tianshuihai Lake area. This is in accordance with previous work by Yu Suhua et al. (1996). In this paper, the authors use the same method to do some R/S analysis on the other two climatic proxies of TS95, δ 13 C and δ 18 O, which are more suitable than the three ferric indexes to be climatic and environmental proxies. It is found that both the δ 13 C and δ 18 O satisfy Hurst law very well with H δ 13 C =0 875 and H δ 18 O =894, which suggests stronger persistence than the three ferric indexes.
文摘Environmental magnetic research on beaches and shoreline processes is limited.Therefore,we carried out environmental magnetic studies on the heavy mineral-enriched,dark-reddish sands on Cedar Beach of western Lake Erie(41.68°N,82.40°W).Magnetite has been identified as the dominant magnetic mineral of these sands.This study reveals a spatial variation in concentration of magnetite particles,distribution of
基金Supported by the Zhejiang Provincial Natural Science Foundation Public Welfare Project"Research on the Construction Method of Ecological Building Curtain Wall Based on Biomimetic Technology"(18082087-D)Science Foundation of Zhejiang Sci-Tech University(ZSTU)"Research on Optimization of Urban Protected Area Planning System Under the Guidance of Collaborative Governance"(22082150-Y)。
文摘The urban lake ecosystem has the characteristics of long-term,complex and comprehensive in its ecological restoration process because it is related to social and economic activities at multiple levels.Located in Hangzhou City,China,the West Lake is a national-level scenic spot and a world heritage cultural landscape.It provides key ecosystem services for the city and has a significant impact on the urban ecological environment and the well-being of citizens.The West Lake has undergone an 1800-year governance process in history,realizing the harmonious coexistence with Hangzhou City.Since modern times,due to the rapid development of urbanization and industrialization,the water quality of the West Lake and its freshwater ecosystem have been greatly damaged.Since 2002,Hangzhou City has achieved the overall restoration of the West Lake ecosystem through a series of measures,such as water diversion projects,dredging projects,and the West Lake comprehensive protection project,and the water environment and lakeshore landscape have been greatly improved.This study analyzed the restoration technology of the West Lake ecosystem from two scales of the watershed and the site and discussed the water ecological governance system of the West Lake in the past 20 years.Through thedata analyses of the West Lake land use,vegetation,TP,TN,NH_(3)-N,COD_(Mn) and other multi-environmental factors,the results showed that the water quality,transparency and eutrophication of the West Lake had been greatly improved.At the same time,the application of large-scale restoration methods and technologies also required long-term observation,and attention should be paid to the proliferation of alien species and the loss of heritage value,so as to further avoid potential ecological risks caused by ecological restoration.
