Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorhe...Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorheic basin in the central region of the Plateau, has expanded more than 600 km2 in area since 1976. Particularly since 1995, the lake has signif- icantly expanded in response to increasing precipitation, decreasing water surface evaporation caused by weaker winds and less solar radiation, and increased glacier meltwater draining to the lake. Glacie^lake interactions are important in governing lake expansion and are also part of a feedback loop that influences the local climate. Worsening climatic conditions (decreased precipitation and increased temperatures) that could have caused the lake to shrink during 1976-1994 were offset by increasing glacier meltwater feeding the lake, which made the lake nearly stable. We demonstrate that this pattern changed during 1995-2009, when glacier meltwater actually decreased but participation runoff increased and evaporation decreased, leading to expansion of the lake. If climatic conditions became suitable for further lake development, which would be indicated by expansion in lake area, glacier meltwater could be saved in a stable reservoir.展开更多
Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic act...Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic activities. The objectives of this study were to determine the spatial and temporal variations of macroinvertebrate community structures in reed pans and the environmental factors (i.e., water quality) responsible for the maintenance of these structures. Reed pans were studied over four different seasons, during which time subsurface water, sediment and macroinvertebrate samples were collected and analyzed. The reed pans studied showed that the macroinvertebrates were able to reflect various changes in reed pans with regard to seasonal variability and anthropogenic impacts on water quality. These anthropogenic impacts caused the disappearance of sensitive macroinvertebrate taxa and the increase of tolerant macroinvertebrate taxa.展开更多
This article endeavours to analyse the recent deformation in the Enfidha region. This analysis has been carried out using the Residual Digital Elevation Model (DEM). It is the altimetric difference between two DEM gen...This article endeavours to analyse the recent deformation in the Enfidha region. This analysis has been carried out using the Residual Digital Elevation Model (DEM). It is the altimetric difference between two DEM generated from the contour lines of two topographical maps over a period of 100 years. This deformation has been studied by some authors who report the presence of recent ground movements by comparing contour lines with a downward trend in elevation from 1893 to 1985. In 2006, this study area was marked by the presence of two earthquakes that occurred in several coastal cities located in the northeastern part of Tunisia. Our study involves a quantitative estimation of altimetric variations under a Geographic Information System (GIS) environment. Our proposed methodology aims at the mapping of residual (DEM) and the extraction of parameters that have a morphological and morphostructural signature. The extraction of quantitative morphostructural parameters requires the integration of multi-source and multi-scale data. This can only be done if the problem of heterogeneity at the level of scale and coordinate system is solved through the use of GIS tools and the obtainment of the vectorial shapefile format. Then, in order to compare the DEM generation errors with reference to recent and old data, they must be projected in the same projection system and on the same scale. The available data are two topographic maps of Enfidha which represent two different epochs. The first one is an old topographic map of 1893 (type 1922) at a scale of 1:50,000 and the second one is a recent topographic map of 1985 at a scale of 1:25,000. These topographical maps have the Lambert (IGN) projection system. This methodological approach, based on residual (DEM), allows to highlight an estimated subsidence of 3 m/100years located in the Enfidha plain and extends to the south coast of Cap Bon area in Tunisia. The variation of the contour lines shape between the old and the recent map can be studied in correlation with a relay structure fault observed and recognized by some analysts in this area. These relay accidents remain active according to the results obtained by the residual (DEM) and validated by the field observations of two sites that we have carried out in the Enfidha endorheic basin.展开更多
This study presents an analysis of the hydrochemical characteristics of Lake Enriquillo in the southwestern region of the Dominican Republic. This lake is hypersaline and endorheic. The climatology of the region is in...This study presents an analysis of the hydrochemical characteristics of Lake Enriquillo in the southwestern region of the Dominican Republic. This lake is hypersaline and endorheic. The climatology of the region is influenced by the Caribbean Regulator Climate Centers (CRCCs). Due to the endorheic nature of the basin, evaporation plays an extremely important role in its dynamics [1]. During the study period, in November 2002, the water level of Lake Enriquillo was 42 m below sea level (BLS), and the salinity level was 104.2‰. By 2014, the water level of the lake rose to 29 m below sea level, and the salinity decreased to 23.4‰, as a result of the high cyclonic activity in the Caribbean region.展开更多
The Aral Sea crisis is considered one of the most severe ecological tragedies from the 1960s in Central Asia.The reasons for this crisis,especially in the twenty-first century,are still scientific disputes.This study ...The Aral Sea crisis is considered one of the most severe ecological tragedies from the 1960s in Central Asia.The reasons for this crisis,especially in the twenty-first century,are still scientific disputes.This study investigated the relationship between land cover change in the Aral Sea related basins and the Aral Sea crisis from 2000 to 2020 by employing the GlobeLand30 dataset with 30 m resolution.Results showed that the cultivated land in the Aral Sea basin increased by 2,291 km^(2),and 75.4%of it occurred in the region of Karakum Canal,the largest water conservancy project for irrigation in the world.The water surface area of reservoirs increased by 1,183.5 km^(2) during the same period.Coincident with this change,the Aral Sea further shrank from 26,280.8 km^(2) in 2000 to 9,285.2 km^(2) in 2020,mainly occurred in the first decade of the twenty-first century.These imply that the Aral Sea crisis is persistent in the twenty-first century and is likely driven by water competition among different regions within the basin for agricultural irrigation.Strengthening the coordination and cooperation of crossboundary water resource management is still the most important management strategy choice to address the crisis from a broader perspective.展开更多
基金funded by the Major State Basic Research Development Program of China (973 Program) under Grant No. 2010CB951701by the Natural Science Foundation of China (No. 41071042)supported by the Innovation Project of Chinese Academy of Sciences (KZCX2-YW-BR-22)
文摘Robust climate warming has led to significant expansion of lakes in the central Tibetan Plateau. Using remote sensing data, our quantitative analysis indicates that Siling Co, a saline lake in a characteristic endorheic basin in the central region of the Plateau, has expanded more than 600 km2 in area since 1976. Particularly since 1995, the lake has signif- icantly expanded in response to increasing precipitation, decreasing water surface evaporation caused by weaker winds and less solar radiation, and increased glacier meltwater draining to the lake. Glacie^lake interactions are important in governing lake expansion and are also part of a feedback loop that influences the local climate. Worsening climatic conditions (decreased precipitation and increased temperatures) that could have caused the lake to shrink during 1976-1994 were offset by increasing glacier meltwater feeding the lake, which made the lake nearly stable. We demonstrate that this pattern changed during 1995-2009, when glacier meltwater actually decreased but participation runoff increased and evaporation decreased, leading to expansion of the lake. If climatic conditions became suitable for further lake development, which would be indicated by expansion in lake area, glacier meltwater could be saved in a stable reservoir.
文摘Reed pans are a very uncommon type of endorheic wetland, and as such the amount of information available is very limited. Thus, they are being impacted on by various agricultural, livestock and other anthropogenic activities. The objectives of this study were to determine the spatial and temporal variations of macroinvertebrate community structures in reed pans and the environmental factors (i.e., water quality) responsible for the maintenance of these structures. Reed pans were studied over four different seasons, during which time subsurface water, sediment and macroinvertebrate samples were collected and analyzed. The reed pans studied showed that the macroinvertebrates were able to reflect various changes in reed pans with regard to seasonal variability and anthropogenic impacts on water quality. These anthropogenic impacts caused the disappearance of sensitive macroinvertebrate taxa and the increase of tolerant macroinvertebrate taxa.
文摘This article endeavours to analyse the recent deformation in the Enfidha region. This analysis has been carried out using the Residual Digital Elevation Model (DEM). It is the altimetric difference between two DEM generated from the contour lines of two topographical maps over a period of 100 years. This deformation has been studied by some authors who report the presence of recent ground movements by comparing contour lines with a downward trend in elevation from 1893 to 1985. In 2006, this study area was marked by the presence of two earthquakes that occurred in several coastal cities located in the northeastern part of Tunisia. Our study involves a quantitative estimation of altimetric variations under a Geographic Information System (GIS) environment. Our proposed methodology aims at the mapping of residual (DEM) and the extraction of parameters that have a morphological and morphostructural signature. The extraction of quantitative morphostructural parameters requires the integration of multi-source and multi-scale data. This can only be done if the problem of heterogeneity at the level of scale and coordinate system is solved through the use of GIS tools and the obtainment of the vectorial shapefile format. Then, in order to compare the DEM generation errors with reference to recent and old data, they must be projected in the same projection system and on the same scale. The available data are two topographic maps of Enfidha which represent two different epochs. The first one is an old topographic map of 1893 (type 1922) at a scale of 1:50,000 and the second one is a recent topographic map of 1985 at a scale of 1:25,000. These topographical maps have the Lambert (IGN) projection system. This methodological approach, based on residual (DEM), allows to highlight an estimated subsidence of 3 m/100years located in the Enfidha plain and extends to the south coast of Cap Bon area in Tunisia. The variation of the contour lines shape between the old and the recent map can be studied in correlation with a relay structure fault observed and recognized by some analysts in this area. These relay accidents remain active according to the results obtained by the residual (DEM) and validated by the field observations of two sites that we have carried out in the Enfidha endorheic basin.
文摘This study presents an analysis of the hydrochemical characteristics of Lake Enriquillo in the southwestern region of the Dominican Republic. This lake is hypersaline and endorheic. The climatology of the region is influenced by the Caribbean Regulator Climate Centers (CRCCs). Due to the endorheic nature of the basin, evaporation plays an extremely important role in its dynamics [1]. During the study period, in November 2002, the water level of Lake Enriquillo was 42 m below sea level (BLS), and the salinity level was 104.2‰. By 2014, the water level of the lake rose to 29 m below sea level, and the salinity decreased to 23.4‰, as a result of the high cyclonic activity in the Caribbean region.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA20100104]the National Natural Science Foundation of China[grant number 41988101],[grant number 42071421].
文摘The Aral Sea crisis is considered one of the most severe ecological tragedies from the 1960s in Central Asia.The reasons for this crisis,especially in the twenty-first century,are still scientific disputes.This study investigated the relationship between land cover change in the Aral Sea related basins and the Aral Sea crisis from 2000 to 2020 by employing the GlobeLand30 dataset with 30 m resolution.Results showed that the cultivated land in the Aral Sea basin increased by 2,291 km^(2),and 75.4%of it occurred in the region of Karakum Canal,the largest water conservancy project for irrigation in the world.The water surface area of reservoirs increased by 1,183.5 km^(2) during the same period.Coincident with this change,the Aral Sea further shrank from 26,280.8 km^(2) in 2000 to 9,285.2 km^(2) in 2020,mainly occurred in the first decade of the twenty-first century.These imply that the Aral Sea crisis is persistent in the twenty-first century and is likely driven by water competition among different regions within the basin for agricultural irrigation.Strengthening the coordination and cooperation of crossboundary water resource management is still the most important management strategy choice to address the crisis from a broader perspective.