Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the unde...Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the underwater stratification of laser photons,then integrating all valid elevation tracks within the water body to interpolate the bathymetry.On this basis,we calculated the capacity and its time series directly,with the aid of lake boundaries and water levels obtained from optical imagery and CryoSat-2 data.Next,we also applied an empirical formula to estimate the water volume changes of Bangdag Co by combining the area and water levels from 2010 to 2023.Finally,we compared the results of Bangdag Co's water volume changes obtained from the two different methods and conducted a detailed analysis of their performance and regional applicability.The bathymetric map of Bangdag Co reveals a distinct spatial pattern,with the northeastern part significantly deeper(with a maximum depth of 35.27 m)and the southwestern part shallower.The average depth of the lake is 13.99 m.We further estimated that the lake storage capacity in November 2023 was 2.95 km^(3).Water volume changes estimated using the empirical formula were highly consistent with those derived from the lake storage capacity time series(from 2010 to 2023,the lake storage capacity increased by 1.04 km^(3)).Our comparison revealed that the empirical formula method reflects only changes in water volume.In contrast,while our method can accurately estimate lake storage capacity,it is constrained to shallow,clear,and elongated east-west lakes(e.g.,Ayakkum Lake).In summary,the ICESat-2 laser altimetry data,which do not rely on measured water depths,offer an essential complement to underwater topography detection and provide a novel perspective on lake volume estimation research.展开更多
In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In th...In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In this study,saline dust storms are reviewed systematically from the aspects of con-cept,general characteristics,conditions of occurrence,distribution and ecological impact.Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions;large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence;there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion;and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions.An under-standing of saline dust storms is important to guide disaster prevention and ecological rehabilitation.展开更多
Poyang Lake in the Changjiang(Yangtze)River catchment has undergone frequent spring drought since 2003,and some researchers attributed this phenomenon to sand mining and the lakebed deformation in the outlet channel l...Poyang Lake in the Changjiang(Yangtze)River catchment has undergone frequent spring drought since 2003,and some researchers attributed this phenomenon to sand mining and the lakebed deformation in the outlet channel linking the lake with Changjiang River main channel.However,there is still a lack of high-resolution subaqueous geomorphological evidence of how sand mining led to lakebed deformation in the outlet channel.We examined the bed morphology and sub-bottom sedimentary structure of the outlet channel,using a multibeam echo sounder and sub-bottom profi ler in Poyang Lake.We found that:(1)the subaqueous micro-topography types of the outlet channel are characterized by sand mining disturbance,natural erosional topography,and fl at bed and dunes,accounting for 44.9%,21.4%,28.6%,and 5.1%of the channel area,respectively;and(2)sand mining activity aff ects the local bed topography extensively and signifi cantly.The depth of sandpits caused by sand mining varied from 1.4 m to 12 m deeper than the surrounding bed surface,with 4.41 m of depth increase on average.Hence,the large-scale high-intensity sand mining activities and their signifi cant geomorphic eff ects demand for an improved assessment for future management and longer-term sustainability.Because of the large-scale and ongoing high-intensity sand mining activities in the Poyang Lake outlet channel,these eff ects should raise caution in the future and contribute to monitoring eff orts that are essential to implement sustainable management solutions.The present study and techniques implemented can serve as a scientifi c reference for dam construction and sand mining within the Poyang Lake basin.展开更多
The Burdur Lake is located in the southwest of Turkey,and its area has decreased by 40% from 211 km^(2) in 1975 to 126 km^(2) in 2019.In this study,we investigated how the soil has changed in the lacustrine material.T...The Burdur Lake is located in the southwest of Turkey,and its area has decreased by 40% from 211 km^(2) in 1975 to 126 km^(2) in 2019.In this study,we investigated how the soil has changed in the lacustrine material.Three soil profiles were sampled from the former lakebed(chronosequence profiles:P1,2007;P2,1994;and P3,1975),and three soil profiles under different land use types(biosequence profiles:P4,native forest vegetation;P5,agriculture;and P6,lakebed)were sampled.The chronosequence and biosequence soil profiles represented various distances from the Burdur Lake and showed different stages of lacustrine evolution.Soil electrical conductivity(EC;18.1 to 0.4 dS m^(-1)),exchangeable Na^(+)(34.7 to 1.4 cmol kg^(-1))and K^(+)(0.61 to 0.56 cmol kg^(-1)),and water-soluble Cl^(-)(70.3 to 2.1 cmol L^(-1))and SO_(4)^(2-)(275.9 to 25.0 cmol L^(-1))decreased with increasing distance from the Burdur Lake,whereas the A horizon thickness(10 to 48 cm),structure formation(0 to 48 cm),gleization-oxidation depth(0 to 79 cm),and montmorillonite and organic matter(OM;25.9 to 46.0 g kg^(-1))contents increased in the chronosequence soil profiles.The formation of P3 in the chronosequence and P5 in the biosequence soil profiles increased due to longer exposure to pedogenic processes(time,land use,vegetation,etc.).Changes in EC,exchangeable cation(Na^(+) and K^(+))and water-soluble anion(Cl^(-) and SO_(4)^(2-))concentrations of the salt-enriched horizon,OM,gleization-oxidation depth,A horizon thickness,and structure formation of the chronosequence and biosequence soil profiles(especially the topsoil horizon)were highly related to the distance from the Burdur Lake,time,and land use.展开更多
基金supported financially by the National Nature Science Foundation of China(No.41901129)the University Natural Sciences Research Project of Anhui Educational committee(2024AH050270)the support from the Joint China–Sweden Mobility Grant funded by NSFC and STINT(CH2019-8250)。
文摘Compared to lake area and water level,lake storage capacity more intuitively reflects regional climate changes.In this study,we first derived lakebed elevation profiles for individual ICESat-2 tracks based on the underwater stratification of laser photons,then integrating all valid elevation tracks within the water body to interpolate the bathymetry.On this basis,we calculated the capacity and its time series directly,with the aid of lake boundaries and water levels obtained from optical imagery and CryoSat-2 data.Next,we also applied an empirical formula to estimate the water volume changes of Bangdag Co by combining the area and water levels from 2010 to 2023.Finally,we compared the results of Bangdag Co's water volume changes obtained from the two different methods and conducted a detailed analysis of their performance and regional applicability.The bathymetric map of Bangdag Co reveals a distinct spatial pattern,with the northeastern part significantly deeper(with a maximum depth of 35.27 m)and the southwestern part shallower.The average depth of the lake is 13.99 m.We further estimated that the lake storage capacity in November 2023 was 2.95 km^(3).Water volume changes estimated using the empirical formula were highly consistent with those derived from the lake storage capacity time series(from 2010 to 2023,the lake storage capacity increased by 1.04 km^(3)).Our comparison revealed that the empirical formula method reflects only changes in water volume.In contrast,while our method can accurately estimate lake storage capacity,it is constrained to shallow,clear,and elongated east-west lakes(e.g.,Ayakkum Lake).In summary,the ICESat-2 laser altimetry data,which do not rely on measured water depths,offer an essential complement to underwater topography detection and provide a novel perspective on lake volume estimation research.
基金funded by the Xinjiang Natural Science Foundation of China (200821162)the National Basic Research Program of China (973 Program) (2009CB825101)the National Natural Science Foundation of China (40671170)
文摘In many arid and semiarid regions,saline playas represent a significant source of unconsoli-dated sediments available for aeolian transport,and severe saline dust storms occur frequently due to human disturbance.In this study,saline dust storms are reviewed systematically from the aspects of con-cept,general characteristics,conditions of occurrence,distribution and ecological impact.Our researches showed that saline dust storms are a kind of chemical dust storm originating in dry lake beds in arid and semiarid regions;large areas of unconsolidated saline playa sediments and frequent strong winds are the basic factors to saline dust storm occurrence;there are differentiation characteristics in deposition flux and chemical composition with wind-blown distance during saline dust storm diffusion;and saline dust storm diffusion to some extent increases glacier melt and results in soil salinization in arid regions.An under-standing of saline dust storms is important to guide disaster prevention and ecological rehabilitation.
基金Supported by the Comprehensive survey of the geological environment along the Changjiang River(No.DD20190260)the Natural Science Foundation of Shandong Province(No.ZR2020QD083)the Postdoctoral Science Foundation(No.2018M642693)。
文摘Poyang Lake in the Changjiang(Yangtze)River catchment has undergone frequent spring drought since 2003,and some researchers attributed this phenomenon to sand mining and the lakebed deformation in the outlet channel linking the lake with Changjiang River main channel.However,there is still a lack of high-resolution subaqueous geomorphological evidence of how sand mining led to lakebed deformation in the outlet channel.We examined the bed morphology and sub-bottom sedimentary structure of the outlet channel,using a multibeam echo sounder and sub-bottom profi ler in Poyang Lake.We found that:(1)the subaqueous micro-topography types of the outlet channel are characterized by sand mining disturbance,natural erosional topography,and fl at bed and dunes,accounting for 44.9%,21.4%,28.6%,and 5.1%of the channel area,respectively;and(2)sand mining activity aff ects the local bed topography extensively and signifi cantly.The depth of sandpits caused by sand mining varied from 1.4 m to 12 m deeper than the surrounding bed surface,with 4.41 m of depth increase on average.Hence,the large-scale high-intensity sand mining activities and their signifi cant geomorphic eff ects demand for an improved assessment for future management and longer-term sustainability.Because of the large-scale and ongoing high-intensity sand mining activities in the Poyang Lake outlet channel,these eff ects should raise caution in the future and contribute to monitoring eff orts that are essential to implement sustainable management solutions.The present study and techniques implemented can serve as a scientifi c reference for dam construction and sand mining within the Poyang Lake basin.
基金supported by the Scientific Research Projects(BAP)(No.2017-2800)of Akdeniz University,Turkeysupported by the Scientific Research Projects(BAP)(No.2019-2757)of Eskisehir Osmangazi University,Turkey for postdoc researchers at the Department of Soil Science,University of Wisconsin-Madison,USA。
文摘The Burdur Lake is located in the southwest of Turkey,and its area has decreased by 40% from 211 km^(2) in 1975 to 126 km^(2) in 2019.In this study,we investigated how the soil has changed in the lacustrine material.Three soil profiles were sampled from the former lakebed(chronosequence profiles:P1,2007;P2,1994;and P3,1975),and three soil profiles under different land use types(biosequence profiles:P4,native forest vegetation;P5,agriculture;and P6,lakebed)were sampled.The chronosequence and biosequence soil profiles represented various distances from the Burdur Lake and showed different stages of lacustrine evolution.Soil electrical conductivity(EC;18.1 to 0.4 dS m^(-1)),exchangeable Na^(+)(34.7 to 1.4 cmol kg^(-1))and K^(+)(0.61 to 0.56 cmol kg^(-1)),and water-soluble Cl^(-)(70.3 to 2.1 cmol L^(-1))and SO_(4)^(2-)(275.9 to 25.0 cmol L^(-1))decreased with increasing distance from the Burdur Lake,whereas the A horizon thickness(10 to 48 cm),structure formation(0 to 48 cm),gleization-oxidation depth(0 to 79 cm),and montmorillonite and organic matter(OM;25.9 to 46.0 g kg^(-1))contents increased in the chronosequence soil profiles.The formation of P3 in the chronosequence and P5 in the biosequence soil profiles increased due to longer exposure to pedogenic processes(time,land use,vegetation,etc.).Changes in EC,exchangeable cation(Na^(+) and K^(+))and water-soluble anion(Cl^(-) and SO_(4)^(2-))concentrations of the salt-enriched horizon,OM,gleization-oxidation depth,A horizon thickness,and structure formation of the chronosequence and biosequence soil profiles(especially the topsoil horizon)were highly related to the distance from the Burdur Lake,time,and land use.
