With changing climatic conditions and snow cover regime, regional hydrological cycle for a snowy basin will change and further available surface water resources will be redistributed. Assessing snow meltwater effect o...With changing climatic conditions and snow cover regime, regional hydrological cycle for a snowy basin will change and further available surface water resources will be redistributed. Assessing snow meltwater effect on runoff is the key to water safety, under climate warming and fast social-economic developing status. In this study, stable isotopic technology was utilized to analyze the snow meltwater effect on regional hydrological processes, and to declare the response of snow hydrology to climate change and snow cover regime, together with longterm meteorological and hydrological observations, in the headwater of Irtysh River, Chinese Altai Mountains during 1961-2015. The average δ^(18) O values of rainfall, snowfall, meltwater, groundwater and river water for 2014–2015 hydrological year were-10.9‰,-22.3‰,-21.7‰,-15.7‰ and-16.0‰, respectively.The results from stable isotopes, snow melting observation and remote sensing indicated that the meltwater effect on hydrological processes in Kayiertesi River Basin mainly occurred during snowmelt supplying period from April to June. The contribution of meltwater to runoff reached 58.1% during this period, but rainfall, meltwater and groundwater supplied 49.1%, 36.9% and 14.0% of water resource to annual runoff, respectively. With rising air temperature and increasing snowfall in cold season, the snow water equivalent(SWE) had an increasing trend but the snow cover duration declined by about one month including 13-day delay of the first day and 17-day advancement of the end day during 1961–2016. Increase in SWE provided more available water resource. However, variations in snow cover timing had resulted in redistribution of surface water resource, represented by an increase of discharge percentage in April and May, and a decline in Juneand July. This trend of snow hydrology will render a deficit of water resource in June and July when the water resource demand is high for agricultural irrigation and industrial manufacture.展开更多
Snowfall in the Tianshan Mountains in China is frequent during winter;thus,avalanches have become a severe issue in snow-covered areas.Accumulation and metamorphosis,as well as hydrothermal exchanges with the environm...Snowfall in the Tianshan Mountains in China is frequent during winter;thus,avalanches have become a severe issue in snow-covered areas.Accumulation and metamorphosis,as well as hydrothermal exchanges with the environment,considerably affect the stability of snow on slopes.Therefore,a hydrothermal model of snow cover and its underlying surfaces must be developed on the basis of meteorological data to predict and help manage avalanches.This study adopted the conceptual model of snow as a porous medium and quantitatively analysed its internal physical processes on the basis of the thermal exchanges amongst its components.The effects of local meteorological factors on snow structure and the redistribution of energy and mass inside the snow cover in the Tianshan Mountains were simulated.Simulation results showed that deformation as a result of overlying snow and sublimation of snow cover at the bottom is the main cause of density variation in the vertical profile of snow cover.Temperature drives water movement in snow.The low-density area of the bottom snow is the result of temperature gradient.The simulation results of the long-term snow internal mass distribution obtained by the method established in this study are highly consistent with the actual observed trend of variation.Such consistency indicates an accurate simulation of the physical characteristics of snow cover in small and microscale metamorphism in the Tianshan Mountains during the stable period.展开更多
Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological functions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the ...Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological functions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the observation and research on it are rare. The estimation of evapotranspiration is significant to ecological and environmental construction, scientific management of pasture and protection of wetland. For studying the evapotranspiration （ET） of low-lying prairie wetland in the middle reaches of the Heihe River, an inland river, in Northwest China, the automatic weather station in Linze Ecological Experimental Station of Lanzhou University （39°15′ 3″N, 100°03′ 52″ E）, Linze, Gansu Province, was selected as a case study. Based on meteorological data collected, Bowen-Ratio Energy Balance （BREB） method was used to calculate the evapotranspiration （ET） of low-lying prairie wetland. The analysis results showed that in a whole year （September 2003 -August 2004）, the total ET was 611.5mm and mean daily 1.67mm/d. The ET varied with different growing stages. In non-growing stage （NGS）, initial growing stage （IGS）, middle growing stage （MGS） and end growing stage （EGS）, the ET was 0.57, 2.01, 3.82 and 1.49mrrdd, with a percentage of total ET of 18.26%, 9.20%, 61.83% and 10.71% respectively. In March, ET began to increase. But in April, the ET increased most. After that, it increased gradually and got the maximal value in July. From then on, the ET decreased gradually. In September, the ET decreased rapidly. With the ending of growing and the freezing of soil, the ET stopped from the middle of November to February in next year. Hourly ET analysis showed that at 8：00 a.m. （during MGS at 7：00 a.m.）, the evapotranspiration began, at 13：00 p.m. got its maximal value and at 19：00 p.m. （during MGS at 20：00 p.m.）, the evapotranspiration stopped. The intensity of ET in sunny day was much larger than that in cloudy day in the same growing stage.展开更多
The terrestrial cryosphere functions to provide critical freshwater and serve societies and ecosystems,driving nature's contributions to people(NCP).This becomes increasingly important for the oasis areas in North...The terrestrial cryosphere functions to provide critical freshwater and serve societies and ecosystems,driving nature's contributions to people(NCP).This becomes increasingly important for the oasis areas in Northwest China.The cryospheric meltwater is in demand to support the economy and reduce poverty,accompanied by growing requirements to protect the environment.We intend to investigate the contributions of cryospheric meltwater by analyzing the spatial functions and services pertinent to provisioning meltwater in China.Based on the currently available datasets during the 2000s of glaciers,snow cover,and permafrost,spatial clustering was utilized to analyze the contributions at the third-level basin scale.Further assessment is carried out for the exposure of primary,secondary,and tertiary industrial sectors to cryospheric meltwater,which reflects the spatiality of potential services that cryospheric meltwater may provide.In results,we spatially cluster the contribution of cryospheric meltwater into six function zones and twenty-seven sub-zones,in association with the degree of their reliance on glaciers,snow cover,and permafrost.Considering the sector's exposure,we further spatially cluster the contribution areas into eleven service zones concerning the potential service of cryospheric meltwater.Generally,the cryosphere contributes approximately 8.3%of the total water resource in China,with function zones mainly distributed in northeastern China,Qinghai—Tibet Plateau(QTP),and other arid regions of Northwest China with various significance.The overall contribution ratios of the glacier,snow cover,and permafrost to cryospheric meltwater are about 35.6%,56.5%,and 7.9%,respectively.By looking into the service zones,the cryospheric meltwater mainly contributes to the primary industry in Northwest China and QTP,even though it has less significant effects on all other industrial sectors,while the services to the ecosystem are mainly located in QTP and high mountain regions.The results offer an overarching view on the contributions of cryospheric meltwater in China.展开更多
基金funded by the Chinese Academy of Sciences (KJZD-EW-G03-04, QYZDJSSW-DQC039)the National Science Foundation of China (NSFC 41630754, 41690144, 41421061)the Foundation of the State Key Laboratory of Cryospheric Sciences (SKLCS) at Northwest Institute of Eco-Environment and Resources (NIEER), CAS (SKLCS-OP-2017-10, SKLCS-ZZ2016)
文摘With changing climatic conditions and snow cover regime, regional hydrological cycle for a snowy basin will change and further available surface water resources will be redistributed. Assessing snow meltwater effect on runoff is the key to water safety, under climate warming and fast social-economic developing status. In this study, stable isotopic technology was utilized to analyze the snow meltwater effect on regional hydrological processes, and to declare the response of snow hydrology to climate change and snow cover regime, together with longterm meteorological and hydrological observations, in the headwater of Irtysh River, Chinese Altai Mountains during 1961-2015. The average δ^(18) O values of rainfall, snowfall, meltwater, groundwater and river water for 2014–2015 hydrological year were-10.9‰,-22.3‰,-21.7‰,-15.7‰ and-16.0‰, respectively.The results from stable isotopes, snow melting observation and remote sensing indicated that the meltwater effect on hydrological processes in Kayiertesi River Basin mainly occurred during snowmelt supplying period from April to June. The contribution of meltwater to runoff reached 58.1% during this period, but rainfall, meltwater and groundwater supplied 49.1%, 36.9% and 14.0% of water resource to annual runoff, respectively. With rising air temperature and increasing snowfall in cold season, the snow water equivalent(SWE) had an increasing trend but the snow cover duration declined by about one month including 13-day delay of the first day and 17-day advancement of the end day during 1961–2016. Increase in SWE provided more available water resource. However, variations in snow cover timing had resulted in redistribution of surface water resource, represented by an increase of discharge percentage in April and May, and a decline in Juneand July. This trend of snow hydrology will render a deficit of water resource in June and July when the water resource demand is high for agricultural irrigation and industrial manufacture.
基金supported by the 13th Five-year Informatization Plan of the Chinese Academy of Sciences,Grant No.XXH13506 and XXH13505-220Data sharing fundamental program for Construction of the National Science Technology Infrastructure Platform(Grant No.Y719H71006)。
文摘Snowfall in the Tianshan Mountains in China is frequent during winter;thus,avalanches have become a severe issue in snow-covered areas.Accumulation and metamorphosis,as well as hydrothermal exchanges with the environment,considerably affect the stability of snow on slopes.Therefore,a hydrothermal model of snow cover and its underlying surfaces must be developed on the basis of meteorological data to predict and help manage avalanches.This study adopted the conceptual model of snow as a porous medium and quantitatively analysed its internal physical processes on the basis of the thermal exchanges amongst its components.The effects of local meteorological factors on snow structure and the redistribution of energy and mass inside the snow cover in the Tianshan Mountains were simulated.Simulation results showed that deformation as a result of overlying snow and sublimation of snow cover at the bottom is the main cause of density variation in the vertical profile of snow cover.Temperature drives water movement in snow.The low-density area of the bottom snow is the result of temperature gradient.The simulation results of the long-term snow internal mass distribution obtained by the method established in this study are highly consistent with the actual observed trend of variation.Such consistency indicates an accurate simulation of the physical characteristics of snow cover in small and microscale metamorphism in the Tianshan Mountains during the stable period.
基金Underthe auspicesofthe Sino-Japan Cooperation Projectand the SpecialFund ofC hina M etrologicalA dm inistration(N o.C CSF-2005-2-Q H 39)
文摘Low-lying prairie wetland, which has characteristics of both grassland and wetland, has irreplaceable ecological functions in inland river basins of Northwest China. Owing to its small-scale distribution, so far, the observation and research on it are rare. The estimation of evapotranspiration is significant to ecological and environmental construction, scientific management of pasture and protection of wetland. For studying the evapotranspiration （ET） of low-lying prairie wetland in the middle reaches of the Heihe River, an inland river, in Northwest China, the automatic weather station in Linze Ecological Experimental Station of Lanzhou University （39°15′ 3″N, 100°03′ 52″ E）, Linze, Gansu Province, was selected as a case study. Based on meteorological data collected, Bowen-Ratio Energy Balance （BREB） method was used to calculate the evapotranspiration （ET） of low-lying prairie wetland. The analysis results showed that in a whole year （September 2003 -August 2004）, the total ET was 611.5mm and mean daily 1.67mm/d. The ET varied with different growing stages. In non-growing stage （NGS）, initial growing stage （IGS）, middle growing stage （MGS） and end growing stage （EGS）, the ET was 0.57, 2.01, 3.82 and 1.49mrrdd, with a percentage of total ET of 18.26%, 9.20%, 61.83% and 10.71% respectively. In March, ET began to increase. But in April, the ET increased most. After that, it increased gradually and got the maximal value in July. From then on, the ET decreased gradually. In September, the ET decreased rapidly. With the ending of growing and the freezing of soil, the ET stopped from the middle of November to February in next year. Hourly ET analysis showed that at 8：00 a.m. （during MGS at 7：00 a.m.）, the evapotranspiration began, at 13：00 p.m. got its maximal value and at 19：00 p.m. （during MGS at 20：00 p.m.）, the evapotranspiration stopped. The intensity of ET in sunny day was much larger than that in cloudy day in the same growing stage.
基金supported by the National Natural Science Foundation of China(41690141,41971083,42071091)the National Key R&D Program of China(2019YFC1510502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23060702)supported by the National Natural Science Foundation of China(41801035)provided by the State Key Laboratory of Cryospheric Science(SKLCS-ZZ-2021)Foundation for Excellent Youth Scholars of Northwest Institute of Eco-Environment and Resources,CAS.Thanks are given to the editors and anonymous reviewers for their valuable suggestions for enriching the content and presentation.
文摘The terrestrial cryosphere functions to provide critical freshwater and serve societies and ecosystems,driving nature's contributions to people(NCP).This becomes increasingly important for the oasis areas in Northwest China.The cryospheric meltwater is in demand to support the economy and reduce poverty,accompanied by growing requirements to protect the environment.We intend to investigate the contributions of cryospheric meltwater by analyzing the spatial functions and services pertinent to provisioning meltwater in China.Based on the currently available datasets during the 2000s of glaciers,snow cover,and permafrost,spatial clustering was utilized to analyze the contributions at the third-level basin scale.Further assessment is carried out for the exposure of primary,secondary,and tertiary industrial sectors to cryospheric meltwater,which reflects the spatiality of potential services that cryospheric meltwater may provide.In results,we spatially cluster the contribution of cryospheric meltwater into six function zones and twenty-seven sub-zones,in association with the degree of their reliance on glaciers,snow cover,and permafrost.Considering the sector's exposure,we further spatially cluster the contribution areas into eleven service zones concerning the potential service of cryospheric meltwater.Generally,the cryosphere contributes approximately 8.3%of the total water resource in China,with function zones mainly distributed in northeastern China,Qinghai—Tibet Plateau(QTP),and other arid regions of Northwest China with various significance.The overall contribution ratios of the glacier,snow cover,and permafrost to cryospheric meltwater are about 35.6%,56.5%,and 7.9%,respectively.By looking into the service zones,the cryospheric meltwater mainly contributes to the primary industry in Northwest China and QTP,even though it has less significant effects on all other industrial sectors,while the services to the ecosystem are mainly located in QTP and high mountain regions.The results offer an overarching view on the contributions of cryospheric meltwater in China.
