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PRIMARY ANALYSIS ON GROUNDWATER,soil moisture AND SALINITY IN FUKANG OASIS OF SOUTHERN JUNGGAR BASIN

Chinese Geographical Science 2002年第4期12卷 333-338页

作者： GUFeng-xue ZHANGyuan-dong CHUYu SHIQing-dong PANXiao-ling InstituteofAridEcologyandEnvironment XinjiangUniversityUrumqi830046P.R.China XinjiangKeyLaboratoryofOasisEcology XinfiangUniversityUrumqi830046P.R.China InternationalCenterforDesertAttairs-researchforSustainableDevelopmentinAridandSemi-airdLand Urumqi830046P.R.China

soil salinity is the most important factor affecting vegetation distribution,and the secondary salinization has affected the development of oasis *** arid areas the spatial variation of soil moisture and sa lt content is marked-ly affected by groundwater,irratio nal irrigation in artificial *** analyzing the soil moisture,salt content and groundwa-ter table in different areas of old oasis,new oasis and desert in Fukang Oa sis,it is shown that topography and l and use are main factors affecting the change of groundwater table,the redistribution of soil moisture and salt cont *** undis-turbed by human,the groundwater tab le rises from mountain to belt of grou nd water spillage,the groundwater t able rises mightily in plain because of the artificial irrigation,and the secondary salinization of soil is very seriou *** oasis the ground-water table raises compared with that in the natural desert at the same *** old oasis of upper reaches o f river salt has not been concentrated too much in rhizosphere because this area is the belt of groundwater drainage,soil t exture is coarse,the groundwater table is very low,and the salt in soil is drained i nto the *** new oasis has been the areas of salt accumulation becau se of the artificial irrigation,the salt content in soil is higher than th at in old oasis,so some cultivated fields here had to be thrown out because of the serious s econdary salinization.

关键词： fukang oasis ground water soil moisture pH electrical conductivity spatial distribution

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Analysis of soil moisture variation by forest cover structure in lower western Himalayas, India

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Journal of Forestry Research 2013年第2期24卷 317-324页

作者： J. V. Tyagi Nuzhat Qazi S. P. Rai M. P. Singh National Institute of Hydrology Forest Research Institute

soil moisture affects various hydrological processes, including evapotranspiration, infiltration, and runoff. Forested areas in the lower western Himalaya in India constitute the headwater catchments for many hill streams and have experienced degradation in forest cover due to grazing, deforestation and other human activities. This change in forest cover is likely to alter the soil moisture regime and, consequently, flow regimes in streams. The effect of change in forest cover on soil moisture regimes of this dry region has not been studied through long term field observations. We monitored soil matric potentials in two small watersheds in the lower western Himalaya of India. The watersheds consisted of homogeneous land covers of moderately dense oak forest and moderately degraded mixed oak forest. Observations were recorded at three sites at three depths in each watershed at fortnightly intervals for a period of three years. The soil moisture contents derived from soil potential measurements were analyzed to understand the spatial, temporal and profile variations under the two structures of forest cover. The analysis revealed large variations in soil moisture storage at different sites and depths and also during different seasons in each watershed. Mean soil moisture storage during monsoon, winter and summer seasons was higher under dense forest than under degraded forest. Highest soil moisture content occurred at shallow soil profiles, decreasing with depth in both watersheds. A high positive correlation was found between tree density and soil moisture content. Mean soil moisture content over the entire study period was higher under dense forest than under degraded forest. This indicated a potential for soil water storage under well managed oak forest. Because soil water storage is vital for sustenance of low flows, attention is needed on the management of oak forests in the Himalayan region.

关键词： soil moisture oak forest soil matric potential tree density degraded forest

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Effects of land use changes for ecological restoration on soil moisture on the Chinese Loess Plateau:a meta-analytical approach

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Journal of Forestry Research 2020年第2期31卷 443-452页

作者： Bowei Yu Gaohuan Liu Qingsheng Liu State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

soil moisture is an important resource for plant growth on the arid and semi-arid Loess Plateau of China where the‘‘Grain for Green’’project was launched in 1999,but there has been no systematic evaluation of soil moisture from the effects of ecological restoration at a regional *** systematically assessed 63 published studies during 2000-2015,including 2050 observations at 68 sites on the Loess Plateau with the aim of determining soil moisture changes and the factors influencing those *** found that,after land use conversion,soil moisture decreased by 17%in the upper 100 cm soil layer and that tree plantations and shrub lands appeared to cause soil moisture depletion which became increasingly serious with soil *** decrease of soil moisture was significantly influenced by the planting species in all restoration types(tree plantations,shrub lands,and grasslands).We also found that tree plantations and grasslands converted from farmlands consumed more soil moisture than from wasteland(including bare land,abandoned land and wild grasslands).Artificial restoration led to significant soil moisture reduction,but natural restoration had little effect on soil ***,natural restoration should be an alternative restoration practice on the Loess *** results will provide helpful information for artificial afforestation and planning ecological restoration campaigns for policy makers on water-limited regions.

关键词： soil moisture Ecological restoration Land conversion Vegetation type Artificial afforestation

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A Multivariable Approach for Estimating soil moisture from Microwave Radiation Imager(MWRI)

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Journal of Meteorological Research 2020年第4期34卷 732-747页

作者： Sibo ZHANG Fuzhong WENG Wei YAO Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094 State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesChina Meteorological AdministrationBeijing 100081

Accurate measurements of soil moisture are beneficial to our understanding of hydrological processes in the earth system. A multivariable approach using the random forest(RF) machine learning technique is proposed to estimate the soil moisture from Microwave Radiation Imager(MWRI) onboard Fengyun-3 C satellite. In this study, soil moisture Operational Products System(SMOPS) products disseminated from NOAA are used as a truth to train the algorithm with the input of MWRI brightness temperatures(TBs) at 10.65, 18.7, 23.8, 36.5, and 89.0 GHz, TB polarization ratios(PRs) at 10.65, 18.7, and 23.8 GHz, height in digital elevation model(DEM), and soil porosity. The retrieved soil moisture is also validated against the independent SMOPS data, and the correlation coefficient is about0.8 and mean bias is 0.002 m^3 m^-3 over the period from 1 August 2017 to 31 May 2019. Our retrieval of soil moisture also has a higher correlation with ECMWF ERA5 soil moisture data than the MWRI operational products. In the western part of China, the spatial distribution of MWRI soil moisture is much improved, compared to the MWRI operational products.

关键词： soil moisture Microwave Radiation Imager(MWRI) machine learning microwave remote sensing

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Impact of Gully on soil moisture of Shrubland in Wind-Water Erosion Crisscross Region of the Loess Plateau

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Pedosphere 2008年第5期18卷 674-680页

作者： HUO Zhu SHAO Ming-An R. HORTON Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China）. Graduate University of the Chinese Academy of Sciences Beijing 100049 （China） Agronomy Department of Iowa State University Ames IA 50011-1010 （USA）

The most serious erosion on the Loess Plateau of China exists in the wind-water erosion crisscross region where the annual precipitation is about 400 mm,the ecological environment is very fragile,and water is the key limiting factor for improving the environment. In this study,changes of soil moisture content for Caragana korshinskii Kom. shrubland in the gully bank of the Loess Plateau were studied using the methods of soil sampling and neutron probe. A typical gully(75 m long,28 m wide,and 10 m deep) was selected,and six neutron probe access tubes(6 m long) were installed at points 50,100,200,300,400,and 500 cm from the gully border for obtaining soil moisture data from July to October 2004 at approximately 10 d intervals. soil samplings were simultaneously carried out for moisture determination at the six points. Results showed that the soil moisture of the shrubland in the gully bank significantly varied between 300 and 400 cm in the horizontal direction and up to 600 cm in vertical direction of the gully. Seasonal changes in soil moisture revealed a curve with a single peak that occurred at the end of August or early September. A linear regression equation was fit for soil water storage and the distance from the gully border,with coefficients depending on rainfall characteristics,sampling point,and time of measurement.

关键词： erosion gully shrubland soil moisture

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Fusion of In-Situ soil moisture and Land Surface Model Estimates Using Localized Ensemble Optimum Interpolation over China

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Journal of Meteorological Research 2020年第6期34卷 1335-1346页

作者： Lipeng JIANG Chunxiang SHI Shuai SUN Xiao LIANG School of Geographic Sciences Nanjing University of Information Science&TechnologyNanjing 210044 National Meteorological Information Center China Meteorological AdministrationBeijing 100081

Land data assimilation(DA)is an effective method to provide high-quality spatially and temporally continuous soil moisture datasets that are crucial in weather,climate,hydrological,and agricultural ***,most existing land DA applications have used remote sensing observations,and are based on one-dimensional(1 D)analysis,which cannot be directly employed to reasonably assimilate the recently expanded in-situ soil moisture observations in *** this paper,a two-dimensional(2 D)localized ensemble-based optimum interpolation(En OI)scheme for assimilating in-situ soil moisture observations from over 2200 stations into land surface models(LSMs)is *** scheme uses historical LSM simulations as ensemble samples to provide soil moisture background error covariance,allowing the in-situ observation information to be propagated to surrounding *** is also computationally efficient because no additional ensemble simulations are needed.A set of ensemble sampling and localization length scale sensitivity experiments are *** En OI performs best for in-situ soil moisture fusion over China with an ensemble sampling of hourly soil moisture from the previous 7 days and a localization length scale of 100 *** the evaluation,simulations for in-situ soil moisture fusion are also performed from May 2016 to September *** En OI analysis is notably better than that without in-situ observation fusion,as the wet bias of 0.02 m3 m-3 is removed,the root-mean-square error(RMSE)is reduced by about 37%,and the correlation coefficient is increased by about 25%.Independent evaluation shows that the En OI analysis performs considerably better than that without fusion in terms of bias,and marginally better in terms of RMSE and correlation.

关键词： soil moisture fusion land surface model(LSM) ensemble optimum interpolation localization

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Impact of Antecedent soil moisture Anomalies over the Indo-China Peninsula on the Super Meiyu Event in 2020

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Journal of Meteorological Research 2023年第2期37卷 234-247页

作者： Yinshuo Dong Haishan Chen Xuan Dong Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science&TechnologyNanjing210044 School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing210044

In the summer of 2020,a super Meiyu event occurred in the Yangtze River basin(YRB),causing enormous economic losses and human *** studies have investigated the possible causes of this super Meiyu event from the perspective of anomalous atmospheric circulation activities and sea surface temperature(SST)anomalies;however,the influence of land surface processes has not garnered considerable *** study investigates the possible contributions of land surface processes to this extreme event based on observational analysis and numerical simulations,and shows that antecedent soil moisture(SM)anomalies over the Indo-China Peninsula(ICP)may have had a vital influence on the super Meiyu in *** SM anomalies in May over the ICP increased the surface temperature and sensible heat ***“memory”of soil allowed the anomalies to persist into the Meiyu *** heating of the lower atmosphere by the surface strengthened the western Pacific subtropical high,which caused an anomalous anticyclone from the ICP to Northwest Pacific and thus enhanced the southwesterly winds and vertical motion over the ***,the water vapor flux and convergence were *** experiments based on the Weather Research and Forecasting(WRF)model further confirmed the results of observational analysis and indicated that the warm air heated by the ICP surface significantly warmed the lower troposphere from the ICP to Northwest Pacific under the influence of the background wind,thus increasing the geopotential height and inducing an *** results of the sensitivity experiments showed that the SM anomalies in May over the ICP increased the precipitation by 10.6%from June to July over the *** findings can improve our understanding of the mechanism of the super Meiyu event in 2020 and facilitate the prediction of extreme Meiyu events.

关键词： super Meiyu soil moisture Indo-China Peninsula surface heating

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Effects of Water-table Depth and soil moisture on Plant Biomass, Diversity, and Distribution at a Seasonally Flooded Wetland of Poyang Lake, China

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Chinese Geographical Science 2015年第6期25卷 739-756页

作者： XU Xiuli ZHANG Qi TAN Zhiqiang LI Yunliang WANG Xiaolong Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and Limnology Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education Jiangxi Normal University

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distri- bution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cineras- cens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical corre- spondence analysis （CCA）, spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community （ranging from q）.5 m above ground to ＋10.3 m below ground）, intermediate in P. australis community （-2.6 m to ＋7.8 m） and shallow- est in C. cinerascens community （-4.5 m to ＋6.1 m）. soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above- and belowground biomass are positively correlated with moisture. Above- and belowground biomass presen

关键词： water-table depth soil moisture species diversity biomass Gaussian model Poyang Lake wetland

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An integrated methodology for soil moisture analysis using multispectral data in Mongolia

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Geo-Spatial Information Science 2017年第1期20卷 46-55页

作者： Enkhjargal Natsagdorj Tsolmon Renchin Martin Kappas Batchuluun Tseveen Chimgee Dari Oyunbileg Tsend Ulam-Orgikh Duger NUM-ITC-UNESCO Laboratory for Space Science and Remote Sensing National University of MongoliaUlaanbaatarMongolia Cartography GIS&Remote Sensing DepartmentInstitute of GeographyGeorg-August University GoettingenGoettingenGermany Department of Environment and Forest Engineering National University of MongoliaUlaanbaatarMongolia Department of Statistics National University of MongoliaUlaanbaatarMongolia School of Agroecology Mongolian University of Life SciencesUlaanbaatarMongolia

soil moisture(SM)content is one of the most important environmental variables in relation to land surface climatology,hydrology,and ***-term SM data-sets on a regional scale provide reasonable information about climate change and global warming specific *** aim of this research work is to develop an integrated methodology for SM of kastanozems soils using multispectral satellite *** study area is Tuv(48°40′30″N and 106°15′55″E)province in the forest steppe zones in *** addition to this,land surface temperature(LST)and normalized difference vegetation index(NDVI)from Landsat satellite images were integrated for the ***,we used a digital elevation model(DEM)from ASTER satellite image with 30-m *** and slope maps were derived from this *** soil moisture index(SMI)was obtained using spectral information from Landsat satellite *** used regression analysis to develop the *** model shows how SMI from satellite depends on LST,NDVI,DEM,Slope,and Aspect in the agricultural *** results of the model were correlated with the ground SM data in Tuv *** results indicate that there is a good agreement between output SM and SM of ground truth for agricultural *** research is focused on moisture mapping for different natural zones in *** innovative part of this research is to estimate SM using drivers which are vegetation,land surface temperature,elevation,aspect,and slope in the forested steppe *** integrative methodology can be applied for different regions with forest and desert steppe zones.

关键词： Remote sensing Landsat soil moisture ground truth measurement modeling

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Enhanced Seasonal Predictability of Spring soil moisture over the Indo-China Peninsula for Eastern China Summer Precipitation under Non-ENSO Conditions

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Advances in Atmospheric Sciences 2023年第9期40卷 1632-1648页

作者： Chujie GAO Gen LI College of Oceanography&State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210024China Key Laboratory of Meteorological Disaster Ministry of Education(KLME)&Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

Seasonal prediction of summer precipitation over eastern China is closely linked to the East Asian monsoon circulation,which is largely affected by the El Niño-Southern Oscillation(ENSO).In this study,results show that spring soil moisture(SM)over the Indo-China peninsula(ICP)could be a reliable seasonal predictor for eastern China summer precipitation under non-ENSO *** springtime SM anomalies are present over the ICP,they trigger a structured response in summertime precipitation over most of eastern *** resultant south-to-north,tri-polar configuration of precipitation anomalies has a tendency to yield increased(decreased)precipitation in the Yangtze River basin and decreased(increased)in South and North China with a drier(wetter)spring soil condition in the *** analyses show that ENSO exerts a powerful control on the East Asian circulation system in the ENSO-decaying *** the case of ENSO forcing,the seasonal predictability of the ICP spring SM for eastern China summer precipitation is ***,in the absence of the influence of ENSO sea surface temperature anomalies from the preceding winter,the SM anomalies over the ICP induce abnormal local heating and a consequent geopotential height response owing to its sustained control on local temperature,which could,in turn,lead to abnormal eastern China summer precipitation by affecting the East Asian summer monsoon *** present findings provide a better understanding of the complexity of summer climate predictability over eastern China,which is of potential significance for improving the livelihood of the people.

关键词： summer precipitation El Niño-Southern Oscillation soil moisture Indo-China Peninsula eastern China East Asian summer monsoon

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