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Evolution of Desertification Types on the North Shore of qinghai lake

Computers, Materials & Continua 2022年第5期71卷 3635-3646页

作者： Wenzheng Yu Jintao Cui Yang Gao Mingxuan Zhu Li Shao Yanbo Shen Xiaozhao Zhang Chen Guo Hanxiaoya Zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China College of Hydrology and Water Resources Hohai UniversityNanjing210098China School of Environmental Science&Engineering Nanjing University of Information Science&TechnologyNanjing210044China Public Meteorological Service Center China Meteorological AdministrationBeijing100081China Center for Wind and Solar Energy Resources China Meteorological AdministrationBeijing100081China China Huaneng Group Co. Ltd.Beijing100036China China Huaneng Group Cleaning Energy Technology Academy Co. Ltd.100081China Faculty of Science The University of Auckland1010New Zealand

Land desertification is a widely concerned ecological environment *** the evolution trend of desertification types is of great significance to prevent and control land *** this study,we applied the decision tree classification method,to study the land area and temporal and spatial change law of different types of desertification in the North Bank of qinghai lake area from 1987 to 2014,based on the current land use situation and TM remote sensing image data of Haiyan County,qinghai Province,The results show that the area of mild desertification land and moderate desertification land in the study area has decreased,while the area of severe desertification land and extreme desertification land has increased significantly in the past 30 *** area of desertification land decreased by 4.02 km2,of which the area of mild and moderate desertification land decreased by 39.73 km2 and 36.8 km2 respectively,and the area of severe and extreme desertification land increased by 32.78 km2 and 39.73 km2 *** for the mutual transformation relationship,the transformation from severe desertification land to extreme desertification land is the main,and the junction of severe desertification land and extreme desertification land is the sensitive area of *** the north shore of qinghai lake,the sandy land tends to expand *** research provides reference basis for local land desertification monitoring,and has a great guidance for local effective land desertification and soil and water conservation.

关键词： qinghai lake desertification evolution mechanism remote sensing

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Classification of Desertification on the North Bank of qinghai lake

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Computers, Materials & Continua 2022年第7期72卷 695-711页

作者： Wenzheng Yu Xin Yao Li Shao Jing Liu Yanbo Shen Hanxiaoya Zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China School of Environmental Science&Engineering Nanjing University of Information Science&TechnologyNanjing210044China Public Meteorological Service Center China Meteorological AdministrationBeijing100081China Center for Wind and Solar Energy Resources China Meteorological AdministrationBeijing100081China Faculty of Science The University of Auckland1010New Zealand

In this paper,RS,GIS and GPS technologies are used to interpret the remote sensing images of the north shore of qinghai lake from 1987 to 2014 according to the inversion results of vegetation coverage(FVC),albedo,land surface temperature(LST),soil moisture(WET)and other major parameters after image preprocessing,such as radiometric correction,geometric correction and atmospheric *** this basis,the decision tree classification method based on landsat8 remote sensing image is used to classify the desertification land in this area,and the development and change of desertification in this period are *** results show that the fluctuation of desertification land area in this area increased during the study period,but from 2003 to 2014,the land area of mild desertification,moderate desertification and severe desertification landwere respectively decreased 0.92,145.89 and 29.39 km2,while the area of serious desertification land still has a slow increasing *** the driving force of desertification change trend in this area is caused by human factors or global change needs to be further studied.

关键词： Remote sensing qinghai lake desertification classification

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Analysis of the distribution characteristics of ^(226)Ra and ^(228)Ra and their sources in the western part of qinghai lake

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Chinese Journal of Oceanology and Limnology 2015年第6期33卷 1402-1412页

作者：孔凡翠沙占江杜金洲苏维刚于晨光赵顺利胡菊芳冶梅 qinghai Institute of Salt lakes Chinese Academy of Sciences University of Chinese Academy of Sciences Zoucheng Bureau of Land and Resources Life and Geographical Sciences College and Education Ministry Key Laboratory of Environments and Resources in the Tibetan Plateau Qinghai Normal University State Key Laboratory of Estuarine and Coastal Research East China Normal University

The ^226Ra and ^228Ra activities of qinghai lake surface water, groundwater, river water, suspended particles, and bottom sediments were measured in a gamma-ray spectrometer. The sources of ^226Ra and ^228Ra were discussed according to their distribution characteristics. ^226Ra and ^228Ra activities （dpm/（100 L）） ranged from 14.13±0.22 to 19.22±0.42 and 17.724-0.66 to 30.96：kl.47 in the surface water of the North Bay, respectively, and from 7.88±0.24 to 33.80±0.47 and 15.73±0.74 to 57.31±1.44, respectively, in the South Bay. The surface water near the estuary had a lower salinity and had a higher concentration of radium isotopes than the samples collected further away. The farther offshore the sample, the higher the salinity was, and the lower the radium isotope activity. The distribution of radium activities in the western part of qinghai lake is controlled by several factors, including Buha River runoff, desorption from suspended particles derived from the river, groundwater discharge, and a small amount of diffusion from the sediment.

关键词： ^226Ra ^228Ra surface water of qinghai lake groundwater river water qinghai lake

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Evaluation of spatial-temporal dynamics in surface water temperature of qinghai lake from 2001 to 2010 by using MODIS data

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Journal of Arid Land 2013年第4期5卷 452-464页

作者： Fei XIAO Feng LING Yun DU Qi FENG Yi YAN Hui CHEN Institute of Geodesy and Geophysics Chinese Academy of Sciences

lake surface water temperature （SWT） is an important indicator of lake state relative to its water chemistry and aquatic ecosystem,in addition to being an important regional climate ***,few literatures involving spatial-temporal changes of lake SWT in the qinghai-Tibet Plateau,including qinghai lake,are *** objective is to study the spatial-temporal changes in SWT of qinghai lake from 2001 to 2010,using Moderate-resolution Imaging Spectroradiometer （MODIS） *** on each pixel,we calculated the temporal SWT variations and long-term trends,compared the spatial patterns of annual average SWT in different years,and mapped and analyzed the seasonal cycles of the spatial patterns of *** results revealed that the differences between the average daily SWT and air temperature during the temperature decreasing phase were relatively larger than those during the temperature increasing *** increasing rate of the annual average SWT during the study period was about 0.01℃/a,followed by an increasing rate of about 0.05℃/a in annual average air *** annual average SWT from 2001 to 2010 showed similar spatial patterns,while the SWT spatial changes from January to December demonstrated an interesting seasonal reversion *** high-temperature area transformed stepwise from the south to the north regions and then back to the south region from January to December,whereas the low-temperature area demonstrated a reversed annual cyclical *** spatial-temporal patterns of SWTs were shaped by the topography of the lake basin and the distribution of drainages.

关键词： surface water temperature (SWT) spatial-temporal changes MODIS qinghai lake

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Rangeland Grasshoppers in Relation to Soils in the qinghai lake Region, China

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Pedosphere 2007年第1期17卷 84-89页

作者： NI Shao-Xiang WANG Jie-Chen JIANG Jian-Jun ZHA Yong College of Geographical Science Nanjing Normal University Nanjing 210097 （China） Department of Urban and Resources Science Nanjing UniversityNanjing 910093 （China）

The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the qinghai lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10 g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.

关键词： qinghai lake rangeland grasshopper soil type soil moisture

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A 16 ka climate record deduced from δ^(13)C and C/N ratio in qinghai lake sediments, northeastern Tibetan Plateau

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Chinese Journal of Oceanology and Limnology 2006年第2期24卷 103-110页

作者：沈吉汪勇刘兴起 Ryo Matsumoto Key Laboratory of lake Sedimentation and Environment Nanjing Institute of Geography and Limnology C.A.S Nanjing 210008 China Graduate School Chinese Academy of Sciences Beijing 100039 China Department of Earth and Planetary Science University of Tokyo Tokyo 113-0033 Japan

On the basis of multi-proxy analysis on TOC, TN, C/N, organic δ^13C and grain size, sediment record from qinghai lake provides evidences of stepwise-pattemed climatic change since 16 ka BE Results show that qinghai lake underwent six environmental stages. From 16.2 to 14.3 ka BP and from 4.0 to 2.1 ka BP, the organic δ^13C value was controlled by the concentration of atmospheric CO2. Relative higher organic δ^13C values occurred between 14.3 to 10.4 ka BP indicative of water hardness decrease resulted from melting ice water, corresponding to two intervals of C/N peak values to the Boling and AIlerod warm periods in Europe respectively. From 10.4 ka BP, qinghai lake entered the Holocene and the climate was warm and a little dry. The Megathermal appeared at about 6.7 ka BP when the vegetation around the lake transformed into a forest. Between 6.3 ka BP and 4.0 ka BP, the temperature decreased and δ^13C value was controlled by the expansion of C3 plants and the retreat of C4 plants in river catchment. Since 4.0 ka BP, the climate gradually became cold and dry. From 2.1 ka BP, the cold-dry climate and human activity resulted in an abrupt increase in C/N with deceased δ^13C value; meanwhile, many coarse grains appeared in sediments.

关键词： Quaternary climate record organic δ^13C C/N ratio sediment qinghai lake

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Paleoclimatic evolution indicated by major geochemical elements from aeolian sediments on the east of qinghai lake

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Research in Cold and Arid Regions 2013年第3期5卷 301-308页

作者： Yuan Shang RuiJie Lu FeiFei Jia LiHui Tian QingLiang Tang Yuan Chen Chao Zhao WangYang Wu Key Laboratory of Environmental Change and Natural Disaster (Ministry of Education) Beijing Normal University Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

As the largest inland lake of China, along with its unique landscape and geographical location, qinghai lake has got much atten- tion of the scientists for a long time. The precursors have done substantive researches by using the lake sediment, which deepen our tmderstanding of the climate changes in this region. Although sand dunes and loess sediment are widely distributed around the lake, so far the researches on geochemical elements from aeolian sediment have been less reported. In this paper, we selected a typical aeolian profile on the east of qinghai lake. Based on systematic sampling and analysis of seven major geochemical ele- ments, combined with OSL dating and previous researches, this paper discusses climate changes in the qinghai lake area since 12.5 ka B.P.. Our conclusions are：（1） Before 12.5 ka B.P., the climate in this region was dry, cold, and accompanied by strong wind-sand activities. （2） During 12.5-11.9 ka B.P., the climate became warm and wet. However, there was an abrupt climate cooling event during 12.2-11.9 ka B.P., which likely corresponded to the Younger Dryas event. （3） During 11.9 8.0 ka B.P., the climate fluctuated greatly and frequently from warm to cold, and three cooling events occurred. （4） During 8.0-2.6 ka B.P., the climate was warm and humid. （5） Since 2.6 ka B.P., similar to the modem climate, the climate was mainly dry and cold.

关键词： qinghai lake OSL dating major elements climate change

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Study on dynamic changes of land desertification in the circum-lake zone of the qinghai lake in the past 30 years supported by Remote Sensing and Geographical Information System

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Research in Cold and Arid Regions 2014年第6期6卷 566-576页

作者： MengJun Hu WenLi Zhang AiLi Yang LiHui Tian DengShan Zhang College of Geography and Environment Science Northwest Normal University Ministry of Education Key Laboratory of Environmental Change and Natural Disaster Beijing Normal University

The circum-lake zone of the qinghai lake is one of the most serious regions of desertification on the qinghai-Tibetan Plateau. Based on Remote Sensing （RS） and Geographical Information System （GIS） techniques, the four sets of remote sensing images acquired in 1976, 1987, 1995, and 2006 were selected to conduct thematic information extraction in 14,300 km2 of land in the circum-lake zone using the Earth Resource Data Analysis System （ERDAS） image and information processing function. In the meantime the off-site interpretation and filed check-correction methods were used to recon- struct the temporal-spatial dynamic changes and differentiation patterns of land desertification in the circum-lake zone in the past 30 years, and based on this, the developmental trend of land desertification in the next 20 years was predicted. The results of the study show that in the past 30 years land desertification in the region experienced a continuous fluctuation between rapid- and slow-development processes in time, while in space it exhibited a few small patchy distributions or sporadic distributions in many places while at the same time, four large sand-dominated distributions stood out and evolved into a circum-lake belt differentiation pattern with a lakeside dike as the connecting line. Due to the integrated effects of climate changes, human activities and artificial rehabilitation, land desertification area in the region in the next 20 years will exhibit an increasing trend in the first 15 years and then increase at a slower rate, and afterward occur in a reverse, decreasing trend.

关键词： qinghai lake land desertification dynamic change RS GIS

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Impact of Tourist Environmental Awareness on Environmental Friendly Behaviors: A Case Study from qinghai lake, China

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Journal of Resources and Ecology 2017年第5期8卷 502-513页

作者：曾瑜皙钟林生中国科学院地理科学与资源研究所北京100101 中国科学院大学北京100049

This paper examines the influence environmental awareness and recreation experience has on the environmentally-friendly behavior of tourists, and identifies the function of perceived quality as an intermediary variable. By providing a conceptual framework based on the combination of environmental awareness theory and tourist perception theory, and a SEM-based methodology, an in-depth analysis of the influence mechanism was carried out in the qinghai lake area of qinghai province. Results show that there exist differences in the ways environmental awareness influences perceived gains and perceived losses, and the influence coefficient of the former is higher than that of the latter. The perceived gains may promote environmentally friendly behaviors, while the perceived losses have an adverse impact on such behaviors. Moreover, the strength of the adverse impact of the latter is less than the strength of the positive impact of the former. The mediating effect of perceived quality was confirmed in the EA（environmental awareness）-EB（environmental behavior） nexus, within which the influence of tourist environmental awareness on environmentally friendly behavior could be transformed. The mediating effect of perceived quality in the perceived-gains model was more obvious than that in the perceived-losses model. This study highlights the importance of understanding the foundations of environmental behavior related to environmental awareness and tourist perceptions.

关键词： tourists environmentally-friendly-index (EFI) environmental awareness perceived quality qinghai lake

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Evaluation of shallow groundwater discharge fluxes and nutrient fluxes in the west of qinghai lake using radium isotopes

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 145-148页

作者： KONG Fancui SHA Zhanjiang SU Weigang YU Chenguang qinghai Institute of Salt lakes Academy of Science University of the Chinese Academy of Sciences

We collected 14 samples and 9 samples for surface water in Quan bay and the north bay of Qinglai lake respectively,as well as 11 samples for groundwater and 3 samples for river *** the water samples were filtered thro... 详细信息

关键词： qinghai lake Radium isotopes shallow groundwater SGD

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