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Overview of the Measures and Techniques Used to Protect Traffic Lines against Shifting Sands in China

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Journal of Resources and Ecology 2021年第1期12卷 124-135页

作者： MA Ning GUO Qun LI Yu LI Shenggong Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China National Ecosystem Science Data Center Beijing 100101China Sino-Danish College University of Chinese Academy of SciencesBeijing 100190China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100190China Key Lab for Resources Use and Environmental Remediation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Shifting sands are one of the main contributors to desertification in China. This paper briefly reviews the measures and techniques which are used to protect traffic lines by stabilizing and fixing sands in the desert and desertification-affected arid and semi-arid areas in north China. We introduce the types and features of these measures and techniques, including mechanical, chemical, and biological measures, and outline how they have been applied in different areas and in different traffic lines over the past six decades, from 1950 s to 2010 s, taking the Baotou-Lanzhou railway, the Qinghai-Tibet railway, and the Tarim Desert highway as examples Mechanical measures such as erecting sand-retaining wind walls and placing straw checkerboards have proved to be very efficient for stabilizing shifting sands and protecting traffic lines that pass through the desert areas. Chemical measures are not widely used in the current sand fixing systems because of their high cost and potential pollution risks. Biological measures are preferred because they exhibit much better sand fixation performance and longer duration than the former two types of measures despite their relatively high cost. A combination of different measures is usually adopted in some areas to attain better sand-fixing effects. Stabilizing sand dune surfaces with mechanical measures or irrigation from underground water or river if available helps early recruitment of some drought-tolerant plants(xerophytes). We also point out the restrictions for existing sand-fixing measures and techniques and future research orientation. This review has implications for addressing eco-environmental issues associated with infrastructure construction that is part of the Belt and Road Initiative in desert and desertification-affected arid and semi-arid areas in the Mongolian Plateau.

关键词： traffic lines desertification shifting sands wind erosion sand fixing system

Start of vegetation growing season on the Tibetan Plateau inferred from multiple methods based on GIMMS and SPOT NDVI data

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Journal of Geographical Sciences 2015年第2期25卷 131-148页

作者： DING Mingjun LI Lanhui ZHANG Yili SUN Xiaomin LIU Linshan GAO Jungang WANG Zhaofeng LI Yingnian Key Lab of Poyang Lake Wetland and Watershed Research of Ministry of Education and School of Geography and Environment Jiangxi Normal University Nanchang 330022 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research (IGSNRR) CAS Beijing 100101 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 10101 China Key Laboratory of Ecosystem Network Observation and Modeling IGSNRR CAS Beijing 100101 China Northwest Institute of Plateau Biology CAS Xining 810008 China

In this study, we have used four methods to investigate the start of the growing season （SGS） on the Tibetan Plateau （TP） from 1982 to 2012, using Normalized Difference Vegetation Index （NDVI） data obtained from Global Inventory modeling and Mapping Studies （GIMSS, 1982-2006） and SPOT VEGETATION （SPOT-VGT, 1999-2012）. SGS values esti- mated using the four methods show similar spatial patterns along latitudinal or altitudinal gradients, but with significant variations in the SGS dates. The largest discrepancies are mainly found in the regions with the highest or the lowest vegetation coverage. Between 1982 and 1998, the SGS values derived from the four methods all display an advancing trend, however, according to the more recent SPOT VGT data （1999-2012）, there is no continu- ously advancing trend of SGS on the TP. Analysis of the correlation between the SGS values derived from GIMMS and SPOT between 1999 and 2006 demonstrates consistency in the tendency with regard both to the data sources and to the four analysis methods used. Com- pared with other methods, the greatest consistency between the in situ data and the SGS values retrieved is obtained with Method 3 （Threshold of NDVI ratio）. To avoid error, in a vast region with diverse vegetation types and physical environments, it is critical to know the seasonal change characteristics of the different vegetation types, particularly in areas with sparse grassland or evergreen forest.

关键词： phenology NDVI start of vegetation growing season method Tibetan Plateau

Climatic Changes Dominant Interannual Trend in Net Primary Productivity of Alpine Vulnerable ecosystems

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Journal of Resources and Ecology 2019年第4期10卷 379-388页

作者： YANG Yihan WANG Junbang LIU Peng LU Guangxin LI Yingnian Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101 China University of Chinese Academy of Sciehces Beijing 100049 China Henan Academy of Land and Resources Sciences Zhengzhou 450053 China Qinghai University Xining 810016 China Northwest Institute of Plateau Biology Chinese Academy of Sciences Xining 81000& China

The Three-River Headwaters(TRH), which is the source area of Yangtze River, Yellow River and Lancang River, is vulnerable and sensitive, and its alpine ecosystem is considered an important barrier for China’s ecological security. Understanding the impact of climate changes is essential for determining suitable measures for ecological environmental protection and restoration against the background of global climatic changes. However, different explanations of the interannual trends in complex alpine ecosystems have been proposed due to limited availability of reliable data and the uncertainty of the model itself. In this study, the remote sensing-process coupled model(GLOPEM-CEVSA) was used to estimate the net primary productivity(NPP) of vegetation in the TRH region from 2000 to 2012. The estimated NPP significantly and linearly correlated with the above-ground biomass sampled in the field(the multiple correlative coefficient R2 = 0.45, significant level P < 0.01) and showed better performance than the MODIS productivity product, i.e. MOD17 A3,(R2 = 0.21). The climate of TRH became warmer and wetter during 1990-2012, and the years 2000 to 2012 were warmer and wetter than the years1990–2000. Responding to the warmer and wetter climate, the NPP had an increasing trend of 13.7 g m^–2(10 yr)^–1 with a statistical confidence of 86%(P = 0.14). Among the three basins, the NPP of the Yellow River basin increased at the fastest rate of 17.44 g m^–2(10 yr)^–1(P = 0.158), followed by the Yangtze River basin, and the Lancang River, which was the slowest with a rate of 12.2 g m^–2(10 yr)^–1 and a statistical confidence level of only 67%. A multivariate linear regression with temperature and precipitation as the independent variables and NPP as the dependent variable at the pixel level was used to analyze the impacts of climatic changes on the trend of NPP. Both temperature and precipitation can explain the interannual variability of 83% in grassland NPP in the whole region, and

关键词： Three-River Headwaters alpine ecosystems net primary productivity climate changes

Mega-cities dominate China's urban greening

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arXiv

arXiv 2023年

作者： Zhang, Xiaoxin Brandt, Martin Tong, Xiaoye Tong, Xiaowei Zhang, Wenmin Reiner, Florian Li, Sizhuo Tian, Feng Yue, Yuemin Zhou, Weiqi Chen, Bin Xiao, Xiangming Fensholt, Rasmus Department of Geosciences and Natural Resource Management University of Copenhagen Copenhagen Denmark Key Laboratory for Agro-ecological Processes in Subtropical Region Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha China Hubei Key Laboratory of Quantitative Remote Sensing of Land and Atmosphere School of Remote Sensing and Information Engineering Wuhan University Wuhan China Huanjiang Observation and Research Station for Karst Ecosystem Chinese Academy of Sciences Huanjiang China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing100085 China Lab Division of Landscape Architecture Faculty of Architecture The University of Hong Kong Hong Kong Department of Microbiology and Plant Biology Center for Earth Observation and Modeling University of Oklahoma NormanOK United States

Trees play a crucial role in urban environments, offering various ecosystem services that contribute to public health and human well-being. China has initiated a range of urban greening policies over the past decades, however, monitoring their impact on urban tree dynamics at a national scale has proven challenging. In this study, we deployed nano-satellites to quantify urban tree coverage in all major Chinese cities larger than 50 km2 in 2010 and 2019. Our findings indicate that approximately 6000 km2 (11%) of urban areas were covered by trees in 2019, and 76% of these cities experienced an increase in tree cover compared to 2010. Notably, the increase in tree cover in mega-cities such as Beijing, and Shanghai was approximately twice as large as in most other cities (7.69% vs 3.94%). The study employs a data-driven approach towards assessing urban tree cover changes in relation to greening policies, showing clear signs of tree cover increases but also suggesting an uneven implementation primarily benefiting a few mega-cities. © 2023, CC BY.

关键词： ecosystems

Climatic and Biotic Controls of Evapotranspiration Across Grassland ecosystems on Tibetan Plateau

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SSRN 2024年

作者： Peng, Siyuan Yang, Yue Luo, Dengnan Zeng, Xiang Liang, Minqi Tao, Long Zhang, Guangru Li, Pan Liao, Weijie Guo, Qun Cao, Ruochen Li, Yuzhe Zhang, Weirong Hu, Zhongmin School of Geography South China Normal University Shipai Campus Guangzhou510631 China Hainan Baoting Tropical Rainforest Ecosystem Observation and Research Station School of Ecology Hainan University Haikou570228 China Facility of Geographical Science Beijing Normal University Beijing100875 China Zhuhai Branch State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Zhuhai519087 China School of Atmospheric Sciences Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Cycle Sun Yat-sen University Guangdong Zhuhai510245 China Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing101408 China International Institute for Earth System Sciences Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing University Jiangsu 210023 China Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications Ministry of Natural Resources School of Geography and Ocean Science Nanjing University Jiangsu 210023 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Comprehending the spatial variations of evapotranspiration (ET) and its components on Tibetan Plateau (TP) is crucial for grasping the dynamics of the regional water cycle and energy balance. However, the influence of various environmental factors on ET and its components remains unclear. This study addresses this gap by utilizing observational data from 14 sites and employing the Shuttleworth-Wallace-Hu (SWH) model to examine the spatial relationships between ET, its components, and influencing factors. The SWH model parameters were optimized using the Monte Carlo method, achieving a satisfactory simulation performance with an average R2 value of 0.75. Our analysis indicates that in alpine meadow, the ratio of transpiration to ET is generally higher (0.55) compared to alpine steppe (0.39). In terms of spatial distribution, both precipitation and leaf area index significantly impact ET and transpiration. Precipitation emerges as the primary driver of interannual spatial variations in ET, while leaf area index plays a pivotal role in regulating proportion of transpiration. Furthermore, our results reveal a transition from water-dominated to energy-dominated in TP grassland ecosystem at an aridity index of 0.73. This finding is significant as it challenges the common application of an aridity index of 0.65 to distinguish arid from humid regions. It suggests that TP grassland, within the 0.65-0.73 range, remain primarily water-driven. These findings enhance our comprehension of the intricate interactions within the water cycle. © 2024, The Authors. All rights reserved.

关键词： Evapotranspiration

Climatic and Biotic Controls of Evapotranspiration Across Grassland ecosystems on the Tibetan Plateau

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SSRN 2024年

作者： Peng, Siyuan Yang, Yue Luo, Dengnan Zeng, Xiang Liang, Minqi Tao, Long Zhang, Guangru Li, Pan Liao, Weijie Guo, Qun Cao, Ruochen Li, Yuzhe Zhang, Weirong Hu, Zhongmin School of Geography South China Normal University Shipai Campus Guangzhou510631 China Hainan Baoting Tropical Rainforest Ecosystem Observation and Research Station School of Ecology Hainan University Haikou570228 China Facility of Geographical Science Beijing Normal University Beijing100875 China Zhuhai Branch of State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Zhuhai519087 China School of Atmospheric Sciences Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Cycle Sun Yat-sen University Guangdong Zhuhai510245 China Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing101408 China International Institute for Earth System Sciences Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing University Jiangsu210023 China Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources School of Geography and Ocean Science Nanjing University Jiangsu210023 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Study region: The Tibetan Plateau in China, the Third Pole of the *** focus: Accurate descriptions of spatial variation in evapotranspiration (ET) and its components on the Tibetan Plateau (TP) are crucial for understanding the dynamics of the regional water cycle and energy balance. However, how various environmental factors affect ET and its components remains unclear. This study addresses this gap using observational data from 14 sites and employing the Shuttleworth-Wallace-Hu (SWH) model to examine the spatial relationships between ET, its components, and underlying *** hydrological insights for the region: The SWH model parameters were optimized using the Monte Carlo method, achieving a satisfactory model performance with an average R² of 0.75. The ratio of transpiration to ET was generally higher in alpine meadows (0.55) than alpine steppes (0.39). Across the TP, precipitation and the leaf area index together shaped spatial variation in ET and transpiration. Precipitation emerged as the primary driver of interannual variation in ET, while the leaf area index strongly regulated the proportion of ET accounted for by transpiration. Furthermore, above aridity index values of 0.73, grassland ecosystems transitioned from water to energy. This finding is significant as it challenges the common application of an aridity index value of 0.65 to distinguish arid from humid regions. It suggests that TP grasslands, with an AI of 0.65-0.73, remain primarily water-limited. © 2024, The Authors. All rights reserved.

关键词： Biotic

Climatic and Biotic Controls of Evapotranspiration Across Grassland ecosystems on Tibetan Plateau

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SSRN 2024年

作者： Peng, Siyuan Yang, Yue Luo, Dengnan Zeng, Xiang Liang, Minqi Tao, Long Zhang, Guangru Li, Pan Liao, Weijie Guo, Qun Cao, Ruochen Li, Yuzhe Zhang, Weirong Hu, Zhongmin School of Geography South China Normal University Shipai Campus Guangzhou510631 China Hainan Baoting Tropical Rainforest Ecosystem Observation and Research Station Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation School of Ecology and Environment Hainan University Haikou570228 China Center for Eco-Environment Restoration Engineering of Hainan Province Hainan University Haikou570228 China Facility of Geographical Science Beijing Normal University Beijing100875 China Zhuhai Branch of State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Zhuhai519087 China School of Atmospheric Sciences Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Cycle Sun Yat-sen University Guangdong Zhuhai510245 China Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing101408 China International Institute for Earth System Sciences Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing University Jiangsu210023 China Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources School of Geography and Ocean Science Nanjing University Jiangsu210023 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Understanding the spatial variations of evapotranspiration (ET) and its components on Tibetan Plateau (TP) is pivotal for grasping the regional water cycle and energy balance dynamics. Yet it is unclear how the changes of the intricate synergy among diverse environment factors significantly impacts the patterns of ET and its transformation state. Addressing this gap, this study employed observational data from 14 sites, utilizing the Shuttleworth-Wallace-Hu (SWH) model to investigate the spatial relationships between ET, its components, and influencing factors. Model parameters of SWH were optimized by Monte Carlo method, achieving a commendable simulation performance with a mean R2 value of 0.75. Our analysis reveals that in alpine meadow, the ratio of transpiration (T) to ET (T/ET) is generally higher (0.55) compared to alpine steppe (0.39). The T/ET values for hover around or below 0.5, indicating a balanced contribution of various ET components. Spatially, both PPT and LAI have an impact on ET and T/ET. PPT emerges as the primary driver of interannual spatial variations in ET, while LAI plays a crucial role in regulating T/ET. Our results further demonstrate that a transition from water-dominated to energy-dominated systems in TP grassland ecosystem at an approximately aridity index of 0.73. This is noteworthy considering the general application of an aridity index of 0.65 to delineate arid from humid regions. It implies that TP grasslands, within the 0.65-0.73 range, remain primarily water-driven. This insight holds substantial implications for comprehending water-energy dynamics in similar ecosystems, challenging the conventional binary categorization of arid and humid areas. Such findings are of immense significance in enhancing understanding of the intricate interactions of the water cycle between land and the atmosphere. © 2024, The Authors. All rights reserved.

关键词： Water supply

Urban Sector Land Use Metabolism Reveals Inequalities and Exploitation Across Cities in Regional Network Analysis

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SSRN 2023年

作者： Xie, Wei Yang, Xuechun Han, Zhixiu Sun, Mingxing Li, Yang Xie, Hongyi Yu, Huajun Chen, Bin Fath, Brian Wang, Yutao Department of Environmental Science & Engineering Fudan University Shanghai200438 China Schlossplatz 1 LaxenburgA-2361 Austria Institute of Circular Economy Faculty of Materials and Manufacturing Beijing University of Technology Beijing100124 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Growth Lab Harvard Kennedy School Harvard University CambridgeMA02138 United States Department of Biological Sciences Towson University Towson MD21252 United States Department of Environmental Studies Masaryk University Brno Czech Republic IRDR International Center of Excellence on Risk Interconnectivity and Governance on Weather Shanghai200438 China Shanghai Institute for Energy and Carbon Neutrality Strategy Fudan University Shanghai200438 China Shanghai200062 China

Urban land is the primary scene for economic manufacturing and services providing, through which the economic activities and trade flows amplify and cascade, interacting the natural and human systems. However, our understanding of the economic sectoral urban land metabolism remains inadequate. Here, we establish a spatially explicit sectoral urban land use inventory and a virtual land flow network for 13 cities in the Jing-Jin-Ji region in China to understand urban land use metabolism. Results show spatial heterogeneity in urban land use among industries and across spatial scales. Four cities exhibit reverse import and export roles in regional and national virtual land flow networks. It also reveals inequalities in benefit-cost and supply chain networks across cities, and a wide range of control and exploitation relationships in the region. We suggest that Beijing and Tianjin, as main beneficiaries in the regional economic network, are responsible for promoting regional sustainable development collaboration. © 2023, The Authors. All rights reserved.

关键词： Metabolism

Climatic and Biotic Controls of Evapotranspiration Across Grassland ecosystems on Tibetan Plateau

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SSRN 2023年

作者： Peng, Siyuan Yang, Yue Luo, Dengnan Zeng, Xiang Liang, Minqi Tao, Long Zhang, Guangru Li, Pan Liao, Weijie Guo, Qun Cao, Ruochen Li, Yuzhe Zhang, Weirong Hu, Zhongmin School of Geography South China Normal University Shipai Campus Guangzhou510631 China Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation School of Ecology and Environment Hainan University Haikou570228 China Center for Eco-Environment Restoration Engineering of Hainan Province Hainan University Haikou570228 China Facility of Geographical Science Beijing Normal University Beijing100875 China Zhuhai Branch of State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Zhuhai519087 China School of Atmospheric Sciences Guangdong Province Data Center of Terrestrial and Marine Ecosystems Carbon Cycle Sun Yat-sen University Guangdong Zhuhai510245 China Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing101408 China International Institute for Earth System Sciences Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing University Jiangsu210023 China Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources School of Geography and Ocean Science Nanjing University Jiangsu210023 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Accurately quantifying spatiotemporal variations in evapotranspiration (ET) and its components on Tibetan Plateau (TP) is crucial for understanding the regional water cycle and energy balance. However, the determinant of spatial variations in ET and its component processes in grassland ecosystems of TP remain unclear. In this study, we used 14 sites observation data and applied Shuttleworth-Wallace-Hu (SWH) model to investigate the spatial relationships between ET, its components, and influencing factors. Our results highlighted the good performance of SWH model. There were corresponding drops in ET on alpine meadow and on alpine steppe. And the ratio of ET and precipitation (ET/PPT) of most sites was less than 1 in alpine meadow. Furthermore, the ratio of transpiration (T) and ET (T/ET) in alpine meadow generally exceeded that in alpine steppe. PPT emerged as the primary driver of interannual spatial variations in ET, while LAI played a crucial role in regulating T/ET. Our results further demonstrated that in the grassland ecosystem of TP, as the aridity index increased, the ET gradually transitioned from being primarily influenced by water supply to energy demand. This transition occurred at an aridity index of 0.73 approximately. The results of this study imply that in the context of global warming, with aridity index in TP decreasing, the ET of more ecosystems will shift from energy-led to water-led. Such findings are of immense significance in enhancing our understanding of the intricate interactions of the water cycle between land and the atmosphere. © 2023, The Authors. All rights reserved.

关键词： Water supply