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Adaptive Statistical Spatial Downscaling of Precipitation Supported by High-Resolution Atmospheric simulation Data for Mountainous Areas of Nepal

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Journal of Meteorological Research 2023年第4期37卷 508-520页

作者： Hua YANG Kun YANG Jun QIN Baohong DING Yaozhi JIANG Yingying CHEN Xu ZHOU Yan WANG Shankar SHARMA National Tibetan Plateau Data Center State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101 University of Chinese Academy of Sciences Beijing 100049 Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceInstitute for Global Change StudiesTsinghua UniversityBeijing 100084 State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101

In complex terrain regions, it is very challenging to obtain high accuracy and resolution precipitation data that are required in land hydrological studies. In this study, an adaptive precipitation downscaling method is proposed based on the statistical downscaling model MicroMet. A key input parameter in the MicroMet is the precipitation adjustment factor(PAF) that shows the elevation dependence of precipitation. Its value is estimated conventionally based on station observations and suffers sparse stations in high altitudes. This study proposes to estimate the PAF value and its spatial variability with precipitation data from high-resolution atmospheric simulations and tests the idea in Nepal of South Himalayas, where rainfall stations are relatively dense. The result shows that MicroMet performs the best with the PAF value estimated from the simulation data at the scale of approximately 1.5 degrees. Not only the value at this scale is qualitatively consistent with early knowledge obtained from intensive observations, but also the downscaling performance with this value is better than or comparable to that with the PAF estimated from dense station data. Finally, it is shown that the PAF estimation, although critical, cannot replace the importance of increasing input station density for downscaling.

关键词： precipitation statistical downscaling precipitation adjustment factor adaptive estimation high resolution dynamical downscaling

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Livestock Sampling Survey Dataset in Prairie Chenbarhu Banner,Hulunbuir Based on UAV Images(July 2023)

全球变化数据仓储（中英文）

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全球变化数据仓储（中英文） 2023年第12期 4-5页

作者： WANG Dongliang LI Yuzhe ZHANG Aochong Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

In July 2023,a sampling survey was conducted in Prairie Chenbarhu Banner,Hulunbuir City,utilizing UAV for aerial *** on the method of human-machine interaction and visual interpretation,the stitched aerial strips were interpreted to obtain livestock location data in the study *** livestock population in the entire Chen Barag Banner was estimated using two different *** dataset includes:(1)boundary data of the study area;(2)boundaries of the sample strips surveyed by UAV in 2023;(3)location of livestock surveyed in 2023;(4)estimated livestock population *** dataset is archived *** *** formats,and consists of 49 data files with data size of 12.5 MB(Compressed into one file with 4.19 MB).

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Revealing climatic impacts on the temporal and spatial variation in vegetation activity across China:Sensitivity and contribution

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Advances in Climate Change Research 2021年第3期12卷 409-420页

作者： JIAO Ke-Wei GAO Jiang-Bo LIU Zhi-Hua WU Shao-Hong Tamara L.FLETCHER Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang110016China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China

Relative weakness in sensitivity and contribution integration,especially lack of specific indicators at spatial and temporal scales,may hinder the formation of systematic knowledge for climate change impact on vegetation *** the interannual variability and periods difference,we investigated the ecosystem sensitivity to hydrothermal conditions and the contribution of individual climatic factors to vegetation activity on spatiotemporal scales during the period of 1980s—2013 in *** ran simulations of the Common Land Model(CoLM)to obtain the photosynthetic rate,and used the satellite-derived Normalized Difference Vegetation Index(NDVI),to which we applied a temporal sensitivity analysis,the slope change ratio of accumulative quantity(SCRAQ),and geographical *** show that the discrepancy between warming and precipitation variation contributed to vegetation activity was more notable than the ecosystem sensitivity to hydrothermal conditions,regardless of which temporal and spatial scale was *** sensitivity of vegetation activity to hydrothermal variation in most parts of northeastern and western China was higher than elsewhere,and the contribution of warming to vegetation dynamics was relatively high in the Inner Mongolian Plateau and Tibetan Plateau(>60%),where the contribution of warming to the vegetation distribution was also greater than elsewhere in ***,the contribution of precipitation variation to vegetation dynamics was comparatively greater in northwestern China and subtropical and tropical regions(>55%).The spatiotemporal contribution of precipitation variation to vegetation activity differed between regions,especially on the Tibetan Plateau and in subtropical and tropical ***,both the temporal and spatial sensitivities to climate change were weak in the subtropical and tropical regions,where the contribution of climatic factors to vegetation distribution was also ***,temperature sensit

关键词： Vegetation activity Climate change Sensitivity Contribution Spatial-temporal scales China

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Exploring the roles of recorded unprecedented rainfall-runoff characteristics and uplifted riverbeds in the catastrophic 2022 Pakistan megaflood

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Advances in Climate Change Research 2025年第2期16卷 409-424页

作者： Bazai, Nazir Ahmed Cui, Peng Hussain, Tahir Zhang, Guo-Tao Wang, Yan Akhter, Muhammad Gulraiz Wang, Hao Alam, Mehtab Key Laboratory of Mountain Surface Process and Hazards/Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Key Laboratory of Land Surface Pattern and Simulation/Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China China–Pakistan Joint Research Center on Earth Sciences CAS-HEC Islamabad 45320 Pakistan Department of Earth Sciences Quaid-i-Azam University Islamabad 45320 Pakistan Department of Civil Engineering Ghulam Ishaq Khan Institute of Engineering Sciences and Technology Swabi Topi 23640 Pakistan

Catastrophic floods triggered by extreme monsoonal rainfall have increasingly posed challenges in flood management, particularly in low-income nations like Pakistan. The 2022 megaflood exposed substantial gaps in understanding the interplay between rainfall, sediment dynamics, and flood amplification processes. This study investigates the causes and impacts of the event, focusing on floodwater sources, geomorphological changes, and future risks and mitigation strategies. A multifaceted approach combined with remote sensing, field observations, hydro-meteorological data, and climate models was employed. In July–August 2022, the lower Hindukush, Koh-e-Suleman, and Kirther ranges experienced rainfall of 200–300 mm, up to 726% above historical averages (1991–2021). This high-intensity rainfall triggered high-magnitude discharges from approximately 1250 streams, 58 % of which were primary contributors with discharge at 4000–5000 m³/s for nearly a month, causing 80%–85% of downstream damage and expanding the flooded area to 49,711 km². Some streams recorded 5–6 m flood levels, resulting in sedimentation deposition of 0.8–1 m in residential areas and about 2 m in the streambeds. Deposition downstream and along the Indus River reached 1.5–2 m, intensifying flood risks by reducing channel capacity and increasing water levels during flood events. Streambed uplift and sediment deposition emerged as critical factors amplifying flood magnitude, severity, and inundation, with floodwater levels rising by up to 2.4–3 m in some areas, posing severe risks for future events. These findings highlight the need to revise traditional flood risk models, which often overlook sediment dynamics and underscore the future challenges posed by ongoing sediment deposition and climate change, which are expected to exacerbate flood risks in the coming decades. The study emphasizes the importance of sediment management, river erosion control, and post-event interventions. Priori

关键词： Extreme monsoon circulation Future challenges Pakistan megaflood Riverbed uplifting Unprecedented high-magnitude streamflow

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China's agricultural land use change and its underlying drivers:A literature review

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Journal of Geographical Sciences 2021年第8期31卷 1222-1242页

作者： WANG Xue LI Xiubin Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Understanding the manifestations and underlying drivers of agricultural land use change in China is of great importance for both domestic and global food security. However, little is known about the holistic pattern of agricultural land use change across China, especially from the perspective of intensity since the evidence has been gathered mainly through case studies at local levels. This study conducts a systemic review of agricultural land use change and its underlying drivers in China by aggregating 169 relevant case studies from 123 publications. The cases related to intensification and disintensification, which are the two types of agricultural land use change, are generally equal, accounting for 50% of the total number of cases. Intensification and disintensification can be further divided into the same three categories: expansion/contraction of agricultural land, changes in agricultural land use activities and changes in land management intensity. Demographic, economic, technological, and institutional drivers, together with location factors, are frequently noted as significant underlying drivers, while sociocultural drivers and farm(er) characteristics are less frequently recognized. Finally, three major land use change trajectories are summarized mainly concerning rising labor costs and the concomitant increase in off-farm employment, the ecological improvement policy, and advances in agricultural technology.

关键词： agricultural land land use intensity driving forces aggregate analysis China

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A Review on Diagnostic Phytoliths for the Application in Paleovegetation Reconstruction and Environmental Archaeology in East Asia

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International Journal of Geosciences 2024年第6期15卷 479-492页

作者： Weiyu Chen Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China College of Resources and Environment University of Chinese Academy of Sciences Beijing China

Phytoliths are extensively utilized as an archaeobotanical indicator in paleovegetation reconstruction and environmental archaeology. Over the past two decades, numerous phytolith morphotypes, particularly those exhibiting diagnostic morphological features and over representative of source plants at the genus and species levels, were discovered and reported. These advancements have significantly contributed to phytolith-based vegetation reconstruction on different timescales, enhanced our understanding of prehistoric plant utilization, and elucidated cultivation and domestication processes of key crops in ancient agriculture. However, there are still inconsistencies and misunderstandings regarding the morphological characteristics of diagnostic phytoliths in various plant groups. This review highlighted the standardization in the classification and description of phytolith morphotypes, and summarized the advancements in phytolith morphology research over the past two decades. Morphological illustrations of diagnostic phytoliths from various plant groups, particularly key crops and their relatives from dryland and rice agriculture in East Asia, were presented as references for phytolith identification and application. Finally, this review proposes future directions for phytolith morphological studies, emphasizing the comprehensive consideration of anatomical structure and morphometric parameters, as well as the need for extensive research on modern plant phytoliths and control experiments on phytolith growth.

关键词： Diagnostic Phytolith Paleovegetation Reconstruction Environmental Archaeology

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西藏羊卓雍错湖面水热通量变化及其与气象因子的关联

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Journal of Geographical Sciences 2024年第2期34卷 397-414页

作者：张雪芹靳铮沈鹏珂郑度 Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200438China National Climate Center China Meteorological AdministrationBeijing 100081China

Lake surface water-heat exchange and its climatic attribution critically influence alpine lakes’evaporation mechanism and water storage balance with climate ***,this paper first explored the hourly,daily,and monthly water-heat flux variations of the lake surface and their correlations with meteorological factors based on the eddy covariance turbulent flux observation over the Yamzhog Yumco,an alpine lake in south Tibet in the non-freezing period(April-December)in 2016 and *** found that the average latent heat flux was much higher than the sensible heat flux on the lake surface from April to ***,the water-heat flux exhibited remarkable seasonal variation,with a prominent role of higher air temperature and humidity in summer jointly controlling the lake-air energy ***,the main controlling meteorological factors for the water-heat flux variation of the lake surface differed with diversified ***,the lake-air temperature difference was the most significant meteorological factor related to sensible heat flux on the half-hourly,daily,and monthly ***,the latent heat flux was strongly positively correlated with wind speed and the synergies of wind speed and water vapor pressure deficit on the daily and half-hourly ***,the lake surface heat flux was significantly negatively correlated with net radiation flux on the daily and monthly *** negative correlation can be attributed to the seasonal variation of the water surface net radiation,and the phase difference in heat flux intensity caused by the lake-air temperature difference and heat capacity *** findings will hopefully improve the understanding of energy exchange and evaporation mechanisms for alpine lakes in a warming climate.

关键词： lake surface water-heat flux meteorological factor eddy covariance alpine lakes Yamzhog

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Divergent effects of climate change on cropland ecosystem water use efficiency at different elevations in southwestern China

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Journal of Geographical Sciences 2022年第8期32卷 1601-1614页

作者： TAO Jian ZHU Juntao ZHANG Yangjian DONG Jinwei ZHANG Xianzhou School of Public Administratio n Shand ong Tech no logy and Business UniversityYantai 264005ShandongChina Nagqu Alpine Grassland Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China

Understanding climatic effects on cropland water use efficiency at different elevations is imperative for managing agricultural water and production in response to ongoing climate change in climate-sensitive areas with complex topography, such as southwestern China. We investigated climatic effects on cropland water use efficiency in southwestern China at each 100-m elevation bin during 2001–2017. The maximum water use efficiency was 1.71 gC kg^(–1) H_2O for the 1900–1999 m elevation bin under the growing season temperature and precipitation of 14.58±0.32℃ and 965.40±136.45 mm, respectively. The water use efficiency slopes were dominated by the evapotranspiration slopes at elevations below 1999 m but were controlled by the gross primary productivity slopes at elevations above 2000 m. This difference was caused by the substantial responses of evaporation to climate change at lower elevations and the increased climatic sensitivity of gross primary productivity at higher elevations. In comparison to those at other elevations, croplands at lower elevations were more vulnerable to extreme drought because of the dominant role fluctuating evapotranspiration played in water use efficiency. The findings will improve cropland water management in the study area.

关键词： cropland water use efficiency southwestern China elevational gradient

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Evolutionary process and development implications of traditional trade routes in the Himalayan region

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Journal of Geographical Sciences 2022年第9期32卷 1847-1865页

作者： WU Shihai YAN Jianzhong ZHANG Yili PENG Ting SU Kangchuan College of Resources and Environment Southwest UniversityChongqing400716China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing100049China College of Geographical Science Southwest UniversityChongqing400716China

Traditional trade routes that penetrate the natural barrier of the Himalayas are critical for connecting major Chinese and South Asian *** on these trade routes can contribute significantly to facilitating the construction of the South Asian Corridor and enhancing trans-Himalayan *** historical literature,field surveys,and geographic information system(GIS)techniques,this study examined the spatial distribution characteristics and evolution process of the routes,focusing on transverse valleys of the Himalayan *** key findings were as ***,there are 21 traditional trade routes traversing the Himalayan region:six Sino-Nepalese routes,four Sino-Bhutanese routes,and eleven Sino-Indian ***,the evolution of traditional trade routes has entailed five distinct phases:an incipient period(pre-7th century),formation(7th century-842 AD),development(842-1959),decline(1959-1962)and recovery(1962-present).Third,the incipient and formative developmental phases were prompted by the spread of Buddhism and the exchange of *** stability of local governments in Tibet and Central China and favourable border trade policies along with Britain’s colonial expansion and commercial interests stimulated further development of traditional trade ***,India’s strategic miscalculation and“Forward Policy”instigated the decline phase,while the demands of regional cooperation and development are currently the key drivers of the restoration and construction ***,to shelve disputes,promote cooperation and development,and enhance political mutual trust,governments should recover and construct traditional trade routes by replanning and constructing border trade markets,expanding border trade,developing pilgrimage and tourism,and strengthening cross-border cooperative resear h under global climate change.

关键词： traditional trade routes evolution process and mechanism cooperation and development Himalayan region

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Extent and spatial distribution of terrace abandonment in China

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Journal of Geographical Sciences 2023年第7期33卷 1361-1376页

作者： DONG Shijie XIN Liangjie LI Shengfa XIE Hualin ZHAO Yuluan WANG Xue LI Xiubin SONG Hengfei LU Yahan Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Lab of Guangdong for Utilization of Remote Sensing and Geographical Information System/Guangdong Open Laboratory of Geospatial Information Technology and Application Guangzhou Institute of GeographyGuangdong Academy of SciencesGuangzhou 510070China Institute of Ecological Civilization Jiangxi University of Finance and EconomicsNanchang 330013China College of Geography and Environmental Science Guizhou Normal UniversityGuiyang 550001China

Driven by urbanization and industrialization,arable land in hilly and mountainous regions of China is gradually becoming marginalized,with the extent of arable land abandonment rapidly expanding from poor-quality sloping arable land to high-quality *** abandonment of large-scale terraces will lead to a series of socio-economic and ecological effects.A national sample survey was used to investigate the extent and spatial distribution of terrace abandonment in China,and a total of 560 valid village questionnaires from 329 counties were collected in the mountainous areas of *** main findings are as follows:(1)The phenomenon of terrace abandonment was widespread throughout the country,with 54% of the total surveyed villages exhibiting terrace abandonment,and the area of abandoned terraces accounting for 9.79% of the total.(2) The degree of terrace abandonment is high in the south and low in the *** most serious region with abandonment was the hilly and mountainous areas in the south,especially in the middle and lower Yangtze River region.(3)The main driving factors of terrace abandonment were rural labor migration,agricultural mechanization level,irrigation conditions,and transportation conditions for *** measures should be taken based on the specific conditions of each area to alleviate terrace *** such as improving terrace mechanization are universally ***,low-quality terraces can be withdrawn orderly,and for high-quality terraces,multiple measures are needed to consolidate agricultural production,such as adjusting the planting structure,strengthening agricultural infrastructure construction,and encouraging the transfer of land-use rights as well as large-scale operation.

关键词： terraces arable land abandonment national sample survey spatial variation China

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