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Long-term reconstruction of flash floods in the Qilian Mountains,China,based on dendrogeomorphic methods

Journal of Mountain Science 2022年第11期19卷 3163-3177页

作者： QIE Jia-zhi ZHANG Yong TRAPPMANN Daniel ZHONG Yi-hua BALLESTEROS-CÁNOVAS Juan Antonio FAVILLIER Adrien STOFFEL Markus Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Climate Change Impacts and Risks in the Anthropocene(C-CIA) Institute for Environmental SciencesUniversity of GenevaGeneva CH-1205Switzerland Dendrolab.ch Department of Earth SciencesUniversity of GenevaGeneva CH-1205Switzerland National Museum of Natural Sciences MNCN-CSICC/Serrano 115bis28006MadridSpain Department F.-A.Forel for Environmental and Aquatic Sciences University of GenevaGeneva CH-1205Switzerland

In China,flash floods are one of the main natural disasters causing loss of life and damage to *** threat of flash floods is exacerbated with climate change and increased human activities,such that the number of disasters has shown a clear upward trend in recent ***,due to the scarcity of instrumental data or overly short timeseries,we are still lacking critical data to understand spatio-temporal patterns and driving factors of extreme flash *** missing knowledge is however crucial for a proper management of these hazards,especially in remote mountain *** forested catchments,dendrogeomorphology allows the reconstruction of past process activity based on growth disturbances(GDs)in trees that have been affected by past flash ***,in our study,for the first time,we reconstruct past flash floods in the Qilian Mountains,northeast Tibetan Plateau,over past *** this end,we sampled 99 Qinghai spruce(Picea crassifolia)trees affected by flash floods,with a total of 194increment cores,and identified 302 GDs induced by past flash *** GDs have been caused by at least 21 flash floods that we are able to reconstruct over the last 170 *** position of GDs within tree rings and the intra-seasonal dating of past events also allowed discussion of the likely synoptic situations that may have led to the triggering of flash floods in the *** regression analysis confirms that significant correlation exists between cumulative maximum 5-day August-September precipitation and reconstructed flash floods,which is corresponding to the majority of scars and related tangential rows of traumatic resin ducts(TRDs)found in the latewood portion of growth *** results support the idea that abundant precipitation occurring at the end of the summer season and early fall is the key factor driving flash floods in our study *** research not only fills the gaps regarding historical flash flood histories in

关键词： Tree ring Dendrogeomorphology Flash floods Qinghai spruce Qilian Mountains

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Seasonal Variations of Global Groundwater Arsenic Response to World Crop Cultivation Areas

SSRN

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SSRN 2022年

作者： Yin, Shuhui Yang, Linsheng Wei, Binggan 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

Geogenic arsenic in shallow groundwater affects more than billions of people worldwide. Seasonal variations of groundwater arsenic have been recorded in diverse sites. Yet, how the variations response to crop cultivation at the global scale is poorly understood. Therefore, distribution of global groundwater arsenic in both dry season and wet season is predicted by using forest random model. Global maps indicate that spatial patterns of groundwater arsenic are varied between dry season and wet season. The increasing of areas with higher groundwater arsenic in the wet season are mainly associated with world grain-producing areas such as Southeast Asia, South Asia, Europe, and North America. Maize cultivation increases the areas with higher arsenic concentrations in the wet season. Rice cultivation increases the rates of areas with higher arsenic concentrations in the wet season when the rates of rice cultivation areas are lower than 10%, then the rates are decreasing, while wheat cultivation decreases the rates when the rates of wheat cultivation areas are lower than 10%, then the rates are increasing. Rates of groundwater arsenic variation areas are obviously affected by the rates of rice, wheat, and maize cultivation areas. Grain-producing may increase areas with higher groundwater arsenic concentrations in the wet season and increases groundwater arsenic levels during the wet season. Therefore, it suggests that drinking groundwater safety, food security and human health risk in relation with groundwater arsenic in the world grain-producing areas is an unavoidable issue except for known arsenic-affected areas. © 2022, The Authors. All rights reserved.

关键词： Arsenic

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Polydimethyldiallylammonium Chloride Stifles Sludge Anaerobic Digestion: key Role of Quaternary Amine Groups

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SSRN 2022年

作者： Jiao, Yimeng Yang, Xiao Chen, Hongbo College of Environment and Resources Xiangtan University Xiangtan411105 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China

Polydimethyldiallylammonium chloride (PDDA) is widely used as a cationic organic flocculant in wastewater treatment and sludge dewatering. However, it is unclear whether PDDA affects the subsequent anaerobic digestion of sewage sludge. This study reveals the potential impact of PDDA on sludge anaerobic digestion and its underlying mechanism. The cumulative methane production in anaerobic digestion is negatively correlated with PDDA concentration. 40 g/kg total suspended solids PDDA reduces methane production from 147.9 ± 0.35 to 131.1 ± 0.84 mL/g volatile suspended solids. The quaternary amine group in PDDA neutralizes the negatively charged amino group in extracellular polymeric substances to form large sludge flocs and hinder the release of organic matter. The quaternary amine groups induce the production of reactive oxygen species and down-regulates the activity of key enzymes, thereby inhibiting hydrolysis, acidification, and methanogenesis. Furthermore, PDDA reduces microbial diversity and makes the microbial community structure unfavorable for anaerobic digestion. The results of this article establish mechanisms that underpin how PDDA affects WAS anaerobic digestion and identify the pivotal role of quaternary amine groups. © 2022, The Authors. All rights reserved.

关键词： Anaerobic digestion

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Evaluating the reliability of global historical land use scenarios for forest data in China

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Journal of Geographical Sciences 2020年第7期30卷 1083-1094页

作者： YANG Fan HE Fanneng LI Meijiao LI Shicheng 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 School of Public Administration China University of GeosciencesWuhan 430074China

Global historical land use scenarios are widely used to simulate the climatic and ecological effects of changes in land cover;however,reliability evaluation of these scenarios for data on China’s forests is *** using a historical document-derived Chinese forest dataset(CHFD)for the years 1700–2000,we evaluated the reliability of data on forests in China over three global scenarios-SAGE(Center for Sustainability and the Global Environment),PJ(Pongratz Julia),and KK10(Kaplan and Krumhardt 2010)-through trend-related,quantitative,and spatial *** results show the following:(1)Although the area occupied by forests in China in the SAGE,PJ,KK10,and CHFD datasets decreased over the past 300 years,there were large differences between global scenarios and *** area occupied by forests in China in the SAGE scenario for 1700–1990 was 20%–40%more than that according to CHFD,and that occupied by forests in the KK10 from 1700 to 1850 was 32%–46%greater than that in *** difference between the PJ and CHFD was lower than 20%for most years.(2)Large differences were detected at the provincial and grid cell scales,where the PJ scenario was closer to CHFD in terms of total forested *** with large differences in terms of trend and quantity were 84%and 92%of all provinces,*** cells with relative differences greater than 70%accounted for 60%–80%of all grids.(3)These global historical land use scenarios do not accurately reveal the spatiotemporal pattern of Chinese forests due to differences in the data sources,methods of reconstruction,and spatial scales.

关键词： land use historical forest natural vegetation global scenarios reliability evaluation China

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Thresholds for the relationships between soil trace elements and ecosystem multifunctionality in degraded alpine meadows

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Agriculture, Ecosystems and Environment 2025年 391卷

作者： Wu, Yuping Ding, Mingjun Zhang, Hua Zou, Tiane Huang, Peng Xu, Huan Zhang, Yueju Zeng, Huan Xiong, Jiaxin Cheng, Liyao Liu, Linshan Zhang, Yili Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education/School of Geography and Environment Jiangxi Normal University Nanchang 330022 China Jiangxi Provincial Key Laboratory of Poyang Lake Comprehensive Management and Resource Development Jiangxi Normal University Nanchang 330022 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Trace elements in soil are known to affect ecosystem functions, such as soil microbial structure, function, and grassland productivity. However, it is largely unknown whether soil trace elements cause abrupt or gradual changes in ecosystem multifunctionality (EMF) in degraded alpine ecosystems and how they depend on environmental drivers. In this study, we investigated the vegetation and soil conditions in 172 sample squares in an alpine meadow area on the Tibetan Plateau, China. This study aimed to analyse the change characteristics in alpine meadow EMF and soil trace element contents at different degradation stages. Furthermore, we evaluated the soil trace element contributions to alpine meadow EMF. This study revealed that EMF decreased with increasing degradation, whereas total soil micronutrient content exhibited the opposite trend. A threshold was identified for regulating EMF using micronutrients during alpine meadow degradation. Soil micronutrients enhanced EMF during the initial stages of alpine meadow degradation. However, as degradation progressed, elevated soil micronutrient levels impeded EMF. In addition, climate can modulate soil trace elements through plant diversity and soil physicochemical properties, thereby influencing the role of soil trace elements in driving EMF. Soil physicochemical properties contributed the most to EMF, whereas soil trace elements, rather than plant diversity, significantly influenced EMF. Overall, soil trace elements in the degraded meadows had a significantly negative impact on EMF. © 2025 Elsevier B.V.

关键词： Degraded ecosystem multifunctionality Soil trace elements Threshold effects Tibetan plateau

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70 years of urban expansion across China: trajectory, pattern, and national policies

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Science Bulletin 2020年第23期65卷 1970-1974,M0003页

作者： Wenhui Kuang Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

新中国成立70年来,国家城市化水平显著提升,城市建设取得了辉煌的成绩.本研究采用卫星遥感、历史地图及文献资料,系统重现了新中国成立70年来(1949~2018年)城市扩展的时空轨迹,揭示了国家城市扩展的格局、态势及政策的驱动作用.研究表明... 详细信息

新中国成立70年来,国家城市化水平显著提升,城市建设取得了辉煌的成绩.本研究采用卫星遥感、历史地图及文献资料,系统重现了新中国成立70年来(1949~2018年)城市扩展的时空轨迹,揭示了国家城市扩展的格局、态势及政策的驱动作用.研究表明, 70年来中国城市土地面积由1949年的5600 km2增长到2018年的74800km2,增长了约12倍,由农业生产为主的社会转变为以现代工业和服务业为主的国家.改革开放以来,国家实施的东部沿海地区率先发展战略极大地推进了东部沿海地区城市扩展."西部大开发"战略显著带动了西部地区城市扩展,有效缩减了区域差异.新时代"美丽中国"生态文明建设城市宏伟蓝图的绘制,提出仍需解决好城市发展的区域不平衡问题,从而塑造未来城市发展的新格局.

关键词：西部大开发区域不平衡西部地区城市区域差异驱动作用生态文明建设文献资料城市化水平

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Precision Characterization of Soil-Groundwater Contamination in an Industrial Park, North China: Bp-Ann Model Prediction and Migration Mechanism

SSRN

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SSRN 2023年

作者： Liu, Siyan Yang, Xiao Liu, Zhaoshu Yan, Xiulan Jin, Xiaoli Zhou, Yaoyu Liang, Tao Key Laboratory of Land Surface Pattern and Simulation 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 Beijing100190 China College of Resources and Environment Hunan Agricultural University Changsha410128 China

Intensive industrial activities cause soil contamination with wide variations and even perturb groundwater safety. The links between contamination and geochemical features, however, have not been established yet due to the intricate hydrogeology and industrial processes. In this study, 880 soil samples and 8 groundwater samples were collected in an industrial park in China to precisely characterize the contamination levels of soil-groundwater system and migration mechanisms. Our research delineated the spatial distribution pattern of contaminants via the back propagation neural network algorithm (BP-ANN) prediction and visualization of a three-dimensional contamination plume model, and clarified the migration mechanisms in both soil and groundwater systems. Arsenic (As) and 1,2-dichloroethane (1,2-DCA) were identified as the primary contaminants in the site soil, and their vertical migration depth arrived to 6-8 m, however, a distinct migration behavior was found in between the two contaminants. Correlation analysis revealed that hydrogeological characteristics were recognized critical for the migration of As, while the migration of 1,2-DCA depended on soil lithology and water content. Contaminants migrate vertically downwards with soil water under gravity-driven conditions and penetrate through the soil barrier to reach the saturated aquifer, forming a contamination plume with groundwater flow. The migration behaviors and influencing mechanisms in the soil-groundwater system of an industrial park were confirmed for the first time through field tests combining machine learning algorithms. Our findings are imperative to build capabilities in monitoring the contamination status of industrial sites and provide valuable technical support for maintaining sustainable industry. © 2023, The Authors. All rights reserved.

关键词： Contamination

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Spatiotemporal process and mechanism of Kashin-Beck disease regression in Xizang during 2000-2015

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Dili Xuebao/Acta Geographica Sinica 2024年第11期79卷 2849-2863页

作者： Wang, Jing Li, Ruonan Wei, Binggan Li, Hairong Guo, Min Key Laboratory for Geographical Process Analysis & Simulation Research Institute of Sustainable Development Central China Normal University Wuhan430079 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing100101 China Xizang Autonomous Region Center for Disease Control and Prevention Lhasa850030 China

Kashin-Beck disease (KBD) control in Xizang has now entered a new stage of consolidation and improvement. Clarifying the spatiotemporal mechanism of its regression is of great significance for promoting the long-term prevention and control of endemic diseases in the plateau. Based on the detection rate data of KBD in Xizang from 2000 to 2015 and by the methods of random forest and spatial statistics, this study analyzed the spatiotemporal variation characteristics of KBD and explored the main factors affecting the regression of KBD and their regional differences. The results showed that: (1) The condition of KBD decreased steadily in all parts of Xizang during 2000-2015. The spatial distribution of KBD gradually converged to the east from the overall pattern of high in the east and low in the west, high in the south and low in the north. The disease was the most serious and had the longest duration in Qamdo wards. (2) The top four major factors affecting the regression of KBD were per capita food consumption of farmers and herdsmen, per capita GDP, per capita disposable income of farmers and herdsmen, and NDVI. Except for NDVI, all the other factors showed negative correlations with the detection rate of KBD. (3) In Ali, the prevalence of KBD was mainly influenced by per capita GDP and the income level of farmers and herdsmen, while in the middle reaches of the Yarlung Zangbo River and Qamdo, wards were more affected by dietary factors. (4) The dominant factors for the prevalence of KBD varied greatly within different years, which specifically manifested as a shift from natural factors to humanistic and social factors. Social economy, dietary nutrition and land use patterns played important roles in the prevention and control of KBD in Xizang. In view of the unique environmental conditions in Xizang, strengthening diversified food supply and adhering to returning farmland to forests and grasslands are still the basic countermeasures for preventing and controlling KB

关键词： influence mechanism Kashin-Beck disease (KBD) random forest spatiotemporal variation Xizang

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Precision Characterization of Soil-Groundwater Contamination in an Industrial Park, North China: Bp-Ann Model Prediction and Migration Mechanism

SSRN

引用

SSRN 2023年

Intensive industrial activities cause soil contamination with wide variations and even perturb groundwater safety. The links between contamination and geochemical features, however, have not been established yet due to the intricate hydrogeology and industrial processes. In this study, 880 soil samples and 8 groundwater samples were collected in an industrial park in China, and the spatial distribution patterns of contaminants were delineated via the back propagation neural network algorithm prediction and visualization of a three-dimensional contamination plume model, and clarified the migration mechanisms in both soil and groundwater systems. Arsenic and 1,2-dichloroethane were identified as the primary contaminants in the site soil, and their vertical migration depth arrived to 6-8 m, however, a distinct migration behavior was found in the two contaminants. Correlation analysis revealed that hydrogeological characteristics were recognized critical for the migration of arsenic, while the migration of 1,2-dichloroethane depended on soil lithology and water content. Contaminants migrate vertically downwards with soil water under gravity-driven conditions and penetrate through the soil barrier to reach the saturated aquifer, forming a contamination plume with groundwater flow. Our findings are imperative to build capabilities in monitoring the contamination status of industrial sites and provide valuable technical support for maintaining sustainable industry. © 2023, The Authors. All rights reserved.

关键词： Spatial distribution

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Spatiotemporal pattern of the dynamics in area,production,and yield of Aus rice in Bangladesh and its response to droughts from 1980 to 2018

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Journal of Geographical Sciences 2022年第10期32卷 2069-2084页

作者： KHONDAKAR Arifuzzaman DONG Jinwei LI Zhichao DENG Xiangzheng SINGHA Mrinal RAHMAN Md.Mizanur JIN Zhenong WANG Shaoqiang ZHEN Lin XIAO Xiangming Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100094China Department of Geography and Environment Pabna University of Science and TechnologyPabna 6600Bangladesh Deputy Director(Monitoring) Field Services WingDepartment of Agricultural ExtensionMinistry of AgricultureBangladesh Department of Bioproducts and Biosystems Engineering University of Minnesota-Twin CitiesSaint PaulMNUSA Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China Department of Microbiology and Plant Biology University of OklahomaNorman OK 73019USA

Bangladesh is one of the most vulnerable countries to natural disasters such as droughts in the *** pre-monsoon Aus rice in Bangladesh depends on rainfall and is threatened by increasing ***,limited information on the changes in Aus rice as well as droughts hamper our understanding of the country’s agricultural resilience and adaption to ***,we collected all the official statistical data of Aus rice at the district level from 1980 to 2018,and examined the interannual variations of area,yield,and *** results showed both area and production of Aus rice decreased significantly(61.58×103 ha yr-1 and 17.21×103 *** yr-1,respectively),while yield increased significantly(0.03 *** ha-1 yr-1).We also found a significantly increasing trend of droughts in 88%of area based on the Palmer Drought Severity Index(PDSI)data,especially in those rainfed agricultural ***,we found significant positive correlations between PDSI and Aus rice area(production)in 33(25)out of 64 *** is hardly a relationship between PDSI and yield,likely due to the improved management and increasing irrigated *** continuous drought monitoring,combined irrigation(surface and groundwater)systems,and conservation and precision agriculture are highly recommended in these drought-prone districts to ensure food security in Bangladesh.

关键词： Aus rice droughts acreage production yield PDSI Bangladesh

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