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Trophic Transfer and Accumulation of Heavy Metal and Arsenic Speciation in Freshwater Aquatic Organisms in Huangshui Creek, Shimen Realgar Mine, China by Quantifying Diet Compositions

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SSRN 2022年

作者： Yang, Fen Wei, Chaoyang Zhang, Huan Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Sino-Japan Friendship Center for Environmental Protection Beijing China

Heavy metal pollution is a worldwide concern and understanding the sources of metal accumulation in aquatic organisms is essential for maintaining a healthy ecosystem. In this study, aquatic organisms and five potential food sources (leaf litter, coarse and fine particulate organic matter (CPOM and FPOM), epilithon and fish) were collected around the carried the Shimen Realgar Mine area and the concentrations of 8 heavy metals and arsenic (As) speciation were analysed. Stomach content analysis and stable nitrogen and carbon isotope analysis, combined with the new Bayesian mixing model (MixSIAR), were used to quantity the diet composition of aquatic organisms. The δ13C and δ15N values varied based on both fish size and sampling sites and were probably related to the diet shift of aquatic organisms. The MixSIAR modelling results showed that large proportion of the aquatic organisms’ food was were FPOM (9%-68%) and epilithon (15%-65%), with leaf litter, CPOM and fish accounted for lower proportions (2%-30%). Concentrations ranged from 0.91 to 1298 mg/kg for As, 0.01 to 1.30 mg/kg for Cd, 0.12 to 37.79 mg/kg for Pb, 0.63 to 1158 mg/kg for Cr, 1.22 to 411 mg/kg for Cu, 0.82 to 1772 mg/kg for Mn, 0.31 to 542 mg/kg for Ni and 21.84 to 1414 mg/kg for Zn in all collected samples, including the aquatic organisms and the relevant food sources. Heavy metal concentrations in CPOM, FPOM and epilithon were significantly higher than those in aquatic organisms and leaf litter. In addition, the biomagnification factors were all less than 1, indicating a biodilution from diet to freshwater organisms. The predominant As species were inorganic in food sources, while organic As was common in aquatic organisms, indicating that As biotransformation occurred within the freshwater food chain. © 2022, The Authors. All rights reserved.

关键词： Heavy metals

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How farmers’non-agricultural employment affects rural land circulation in China?

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Journal of Geographical Sciences 2020年第3期30卷 378-400页

作者： WANG Jiayue XIN liangjie WANG Yahui 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 Geographical Science Southwest UniversityChongqing 400715China

To clarify the impact of non-agricultural employment on rural land circulation in China,we built logit models using the Chinese Household Income Project 2013 dataset,which includes 18,948 household samples over 15 provinces,126 cities and 234 counties of China in *** use the proportion of non-agricultural income,the proportion of non-agricultural laborers and non-agricultural fixed operating assets to reflect the degree of the households’dependence on agriculture,the degree of the households’laborers committed to non-agricultural employment and the stability of non-agricultural employment,*** results show that the stability of non-agricultural employment is an important reason for farmers to transfer out their land,and an increase in non-agricultural income is the fundamental *** proportion of non-agricultural assets has the greatest impact on the decision to transfer land,followed by the proportion of non-agricultural *** unit increase in the non-agricultural income ratio has a stronger effect on the transfer-out decision than it does on the transfer-in decision,which is a 0.09 increase of the probability of transfer-out the land and a 0.07 decrease of the probability of transfer-in the *** terms of regional differences,when considering the impact of non-agricultural employment on the land transfer-out decision,the impacts of non-agricultural income and labor force are the greatest in the Central *** impact of non-agricultural assets is the greatest in the Eastern *** the Eastern region,the decision to transfer out land is mainly affected by non-agricultural assets and the non-agricultural labor force,and the decision to transfer in land is mainly affected by non-agricultural *** the Central and Western regions,the decision to transfer out land is mainly affected by non-agricultural assets,non-agricultural income and the non-agricultural labor force,in that *** decision to transfer in land in the Central

关键词： farmers’non-agricultural employment rural land circulation moderate scale management China CHIP2013 dataset

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The Research on Optimization of Rice Phenology simulation Based on Bayesian Model Averaging

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SSRN 2022年

作者： Zheng, Jinhui Zhang, Shuai Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China

With the development of crop models, crop phenology models are widely used to simulate crop growth processes. The accuracy of crop phenology simulations using individual models varies, each with its strengths. The phenology simulation results of multi-model ensemble may be also not the best. Bayesian model averaging (BMA) accurately estimates model weights according to model simulation performance and has been widely used in many fields to get the best simulation by averaging multi-model simulations. This paper uses BMA to improve the simulation performance of phenology growth for rice from five phenology models in China. Firstly, five widely used rice phenology models (CERES-Rice, Beta model, ORYZA2000, RCM, and SIMRIW) are calibrated and validated based on rice phenology observation data from 1981 to 2009. The calibrated models have well performances for simulating the phenology of rice, with average RMSE (Root Mean Square Error) ranging from 3.98 to 4.43 days. Then, to optimize the phenology simulation results, BMA and the mean values of multi-model ensembles (Mean-MMEs) are applied to the phenology simulations from the five rice phenology models. The result indicates that the accuracies of the results from Mean-MMEs and BMA are improved by 11.48% and 12.75%, respectively. BMA performs the best, effectively optimizing the phenology simulation results of the individual model. The future climate scenario is constructed from Regional Integrated Environmental Model System (RIEMS). Under future climate scenarios, the phenology predictions of BMA, Mean-MMEs, and the five models all show that the vegetative growth period (VGP) and reproductive growth period (RGP) are shortened by 0.26-4.17 days;but in northeast China, they are prolonged by 0.39-4.44 days. Specifically, the five models predict a range of 0.40-9.78 days in the phenological period, while Mean-MMEs and BMA predict a smaller range of 0.54-1.63 days, which shows the MMEs reduce the uncertainty of the individu

关键词： Climate change

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

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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

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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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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

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

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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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