检索结果-南通市图书馆

Temporal variability of global potential water erosion based on an improved USLE model

International Soil and Water Conservation Research 2024年第1期12卷 1-12页

作者： Jialei Li Muqi Xiong ranhao sun Liding Chen State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China University of Chinese Academy of Sciences Beijing100049China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China

Assessing spatiotemporal variation in global soil erosion is essential for identifying areas that require greater attention and management under the effects of anthropogenic activities and climate *** erosion can be modelled using the universal soil loss equation(USLE),which includes rainfall erosivity(R-factor),vegetation cover(C-factor),topography(LS-factor),soil erodibility(K-factor),and management practices(P-factor).However,global soil erosion modeling faces numerous challenges,including data acquisition,calculation processes,and parameter calibration under different climatic and topographic ***,we presented an improved USLE-based model using highly distributed *** R-,C-,and P-factors were modified by the climate zone,country,and *** distributed model was applied to estimate the intensity and variations in global soil erosion from 1992 to *** validated the accuracy of this model by comparing simulations with measurements from 11,439 plot years of erosion *** results showed that i)the average global erosion rate was 5.78 t ha^(-1)year^(-1),with an increase rate of 4.26×10^(-3)t ha^(-1)year^(-1);ii)areas with significantly increasing erosion accounted for 16%of the land with water erosion,whereas those with significantly decreasing erosion accounted for 7%;and iii)areas with severe erosion included the western Ghats,Abyssinian Plateau,Brazilian Plateau,south and east of the Himalayas,and western coast of South *** erosion occurred mainly on the Amazon Plain and the northern coast of the *** study provides an improved water erosion prediction model and accurate information for researchers and policymakers to identify the drivers underlying changes in water erosion in different regions.

关键词： Soil erosion Distributed USLE model Rainfall erosivity Soil conservation Global change

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A conceptual model for a process-oriented landscape pattern analysis

引用

Science China Earth Sciences 2019年第12期62卷 2050-2057页

作者： Liding CHEN ranhao sun Yihe LU State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China The University of Chinese Academy of Sciences Beijing 100049China

Linking landscape patterns to specific ecological processes has been and will continue to be the key topic in landscape ***,this goal is difficult to achieve by using the traditional landscape metric based on the Patch-Mosaic Model(PMM),as they don’t integrate ecological processes with landscape *** this paper,we proposed a conceptual model,i.e.,the Source-Pathway-Sink Model(SPSM),which designates the role of a landscape unit into "source", "sink",or "pathway" based on specific ecological processes during the landscape pattern *** the traditional landscape metrics derived from the PMM model is visual-or geometrical-oriented and lack of linkage to ecological significance,the SPSM model is process-oriented,dynamic,and scale dependent.A comparison between the PMM and the SPSM models shows that the SPSM model is complementary to the PMM model,and can provide a simple and dynamic perspective on landscape pattern *** SPSM model may represent a conceptual innovation in landscape ecology.

关键词： Landscape metric Landscape pattern analysis Process-oriented Patch-Mosaic Model(PMM) Source-Pathway-Sink Model(SPSM) Ecological significance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Regional-scale Identification of Three-dimensional Pattern of Vegetation Landscapes

引用

Chinese Geographical Science 2014年第1期24卷 104-112页

作者： sun ranhao ZHANG Baiping CHEN Liding State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

The altitudinal pattern of vegetation is usually identified by field surveys,however,these can only provide discrete data on a local *** studies identifying and analyzing the altitudinal vegetation pattern on a regional scale are *** study selected central Inner Mongolia as the study area,presented a method for extracting vegetation patterns in altitudinal and horizontal *** data included a vegetation map at a 1∶1 000 000 scale and a digital elevation model at a 1∶250 000 *** three-dimensional vegetation pattern indicated the distribution probability for each vegetation type and the transition zones between different vegetation *** low to high elevations,there were five vegetation types in the southern mountain flanks,including the montane steppe,broad-leaved forest,coniferous mixed forest,montane dwarf-scrub and sub-alpine ***,only four vegetation types were found in the northern flanks,except for the montane *** study could provide a general model for understanding the complexity and diversity of mountain environment and landscape.

关键词： landscape pattern vegetation pattern altitudinal zone landscape identification mountain landscape

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis and assessment of heavy metal contamination in surface water and sediments： a case study from Luan River, Northern China

引用

Frontiers of Environmental Science & Engineering 2015年第2期9卷 240-249页

作者： Zhaoming WANG ranhao sun Haiping ZHANG Liding CHEN State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

Concentrations of the heavy metals Cu, Ni, Pb, Zn, Cd, and Cr were examined in surface water and sediment from the Luan River inChina,. With a decline in Cu and Ni concentration found in surface water at downstream stations. This finding suggests that water currents are a major explanatory factor in heavy metal contamination. The abundance of Cr, Pb, and Cd observed in the middle reaches of the river indicates heavy metal contamination in local areas, although there was an obvious decrease in concentrations in the water downstream of the Daheiting Reservoir. The significant rising trend in Cu, Pb, and Ni seen the sediment farther away from the river also suggests that anthropogenic activities contribute to heavy metal pollution Sediments were therefore used as environmental indicators, with sediment assessment was conducted using the geo-accumulation index （Igeo） and the potential ecological risk index （R/）. The Igeo values revealed that Cd （3.13） and Cr （2.39） had accumulated significantly in the Luan River. The R/values for most （89%） of the sampling stations were higher than 300, suggesting that sediment from the Luan River poses a severe ecological risk, with the potential ecological risks downstream higher than that in the upper and middle streams. Good correlations among Pb/Ni, Pb/Cd, Cu/Pb, and Cu/Cd in the water and Cr/Ni in the sediment were observed. Cluster analysis suggested that Cd may have various origins, being derived from anthropogenic sources.

关键词： tion index heavy metal water sediment geo-accumula- Luan River

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of riparian vegetation patterns on the distribution and potential loss of soil nutrients： a case study of the Wenyu River in Beijing

引用

Frontiers of Environmental Science & Engineering 2015年第2期9卷 279-287页

作者： Erhui GUO Liding CHEN ranhao sun Zhaoming WANG State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

A riparian ecosystem is an ecological transition zone between a river channel and terrestrial ecosystems. Riparian ecosystems play a vital role in maintaining stream health and bank stabilization. The types of riparian vegetation have changed greatly because of human activities along the Wenyu River. This study examines the impact of riparian vegetation patterns on water pollution due to soil nutrient loss. Four riparian vegetation patterns from the river channel to the upland were chosen as the focus of this study： grassland, cropland, grassland- cropland, and grassland-manrnade lawn. The different distributions of soil nutrients along vegetation patterns and the potential risk of nutrient loss were observed and compared. The results showed that riparian cropland has the lowest value of total nitrogen （TN）, total phosphorus （TP）, available nitrogen （AN）, available phosphorus （AP）, and organic matter （OM）, but it has the highest soil bulk density （BD）. The distributions of soil TN, TP, AN, AP, and OM exhibited a declining trend from the upland toward the river channel for riparian cropland, whereas a different trend was observed for the riparian grassland. The vegetation patterns of grassland-cropland and grassland- manmade lawn show that the grassland in the lower slope has more nutrients and OM but lower soil BD than the cropland or manmade lawn in the upper slope. So, the lower-slope grassland may intercept and infiltrate surface runoff from the upland. The lower-slope grassland has higher levels of soil TN, TP, AN, and AP, and thus it may become a new source of nutrient loss. Our results suggest that the management of the riparian vegetation should be improved, particularly in densely populated areas, to control soil erosion and river pollution.

关键词： riparian vegetation pattems soil nutrientdistribution nutrient loss management

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatial Scale Effects of Water Erosion Dynamics:Complexities, Variabilities, and Uncertainties

引用

Chinese Geographical Science 2012年第2期22卷 127-143页

作者： WEI Wei CHEN Liding YANG Lei FU Bojie sun ranhao State Key Laboratory of Urban and Regional Ecology Research Center for Eco-environmental SciencesChinese Academy of SciencesBeijing 100085China

Severe water erosion is notorious for its harmful effects on land-water resources as well as local societies. The scale effects of water erosion, however, greatly exacerbate the difficulties of accurate erosion evaluation and hazard control in the real world. Analyzing the related scale issues is thus urgent for a better understanding of erosion variations as well as reducing such erosion. In this review article, water erosion dynamics across three spatial scales including plot, watershed, and regional scales were selected and discussed. For the study purposes and objectives, the advantages and disadvantages of these scales all demonstrate clear spatial-scale dependence. Plot scale studies are primarily focused on abundant data collection and mechanism discrimination of erosion generation, while watershed scale studies provide valuable information for watershed management and hazard control as well as the development of quantitatively distributed models. Regional studies concentrate more on large-scale erosion assessment, and serve policymakers and stakeholders in achieving the basis for regulatory policy for comprehensive land uses. The results of this study show that the driving forces and mechanisms of water erosion variations among the scales are quite different. As a result, several major aspects contributing to variations in water erosion across the scales are stressed: differences in the methodologies across various scales, different sink-source roles on water erosion processes, and diverse climatic zones and morphological regions. This variability becomes more complex in the context of accelerated global change. The changing climatic factors and earth surface features are considered the fourth key reason responsible for the increased variability of water erosion across spatial scales.

关键词： water erosion spatial variation scale effect driving force uncertainty complexity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mass elevation effect and its forcing on timberline altitude

引用

Journal of Geographical Sciences 2012年第4期22卷 609-616页

作者： HAN Fang YAO Yonghui DAI Shibao WANG Chun sun ranhao XU Juan ZHANG Baiping Geographic Information and Tourism College Chuzhou UniversityChuzhou 239000AnhuiChina State Key Laboratory of Resource and Environment Information System Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental ScienceCASBeijing 100085China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China

The concept of mass elevation effect （massenerhebungseffect, MEE） was introduced by A. de Quervain about 100 years ago to account for the observed tendency for temperature-related parameters such as tree line and snowline to occur at higher elevations in the central Alps than on their outer margins. It also has been widely observed in other areas of the world, but there have not been significant, let alone quantitative, researches on this phenomenon. Especially, it has been usually completely neglected in developing fitting mod- els of timberline elevation, with only longitude or latitude considered as impacting factors. This paper tries to quantify the contribution of MEE to timberline elevation. Considering that the more extensive the land mass and especially the higher the mountain base in the interior of land mass, the greater the mass elevation effect, this paper takes mountain base elevation （MBE） as the magnitude of MEE. We collect 157 data points of timberline elevation, and use their latitude, longitude and MBE as independent variables to build a multiple linear regression equation for timberline elevation in the southeastern Eurasian continent. The results turn out that the contribution of latitude, longitude and MBE to timberline altitude reach 25.11%, 29.43%, and 45.46%, respectively. North of northern latitude 32°, the three factors＇ contribution amount to 48.50%, 24.04%, and 27.46%, respectively; to the south, their contribution is 13.01%, 48.33%, and 38.66%, respectively. This means that MBE, serving as a proxy indi- cator of MEE, is a significant factor determining the elevation of alpine timberline. Compared with other factors, it is more stable and independent in affecting timberline elevation. Of course, the magnitude of the actual MEE is certainly determined by other factors, including mountain area and height, the distance to the edge of a land mass, the structures of the mountains nearby. These factors need to be inctuded in the study of MEE qu

关键词： mass elevation effect mountain base elevation altitudinal belts quantification Eurasia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

区域气候背景对城市热岛效应的影响规律

引用

生态学报 2021年第11期41卷 4288-4299页

作者：王阳孙然好云南大学国际河流与生态安全研究院昆明650009 中国科学院生态环境研究中心城市与区域生态国家重点实验室北京100085

城市热岛效应受到区域气候背景的影响而具有显著的时空差异性,尚缺少大尺度对比研究。利用1991—2019年的月均气象数据,量化了我国69个典型城市的大气城市热岛效应强度,从热带、干带、暖温带、冷温带和极地带五个气候带,分析城市热岛效... 详细信息

城市热岛效应受到区域气候背景的影响而具有显著的时空差异性,尚缺少大尺度对比研究。利用1991—2019年的月均气象数据,量化了我国69个典型城市的大气城市热岛效应强度,从热带、干带、暖温带、冷温带和极地带五个气候带,分析城市热岛效应的时空特征规律。结果表明:(1)区域差异:干带热岛效应明显高于其他气候带,极地带最弱,且表现为较强的冷岛效应,热带、暖温带、冷温带热岛效应较弱,而冷温带的京津冀地区由于城市化程度较高,表现出较强的热岛效应,温暖带中西南地区较为明显;(2)季节性差异:不同季节城市热岛效应的强弱关系在不同气候带有所不同,秋季热岛效应较为稳定,热岛和冷岛效应均主要处于弱强度范围,春、冬热岛效应较为波动,易出现强热岛、强冷岛效应的极端现象,夏季热岛效应发生率最高;(3)时间演变规律:城市热岛效应的多年演变规律在相同气候带较为一致,2010年前后是各气候带各季节城市热岛效应的变化拐点,2010年后,干带、冷温带、暖温带热岛效应均有所下降,热带、极地带有所上升。

关键词：城市热岛效应大气城市热岛效应气候带冷岛效应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

金沙江下游典型库区消落带植被恢复模式

引用

生态学报 2023年第2期43卷 826-837页

作者：孙龙卢涛孙涛孙然好中国科学院生态环境研究中心城市与区域生态国家重点实验室北京100085 中国科学院成都生物研究所成都610041 中国科学院大学北京100049

消落带植被分布、生活型、多样性的调查研究显著促进了消落带植被恢复技术的进步,然而相邻两梯级库区消落带植被分布的差异以及植被群落特征的年际变化并不明确。此外,金沙江下游部分区域表现出一定的干热特征,其影响下的消落带植被群... 详细信息

消落带植被分布、生活型、多样性的调查研究显著促进了消落带植被恢复技术的进步,然而相邻两梯级库区消落带植被分布的差异以及植被群落特征的年际变化并不明确。此外,金沙江下游部分区域表现出一定的干热特征,其影响下的消落带植被群落特征有待深入了解。基于2019年和2021年向家坝和溪洛渡库区消落带植被调查结果,分析表明:(1)金沙江下游消落带按照下垫面特性主要分为硬岩型、软岩型、松软堆积型3种类型,坡度平缓的松软堆积型消落带是植被恢复的主要类型;(2)整体上,消落带优势植被类型是一年生和多年生草本,单优势种、少优势种群落较为普遍,两个库区消落带优势种重要值差异显著,植被生活型较少;(3)向家坝、溪洛渡库区消落带在分别经历6次和8次周期性水淹后,消落带植被分布与群落物种多样性特征变化不显著,表明消落带植被群落结构相对稳定。综上说明向家坝、溪洛渡两个相邻的梯级库区消落带植被恢复需要以灌草为主,且具有不同的潜在恢复模式,因此需要对应采取不同的恢复策略。研究对于科学指导金沙江下游梯级水电站库区消落带植被恢复具有重要意义。

关键词：梯级水库消落带植被生活型重要值多样性

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

城市绿地和建筑格局影响热环境的模拟研究

引用

生态学报 2021年第11期41卷 4300-4309页

作者：魏琳沅孙然好中国科学院生态环境研究中心城市与区域生态国家重点实验室北京100085 中国科学院大学北京100049

景观类型和格局能够影响城市热环境,但是在不同小区域背景下,它们的贡献差异尚缺少定量研究。将实地监测与数值模拟技术相结合,对北京市典型景观的风速场与温度场进行模拟研究,分析天空开阔度、绿地面积与风速、地表温度之间的关系。在... 详细信息

景观类型和格局能够影响城市热环境,但是在不同小区域背景下,它们的贡献差异尚缺少定量研究。将实地监测与数值模拟技术相结合,对北京市典型景观的风速场与温度场进行模拟研究,分析天空开阔度、绿地面积与风速、地表温度之间的关系。在此基础上,探讨绿地形态与绿地温度及地表温度的关系,同时设计多种典型的城市绿地、建筑格局在计算机中进行模拟,揭示不同绿地、建筑景观配置下热环境的影响因素。结果表明:(1)天空开阔度和风速是影响城市小区域热环境的重要因素,天空开阔度与地表温度显著负相关,高风速会明显降低地表温度;(2)绿地面积和形态是影响区域地表温度与气温的重要因素,占比10%—50%的绿地降温强度为1.4—2.2℃,面积越大、形态越复杂,降温效应越明显,分散的绿地降温效应优于集中式绿地;(3)迎风向呈两端低中间高的建筑分布可显著改善热环境,较其它格局气温约低1.6℃。研究结果对于指导城市景观设计改善城市热环境具有一定的参考价值。

关键词：景观格局配置热环境风速天空开阔度降温效应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：