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31.
Mega-urban agglomerations are strategic core areas for national economic development and the main regions of new urbanization. They also have important roles in shifting the global economic center of gravity to China. However, the development of mega-urban agglomerations has triggered the interactive coercion between resources and the eco-environment. The interactive coupled effects between urbanization and the eco-environment in mega-urban agglomerations represent frontier and high-priority research topics in the field of Earth system science over the next decade. In this paper, we carried out systematic theoretical analysis of the interactive coupling mechanisms and coercing effects between urbanization and the eco-environment in mega-urban agglomerations. In detail, we analyzed the nonlinear-coupled relationships and the coupling characteristics between natural and human elements in mega-urban agglomerations. We also investigated the interactive coercion intensities between internal and external elements, and the mechanisms and patterns of local couplings and telecouplings in mega-urban agglomeration systems, which are affected by key internal and external control elements. In addition, we proposed the interactive coupling theory on urbanization and the eco-environment in mega-urban agglomerations. Furthermore, we established a spatiotemporal dynamic coupling model with multi-element, multi-scale, multi-scenario, multi-module and multi-agent integrations, which can be used to develop an intelligent decision support system for sustainable development of mega-urban agglomerations. In general, our research may provide theoretical guidance and method support to solve problems related to mega-urban agglomerations and maintain their sustainable development.  相似文献   
32.
鄱阳湖沙地是亚热带湿润区典型风沙化土地,土地沙化问题严峻。鄱阳湖沙地研究多在小范围开展,研究意义有限,应在多处进行沙地粒度比对研究。选取庐山市、都昌县、永修县和南昌市新建区等沙地样品57个,分析其粒度特征。结果表明:(1)鄱阳湖沙地主要由中沙、细沙和粗沙组成,三者总含量超90%;Mz均值为1.79Φ,分选较差,呈正偏和尖锐分布;(2)鄱阳湖沙地不同土地类型沉积物表层(0-5 cm)与20-40 cm深度粒度特征存在一定差异,固定沙丘、半固定沙丘、流动沙丘和河滩表层比20-40 cm深度粒径大,但流动沙丘和湿地草滩表层分选优于20-40 cm深度;湿地草滩和河滩优势粒级含量和粒度参数有别于沙丘;(3)鄱阳湖沙地固定沙丘、半固定沙丘和流动沙丘为风成沉积;河滩以河流作用为主,风蚀为辅;湿地草滩是在风力和水动力共同作用下形成的。鄱阳湖沙地沿盛行风向从南到北S、SK、K依次减小,风沙运动多以两跳一悬式为主,以就地起沙为主,河滩湖滩作为补充。  相似文献   
33.
李奇  董晔  刘云刚 《热带地理》2021,41(2):290-302
基于人口普查数据、自然环境、经济产业及交通路网等公开数据,运用城镇体系金字塔、城镇规模基尼系数以及核密度分析等方法,对巴基斯坦城镇体系特征及其影响因素进行分析,发现:1)规模结构方面,城镇规模分布较集中,表现为"大城市化"与"小城市化"并重的特征,中间级别城市发展滞后,城镇人口金字塔大致呈现沙漏形态;空间结构方面,整体...  相似文献   
34.
Wang  Lifang  Wu  Xiangbin  Zhang  Baoyi  Li  Xuefeng  Huang  Anshuo  Meng  Fei  Dai  Pengyao 《Natural Resources Research》2019,28(3):587-607
Natural Resources Research - Quantitative prediction of concealed mineralization is always confronted with difficulties in comprehensive analysis between 2D and 3D data and between qualitative and...  相似文献   
35.
暖温带地理景观中土壤硒的分异特征   总被引:17,自引:0,他引:17  
本文按垂直自然带谱研究了暖温带地理景观中山地草旬土、山地棕壤、山地淋溶褐土和潮土中硒的分异特征。结果表明:(1)硒在土剖面上的分异,除受生物富集的影响外,淋溶和粘人作用强烈地制约着硒在剖面上的迁移;(2)不同机械组分中的硒含量以粘粒中最高,呈明显的粘粒>细粉粒>中粉粒>砂粒序列。因此,成土过程中,不同机械组分以及次生或们生矿物和垂直运动和自然分选作用对土壤硒的地理分异具有非常重要的作用。(3)易于淋溶失的有机态或钙结合的硒对所研究的土壤表层硒的贡献都大于50%。提出淋溶作用是我国低硒带形成的主要外营力。  相似文献   
36.
Yang  Wei  Zhang  Liping  Zhang  Yanjun  Li  Zongli  Xiao  Yi  Xia  Jun 《地理学报(英文版)》2019,29(3):389-405
Journal of Geographical Sciences - The Interconnected River System Network (IRSN) plays a crucial role in water resource allocation, water ecological restoration and water quality improvement. It...  相似文献   
37.
Patterns of spatial development and protection form a basic category of geoscience,and redesigning them is a popular subject of research in regional sustainable development that is important for ecological civilization construction.The authors here report a case study of Wuhan city using the circuit theory model and minimum cumulative resistance(MCR)model to rebalance its spatial protection and development.The results show the following:(1)Using the density of the gross domestic product(GDP),density of population,rate of urbanization,and access to transportation as evaluation indicators,seven core areas of development in Wuhan were identified,accounting for 59%of the total number of streets,that exhibited a “circular-satellite”spatial structure.(2)According to the importance of ecosystem services,ecological sensitivity,land use type,and slope of the terrain,the resistance surface of spatial development in Wuhan had a stereoscopic spatial form of an“inverted pyramid,”with high surroundings and a low center.The area of low resistance accounted for 6.64%of the total area of Wuhan.(3)Based on coupling analysis using the MCR and spatial morphological characteristics of current,nine axes of spatial development with a total area of 427.27 km2 and eight key strategic points with a total area of 40.02 km2 were identified.Streets that were prioritized for development accounted for 9.63%of Wuhan's total area.(4)By combining the characterization of the development axis with the structure of the three-level core area,we extracted the structure of spatial development of "one heart,two wings,and three belts" in Wuhan.The research framework and empirical results can provide scientific guidance for the urban spatial layout,the development of regional linkages,and ecological environmental protection in China.  相似文献   
38.
城市空间框架数据研究   总被引:6,自引:0,他引:6  
该文基于地理空间概念和地理信息数字化表达与共享的特点,探讨了框架数据的作用、确定原则,推导出城市空间框架数据体系,即建立城市直接空间参照体系和间接空间参照体系。后者中,基于地块的多尺度无缝不规则网格是整合城市社会经济数据的关键,也是当前城市空间数据基础设施框架数据体系建设中的薄弱环节。  相似文献   
39.
According to the meteorological observation data of 72 stations from 1960 to 2010 in the Huanghe (Yellow) River Watershed, China, the long-term variations of potential evapotranspiration, calculated in the modified Penman-Monteith model of Food and Agriculture Organization of the United Nations, were presented, as well as the meteorological causes for the decrease of potential evapotranspiration were discussed. Since 1960, temperature has risen significantly and potential evapotranspiration a decreasing trend, which indicated the existence of "Evaporation paradox" in the Huanghe River Watershed. This phenomenon was not consistent spatially or temporally with the increase of temperature, potential evapotranspiration decreased in spring, summer and winter, mainly over most parts of Shanxi and Henan, and some parts of Gansu, Ningxia, Inner Mongolia, and Shaanxi. During the recent half century, the trends of temperature and potential evapotranspiration were negatively correlated at most of the stations, while precipitation and potential evapotranspiration exhibited a contrary trend. Calculated in multiple regressions, the contribution to potential evapotranspiration change of related meteorological factors was discussed, including mean pressure, maximum and minimum temperature, sunshine hours, relative humidity and average wind speed. The decrease of wind speed in the Huanghe River Watershed may be the dominating factor causing potential evapotranspiration decreasing.  相似文献   
40.
Copper is a moderately incompatible chalcophile element. Its behavior is strongly controlled by sulfides. The speciation of sulfur is controlled by oxygen fugacity. Therefore, porphyry Cu deposits are usually oxidized (with oxygen fugacities > ΔFMQ +2) (Mungall 2002; Sun et al. 2015). The problem is that while most of the magmas at convergent margins are highly oxidized, porphyry Cu deposits are very rare, suggesting that high oxygen fugacity alone is not sufficient. Partial melting of mantle peridotite even at very high oxygen fugacities forms arc magmas with initial Cu contents too low to form porphyry Cu deposits directly (Lee et al. 2012; Wilkinson 2013). Here we show that partial melting of subducted young oceanic slabs at high oxygen fugacity (>ΔFMQ +2) may form magmas with initial Cu contents up to >500 ppm, favorable for porphyry mineralization. Pre-enrichment of Cu through sulfide saturation and accumulation is not necessarily beneficial to porphyry Cu mineralization. In contrast, re-melting of porphyritic hydrothermal sulfide associated with iron oxides may have major contributions to porphyry deposits. Thick overriding continental crust reduces the “leakage” of hydrothermal fluids, thereby promoting porphyry mineralization. Nevertheless, it is also more difficult for ore forming fluids to penetrate the thick continental crust to reach the depths of 2–4 km where porphyry deposits form.  相似文献   
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