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  • Research Articles
    GAO Jiangbo, JIAO Kewei, WU Shaohong
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    Climate change is a major driver of vegetation activity, and thus their complex processes become a frontier and difficulty in global change research. To understand this relationship between climate change and vegetation activity, the spatial distribution and dynamic characteristics of the response of NDVI to climate change were investigated by the geographically weighted regression (GWR) model during 1982 to 2013 in China. This model was run based on the combined datasets of satellite vegetation index (NDVI) and climate observation (temperature and moisture) from meteorological stations nationwide. The results showed that the spatial non-stationary relationship between NDVI and surface temperature has appeared in China: the significant negative temperature-vegetation relationship was located in Northeast, Northwest and Southeast China, while the positive correlation was more concentrated from southwest to northeast. By comparing the normalized regression coefficients from GWR model for different climate factors, it presented the regions with moisture dominants for NDVI were in North China and the Tibetan Plateau, and the areas of temperature dominants were distributed in East, Central and Southwest China, where the annual mean maximum temperature accounted for the largest areas. In addition, regression coefficients from GWR model between NDVI dynamics and climate variability indicated that the higher warming rate could result in the weakened vegetation activity through some mechanisms such as enhanced drought, while the moisture variability could mediate the hydrothermal conditions for the variation of vegetation activity. When the increasing rate of photosynthesis exceeded that of respiration, the positive correlation between vegetation dynamics and climate variability was reflected. However, the continuous and dynamic process of vegetation activity response to climate change will be determined by spatially heterogeneous conditions in climate change and vegetation cover. Furthermore, the dynamic description of climate-induced vegetation activity from its rise to decline in different regions is expected to provide a scientific basis for initiating ecosystem-based adaptation strategies in response to global climate change.

  • Research Articles
    LIAO Xiaoyong, TAO Huan, GONG Xuegang, LI You
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    A model integrating geo-information and self-organizing map (SOM) for exploring the database of soil environmental surveys was established. The dataset of 5 heavy metals (As, Cd, Cr, Hg, and Pb) was built by the regular grid sampling in Hechi, Guangxi Zhuang Autonomous Region in southern China. Auxiliary datasets were collected throughout the study area to help interpret the potential causes of pollution. The main findings are as follows: (1) Soil samples of 5 elements exhibited strong variation and high skewness. High pollution risk existed in the case study area, especially Hg and Cd. (2) As and Pb had a similar topological distribution pattern, meaning they behaved similarly in the soil environment. Cr had behaviours in soil different from those of the other 4 elements. (3) From the U-matrix of SOM networks, 3 levels of SEQ were identified, and 11 high risk areas of soil heavy metal-contaminated were found throughout the study area, which were basically near rivers, factories, and ore zones. (4) The variations of contamination index (CI) followed the trend of construction land (1.353) > forestland (1.267) > cropland (1.175) > grassland (1.056), which suggest that decision makers should focus more on the problem of soil pollution surrounding industrial and mining enterprises and farmland.

  • Research Articles
    FAN Zemeng, BAI Ruyu, YUE Tianxiang
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    For quantitatively explaining the correlations between the vascular plant species abundance (VPSA) and habitat factors, a spatial simulation method has been developed to simulate the distribution of VPSA on the Qinghai-Tibet Plateau. In this paper, the vascular plant type, land cover, mean annual biotemperature, average total annual precipitation, topographic relief, patch connectivity and ecological diversity index were selected to screen the best correlation equation between the VPSA and habitat factors on the basis of 37 national nature reserves on the Qinghai-Tibet Plateau. The research results show that the coefficient of determination between VPSA and habitat factors is 0.94, and the mean error is 2.21 types per km2. The distribution of VPSA gradually decreases from southeast to northwest, and reduces with increasing altitude except the desert area of Qaidam Basin. Furthermore, the scenarios of VPSA on the Qinghai-Tibet Plateau during the periods from 1981 to 2010 (T0), from 2011 to 2040 (T2), from 2041 to 2070 (T3) and from 2071 to 2100 (T4) were simulated by combining the land cover change and the climatic scenarios of CMIP5 RCP2.6, RCP4.5 and RCP8.5. The simulated results show that the VPSA would generally decrease on the Qinghai-Tibet Plateau from T0 to T4. The VPSA has the largest change ratio under RCP8.5 scenario, and the smallest change ratio under RCP2.6 scenario. In general, the dynamic change of habitat factors would directly affect the spatial distribution of VPSA on the Qinghai-Tibet Plateau in the future.

  • Research Articles
    VALDERRAMA-LANDEROS Luis H., MARTELL-DUBOIS Raúl, RESSL Rainer, SILVA-CASARÍN Rodolfo, CRUZ-RAMÍREZ Cesia J., MUÑOZ-PÉREZ Juan J.
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    The goal of our work was to locate and quantify changes that occurred in 66% of the Mexican coastline, based on four land cover maps generated by the Mexican Mangrove Monitoring System (SMMM) of the National Commission for the Knowledge and Use of Biodiversity (CONABIO) for the years 1970/81, 2005, 2010, and 2015. Our results showed overall dominance of erosion over accretion processes, beaches being the most affected coastal land cover. Emphasis was placed on identification and description of coastline sites in which land was either continuously lost (erosion) or gained (accretion) during the studied time periods. These sites were defined as continuous unidirectional dynamic sites and were compared with previous knowledge about the geodynamics of Mexican coasts. Continuous unidirectional dynamic sites were distributed throughout the study area and within all land cover types, but predominantly corresponded to areas covered by mangroves in the states of Campeche and Nayarit. Finally, we found an intensification of coastal erosion-accretion processes over time; coastline change rates having duplicated between the earliest (1970/81-2005) and the two more recent (2005-2010, and 2010-2015) analysed time periods, with erosion rates for each corresponding period of -3 m/yr, -7.5 m/yr, and -7.3 m/yr, and accretion rates of 2.8 m/yr, 7.3 m/yr, and 6.9 m/yr, respectively.

  • Research Articles
    HU Yunfeng, ZHANG Yunzhi
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    Wind-driven soil erosion results in land degradation, desertification, atmospheric dust, and sandstorms. The Hunshandake Sandy Land, an important part of the Two Barriers and Three Belts project, plays important roles in preventing desert and sandy land expansion and in maintaining local sustainability. Hence, assessing soil erosion and soil accumulation moduli and analyzing the dynamic changes are valuable. In this paper, Zhenglan Banner, located on the southern margin of the Hunshandake Sandy Land, was selected as the study area. The soil erosion and accumulation moduli were estimated using the 137Cs and 210Pbex composite tracing technique, and the dynamics of soil erosion and soil accumulation were analyzed during two periods. The results are as follows: (1) the regional 137Cs reference inventory was 2123.5±163.94 Bq/m 2, and the regional 210Pbex reference inventory was 8112±1787.62 Bq/m 2. (2) Based on the 137Cs isotope tracing analysis, the erosion moduli ranged from -483.99 to 740.31 t·km -2·a -1. Based on the 210Pbex isotope tracing analysis, the erosion moduli ranged from -441.53 to 797.98 t·km -2·a -1. (3) Compared with the earliest 50 years, the subsequent 50 years exhibited lower soil erosion moduli and accumulation moduli. Therefore, the activities of local sand dunes weakened, and the quality of the local ecological environment improved. The multi-isotope composite tracing technique combining the tracers 137Cs and 210Pbex has potential for similar soil erosion studies in arid or semiarid regions around the world.

  • Review Articles
  • Review Articles
    HUANG Xiaoli, TANG Guoan, ZHU Tongxin, DING Hu, NA Jiaming
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    Geomorphic evolution often presents a spatial pattern of a “young to old” distribution under certain natural environmental conditions, whereby sampling the geomorphic types and characteristics in spatial sequence can provide evidence for the individual landform evolution and change. This so-called space-for-time substitution has been a methodology in geomorphologic research. This paper firstly introduced the basic concepts and background of the space-for-time substitution, then a full review has been conducted of recent research progress in geomorphic evolution based on the space-for-time substitution, such as fluvial landform, structural landform, estuarine landform and coastal landform. Finally, the basic principle of space-for-time substitution in geomorphology is developed. This review is intended to introduce the achievements of geomorphic evolution research using space-for-time substitution method and to point out the critical research needs to better understand and predict the geomorphic evolution in the future.

  • Review Articles
    CHEN Mingxing, YE Chao, LU Dadao, SUI Yuwen, GUO Shasha
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    Since the reform and opening up in China, rapid urbanization has boosted the development of economy and society, but it has also been confronted by tremendous challenges. Multidisciplinary research has focused on the issue of a national new type of urbanization planning, leading to a transformation of China’s urbanization strategy. Further research, however, is needed to explore the theoretical basis for this new approach to urbanization. This paper summarizes the process of development of urbanization in China and describes its specific characteristics, including peri-urbanization, special national conditions, complicated factors, and governance system. China’s urbanization makes a great contribution to urbanization on a world scale. Moreover, the literature on the subject demonstrates the significance of urbanization to the discipline of human and economic geography and the scientific connotations of new urbanization, which is people-oriented, harmonious, inclusive, and sustainable. Against a background of humanism, new urbanization represents a transformation from population urbanization to people-oriented urbanization. There are six crucial scientific issues involved: people-oriented urbanization and equalization of basic public services; urbanization with integrated and coordinated urban and rural development; urbanization in the context of resources and environmental carrying capacity and climate change; diverse regional modes; spatial effect and mechanism; and big data and technical innovation. The paper aims to illustrate the theoretical framework of China’s new urbanization, providing references for both theoretical research and policy formulation.

  • Review Articles
    FANG Chuanglin
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    Urban agglomerations are formed when a country is in the advanced stages of industrialization and urbanization. They are highly integrated groups of cities that form and develop through a natural, gradual process as the relationship between them changes from one of competition to assimilation following law of natural development. China is currently in a new stage of transitional development characterized by its New-Type Urbanization Plan. It has entered a new era in which it is a global leader in urban agglomeration development, and China’s research and development models are being imitated and adopted by countries around the world. This paper adopts a theoretical approach to propose the basic law governing the formation, development and expansion of urban agglomerations. This includes the stage-based formation and development law, multi-scale intensive-use transmission law, crystal-structure spatial composition law, egg-shaped expansion evolution law, “saplings-to-forest” natural growth law, and sustainable development incremental increase law. Guided by these law, China has created a hierarchical organizational configuration for optimizing the spatial structure of its urban agglomerations. It has also formulated urban agglomeration development plans and proposed research-based measures to resolve problems specific to urban agglomerations and to promote their sustainable development. The law governing the formation, development and expansion of urban agglomerations play an important role in guiding their development in China and will play a greater role in the future.

  • Review Articles
    ZHANG Bailin, SUN Piling, JIANG Guanghui, ZHANG Ruijuan, GAO Jiangbo
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    The cultivation of mountainous land results in water loss and soil erosion. With rapid urbanization and industrialization in China, labor emigration relieves the cultivation of mountainous areas in regions with high poverty and leads to a significant land use transition. This research built an analysis framework for “land use transition - driving mechanism - effects - responses” for mountainous areas of China undergoing land use transition and then proposed the direction of mountainous land consolidation. The results showed that the turning point of land use morphology was the core of rural land use transition in mountainous areas. The expansion of cropland and the contraction of forestland have transitioned to the abandonment of cropland and the expansion of forestland; this transition was the main characteristic of the dominant land use change. Land marginalization and land ecological functional recovery were the main characteristics of the recessive land use transition in mountainous areas. Socioeconomic factors were the primary driving forces during land use transition in mountainous areas, with labor emigration being the most direct force. The rising costs of farming and the challenging living conditions causing labor emigration were fundamental driving forces. Rural land use transition in mountainous areas reduced the vulnerability of the ecological function of land ecosystems. The advantages and disadvantages of the socioeconomic effects should focus on rural development of mountainous areas as well as the livelihood of farmers; this should be further supported by empirical and quantitative research. Rural land use transition of mountainous areas improves natural restoration and is related to socioeconomic development. Rural land consolidation of mountainous areas should conform to land use transition, with the goal of shifting from the increase of cultivated land to the synergies of ecological and environmental protection.

  • Review Articles
    JIN Fengjun, CHEN Zhuo
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    This paper reviews the process of transportation construction in China and investigates the developmental and spatial characteristics of transportation patterns. The principles of transportation evolution including stages, structures and orders are systematically analyzed. The investigation shows that China’s transportation construction mode has upgraded from investment-driven scale expansion to quality improvement driven by efficiency and promotion. The rapid growth and development of transportation networks has significantly influenced economic and social activities in time and space. The resulting spatial convergence and dominance have improved distribution, promoting development of the socioeconomic structure. Regional development that has traditionally been based on corridors has changed into a networked mode centered on cities and metropolitan areas. The transportation pattern follows evolutionary principles. China has been moving from a hierarchical structure to a cascade structure. Simultaneously, the socioeconomic pattern has changed from an axis to a hub-and-spoke structure with a preliminary ordered network. As transportation networks grow, China’s functional spatial structure and ordered network will gradually become stabilized and balanced.

  • Review Articles
    MUHAMMAD Khurshid, MOHAMMAD Nafees, ABDULLAH Khan, MEHMET Somuncu, ASHFAQ Ahmad Khan, WAJID Rashid
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    Pastoralism is a viable socio-economic system-shaped by landless and agro-pastoral communities in many pastoral regions of the world. This system is mainly based on seasonal migration of pastoralists and their livestock herds between upland and lowland pastures. Traditionally pastoral activities make significant contributions to mountain livelihood subsistence, regional economies and environmental sustainability. However, the pastoralist’s lifestyle and their economies are increasingly confronted to various socio-political, economic and ecological stresses from the last few decades. Extensive literature reviewed on this subject with the aim to explore the current emerging challenges faced by pastoral communities in different pastoral regions. It has been revealed from literature that the prevalent socio-political and economic stress on pastoralism caused by modernization, insecure land tenure, integration of market economy, civil insecurities and pastoralist’s exclusion in states policies while ecological stress on pastoral activities emerged with increasing focus on nature conservation in pastoral regions and climate change induced hazards and disasters. As a consequence of these challenges, pastoral households are abandoning livestock herding-as a traditional way of life and are in continuous transition to transform their pastoral practices and institutions. Thus, the attention and consultation of key stakeholders are needed toward pastoral resource development that improve and sustain traditional pastoral practices in a socio-politically and ecologically stressed environment of the world.