Table of Content

    28 July 2019, Volume 34 Issue 7 Previous Issue    Next Issue
    Resources and Strategy
    Pattern changes of China's agricultural trade and countermeasures for the utilization of overseas agricultural resources
    JIA Pan-na, LIU Ai-min, CHENG Sheng-kui, QIANG Wen-li, WU Liang, LI Peng
    2019, 34 (7):  1357-1364.  doi: 10.31497/zrzyxb.20190701
    Abstract ( )   HTML ( )   PDF (815KB) ( )   Save
    In 2017, the net import of virtual farmland of bulk agricultural products in China reached 67.84 million ha and the external dependence was 33.4%, in which Brazil and the United States are the major importing countries. In China, large import of land-intensive agricultural products focused on soybeans ensures a certain degree of food supply. However, implementing the "going- out" strategy of agriculture can fundamentally protect China's food security. Although China's overseas agricultural investment has increased year by year, the enterprises have poor control in overseas agricultural resources and high production risks due to lack of long-term investment strategy guidance. For protecting China's food security, from the strategic perspective of building a community with a shared future for mankind and enhancing global agricultural product supply capacity, China should choose the best overseas investment area to develop international soybean and palm oil and other types of edible oil and fat feedstocks with large import volume and high foreign dependence in priority; encourage the multiple enterprises to join the overseas agricultural resources development; cooperate deeply with the investment destination country through the "order + farmer" model and integrate into the global agricultural trade system.
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    Resource Utilization and Management
    Predicting productivity and spatial distribution of Larix principis-rupprechtii plantation
    LI Wen-bo, LYU Zhen-gang, HUANG Xuan-rui, ZHANG Zhi-dong
    2019, 34 (7):  1365-1375.  doi: 10.31497/zrzyxb.20190702
    Abstract ( )   HTML ( )   PDF (2303KB) ( )   Save
    The accurate prediction of forest site productivity is crucial for the effective forest management. Site index (SI) is one of the main measures of forest productivity. In this study, we integrated 220 field inventory, topography, climate and soil factors to predict SI of Larix principis-rupprechtii using regression Kriging (RK) model in Saihanba Mechanized Forest Farm, Hebei province. The influence of different semivariograms on the accuracy of RK model was also analyzed. Fitting results showed that the accuracy of RK model based on Gaussian semivariogram was higher than that based on spherical and exponential semivariogram, and had little residual variation (RMSE=0.82 m and MAE=0.66 m), indicating RK model based on Gaussian semivariogram had a highly predictive power to predict SI in the study area. Gaussian semivariogram analysis showed that there was a strong spatial autocorrelation in SI in the study area, and the spatial variation was significant in the range of 724.89 m; The major environmental factors affecting spatial variation in SI of L. principis-rupprechtii plantations included: soil total nitrogen (TN), soil pH, mean summer precipitation (SUP) and mean spring precipitation (SPP). The sites with high productivity of L. principis-rupprechtii might tend to potentially occur in the southeast part with suitable SPP, relatively high SUP, neutral or acidic soil and relatively high TN, accounting for 32.00% of the total area of the study region. However, sites with low productivity of L. principis-rupprechtii were typically found at the northern edge with excessive SPP or lower SUP, high soil pH and extremely low TN, only accounting for 8.90% of the whole region. Accordingly, the distribution patterns of productivity for L. principis-rupprechtii plantation were jointly determined by climatic and soil factors as well as tree growth characteristics in the study area. Improving productivity of L. principis-rupprechtii plantation can be realized by soil pH reduction and appropriate nitrogen increase in the study area.
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    Does rural resettlement accelerate farmland abandonment in mountainous areas: A case study of 1578 households in Southern Shaanxi
    WANG Qian, QIU Jun-jie, YU Jin
    2019, 34 (7):  1376-1390.  doi: 10.31497/zrzyxb.20190703
    Abstract ( )   HTML ( )   PDF (980KB) ( )   Save
    Rural resettlement, an effective measure to eliminate poverty and improve the ecological environment, develops rapidly in China. Since farmland abandonment closely relates to the stability of migration as well as the national food security, the research regarding whether resettlement accelerates farmland abandonment in mountainous areas is of great importance in China. We used panel Logit and panel Tobit models to analyze the influencing mechanism of resettlement on farmland abandonment with data of 1578 households in 8 counties in prefectures of Shangluo, Ankang, and Hanzhong, the southern part of Shaanxi province. The results show that farmers' resettlement behavior had a significant positive effect on farmland abandonment behavior. The coefficient of migration period was significant at 1% in all regressions, and farmers were more likely to abandon farmland when migration distance was larger than 0.5 kilometer. All types of migration can accelerate farmland abandonment, among which engineering resettlement had the largest effects on farmers' land abandonment behavior, while disaster avoidance resettlement had the least effects. In addition, householder characteristics, household characteristics, resource endowment characteristics, and land rental market are all important influencing factors of farmers' land abandonment behavior. We thus conclude that farmers' enthusiasm of agricultural production decreases after migration, and the phenomenon for land abandonment becomes more obvious with the implementation of resettlement and relocation project in Southern Shaanxi. The transformation to town life and increased time opportunity cost of farming are the main reasons for resettled farmers' land abandonment behavior. The government is suggested to reallocate farmland to engineering resettled farmers, and encourage resettled farmers to participate in the slopping land conversion program with more supporting policies, as well as solve the livelihood problem by developing characteristic industries. In addition, land rental market should be promoted by establishing the information platform of land transfer in all resettlement areas.
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    Land use pattern change and its topographic gradient effect in the mountainous areas: A case study of Jinggangshan city
    ZANG Yu-zhu, LIU Yan-sui, YANG Yuan-yuan
    2019, 34 (7):  1391-1404.  doi: 10.31497/zrzyxb.20190704
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    Topography is one of the most important natural environment factors that determines land use pattern, especially in the mountainous areas. Jinggangshan city is located in the Luoxiao Mountains, where the land use activity is extremely limited by terrain conditions. Taking Jinggangshan city as a case study, we selected DEM data and remote sensing data during 1995-2015 to explore the relations between topographical factors and land use pattern. Altitude, slope and terrain niche were chosen as indicators to explain how topographical conditions influence land use spatial pattern, land use change and landscape pattern. Results indicated that land use spatial pattern was affected by the topographical factors. Cultivated land, construction land and water areas were concentrated in plains and gentle rolling hills with altitude <400 m and slope <15°, while forest and meadow were mainly distributed in mountains with altitude >400 m and slope >15°. Moreover, land use transitions had close relations with terrain factors, which mainly occurred in plains and gentle rolling hills with altitude <800 m and slope <15°. The major land use changes during 1995-2015 were featured with 992 km2 decrease of forest land and 352 km2 increase of construction land. In addition, topographical conditions contributed to the variation of landscape pattern. Patches distributed multitudinously and intensively in plain and gentle rolling hills, which resulted in higher values of landscape diversity index, interspersion juxtaposition index, patch density and land use structure entropy. However, there were scattered and single patches in mountainous areas, so the largest patch index and contagion index were usually high. The terrain difference was an important factor influencing land use structure, land use transition and landscape pattern. It should be taken into full consideration when people determine to change the land use types, especially in the mountainous areas. The reallocation of land resources plays an important role in promoting poverty alleviation and rural development, but it may also jeopardize the natural environment and ecological system. It must be emphasized that people should take appropriate measures to optimize land use types according to local natural conditions. Only in this way can we realize sustainable development.
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    Effects of different plant measures on soil and water conservation in typical tableland zones on the Loess Plateau
    SUN Cong-jian, HOU Hui-xin, CHEN Wei, YANG Wei, ZHENG Zhen-jing
    2019, 34 (7):  1405-1416.  doi: 10.31497/zrzyxb.20190705
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    This article, based on the observations of the measured (2014-2016) rainfall data from typical loess tableland zones and slope runoff and sediment yield with five vegetation measures (arbor, shrub, woodland, artificial grass and cultivated field), systematically analyzes the effects of different types of erosive rainfall on the soil and water conservation on loess sloping land under different vegetation coverages. The results are shown as follows. (1) Most of the rainfall in the research area occurred in the period April to October, in which the erosive rainfall induced from soil erosion was concentrated in July and August. (2) Erosive rainfall can be achieved based on the maximum 30-minute rainfall intensity and total rainfall. It is divided into five types, among which the event with small rainfall and low intensity is the most frequent type, and the erosive force of the 5th pattern is the largest, followed by the 1st pattern with the largest rainfall, and the erosive force of the 2nd pattern is the lowest. (3) Five types of vegetation measures show obvious soil and water conservation effect under different types of rainfall. And the changing rules of the rate of sediment reduction and the rate of reduction of flow under different rainfall conditions are different.
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    Resource Evaluation
    The rational assessment of developing transformation and obstacle diagnosis for resources exhausted cities : A case study of Daye, Hubei
    HUANG Tian-neng, LI Jiang-feng, XU Jin-long, LIAO Xiao-li
    2019, 34 (7):  1417-1428.  doi: 10.31497/zrzyxb.20190706
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    The performance evaluation of transformation and the diagnosis of obstacle factors are important basis for sustainable development of resource-exhausted cities. Based on the connotation of transitional development, this paper constructed an evaluation index system from the aspects of economic development, improvement of people's livelihood, resource utilization, environmental remediation and industrial transformation. The improved TOPSIS method was used to evaluate the rationality of transitional development and obstacle factors of Daye city in Hubei province from 2007 to 2016. The results show that: (1) Daye city has made remarkable achievements in transitional development, and the performance evaluation scores of the 10-year transformation are above 0.9 from 2007 to 2016. Two phases are identified, 2007-2010 and 2011-2016. The first stage witnessed the beginning of the transition, and industrial succession, and the performance was unstable, from 0.9976 in 2007 to 0.9998 in 2008, and fell to 0.9098 in 2010. The second stage is a period of stable transformation, and the performance of transitional development was steadily improved, during which evaluation scores increased from 0.9142 to 0.9458. (2) The main obstacle factors affecting the transformation and development of Daye are consistent in the ten years. The order of obstacle degree of factors from strong to weak is: the number of hidden danger points of mine geological disasters, urban registered unemployment rate, the added value of high-tech industry to GDP, and the comprehensive utilization of industrial solid waste, per capita disposable income of rural residents and general budgetary revenue of local finance. Based on the evaluation results, the work proposal for the future transitional development of Daye city was put forward.
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    The relationship between the change of water system and the urban land expansion in Changsha
    JIANG Qi, ZHENG Bo-Hong
    2019, 34 (7):  1429-1439.  doi: 10.31497/zrzyxb.20190707
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    In order to examine the connection between water system changes and the expansion of urban land use, and provide evidence and experience for the future coordinated development of water ecological restoration and urban and ecological environment, statistical methods were used to analyze the five-phase water system and urban land expansion in Changsha in the past 60 years. We selected river net density, water surface rate, mainstream river curvature indexes and river development coefficient to quantitatively describe changes in water system characteristics and used urban intensity expansion index to measure the strength and speed of expansion of urban construction land in the same period based on the topographic maps and urban construction land data of Changsha city in the 1950s, 1970s, 1990s, 2010s and 2016. After superimposing the water system change index and urban expansion intensity index in each basin, we analyzed the relationship between the water system changes in various stages of Changsha and the urban land expansion intensity. The results show that: (1) The expansion of urban construction land has a direct impact on the quantity and shape of urban water coefficients. In the past 60 years in Changsha, the main characteristic values of the water system experienced a large attenuation. In general, the amount and area of the water surface were greatly reduced, and both the river structure and the water system tended to be simple. Meanwhile, the river network density and water surface rate reflecting the characteristics of water coefficient decreased by 3.74% and 26.26%, respectively. (2) The intensity of urban expansion in each period was positively related to the decay rate of water quality index values. From the 1950s to the 1990s, the urban expansion of Changsha was concentrated in the Xiangjiang River system, the Liuyang River system and the Guitang River system east of the Xiangjiang River. During this period, the water surface rates in the three water systems decreased by 6.7%, 6.38%, and 6.75%, respectively. After 1990, Changsha entered the stage of rapid urbanization, but the urban expansion intensity in areas west of the Xiangjiang River was stronger than that in areas east of the Xiangjiang River. At the same time, the density of river network west of the Xiangjiang River was faster than that east of the Xiangjiang River, down by 1.13% and 6.19%, respectively. (3) Destruction of water system in urban expansion will increase the risk of ecological and natural disasters, and effective water ecological protection policies and protection measures can not only slow down the shrinking trend of the water system in the area, but also accelerate the expansion of surrounding land use.
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    Spatial pattern and evolution mechanism of China's soybean processing plants
    YANG Xiao, LIU Ai-min, JIA Pan-na, XUE Li
    2019, 34 (7):  1440-1456.  doi: 10.31497/zrzyxb.20190708
    Abstract ( )   HTML ( )   PDF (3244KB) ( )   Save
    With the improvement of the living standards of Chinese residents, the domestic demand for meat, eggs and milk has increased year by year. As the main food protein, soybean meal is the main product of the soybean processing industry. As an important part of the soybean industry chain, the soybean processing industry has influence on the distribution of soybean production, feed, and animal husbandry. This paper chooses the soybean processing plants from 1996 to 2016 as the study object. We explore the spatial pattern of China's soybean processing plants by using the average nearest neighbor analysis and nuclear density analysis method. Then we analyze the factors that influence the layout of soybean processing plants in different periods using the conditional Logit regression model. The results show that since 1996, the layout areas of China's processing plants have shifted from the main soybean producing areas to the coastal ports to soybean market area. Up to now, a belt-like pattern has formed, which takes the coastal port cities as the core, and the Yangtze River, Harbin-Dalian Railway and Longhai Railway as diffusion paths. Raw material supply, transportation cost, market size and potential, agglomeration and policy are all important factors which affect the spatial pattern of soybean processing plants and the main factors are different in different periods. Raw material supply, transportation cost, market size and agglomeration have the most important influence on the layout decisions of soybean processing plants from 2000 to 2015. But the agglomeration and policy were the dominant factors from 2006 to 2010 and it turned into market potential after 2010. The change of distribution of raw materials and soybean meal market lead to the change of transportation cost. The cost and expansion of soybean meal market attracted plants agglomeration from domestic soybean producing areas to the coastal port areas. With the agglomeration in the coastal ports, the increased competition among enterprises promoted the diffusion of enterprises from coastal port areas to soybean meal consumption areas.
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    Resource Economics
    The study on industrial water use efficiency of Chinese provinces: Based on network SBM-DEA model and GML index
    DENG Guang-yao, ZHANG Zhong-jie
    2019, 34 (7):  1457-1470.  doi: 10.31497/zrzyxb.20190709
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    In recent years, China's industrial water consumption accounts for about 20% to 30% of all water use. Improving industrial water efficiency and saving use of water resources have become one of the important issues affecting the sustainable development of China's national economy. Based on the network SBM-DEA model and GML index, this paper studies the industrial water use efficiency of each province in China from 2007 to 2015. The results show that: (1) From the annual average, the production stage is at the forefront compared with the sewage treatment stage. There are more provinces at the forefront, and the gap between provinces and frontiers is relatively small. Industrial water use efficiency is high in the production stages of Beijing, Tianjin, Inner Mongolia, Shandong, Guangdong, Hainan, but the efficiency of sewage treatment is low; For Liaoning, Jilin, Anhui, Fujian, Jiangxi, Hubei, Hunan, Guangxi, Guizhou, Yunnan, Qinghai, the efficiency value is lower in the production stage, but the efficiency value in the sewage treatment stage is higher. This is because there are differences in the requirements for sewage treatment in different provinces of China, or even the same requirements, the implementation of different local policies is not the same, and some provinces (such as Beijing) have higher requirements for sewage treatment and policy implementation than other provinces. (2) From the geometric mean of each time period, the GML index value of most provinces in the network and sewage treatment stage is less than 1, but the GML index value in the production stage is greater than 1. It can be seen from the average of 30 provinces that both the EC index and the BPC index in the production stage have improved (greater than 1), but the EC index and BPC index in the network and sewage treatment stages have decreased (less than 1). Therefore, to enhance the industrial water efficiency in the production stage, it is necessary to increase the treatment of industrial wastewater, improve the efficiency of the sewage treatment stage, and raise the awareness of industrial production and pollution control, especially in Beijing, Tianjin, Inner Mongolia, Shandong, Guangdong, and Hainan with low sewage treatment efficiency.
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    Spatial-temporal coupling relationship between chemical fertilizer application and grain yield in China at city scale
    ZHAO Xue-yan, LIU Jiang-hua, WANG Rong, WANG Xiao-qi
    2019, 34 (7):  1471-1482.  doi: 10.31497/zrzyxb.20190710
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    Fertilizer application is viewed as a double-edged sword, for it can increase grain production and ensures food security, at the same time, it can lead to degradation of eco-environment. At present, it is urgent to explore the spatial-temporal coupling relationship between fertilizer application and grain production, so as to provide effective measures and references to maintain food security and ecological safety. Selecting 336 administrative regions at the prefecture level as study units, the paper analyzes the changing features of China's grain production and fertilizer application in the spatial-temporal pattern, and the coupling relationship between fertilizer application and grain production as well as its dynamic process from 2005 to 2015. The findings are obtained as follows. (1) Both fertilizer application and grain production showed upward trends from 2005 to 2015, and regional differences in fertilizer application presents a decreasing trend from "main production areas, production-and-sales balancing areas to main sales areas". Meanwhile, the overall trend of grain production among different regions tends to increase from "main production areas, production-and-sales balancing areas to main sales areas". (2) Fertilizer application roughly presents a stepwise increase from "East-Centre-West", while grain production growth apparently shows north-south differential characteristics. (3) From the perspective of spatial distribution, the areas east of Aihui-Tengchong line were featured as "double-high areas" compared with "double-low areas" west of the line; moreover, "inefficiently-fertilized" areas were shrinking and "other-factor-influenced" areas expanding. (4) In the course, the coupling relationship between grain and fertilizer was dominated by "double-increase type" with other types positioning secondarily; and the relationship was mainly transforming towards "double-increase type" and "other-factors-affected type".
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    Impact of economic agglomeration on regional water pollutant emissions and its spillover effects
    ZHOU Kan, WANG Qiang, FAN Jie
    2019, 34 (7):  1483-1495.  doi: 10.31497/zrzyxb.20190711
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    Based on the database of COD and NH3-N emissions from 339 cities at prefecture level in China, this paper explores the impact of economic agglomeration on regional water pollutant emissions and the differences in the impact levels between different city-size by using the econometric model. Meanwhile, a bivariate spatial autocorrelation method is adopted to analyze the spillover effect of economic agglomeration on water pollutant emissions, which provides a reference for making a benign interactive countermeasure to promote economic agglomeration and pollution mitigation. The results show that: according to the whole sample, economic agglomeration can effectively reduce the intensity of the regional water pollutant emissions. The degree of economic agglomeration increases by 1%, and the COD and NH3-N emissions will decrease by 0.491% and 0.166% respectively. Compared with the large cities and mega-cities, economic agglomerations have more prominent reduction effects on water pollutant in small and medium-sized cities. Economic agglomeration and water pollutant discharge have shown significant spatial spillover effects, and present spatial agglomeration patterns of high agglomeration-high emission, low agglomeration-low emission, and low agglomeration-high emission. High agglomeration-high emission areas are located from Beijing-Tianjin-Hebei region to the Shandong Peninsula, as well as other highly urbanized area such as Harbin-Changchun, the Yangtze River Delta, the Pearl River Delta and Changsha-Zhuzhou-Xiangtan. Policy implications and suggestions include: actively nurturing small and medium-sized cities, exerting significant reduction effects of economic agglomeration, promoting technological upgrade and diffusion of production technologies, improving energy efficiency and environmental protection input; rationally controlling the economic and population size of large cities and mega-cities, improving environmental regulations to prevent "Pollution Haven" effects, and accelerating industrial restructuring and outdated production capacity to eliminate and strictly control over-standard and over-total emissions; reducing the negative externalities of economic agglomeration, with a focus on promoting joint prevention and basin governance of high agglomeration-high emission area.
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    Resource Ecology
    The heterogeneity of climate change and its genesis in the Northeastern Qinghai-Tibet Plateau
    LI Lin, LI Xiao-dong, XIAO Rui-xiang, SHEN Hong-yan
    2019, 34 (7):  1496-1505.  doi: 10.31497/zrzyxb.20190712
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    The northeastern part of Qinghai-Tibet Plateau is situated in the transitional zone of the Qinghai-Tibet Plateau and Loess Plateau. Known as Qinghai's Hehuang areas, it is the valleys of Yellow River and Huangshui River. And it is the birthplace of civilization and cradle of economic and social development of the Qinghai-Tibet Plateau, especially Qinghai province. It is also one of the areas of earliest human activities in the Yellow River Basin. Because it is located in the intersection of China's two high plateaus, its climate and its changes have a certain heterogeneity. The northeastern part of Qinghai-Tibet Plateau has some characteristics of the East Asian monsoon climate, which is different from complete plateau continental climate. Therefore, due to complexity of its climate change and significance of its impact on economy and society, the issue of climate change in the region has received wide attention from academic community. Based on analysis of climate change in the northeastern part of Qinghai-Tibet Plateau from 1961 to 2016 and its heterogeneity in climate change over the Qinghai-Tibet Plateau, this paper discusses the causes of climate change from evolution of atmospheric circulation and changes in vegetation cover. The meteorological data such as temperature, precipitation and other meteorological data of 13 meteorological stations in the northeastern Qinghai-Tibet Plateau from 1961 to 2016, the data of atmospheric circulation characteristics such as the South China Sea summer monsoon index and Siberian High Index released by the National Climate Center were analyzed in this paper. And, the heterogeneity between climate change and plateau main body and their possible climate genesis were also analyzed in the past 56 years. The results are shown as follows: (1) Climate warming trend in the northeastern part of Qinghai-Tibet Plateau is very significant in the past 56 years. The climatic tendency rate of annual average temperature is as high as 0.39 °C/10 a, showing three obvious stepwise increases and it has mutations from cold to warm around 1994 with significant spatial variability. (2) There is no obvious change in annual and seasonal precipitation. Although it has experienced less to more changes around 2002, there is no significant mutation. The annual precipitation has a quasi-periodic variations of 3 years and 5 years, while the number of annual precipitation days is slightly reduced and precipitation intensity is increasing. (3) The interannual variability of climate change in this region is mainly affected by interannual oscillations of East Asian monsoon, plateau monsoon and South China Sea monsoon and their interactions, while effect of westerly circulation is not obvious. The restoration of vegetation cover has not only responded to precipitation increase since 2002 but also played a certain role of mitigative effect in climate warming trend.
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    Glacier changes along the Silk Road Economic Belt in China in the past 50 years: Based on the revised First and Second Chinese Glacier Inventory
    LI Long, YAO Xiao-jun, LIU Shi-yin, BU Ya-ping, GONG Peng, LI Xiao-feng
    2019, 34 (7):  1506-1520.  doi: 10.31497/zrzyxb.20190713
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    Glaciers, important water resources in northwestern China, are of great importance to the agricultural construction and economic development of the Silk Road Economic Belt. Based on the revised First (1956s-1983s) and the newly released Second Chinese Glacier Inventory (2005s-2010s), glacier changes in the glaciated regions along the Silk Road Economic Belt in China were analyzed. The results show that: (1) Glaciated areas along the Silk Road Economic Belt in China contained 22523 glaciers, covering an area of 25516.80 km2 and ice volume of 2592.85 km3, respectively, accounting for 46.37%, 49.22% and 57.39% of the total glacier area accordingly, and among which the total amount of glacier resources in Xinjiang was the largest. (2) While most glaciers were small (15519 glaciers, 68.9% was smaller than 0.5 km2), some larger ones (totally 6833.71 km2, with each having 1.0 and 5.0 km2) covered 26.78% of the total glacier area. The altitude of concentrating regions in the glacier retreat of each mountain range was different, and the rate of area reduction differed in each height zone. (3) During the period from 1956 to 2010s, the glacier area in glaciated regions along the Silk Road Economic Belt decreased by 4547.43 km2 with a percentage change of -20.88%. In the past 50 years, 3114 glaciers have disappeared, 1318 glaciers have been separated into 2964, and 73 glaciers have been merged into 35, and the loss of glacial ice volume was about 419.35 km3. (4) The glacier changes along the Silk Road Economic Belt had the generally accelerated trend from west to east and accordingly the rate of reduction appeared from southwest to northeast. The number of glaciers that disappeared in the north was greater than that in the south. The area of the northeast was reduced most, and the largest reduction rate was found in the southeast. (5) During the period from 1961 to 2010, a warming and humidification trend was observed in the glaciated regions along the Silk Road Economic Belt, the increase rate of temperature in the dry season was greater than that in the wet season, and the increase in the precipitation in the dry season was smaller than that in the wet season. The pattern of climate combination was not conducive to the accumulation of glaciers, hence leading to the retreating of glaciers. The scale of glacier development also had some impact on the retreat of glaciers, but there were spatial differences in terms of the driving forces of glaciers in each mountain range.
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    Causes for human-wildlife conflict on Changtang Plateau in Tibet
    XU Zeng-rang, JIN Ming-ming, ZHENG Xin, WEI Zi-qian
    2019, 34 (7):  1521-1530.  doi: 10.31497/zrzyxb.20190714
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    With the great progress of nature conservation in the last decades, human-wildlife conflict (HWC) has emerged as a new issue regarding protected areas. It is important to understand the causes for HWC and take effective measures to reduce HWC. However, research on HWC, characterized by systematicity, complexity, composed by multi-agents, and having feedback mechanism among agents, is difficult for us. Taking the Changtang Plateau in Tibet as an example, with the concept of social-ecological system of human-wildlife interactions, the distribution and quantity of agents of HWC is illustrated by field survey, statistical data and remote sensing data. Three main types of HWC in the study area is identified: (1) Forage competition between domestic livestock (sheep, goats and domestic yak) and herbivore wildlife (Pantholops hodgsonii, Equus kiang, Procapra picticaudata, Gazelle); (2) Living space competition between human settlements and wildlife habitats; (3) Fence separated the pasture and blocked the migratory routes of wildlife like Tibetan antelope. The pasture carrying capacity is examined by integrating wildlife with domestic livestocks. The overlaying of grazing pasture with wildlife habitat was modelled with the Maxent niche model and analyzed with the aid of GIS (geographic information system). Carrying capacity rate including both domestic livestock and herbivore wildlife was 110%, while domestic livestock stock rate was only 98%. Spatial overlapping rate was more than 50% for Tibetan antelope and domestic livestock. The impact of fence on habitat and migratory route of wildlife is also analyzed. Finally, causes for HWC are assembled from the aspects of the resource competition, the overlaying of living space, and the disturbance from human activities such as fence. The study is helpful to clarify the HWC cause and formation mechanism, and to improve the performance of conflict reduction measures.
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    The long-term trend of surface wind speed in China from 1979 to 2014
    WANG Nan, YOU Qing-long, LIU Ju-ju
    2019, 34 (7):  1531-1542.  doi: 10.31497/zrzyxb.20190715
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    Based on the monthly homogenized data, this paper explored the spatial and temporal changes of surface wind speed of 2268 stations in China during 1979-2014. In this paper, the linear regression and the five-point moving average are used to examine the trend of the climate change. The Pearson correlation coefficient is used to analyze the correlation. The Cressman interpolation method commonly used in meteorological data is adopted to interpolate the site data to grid data. In order to study the changes of surface wind speed in different parts of the country, China is divided into seven regions. The results are shown as follows. The mean surface wind speed in China generally showed a significant downward trend with an annual rate of -0.142 m/s/10 a, and it decreased with the largest trend magnitude in spring (-0.18 m/s/10 a), followed by winter (-0.135 m/s/10 a), summer (-0.13 m/s/10 a) and autumn (-0.129 m/s/10 a). Furthermore, about 82% (1868) of the selected stations showed a downward trend of surface wind speed. The significantly declining trend was found in the Tibetan Plateau and northeastern sub-regions classified in this paper, with the declining trend in North China being the smallest, and all passed the 0.05 significance test. In terms of interdecadal changes, the downward trend is slowing down. The declining trend of the whole country was most significant in the 1980s (-0.235 m /s /10 a), and was slowed down to -0.112 m/s/10 a in the 1990s, then turned to the smallest in 2000-2014 with a rate of -0.099 m/s/10 a. During the study period, there was a significant negative correlation between surface wind speed and surface air temperature, indicating that the recent warming of China may cause the wind speed to weaken.
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    Spatio-temporal changes of the extreme drought and wet events in Northern China from 1960 to 2016
    JIA Yan-qing, ZHANG Bo
    2019, 34 (7):  1543-1554.  doi: 10.31497/zrzyxb.20190716
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    Global warming has caused non-uniform changes in precipitation intensity and distribution. Therefore, drought and flood events may increase accordingly in Northern China. Based on the daily data of 424 meteorological stations in northern China from 1960 to 2016, ET0 was calculated by using the Penman-Monteith method to examine the changes of extreme drought and wet events in the study region. We calculated the surface humid indexes based on ET0 and precipitation, and used the Mann-Kendall (MK) trend test to analyze the frequencies of extreme drought and wet events by standardized surface humid indexes. All spatial distribution maps were plotted using the linear regression interpolation method embedded in the ArcGIS 10.1 software. This paper analyzed the spatio-temporal variations and multiple scale evolvement of extreme drought and wet events in northern China from 1960 to 2016, and explored the influence of El Niño Southern Oscillation (ENSO) on the extreme drought and wet events threshold using the correlation analysis method. The tendency rates of extreme drought and wet frequency were about -0.10 per decade and 0.13 per decade, respectively. In terms of spatial trends, the frequency of overall trend of extreme drought and wet events decreased and increased significantly from 1960 to 2016, respectively. The area where the number of extreme drought events decreased corresponded to the area where that of extreme wet events increased, including Tibetan Plateau, Northwest China, and Northeast China. The frequency of extreme drought decreased significantly in Northwest China, while that of extreme wet events increased significantly in central Tibetan Plateau, northern Xinjiang, and north of Northeast China. The annual occurrence frequency of extreme drought events was greater than that of extreme wet events. In different sub-regions, the frequency of extreme drought decreased, while that of extreme wet events increased. In different decades, the frequency of extreme drought events was higher in North China, while that of extreme wet events was higher in Northeast China and Tibetan Plateau. On month scales, summer witnessed higher probability of occurrence of extreme wet events, and the probability of occurrence of extreme drought in each month was far greater than that of extreme wet events. The probability of extreme drought was greater than that of extreme wet events in sub-regions, with the probability of extreme drought being the highest in North China and that of extreme wet events being the highest in the Tibetan Plateau. The relationship between the ENSO and the humidity index arrived with a delay. The wet events occurred frequently following El Niño, the drought events happened generally following La Nina. SSTA and the humidity index of next year had a significant positive correlation on annual and summer time scales. The SSTA had an important effect on drought and wet conditions in most parts of Northern China. Finally, this paper can benefit drought/flood characterization from the perspective of the overall dimensions of Northern China, and help decision making in risk-based drought/flood management in the context of global warming.
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    Geographer Spotlight
    A pioneer in the studies on Chinese biogeography of different historical periods: The 100th anniversary of Mr. WEN Huan-ran's birth
    WEN Rong-sheng
    2019, 34 (7):  1555-1568.  doi: 10.31497/zrzyxb.20190717
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    WEN Huan-ran, a famous geographer in the 20th century, pioneered biogeography of different historical periods. His contribution to plant geography focused on four aspects: (1) The publication of his works was earlier than the formation of historical geography in China. (2) His research was conducted on community and subject classification system, especially on the bamboo forests of northern China, as well as the distribution and change of forests at national and provincial scales. (3) His research methods are concerned with both natural sciences and humanities, such as in-depth field visits, investigations, revision of errors, supplement of omissions in the literature, and discussion on the influencing factors and recommendations. (4) After overcoming difficulties, he carried out studies in the entire context and opened new far-sighted perspectives for further studies. His contribution to animal geography of historical periods included the following. (1) He published the earliest works in this field. (2) He was mainly involved in the study of many rare species in the reptilia, aves and mammalia. (3) The results can be used as surrogate indicators for eco-environmental change, reference for ancient vertebrates and modern animals and related disciplines, evidence of forest and bamboo forest distribution. It was mainly Wen's long-lasting achievements in historical geography that made his studies so valuable and unique, and aroused attention from foreign scholars. All this must be considered a highlight that can stand the test of time, and should have received more international appreciation.
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