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  • Orginal Article
    Fan Jie, Liu Hanchu, Wang Yafei, Zhao Yannan, Chen Dong
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    From the recent “The Northeast China Phenomenon”, three stable factors have been put forward that influence the optimization of protection and development of territorial space: resources and environment carrying capacity, geopolitical relations, regional culture and mechanism. The analysis on the three stable factors in the Northeast China respectively shows that the background of resources and environment carrying capacity in Northeast China is strong, but the efficiency of development and utilization is poor. The distinct manifestations are that the area of optimized region and prioritized region is small, the efficiency of restricted zones is poor, and the overload early-warning of resources and environment carrying capacity is low. Northeast China is located in the core of the Northeast Asian region, one of three economic circles. Its geopolitical advantages are prominent, but it fails to convert economic advantages. The distinct manifestations are the proportion of export-oriented economy is too small, and without prominent position in the trades with Japan and Public of Korea. Regional culture and mechanism have become the core obstacles to the development of Northeast China. The distinct manifestations are irrational industrial structure, the high proportion of state-owned economy. Combing with the problems of Northeast China revitalization, this article takes “innovation, coordination, green, open and sharing” development concept as guidelines, and then prejudge some core problems in Northeast China. The suggestions are: 1) Improving technology innovation ability to solve transformation of development driving force; 2) Innovating the mode of the stated-owned enterprises reform and promoting coordinated development of various ownership economy; 3) Centering on strategy of “one belt one road initiative” to implement the open economy transformation and vacating domestic market to promote the advantage industry in Northeast China, and continuing to maintain the vigor; 4) Eliminating urban poverty and increasing people's livelihood in Northeast China based on sharing concept; 5) Adopting the principle of the unity of economic, social and ecological balance to realize the main function in Northeast China.

  • Orginal Article
    Shi Peijun, Kong Feng
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    Recent studies have noted a worldwide increase in the occurrence of extreme-precipitation events, this increase has been attributed to warming climate. Although other anthropogenic factors are recognized to be important, their relative contributions remain unclear. We use daily rainfall data from 659 meteorological stations in China, large scale climatic and anthropogenic indices to identify major causes of, and quantify their contribution to, a marked increase in heavy rainfall in 1951-2010. The decadal heavy rainfall amount (HRA), heavy rainfall days (HRD) and heavy rainfall intensity (HRI) increased by 58.6-68.7, 46.5-60.2 and 7.1-11.5 percent respectively. Our analysis suggests that although this trend could be explained by both large-scale climate phenomena, and local and regional anthropogenic activities, the latter such as urbanization, industrialization and associated air pollution have the strongest influence. Contributing roughly at the same magnitude, such factors explain 61.5, 58.5 and 65.5 percent of the variance in HRA, HRD and HRI, respectively, where as the large-scale climate phenomena explain only 24.3, 26.2 and 21.9 percent respectively. The expansion of spatial distribution of accumulated HRA and HRD over time shows a statistically significant and increasing correlation with the spatial distribution of population density and annual low-visibility days. Taken together, these results suggest that the substantial increase in heavy rainfall across large parts of China during the past six decades is very likely triggered by large scale and rapid urbanization, industrialization and associated air pollution. Previous studies linking urbanization to rainfall are mostly focusing on the impact on total rainfall and mostly considered only the local or city scale. Previous studies found urbanization as likely cause of increased heavy rainfall in India over five decades. Our results support this finding, but also show that urbanization is only one of the factors- industrialization and air pollution each contributes at equivalent magnitude. Our analysis is the first, to our knowledge, to establish urbanization, industrialization and air pollution as the primary cause of a nation- or sub-continental-scale increase in heavy rainfall over decades, and to quantify relative contributions of anthropogenic and climate factors. Our findings indicate that local anthropogenic processes may shift the regional climate beyond through GHG emissions. Such connections need to be better understood and reflected into the climate models. With cities in China increasingly experiencing extreme rainfall events, compounded by the increasing extreme summer heat in the same region, our findings call for a careful reevaluation of the risks of extreme weather in formulating national policies on urbanization, industrialization and environmental management in China in formulating. Rapidly growing and industrializing cities and nations will need to better control the air pollution, and to anticipate and accommodate these regional climate consequences, if they are to reduce the risk of flooding and waterlogging.

  • Orginal Article
    Yang Yongchun, Song Meina, Shi Kunbo, Jin Shuting, Wang Meimei, Zhang Weifang
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    Since the implementation of China’s reform and opening-up policy, a hybrid institutional model has gradually evolved and been further refined to drive the country’s modernization and rejuvenation. At the same time, with the development of the model of gradual institutional changes, the city, along with contradictions among urban, resources, environment and economic development, has forced us to deepen institutional reform and transformation. And in the process of the rapid change and transformation of cities, the institution plays a quite important role in the development of urban transition, which often includes the indicators of labor, enterprise, foreign investment, etc. Based on these indicators, we build an index system which includes four dimensions, and undertake research on the results and effects of institution transformation. By the means of spatial interpolation, regression analysis and synthesis of spatial data and the date from 2003 to 2013, we conducted a comprehensive measure for the level of Chinese urban transformation under the influence of a gradual institution in the 286 prefectures of China. The results showed that: 1) From 2003 to 2013, the results and effects of institution transformation all decrease from the east coast to the inland areas in the space. In terms of time, the effects vary from scattered in 2003 to linear spread in 2008, and there is a tendency to become planar extension in 2013. 2) With urban agglomeration becoming the new regional unit participating in international competition and the division of labor, the institutional changes of its surrounding areas are typical representative. The institutional results and effects of its surrounding areas are significant and meet the Concentric Zone Theory, which present the law of diminishing circle from the center to the periphery. 3) The high centers are mostly single cities, especially the capital cities in the central and western regions, except Chengdu-Chongqing Urban Agglomeration. And part of them have a relationship with large-scale development of natural resources. 4) The effects are largely correlated with the result of institution change and the correlation is becoming more and more significant with the passage of time.

  • Orginal Article
    Wang Ningning, Chen Rui, Zhao Yu, Zhong Shaoying
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    In the context of informatization, the information system and the population system interact with each other, and the information elements and the demographic factors affect the regional development more and more deeply. Therefor the study on the coupling of information space and population space could provide the government departments with scientific decision for regional development layout. From the perspective of the flow space, a spatial coupling model based on relations measurement is established in this paper. What’s more, complex network analysis and gray correlation analysis are used to discuss the characteristics of the coupling and coupling pattern. The results show that the coupling network of the population space and information space presents "core - periphery" model. As central provinces, Beijing, Shanghai, Guangdong, Tianjin, Xinjiang and Gansu provinces dominate in all provinces, which are attached cores of the other provinces. On the one hand, a coupling degree responses to the national strategy of interoperability, on the other hand it is the inevitable result of the integration of Beijing, Tianjin, and construction of the Silk Road economic belt. All the provinces are divided high coupling coordination group, running coupling group and low coupling development group.

  • Orginal Article
    Song Zhengna
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    Competitive public facilities are both public-welfare and competitive, among them the comprehensive hospitals are most representative. Their location decision is relatively more complicated. This study aims to solve the problem that how to seek the optimal locations of such facilities. First of all, this study puts forward the concept of “competitive public facilities” which had been not defined systematically and normatively, pointed out that “the spatial equilibrium to coordinate the efficiency and equity” is the basic principle in location selection of competitive public facilities, and summarized a series of location requirements that they are to abide by the spatial interaction between the supply and demand, to limit the extreme travel cost from the settlement to the nearest facilities, to minimize the weighted total travel cost, to restrain the facility scale threshold, and to distinguish appropriately in spatial distribution between the higher level competitive public facilities and the ones. Secondly, gravity P median model was constructed with the probability distribution to replace the proximity rule by embedding the improved Huff probability model in the classic P median model. In such new model, the facility scale factor was introduced to solve facilities location and scale simultaneously, and then two factors were constrained that they are the biggest travel cost from some settlement to the corresponding nearest facility as well as the minimum facility scale. The objective function and a series of constraints just been mentioned can guarantee to realize the multiple targets including the spatial equity—efficiency, quality of service fairness and scale efficiency. Finally, the model was applied to the empirical test as to the comprehensive hospitals location decisions in Wuxi urban district, the results showed that: 1) The optimal facilities distribution is more balanced, and new hospitals locations form three layers that are the main core, secondary core and outer layers, which can comprise reasonable structure with more appropriate division, meanwhile the scale configuration of hospitals is in conformity with the population distribution on the whole. 2) The spatial equity of the optimal locations calculated with the new model shows bigger advantage, since a class of related indicators are improved that they are the Gini coefficient of available service resources quantity potentially for residents and other such indexes. 3) And at the same time, it is decreased properly that is the weighted average travel time from the settlements to all the hospitals, which can achieve the collaborative layout and spatial mismatch among the hospitals and the community health service organizations. In addition, it is important to note that this study focuses on the discussion of theory and approach, rather than the application with the intact model. Futhermore, when the new model is applied to the actual planning and location selection, concerned parameters and constraints should be adjusted appropriately by planning situation. All in all, the above study can support certain decision basis for future public facilities distribution adjustment or new town construction, meanwhile can enrich the concerned research about public facilities location allocation both here and abroad.

  • Orginal Article
    Zhao Lin, Zhang Yushuo, Jiao Xinying, Wu Di, Wu Dianting
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    Basic public service is the foundation of maintaining social fairness and justice. It is of significance to build a comprehensively well-off society by establishing and perfecting the basic public service system and promoting the equal basic public service. By establishing the evaluation system of basic public service, this article evaluated the level of basic public service in Henan Province, then analyzed the spatial pattern of basic public service quality by using the spatial autocorrelation method, and finally studied the spatial spillover effects and the influence factors of basic public service by using Spatial Durbin Model. The results show that, 1) The level of basic public service quality in cities of Henan Province shows the different rising trend during 2005-2013, but the overall level remains to be improved. The relative difference among cities shows the trend of shrinking. The low level area shows obvious “catch-up effect” to high level area. 2) The spatial pattern of basic public service shows the structure of half band characteristics and the level of basic public service decreases from northwest to southeast. From the global trend, the basic public service level in west area is higher than the east area, the north area is superior to the south area and the latitudinal direction difference is less than the east-west differences. Compared with sub-region in Henan Province, the level of the Central Plains Urban Agglomeration is the highest, the level of the western and southwest region and the northern region is the higher, and the level of Huanghuai region is the lowest. 3) The global Moran’s index during 2005-2013 is positive. The spatial pattern of basic public service shows the positive spatial correlation. The various types of basic public service show the spatial evolution mode of agglomeration-dispersion-agglomeration. The local auto-correlation results show that the spatial club convergence characteristics of High-High and Low-Low agglomeration is obvious. The distribution and amount of various agglomeration types remain stable. 4) The spatial Durbin Model test shows that there exists spatial spillover effects of basic public service among cities in Henan Province. The level of regional basic public service is not only influenced by the region itself factors, also affected by the basic public service level of adjacent areas. The regression results show that the urbanization level, local financial expenditure and regional economic vitality have a positive influence on the basic public service.

  • Orginal Article
    Li Yangbing, Li Xiaoran, Zhang Heng, Qiu Conghao, Luo Guangjie, Bai Xiaoyong
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    Investigating the reconstruction and integration method of the karst mountain settlement spatial structure has important practical significance, as it promotes the trend of intensification development of rural residential land and the construction of new socialist countryside. The Houzhaihe area which is a typical karst mountain located in the Puding County of the Guizhou Plateau was selected as study area in this study. Having adopted high resolution remote sensing images and field investigation data, this article probed into the population change in karst mountain settlements in 1963-2010. The rural settlements development suitability evaluation method and settlement control type were developed based on the settlement scale development and the population density spatial distribution of the study area. Large settlement and larger settlement were mainly distributed in both sides of the east and west of the central peak-cluster depression area which with better land conditions and traffic conditions in the study area. The high value center of population density is of the corresponding level tend to be large settlements which are apart from each other. The settlements in the study area can be divided into 5 classes, namely, key villages and towns, prior development, conditional priority to expand, restricted extension type and abandoning type. The results in this study may serve as cases of the karst mountain settlement space reconstruction and integration.

  • Orginal Article
    Tang Linnan, Liu Yu, Pan Yuchun, Ren Yanmin
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    This research considering the 297 villages of Pinggu as the basic unit, comprehensively evaluates the rural regional functions such as agricultural production function, industrial production function, living function and ecological regulation function by BP model, and then sorts these villages into 6 different function zoning areas based on the BP evaluation results and regional spatial properties by Ward method. The results show that: 1) The villages whose agricultural production function develop better also develop well in ecological regulation function. Influenced by location, the villages with higher index of industrial production function mainly distribute in the central area of the town and its surrounding region, so do those with higher index of living function. Under effects of various functions, the rural regional multifunction develops such a pattern that agricultural production function is stronger in plain area, life function domains in the center or surrounding villages, and ecological function develop fast in the mountain region. And it indicates BP model is suitable to assess rural regional functions. 2) All the villages of Pinggu district can be divided into six regions, which are eastern plain production area, eastern hilly ecological production area, the central urban plain living area, suburban central plain living area, and eastern ecological and living area, north mountain ecological area by Ward method. And the western plain production area, the central urban plain living area, northern mountainous ecological regions develop better in Pinggu and distribute relatively concentrated. In the future, we advise Pinggu should promote its rural multifunction according to such a guide-strong function optimization, and the weak function improvement, medium function ascension work to make all villages develop in order.

  • Orginal Article
    Liang Liutao, Zhai Bin, Fan Pengfei
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    The problem of agricultural environment is closely related to the land use of the household, and it is derived from the household’s land use behavior. Under the background of the increasingly serious environmental problems caused by the household’s land use, the measure of household land use efficiency which only considering the ‘good’ output, but ignoring the ‘non-intended’ environmental output, may result in inaccurate measurement. Therefore, this article will introduce the ‘non-intended’ environmental output into the evaluation model of household land use efficiency, based on household survey data of the core area of ??food production in Henan Province, make use of directional distance function model to measure household land use efficiency which considering environmental factors, and lastly explored household land use efficiency condition and its influencing factors. The main findings are: 1)the average household land use efficiency which base on environmental factors of Henan Province was 0.612, indicating that in considering environmental factors, the actual output of household land use accounted for optimal output, compared with only 61.2%. More than half of households efficiency values are under 0.6. It can be seen that the efficiency of the value is not high, there is enormous room for growth. Household land use efficiency of different scale household are with great differences, they presenting ‘U-type’ trend. The number of households in the middle land scale is the largest, and the proportion is 44.15%, but the average value of the land use efficiency is the smallest, which shows the potential threat to the current land use and so on. 2) The empirical results show that affecting factors of household land use efficiency considering environmental factors are multifaceted, such as the farm household characteristics (age of household head, education and labor force), household livelihoods, planting structure, household production scale, the degree of fragmentation of agricultural commercialization. Among them, the household livelihoods of concurrent business can reduce the household land use efficiency in a certain extent. Although the adjustment of planting structure can increase the household’s agricultural income, but it is not conducive to the improvement of household land use efficiency which under the constraints of environmental factors. Expanding household agricultural land scale has a positive impact on household land use efficiency, but in reality small-scale land and fragmentation land are widespread exist,which reduced the positive impact. The stability of land property rights can improve household land use efficiency which under the environment factors, but whether the collective land property rights or the right of contract management, and the informal land transfer among the farmers,the property right relationship is poor, and this is not conducive to improve household land use efficiency which under the constraints of environmental factors.

  • Orginal Article
    Long Maoqian, Xiang Ran, Zhang Jianzuo
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    In 2011, the proportion of China′s urban population exceeded 50%. In the past 30 years, urbanization has contributed enormously to economic growth and modernization in China. For China,the primary strategic task of economic and social development is to continue to increase the level of urbanization,and manage the orderly transfer of the rural population to the cities. The government announced that China′s future development roadmap is a ‘new type of urbanization’, which requires the coordinated development of cities and towns. This article generalizes four gradients of migration destination of rural population, and proposes the concept of ‘gradient urbanization’. Based on the 311 village questionnaires of Shanghang County in Fujian province, we identify the factors for different gradient migration. The result shows: 1) The size of village and population outflow are negatively correlated. A 1% increase in the population size of the village would cause a 0.4% decrease in the outflow proportion of the population. There is a significant distance attenuation in the migration from villages to the county. 2) Villages with high elderly dependency ratios are more likely to lose their villagers, as the aged lower the migration cost to the county for the young people. In contrast, the villages with high child-age dependency ratios are less likely to lose their villagers. 3) Education is an important driving force for urbanization. As educational resources gradually become concentrated in the county, an increasing number of young parents choose to move to the county, where their children can receive a better primary education. Furthermore, significant evidence has been found to show that the villagers with high human capital are more inclined to migrate to the prefecture-level city.

  • Orginal Article
    Yang Qingke, Duan Xuejun, Wang Lei
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    Based on the interactions between water environment protection and regional development, the connection of water and the restriction of water environmental carrying capacity are comprehensively considered on the regional industrial layout. The constraint regionalization system of water environment is constructed, which is composed of water environment capacity and pressure. Due to industrial cluster and condensed water but strong sensitivity of water environment, Taihu Lake Basin in Jiangsu Province is taken as an example in order to explore the small watershed evaluation unit division, constraint index selection and spatial overlay analysis. The results show that: regional differences of water environmental carrying capacity in Taihu River Basin are enormous. The indexes decrease gradually from the northeast to the southwest along the Yangtze River. Due to good water accessibility and strong exchange capacity in the plain area, make water environmental carrying capacity higher. In the meantime, the influence of drinking water sources, water channel and important lake wetland protection zone causes water environment sensitivity stronger in Taihu Lake, Gehu Lake and southwest hilly region. As the corresponding, it is lower for water environmental carrying capacityin the regions. As to the water environment pressure, region with the higher index is mainly distributed in the central city. The developed economy, dense population and high land development intensity make industrial COD emission intensity higher and water environment pressure stronger. Affected by the designated drinking water source protection areas, Taihu primary protection zone, hilly and mountainous areas of water conservation, regional economic development is limited and the index of water environment pressure is relatively lower. These areas are mainly distributed in the upstream of Changdang Lake, the surrounding of Gehu Lake, Yixing and Wuzhong. Through the comprehensive coordination of regional water environmental capacity and pressure, Taihu Lake Basin is divided into four types, namely, high-pressure and low-capacity area, low-pressure and low-capacity area, high-pressure and high-capacity area, and low-pressure and high-capacity area in the township (street) space scale. And then, the guidance scheme of industrial optimization adjustment is put forward, which can control the output of water pollutants from the source. The findings can provide scientific basis for synergistic effect between water environment quality and regional sustainable development and the policy formulation of differentiated industrial access policy. As a result, it will promote the harmonious development of industry development and water environment quality and realize the maximization of regional social economy and water environment.

  • Orginal Article
    Chen Shanshan, Liu Kang, Bao Yubin, Chen Hai
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    As a major water source region of the of South to North Water Diversion Project, Shangluo City was selected as a case study. Water yield sub-model of the InVEST Model and Water Retention Model were used to reveal the spatial heterogeneity and influencing factor of the service of water retention. Through the process of in-situ acquisition, the field calibration and model verification, several conclusions were drawn as the following: 1) The gross amount of water conservation was 2.748×109m3/a, and the capacity of water conservation was 324.85 mm in Shangluo City. The order of the capacity of water conservation of five watersheds was the Xunhe River, the Qianyou River, the Jinqian River, theDanhe River and the Luohe River. 2) Climate factors had the greatest effect on the spatialpattern of water yield capacity, and the land use change in recent 10 years and vegetationand soil properties in different underlying surface impacted significantly on the spatial heterogeneity of water conservation. 3) There was probably a stronger correlation among the space of water yield capacity and mean annual precipitation, actural vaporation, and the effect of plant available. The key driving factors of water conservation function was potentialevaporation, soil saturated hydraulic conductivity and forest cover rate.

  • Orginal Article
    A Duo, Xiong Kai, Zhao Wenji, Gong Zhaoning, Jing Ran, Zhang Lei
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    North China plain is a geographically significant part of China. The climate change, which created the unique climate pattern and characteristics, has a non-negligible impact on the eco-system of the countryin this area. Based on historical data (1960-2013) on daily temperature and precipitation obtained from 82 meteorological stations, together with solar activity and atmosphere environment data scattered in North China plain, this paper makes a comprehensive investigation of the patterns and features of the climate using climate tendency method, Mann-Kendall test method and cumulative anomaly method. The results reveal that the annual mean temperature varied between 11.86℃ and 14.33℃, and the temperature increased slightly with the rate of 0.23°C/10a, (P< 0.01). This ascend may be due to the rise of turbidity in the atmosphere environment, the disappearance of the 0°C isotherm, the rise of spring temperatures , and the increase of the isotherm (>15°C) area. At the same time, precipitation varied between 617.96-1060.30 mm, decreased significantly with the rate of -1.75 mm/10a,(P>0.05). The expanding of the 400-600 mm precipitation contour area, the narrowing of ranges of 600-800 mm and 800-1000 mm, and excessive reduction of autumn precipitation indicates less precipitation. And all precipitation contours showed a northward movement. The sensitive areas of characteristic climatic change were mainly located between the latitudes 35°-39°. The climate mutation, occurred during 1991-1994, has been proved have more relationship with the solar activity. The influence of solar activity on maximum temperature was bigger, and the influence of turbidity on minimum temperature was more significant. Atmosphere environmental factors of the sunshine percentage, relative humidity, and wind speed had the high correlation with the temperature change,which the average correlation coefficient was 0.74. The better climatic condition, the lower content of aerosol, and the correlation coefficient of solar radiation and annual average temperature was higher. The correlation coefficient of turbidity and annual average temperature was higher when the content of aerosol is higher. The increase of the content of aerosol caused by human activity is the main external cause to the rise of the area temperature.

  • Orginal Article
    Xie Xuefeng, Pu Lijie, Zhu Ming, Xu Yan, Wang Xiaohan, Xu Caiyao
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    The mechanism of soil water and salt movement research is one of the core issues in soil salinization research. The study of modeling in soil water-salt transport is of great significance for find out the soil water and salt movement law. This article reviews the achievements of soil water-salt transport model, divided the soil water-salt transport model into water-salt balance models, physical models and system models in accordance with the principles and trends of water-salt transport in different soils. Introduced the theories and applications of existing models by means of literature at domestic and foreign, then analyzed the problems of existing models and prospected the future trends of soil water-salt transport model in the new situation and priorities for future research. Integrated modelling of soil water-salt transport, field and regional scalemodel for simulating soil water-salt transport, and water-salt transport model coupled with crop growth model are considered to be the key point of the research on water-salt transport model in the future. This article aims to provide new ideas for the study of soil water-salt transport model in the future.

  • Orginal Article
    Chen Shifa
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    Soil erosion is one of the world’s three major environmental problems and is the primary cause of land degradation. Its origin is related to a series of natural factors including rainfall, topography, soil and vegetation properties, and inharmonious human activities that aggravate soil erosion. The rainfall is one of the main powers that lead to soil erosion. Rainfall erosivity is the tendency of rainfall to erode the soil, long time sequence rainfall erosivity is influenced by large scale circulation situation. Rainfall erosivity is highly dependent on rainfall, which is closely related to the ENSO (El Ni?o-Southern Oscillation) indices. Pearson’s correlation coefficient can be used to evaluate the validity of the relationship between the ENSO indices and annual rainfall erosivity. This article investigated the influence on rainfall erosivity in Shaoguan City of the El Ni?o SST (Sea Surface Temperatures) anomaly, the SOI (Southern Oscillation Index) and the MEI (Multivariate El Ni?o-Southern Oscillation Index) as representations of ENSO phenomena. These index were selected because of three teleconnection patterns that are known to be important for rainfall erosivity. Through selects month rainfall as calculate rainfall erosivity during 1951-2013 and analyze that ENSO events influence rainfall erosivity in Shaoguan City. The results are indicated as follows: 1) The rainfall erosivity show upward trend and evident seasonal variation and great variation between years. At the same time, the 5 a moving average curve of rainfall erosivity indicates that the general trend is an increase accompanied by fluctuations; 2) Correlation analyses were applied to rainfall erosivity and SST anomalies. The effects of the SST anomalies on rainfall erosivity are highly evident. The rainfall erosivity showed that increased at first and decreases afterwards with the increase of the SST anomalies, and low rainfall erosivity during cold events and slightly high rainfall erosivity during warm events. When other factors that affect soil erosion were fixed, soil erosion was slightly serious during El Ni?o, whereas it was light during La Ni?a; 3) The influence of the SOI on rainfall erosivity was shown by a significant correlation, the rainfall erosivity showed decreases with the increase of the SOI; 4) The MEI explains the effects of the ENSO on Shaoguan rainfall erosivity better than did the other indices assessed in this study. Empirical evidence has shown positive correlation between rainfall erosivity and MEI. Obviously, the MEI includes six variables rather than one variable (SOI and SST), providing a better indicator for representing the state of the ENSO. Through analysis of the effects of the ENSO events on rainfall erosivity in Shaoguan city, these findings can provide a theoretical basis for the comprehensive treatment and prevention of soil erosion, and it has significant importance for the monitoring, evaluation, prediction and treatment of soil erosion.

  • Orginal Article
    Deng Yujiao, Tian Yongjie, Wang Jiechun
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    Using Channel VIS, IR1 and IR4 of the domestic geostationary meteorological satellite FY2E/VISSR data, the multichannel method was proposed to detect the daytime sea fog. Firstly, the existing dynamic threshold method was revised in the paper in order to improve the accuracy of distinguishing sea surface from cloud and fog. The thresholds were based on the histogram statistics of the reflectance of Channel VIS, and adjusted dynamically in different regions or different seasons. Secondly, cloud height estimated from the bright temperature of Channel IR1 was used to separate middle- and high-level cloud from low-level cloud and fog. When the height was greater than 2 000 m, the object was middle- and high-level cloud. Thirdly, fog index computed from Channel IR1,IR4 and VIS was used to divide low-level cloud from fog preliminarily. If the fog index was greater than 20, the object was possibly fog. Finally, smoothness and stability index were used to tell fog from low-level cloud further, and it was greater than 0.9 for fog. Ground-based fog observation data from thirteen sites on the coast of Guangdong were used to do the verification of the FY-2E fog detection products, which were Zhanjiang, Wuchuan, Leizhou, Yangjiang, Shangchuandao, Zhuhai, Doumen, Shanwei, Lufeng, Shantou, Nan’ao, Chaoyang and Chenghai. The statistical calculation showed that the probabilities of detection(POD) was 92.7%, the false alarm ratios(FAR)was 29.4%, and the critical success index(CSI) was 64.7%. The FAR was a little high mainly because of two reasons: on one hand, the FY2E data didn’t have the penetrability for clouds, so fog covered by clouds would be misjudged to clouds; on the other hand, the recognition capability of FY-2E data with a spatial resolution of 5 km was limited so that some fog pixels couldn’t be distinguished correctly. Both of them were decided by the remote sensor of FY-2E, not decided by the fog detection algorithm. Nonetheless, the fog detection method was generally efficient and feasible. In the case study of the fog occurred on February 26, 2014, the remote sensing products showed the dynamic change of fog every hour from 9:00 AM to 16:00 PM. The sea fog almost kept unchanged between 9:00 AM and 13:00 PM, and the fog edge dissolved slowly on the junction of Bohai Gulf and the Yellow Sea between 14:00 PM and 16:00 PM. It was seen that the high time resolution data of geostationary satellite data were more effective in continuous and dynamic detection of sea fog than other satellite data.

  • Orginal Article
    Ye Jian, Chen Jinxiong, Chen Xiaoqing, Zhu Jun, Xu Zhu
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    Featured with suddenness and rapid expansion, the confluence of gully debris flow in the nature can cause huge economic loss to the residents along the accumulation areas. Therefore, it is necessary and urgent to predict the hazardous range for the confluence of gully debris flow. Through utilizing discrete element method and GPU parallel computing approaches, this paper establishes debris-flow deposit model. By taking the debris-flow deposit characteristics after the confluence of gully debris flow in the nature and simplifying the interaction between debris-flow gully, this article completes numerical simulation of debris-flow confluence with different confluent angles and the prediction of deposit hazardous areas. The experiment results indicate that numerical simulation of debris-flow confluence can not only simulate the characteristics of deposit produced by the confluence from circulation areas of debris flow in the nature, but also simulate the reasonable hazardous range for the debris-flow deposit under the action of pressure component and shear force component of different gully confluence angles. In addition, the advantages of GPU parallel computing can be used to simulate the large-scale debris flow confluence phenomena, and the expandability of this model lays simulation basis for analyzing the hazardous range for the confluence accumulation of debris flow in a more complicated geographical environment.

  • Orginal Article
    Zhang Jian, Hu Xiaofei, Geng Haopeng, Chen Dianbao, Pan Baotian
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    The northern Qilian Mountains have been experiencing intense tectonic uplift and denudation since the late Cenozoic, which resulted in an exceptionally thick sediment building up in the Hexi Corridor. The mineral characteristics of these deposits preserved substantial information about the mountain uplift and drainage evolution. Heavy minerals are the stable components in the sedimentary cycle; its characteristics and assemblages are useful tools to acquire the sediment provenance information, by inference, drainage pattern evolution. With the purpose of deciphering the drainage evolution history in Jiudong Basin, we collected heavy mineral samples from two cores (DWJ and XKJD) and modern fluvial samples in Jiudong Basin. We find that: 1) The heavy mineral characteristics in the lower part of DWJ Core (140-69.7 m) are similar to those in the two tributaries, Bailang River and Maying River; 2) The heavy mineral characteristics in the upper part of DWJ Core (69.7-0 m) and the XKJD Core (65.6-0 m) are similar to those in the trunk Heihe River as well as two tributaries, Liyuan River and Shandan River. The concentration of heavy mineral grains in sand-sized terrigenous sediments may fluctuate considerably because of several factors, mainly the sedimentary processes and post-depositional dissolution. To eliminate the effects of these fators on heavy mineral assemblages as much as possible,we analyize the samples with same grain size (63-125 um), which means they represent similiar hydrodynamic condition. The presence of abundant less resistant minerals (e.g. amphiboles, epidotes) in cores indicates that chemical weathering is negligible and most unstable grains are preserved. Given the significant changes of both lithology and sedimentary facies around 70 m in DWJ Core, the change of heavy assemblages in cores could be attributed to the drainage reorganization of midstream of Heihe River. By comparing sedimentary features from DWJ Core with previous studies in the Hexi Corridor, we speculated that this drainage evolution and subsequent sedimentary environment change occurred between early and middle Pleistocene. This drainage reorganization of Heihe River in the Hexi Corridor happened during the Kunlun-Huanghe Movement, which allow us to attribute there organization to the tectonic movement surrounding this areas. As a whole, the paleodrainage evolution of the Jiudong Basin since the Pleistocene may be summarized as follows: during the Middle Pleistocene, Jiudong Basin were mainly sourced from Maying River and Bailang River, while the Heihe River flowed to the Minle Basin. At the end of the middle Pleistocene, the tectonic uplift of the Qilian Mountain caused a progressive reorganization of the drainage pattern of the Jiudong Basin. The provenance of the upper part of DWJ Core (69.7-0 m) and the XKJD Core (65.6-0 m) samples from trunk Heihe River indicates the northwestward shifting of Heihe River to its present-day position in the Jiudong Basin.