This article describes the significance of the ‘Belt and Road Initiative’ on the rise of China. It is analyzed that the global basic geopolitical pattern, geopolitical tendency of important areas (nations), as well as the prospects of economic and trade cooperation with China. The possible problems that China is facing the ‘Belt and Road Initiative’ strategy implementation are also analyzed. Finally, it’s pointed out that the government and scholars should strengthen the research, data collection and management of the ‘Belt and Road Initiative’.
This article attempted to analyze the spatial-temporal evolution and regional differences of carbon emissions from transport in China over the period 2000-2012 based on the transport carbon-emission model. Moreover, a two-way fixed effect model was developed to study the factors in terms of socioeconomic, urban form and transport development that influenced transport carbon emissions in China through the regression method of "general to specific". The results indicated that China’s total and per capita CO2 emissions from transport were growing at 9.29% and 8.69% a year respectively, appearing the different characteristics of stages. The regional differences of the total CO2 emissions from transport first increased and then decreased, while the regional differences of the per capita CO2 emissions from transport first had a cyclical fluctuation and then kept decreasing. Provinces with higher total CO2 emissions from transport were mainly concentrated in the eastern coastal region which had a prosperous economy and a large population, while provinces with higher per capita CO2 emissions from transport were predominantly concentrated in developed regions such as Shanghai, Beijing and Tianjin as well as some western provinces with lower population density. In the aspect of socioeconomic influential factors, per capita GDP and per capita disposable income of urban households both had significant positive effect on per capita CO2 emissions from transport, which indicated that the development of social economy and the increase in residents' income level were main drivers of transport CO2 emissions growth. The urbanization level also had a positive effect, but it was not statistically significant. In addition, industrial structure was the least significant factor. In the aspect of urban form influential factors, urban population density also had a significant positive effect on transport CO2 emissions, which was contrary to the conclusions of study abroad. Moreover, the city size also had a positive effect, but it was not statistically significant. In the aspect of transport development, the effect of urban road density was positive and was more significant than urban road ratio and highway density. The effect of public transport development was significantly negative. However, the effect of car ownership was not statistically significant. Finally, the effect of time was negative to transport CO2 emissions, which reflected that the effect of some unobserved factors for controlling the growth of transport CO2 emissions in China was gradually appearing.The better understanding of the relationship between socio-economy, urban form, transport development and transport CO2 emissions will help China to curb transport CO2 emissions growth and construct city space environment towards low-carbon and sustainable.
‘One Belt, One Road’ (OBOR) was proposed by President Xi Jinping in 2013 when he visited Kazakhstan and Indonesia. It is now the core regional development strategy in China. A series of studies (mainly in Chinese) have been conducted to provide the contextual knowledge or suggestion for this strategy. However, a theoretical examination of OBOR remains at the very superficial level among existing scholarship. This study aims to analyze the nature and impacts of OBOR from the perspective of rescaling and scalar politics, with a balanced consideration on the political geographical mechanisms and potential risks for promoting OBOR. It is argued that OBOR reshapes the roles and territoriality of Chinese state and produces a number of new geographical scales based on construction of international infrastructure, capital flows and trade cooperation. Specifically, the state power is re-territoralized through forming new international organizations and investing in the international infrastructure; the importance of some large cities are also highlighted as the nodes of OBOR. In other words, the inter-national processes are embedded in sub-national regions or new state spaces, confirming the previous theories on ‘localization’. The rescaling strategies enable China to gain more influence on Eurasian geo-political and economic processes and more space to accelerate its capital accumulation. This echoes Lefebvre's arguments that the spatial fix of urban growth is based on scalar fixes. Therefore, it is interesting to note that the scale and power relations are mutually constructed. On the one hand, scale is produced and reconstructed by both international and domestic political powers and capitals; on the other hand, the rescaling processes have great impacts on the existing power relations and capital accumulation. The perspective of scalar politics suggests that there are some potential hindrance and risks behind this new initiative. At the international level, China is not only facing complex up-scaling forces related to the multilateral and international relations and local unrests, but also confronting the down-scaling forces based on the existing boundary and scalar discourses. At the domestic level, OBOR may lead to excessive competition, over accumulation and repeated construction due to local protectionism determined by the political promotion system in China. Some potential risks may also be caused by Xinjiang separatists, who can get supports easier than with the further opening of China to the rest of the world in the OBOR strategy. China must cope with these scalar politics actively in order to promote "one belt one road" strategy. This research has much policy implication for Chinese government to smooth the mechanisms of scalar politics on internationalization and reduce the potential risks of oversea investment, inter-national cooperation and regional governance. This aticle also furthers the understanding of scale in human geography by integrating discussions of rescaling and scalar politics from different sub-disciplines.
The efficient and coordinated development of industrialization, urbanization, information and agricultural modernization (so called ‘Sihua Tongbu’ in Chinese) is not only a practical need but also an important strategic direction of integrating urban-rural development and regional development in recent China, and it also provides a significant perspective for identifying problems so as to improve the regional policies using scientific methods. The existing studies are instructive for the overall grasp of this issue at national and provincial levels. However, they failed to uncover the regional patterns and impact factors of the ‘four modernizations’ development at an appropriate scale from the geographical perspective, and the interactions between four modernizations development and regional policies have been neglected as well. This article evaluated the comprehensive development index, coupling development index and coordinated development index of the‘four modernizations’ of China’s 343 prefecture-level administrative units, and calculated their efficiency of the ‘four modernizations’ in 2001 and 2011. Then, this article establishes the evaluation index system of the coordination development efficiency of the ‘new four modernizations’ , which includes four input elements of per capita consumption expenditure of urban and rural residents, per capita local fiscal budget, the total social investment in fixed assets and per capita local or foreign currency and one output element of the coordinated development index of the ‘four modernizations’ . Based on the data from 343 prefecture-level administrative units, the efficiencies of four modernizations and their changing trends during the period 2001-2011 were investigated using DEA (Data Envelopment Analysis) model. Spatial-temporal pattern of coordination development efficiency of the ‘new four modernizations’ of China’s prefecture-level regions was explored by using exploratory spatial data analysis (ESDA). Finally, the main influencing factors of coordinated development efficiency of four modernizations of China’s prefecture-level regions were revealed with the aid of geographically weighted regression (GWR) model. Results indicate that the comprehensive development index, coupling development index, coordinated development index and efficiency of four modernizations of China’s 343 prefecture-level administrative units have obvious spatial differences and show diverse regional patterns. Overall, the ‘four modernizations’ coordinated development efficiency is relatively low, and only few cities with small urban population and economic scale were in DEA efficiencies. The higher efficiency regions concentrated in the central China. The efficiency changing trends were decreasing in 2001-2011, with a transfer of high efficiency area from the inland area to the eastern coastal areas. The difference between urban and rural per capita investment in fixed assets boasts the greatest influence on the coordinated development efficiency of the ‘four modernizations’. Per capita GDP is the second largest influencing factor. Per capita total retail sales of consumer goods, per capita expenditure on education and per capita income ratio between urban and rural residents show obvious impacts on the coordinated development efficiency of the‘new four modernizations’.
Based on the platform of GIS, this article analyzes the effect of Harbin-Dalian high-speed railway to the tourist traffic network of the cities in Northeast China with establishing accessibility model. Then through modifying the gravity model , we analyzed the change of the cities' tourism economy from the aspects of time space compression effect, the formation of the high speed railway tourism belt, the spatial differentiation of the tourism commuter circle, and the effect of the tourism polarization. The result showed that: the time compression effect brought by the high speed rail has greatly strengthened the tourism traffic accessibility and tourism economy of the cities in Northeast China. The entire commuter circle compressed about 2 hours, the degree of the promotion present the phenomenon that the distance between cities and high speed railway become farther, the degree of the change become lower, the change outside of the province was more clear than that in the province, the change in the three provinces in northeastern area was more obvious than that in the eastern region of Inner Mongolia. Cities along the Harbin-Dalian high-speed railway obtained greater kinetic energy in the tourism development, then this will accelerate the formation of Harbin Dalian High-speed Rail tourism belt. One day and two days tour of the cities along the railway benefit significantly, but for the remote cities, seven days tour benefits obviously. Northeast tourism should take the high-speed rail as an opportunity to carefully develop Boutique tourist routes, and speed up the integration of tourism cooperation, create a new image of tourism in Northeast China. High speed rail makes the distribution of tourism market space appears ‘polarization effect’, although it improves the supply and demand efficiency of the tourism industry, it widened the gap between urban tourism, so it is not conducive to the coordination of tourism industry development. In the future, we should speed up the other high-speed rail line or branch construction and improve the net shaped layout to make more tourist cities and tourism spots into the high-speed rail commuter circle.
With the acceleration of urbanization in China, a large number of rural people have shifted towards into urban area. With the number of local people decreasing in recent years, the result has influenced the problem on how to spatially arrange public basic service facilities in rural area. The centralized layout, expanded size, service quality improved for the public services is the common phenomenon in rural area by merger of village and by abolishing village government. However, with the limitation on the resources, the expanding for each facility lead to the number of facilities decreased, serving radius of facilities increased, and their accessibility lowered. The study on that “how-to” in a scientific and reasonable way provides an effective way for solving the contradiction between quality and accessibility. The spatial arrangement of public health facilities is the key component of the study on the equalization of public services. Therefore the study on their spatial optimization has been paid more and more attention in research fields, such as human geography, medicine, public health and sociology. Taking Xiantao City in Hubei Province as a survey region, we analyzed the spatial optimization of medical services in rural area. The attributes from economy and the natural geography shows homogeneity in our survey region with the typicality in the Jianghan Plain, which is easy to further our research and construct model.
Firstly, according to traditional location-allocation model, based on medical demand preference questionnaire from rural residents and rank-size index evaluation system, the medical behavior preference coefficient from residents, namely the rank-size preference coefficient is built, which is introduced to traditional location configuration model to establish the improved location-allocation model. Secondly, with the integration of GIS network analysis, linear programming modeling tools PuLP and linear programming software Cplex, this article optimizes geographic visualization layout results by using programming language Python to achieve the improved location in ArcGIS10.2 configuration model building, model solvers and rural medical facilities in ArcGIS10.2 Geoprocessing framework. Finally, the experiments by optimizing the size and number of medical facilities in rural areas can significantly reduce the cost of resident medical space, meet more medical needs, improve utilization and coverage of medical resources, and also verify the practicality and effectiveness of the secondary development tools. The results show that: the spatial arrangement of medical service after adjustment is more reasonable, which represents the spatial cost from the settlement to medical service facilities decreased. The experiment shows that the more medical service is fulfilled in 15 minutes, which enhance the efficiency and also reduce the time cost for local people seeking medical advice. The improved regional-allocation model provides an effective way for answer that “how-to” question. Therefore, the model has a universal function which can be applied to location-selecting problem for other public service facilities. In practical application, the model can be adjusted according to demands and circumstances. The model construction and simulation methods in our study are suitable for spatial optimization of medical facilities arrangement in rural area in plain region. Moreover, it provides the reference to the spatial optimization of medical facilities arrangement, especially of county-level which is of complex terrain and road network structure.
Island is an important part of marine ecosystem. The society experienced the evolution of the original human society economy era, agricultural economy era, industrial economy era and knowledge economy era which affects the ecological environment for human survival. We chose U.S. Channel Islands as an example to straighten out the destruction of ecological environment, ecological restoration and environment protection of the islands, in time and events dimensions, especially focused on the era of knowledge economy in the National Park Service. Selected U.S. Channel Islands as the research object for the following reasons. Firstly, there are original residents on the islands, and the islands not only has cultural and historical integrity, but also the relative independence of the island's original inhabitants of the geographical unit. The Islands have a relatively simple and economic form of continuous change, and the spatial and temporal evolution of context are clear. So we can also be easy to describe the problem of it. Secondly, we had repeatedly visited the Channel Islands museum, local museum, maritime museum, the Channel Islands National Park Visitor Center, and collected a lot of data and information; And attended local colleges and universities graduate programs of the Channel Islands as well. Thirdly, we had experienced the ecological rehabilitation of the island. The difficulties of the islands large engineering were quite touched, so islands ecological restoration is a new task faced by the human. Use the case study method, through a lot of literature data analysis and carding detailed the history of the U. S. Channel Islands and their ecological evolution. According to the changing of Channel Islands in the original human society economy era, agricultural economy era, industrial economy era and knowledge economy era in the evolution of the economic form analysis. Make form to explain the event of ecological restoration since the establishment of the Channel Islands National Park; and the content and status quo of the ecological restoration for the five islands of Channel Islands National Park. The five islands are San Miguel Island, Santa Rosa Island, Santa Cruz Island, Anacapa Island, Santa Barbara Island. The research focused on ecological restoration and environmental protection through the management of the National Park Service in knowledge economy era. Many managements were made for protecting islands ecological environment planning: such as establishing all kinds of sea islands reservation; to formulate detailed rules in the park; mobilizing the shore city and community participation in ecological restoration and environment protection; using the Internet to publicity and education; and making park management plan and so on. The development of the Channel Islands and the ecological restoration and management of the Channel Islands in recent years provided a good lesson for other countries.
This is a case study of cybergeography with case of Chinese tourism websites' quality. In this paper, it assesses the portal websites' quality of China's 112 5A rated tourism attractions and analysis the spatial distribution. The assessment system is defined as four parts: evaluation of user experience, technique support, content completeness and effect functionality. In order to easily calculate, the paper decomposes the four parts to 21 specific indicators, such as usability, content amount and quality, interactivity, information architecture and so on. With investigation of 112 5A attractions' portal websites, it is shown that the distribution of websites' quality in China is spatially differentiated and presented a situation of relative concentration and centrality. Jiangsu and Zhejiang province have the most high quality websites, which represent the center of China's online business. With Sichuan, Chongqing, Anhui and Hubei together, these 6 provinces constitute a collective belt of highest quality websites which around Changjiang River. Another collective belt of higher quality websites is in the east of our country, which is consisted of Shandong, Jiangxi, Fujian, Guangxi and Hunan. On the contrary, the northwest and southwest parts of China have low information levels. Besides, the results of each evaluation show that the spatially distribution of websites' quality in China are different. The center of gravity to effect functionality is the most west and north position. This means that the gap between east and west of China isn't so big by the reason of tourists' attention. The attractions in the middle and west parts of China occupy more and more tourism market, so the information demand from tourisms holds high level, which can be reflected by page views from goole.com and baidu.com. On the content completeness, the center of gravity is most east position and concentration of four parts. This attributes to the close cooperation and collection between tourism attractions and other tourism enterprises. The user experience evaluation shows a state of relatively dispersion because of good performances from websites in the middle and west regions, that means the technical problem of interact experience on website is no longer the restriction to the construction of portal attraction website. In the end, the result of technique support evaluation is more or less same with the overall evaluation result. The turning radius of standard deviation ellipse is 26.26, which presets typical northeast-southwest orientation and shortest transmeridional radius. It reflects that websites of which get high scores in this part frequency concentrates in the eastern coastal regions.
‘Red Beds Desert’ is a special degradation landscape,and one type of red beds landform with desert-like landscape, distributed on red beds mother rock and it’s also called as ‘red beds badland’. Its formation is called ‘Red Beds Desertification’. In the course of land extreme degradation, the red beds are influenced by humanity, original ecological structure on the earth’s surface is damaged, and then by the action of exogenetic force, the soil layer is rapidly eroded and the bedrock or its weathered crust is exposed, and finally land productivity is exhausted. Due to the special natural aspects, with excessive resource exploitation by humans, a kind of special process of land degradation-redbeds desertification occurred in redbeds areas in Southern China. The interruption of people is the trigger factor, and strong weathering and water erosion are dynamic factor. Red beds desert can be subdivided into two types, redbeds desertification with bare top and badlands-like redbeds desertification. In this article, we put more emphasis on the badlands-like redbeds desertification and its tourism exploitation. In China, redbeds desert (especially in humid regions) received no attention, we analyzed its feasibility by discussing its features, types, and so on. Red beds deserts are tensely distributed in Guangdong, Jiangxi, Hunan and other humid areas in Southern China. Generally, the areas of serious desertification are less developed areas and thus it’s significant to study red beds desert and its rational development and utilization. The protection and utilization of badlands-like redbeds desertification abroad has three main approaches, first, protection for the purpose, second, fix it for farming, third, open to tourists as one special landscape. This article points out that as a tourism resource, because of its desolation, fire-like collour against the landscape of green mountains and clear waters in South of China, redbeds desert can be a attraction with features of common sense subversion, ecological science popularization and integrated landscaping and that it also has high tourism development value and feasibility to tourists. Redbeds desert is fourth grade tourism resource containing recreational value, science and educational value, economic value, environmental value, social value et al. The exploitation of redbeds desert should not follow the conventional mode. Only maintaining landscape without vegetation and optimizing the surrounding environment can ensure the comprehensive benefits of exploitation. This article claims that during the development course, in the principle of environmental protection, characteristics strengthening and comprehensive benefit maximization, attention should be paid to agricultural tourism and science popularization tourism according to resource endowment in red beds deserts and landscape composition. Conceiving different kinds of tourism products by combination of historical culture, country relaxation, mountains and waters, and combination of red beds desert and ecological demonstration area. red beds knowledge popularization tourism, eco-agriculture tourism and red beds countryside tourism and photography theme tourism should be developed. Meanwhile, this paper also claims that measures should be adopted to suit the local conditions and that reasonable planning should be made for the resource features, market demand and environmental protection, to seek differential development with similar scenic spots nearby, cooperate with scenic spots nearby and realize regional tourism development in complementarity.
By using the remote images in 2003, 2006, 2009, 2013, the article classifies the land use of Changsha City. With the support of ArcGIS 10.0, ENVI 4.8, Fragstats 4.0 and Excel 2007 software, it analyzed spatial grain effect of land use pattern changes by changing the space grain sizes on class level pattern indices and landscape level pattern indices. The optimal proportion method was used. We have drawn the follow conclusions: 1) On class level, with the increase of spatial grain sizes, all kinds of index change present three trends,increase, decrease, regularity is not obvious. With the change of time, the smaller the spatial grain sizes, the more the effect of patch plaque density changes and patch shape index changes, the bigger the spatial grain sizes, the more the effect of patch cohesion index changes and patch aggregation changes. 2) On landscape level, with the increase of spatial grain sizes, the contagion index decrease before they are basically remain unchanged, the Shannon’s diversity index and Shannon’s evenness index is slowly reduced. As the change of time, the contagion index showed a trend of decrease on the whole, the Shannon’s diversity index and Shannon’s evenness index showed a trend of increase. The size of 90 m is the optimization analysis spatial grain sizes in this study.
It is widely recognized that human activities and climate variability are two important factors that affect water resources and freshwater ecosystems. Previous evaluation work on water resources has predominantly focused on the qualification of blue water flow. Meanwhile the green water flow, another important part of water resources for the healthy development of rivers and basins, is seldom discussed. In arid and semi-arid regions, the analysis of spatiotemporal distribution of blue and green water resources under human activities and climate variability is critical for water resources planning and management, and for harmonizing agricultural water use and eco-environmental water requirements. The Weihe River is the largest tributary of the Yellow River in China and an important water source for the Central Shaanxi Plain, which acts as the main driving force in the western economic development of China. However, this region also suffers great resource shortages. Ensuring sufficient freshwater resources supply is one of the most essential prerequisites for economic development and environmental protection in the Wei River Basin. Using the Soil and Water Assessment Tool (SWAT) model, this study investigated the spatiotemporal variations of blue and green water resources under different human activities (land use/cover change and irrigation) and climate variability scenarios during the 1980s-2000s for the Weihe River Basin. The results showed that: 1) Under the impact of land use/cover change, irrigation and climate variation, the blue water flow, green water flow and green water storage decreased by 23.56 mm/a, 39.41 mm/a and 17.98 mm/a, respectively, during 1980-2009. Blue water flow and green water storage presented an increasing trend in the north of study area, and the green water flow showed a decreasing trend in the upstream regions. 2) Attribution analysis showed that climate variability accounted for a decrease of 13.17 mm/a, 44.99 mm/a and 22.79 mm /a in blue water flow, green water flow, and green water storage, respectively. The blue water flow increased in the north of the Weihe River Basin, but decreased in the south of the Weihe River Basin. The green water flow decreased in the whole basin. Land use/cover change accounted for a decrease of 0.42 mm/a and 0.37 mm/a respectively in blue water and green water flow, but an increase of 0.79 mm/a in green water storage. In addition, irrigation accounted for a decrease of 9.97 mm/a in blue water flow and an increase of 5.95 mm/a and 4.02 mm/a in green water flow and green water storage, respectively. 3) Green water coefficient showed an increased trend in the southeast, but a deceased trend in the Jinghe River Basin due to the climate variability. Land use/land cover change drived the green water coefficient increased in some sub-basins of southwest. It should also be noted that the green water coefficient significantly increased in Central Shaanxi Plain when considered the irrigation factor.
The assessment index system was firstly constructed for ecosystem vulnerability from the viewpoint of ecosystem structure-function-habitat. And then, with MODIS satellite-derived datasets as the main data resource, this paper assessed the ecosystem vulnerability for Tibetan Plateau (TP) and detected its spatial heterogeneity. It is shown that the spatial patterns of TP ecosystem vulnerability, based on climatic factors, structural indices and functional indices, respectively, are consistent. The vulnerability degrees gradually increase from southeast to northwest of TP. However, the changing trend is opposite for topography-based vulnerability assessment. This indicates that compared with topography indices, including slope, relief amplitude, earth’s surface incision and roughness in elevation, climatic factors, such as monthly maximum temperature, monthly minimum temperature and drought severity index, are more important to determine the spatial pattern of ecosystem structure and function. Furthermore, taking the indices for ecosystem structure, function and habit (i.e. climate and topography) into account, both the comprehensive ecosystem vulnerability and its classification present the spatial characterization of increasing from southeast to northwest, similar to the above-mentioned trend. According to the spatial statistics in ArcGIS software, the classes higher than middle of ecosystem vulnerability accounts for 74% of evaluation area, while the very high class accounting for 45.8%, indicating the serious overall conditions for ecosystem vulnerability in TP. Identifying the ecosystem vulnerability degree and its spatial patterns can provide scientific basis for vulnerable ecosystem monitoring and comprehensive assessment, which is further helpful for ecological regulation and management in TP.
The source area of the Yellow River (SAYR) is located in the eastern-to-medium part of the Qinghai-Tibet Plateau. Permafrost in the SAYR experienced remarkable degradation in the past. Taking distribution patterns of frozen soil and permafrost stability as research object, the characteristics of permafrost development and distribution patterns at various terrains and land covers were analyzed based on a large amount of field investigations and the measurements. In addition, thermal features of permafrost were analyzed based on the measured ground temperatures at various depths. The effects of the geological and geographic factors on permafrost distribution and thermal stability were discussed. It was indicated that: 1) Permafrost was occasionally developed in the various fluvial and proluvial plains with elevation generally lower than 4 300 m; 2) Permafrost was widely distributed in the mountains higher than 4 350 m except for the sunny slope terrain, where local terrain played an important role in permafrost development and distribution; 3) The combinations of local terrain, surficial vegetation, soil wetness and moisture conditions all contributed to the formation and distribution of permafrost in the low hills and mountains where elevation ranged in 4 300-4 350 m.Taking the annual mean ground temperature (MAGT) as the basis, an experiential-statistical MAGT-based model was constructed, of which latitude, longitude and elevation were set up as independent variables. Together with DEM data, permafrost MAGTs were primarily modeled using the statistically regression model. And then, the modeled results in the south-facing areas were slightly adjusted, and a secondly model was constructed to model permafrost distribution in the shady areas. Thirdly, the combined modeling results were locally adjusted using the measurements. The frozen soil map in the SAYR was thus compiled. Taking 0oC as the boundary between permafrost and seasonally frozen soil, it was indicated that permafrost was distributed in an area of 2.5×104km2, which occupied approximately 85.1% in the SAYR, and that seasonally frozen soil was distributed in an area of 0.3×104km2 with an areal percentage of 9.7%. Permafrost was further divided into seven stability taking 0.5oC or 1.0oC of MAGTs as intervals.They were the first zone with permafrost MAGT smaller than -4.0oC, the second zone with permafrost MAGT varying between -4.0oC and -3.0oC, the third zone with permafrost MAGT varying between -3.0oC and -2.0oC, the fourth zone with permafrost MAGT varying between -2.0oC and -1.0oC, the fifth zone with permafrost MAGT varying between -1.0oC and -0.5oC, the sixth zone with permafrost MAGT varying between -0.5oC and 0oC, and the seventh zone with permafrost MAGT higher than 0oC.
The suitable method used to realize spatial interpolation of different landforms is different. Elevation of Changchun Jingyuetan area is the research object, this area is typical hilly and gully region,we interpolated elevation with inverse distance weighting, nearest neighbor,trend interpolation and Kriging on ArcGIS9.2. We obtained the accuracy of elevation of inverse distance weighting method, nearest neighbor, trend surface method, spline function and Kriging with Cross Validation, the conclusion is the nearest neighbor is the most accurate, followed Kriging, spline function, elevation of inverse distance weighting method, trend surface method. This research provide reference of selection for interpolation of the elevation data such as Jingyuetan area of hill landform.
Water conservation is a comprehensive regulation function of forest ecosystem on water resources through various hydrological processes, including canopy interception, litter containment and soil retention. Forest ecosystem in Southern and Northern Pan River watershed is one of the significant ecological barriers in the upper reaches of the Pearl River, and its water conservation function would greatly influence the local development. Especially, it is also a typical karst mountain area in China, in which water is essential to the ecosystem recovery. Based on the forest resource inventory data, the integrated storage capacity method was applied to estimate the water conservation amount of forest ecosystem and its spatiotemporal variation in regional scale was also analyzed.
The results showed that the water conservation amount of forest ecosystem in the study area could reach to approximately 6.13×108 m3, in which the soil contributed to 73.65%. The broad-leaved forest and shrub contributed largest to the amount of water conservation(reaching 52.42%), while the bamboos contributed least. Analysis on different stand age showed that the young forest contributed largest to the amount of water conservation (reaching 45.95%). Forest in the middle of the mountain contributed largest to the amount of water conservation with the proportion of 75.46%. In terms of slope position, forest in middle slope and flat ground contributed largest to the amount of water conservation, while forest in valley contributed least. In recent 35 years, with the implementation of ecological projects, water conservation amount of forest ecosystem in study area was increased with the rate of 14 478 865 m3/a.
In terms of water conservation capacity per unit area, the forest ecosystem in the study area could reach to 629.85 t/hm2, which was higher in eastern part and lower in western. Water conservation capacity was varied for different forest types, in which the mixed forest was largest (reaching 851.78 t/hm2). Over-mature forest was highest in water conservation capacity (reaching 909.84 t/hm2) while young forest was lowest. Forest in the middle of the mountain was slightly lower in water conservation capacity than that of the forest in the lower of mountain which was up to 763.46 t/hm2. In terms of slope position, water conservation capacity of forest in valley was highest, and forest in ridge was lowest. With the implementation of ecological projects during the past 35 years, water conservation capacity in the study area continued to rise with the rate of 5.33 t/（hm2·a）, thus, the ecological projects contributed significantly to the increase of the water conservation function of forest ecosystem in the Southern and Northern Pan River watershed.
Understanding the water conservation function of different forest ecosystems and their temporal and spatial distribution patterns is applicable for sustainable forest management and ecological recovery in Karst region, and useful for reaching the aims of maximizing water conservation capacity of forest ecosystem.
Based on the data of 110 meteorological stations in coastal region of China in 1960-2013, the variation of extreme temperature indices was analyzed. The result showed that in the last 54 years the absolute indices, i.e., coldest day (TXn), warmest day (TXx), coldest night (TNn) and warmest night (TNx), have increased significantly, and TNn showed an increasing rate of 0.40℃ per decade. The diurnal temperature range (DTR), cool days (TX10p) and cool nights (TN10p) have decreased significantly by -0.12℃, -0.7 days and -2.19 days per decade, respectively. The percentile indices, including warm days (TX90p) and warm night (TN90p), have increased by 1.31 days and 2.24 days per decade, respectively. In the recent 30 years, summer days (SU25) and tropical nights (TR20) have increased by 6.35 days and 5.28 days per decade, respectively. For the spatial distribution of TXn, TXx, TNn and TNx, 97%, 71%, 97% and 97% of meteorological stations showed increasing trends during 1960-2013, respectively, and most stations are statistically significant at the 0.01 level. For TX10p, TN10p and DTR, the proportions of meteorological stations with decreasing trends are up to 90%, 99% and 81%, respectively. Most extreme temperature indices show a good correlation with latitude, longitude, and altitude. After the detected climate abrupt changes, TX10p, TN10p and DTR decreased, and the other indices increased significantly.
Topography factor is one of the main components for soil loss prediction in soil erosion model. Here topography factor includes slope length factor and slope gradient factor, which have been the emphasis and difficulty in related research. Although many of LS factor algorithms have been proposed in literatures, it is not yet clear for the differences between them. In this article, L factor is calculated based on the algorithm of Desmet,which evolved from the unit contributing catchment area. With S factor value calculated based on different algorithms, LS factors are presented, which are called the kind of LS factor from unit contributing catchment area. Then they are compared with the LS factor from modified AML program of Remortel. The AML program is designed to calculate the L factor based on the grid cumulative length in the runoff path. When compared to the LS factor value from modified AML program, the method of unit contributing catchment area yields broadly greater results. In the limited range of slope gradient in the study area, different methods yield similar slope factor values. In contrast, it is obvious for the difference of slope length factor from different algorithms. This is especially true for the algorithms of Govers, in which the slope length index is constant value. This indicated that with the condition of long slope length and low slope gradient in study area, different LS algorithms have more influence on the slope length factor. Meanwhile, through the analysis of soil erosion mechanism, we concluded that it’s more reasonable for the slope length factor index to use variable values related to slope gradient. With the introduction of the use of DEM in soil erosion prediction, it’s more possible to calculate the soil loss for a wide range of region. However, the calculation is based on cell, which means that the slope gradient is not the same for all cells, e.g. the slope of each cell has a larger range, esp. for the small area with large elevation difference. In this case, it’s especially true for the slope length index values to be variable values related to slope gradient.
In accordance with the data of radio sounding data and the data of surface temperature and precipitation in Northeast China in 1971-2005, the temporal and spatial change characteristics of free atmospheric specific humidity and relative humidity as well as the relationship between humidity and surface temperature and precipitation are analyzed. The results indicate that, the spatial distribution of specific humidity is impacted by water vapor source in Northeast China, decreased from the southeast to the northwest on the ground, and decreasing from the south to the north at upper air. The spatial distribution of relative humidity is impacted by water vapor, altitude and latitude, decreased firstly and then increased from the south to the north from the ground to lower layer of troposphere, increased from the south to the north in the mid layer of troposphere, and the southwest-northeast drought tongue from Chifeng to Tongliao is the most obvious, and gradually weakened with height increased. In 1971-2005, annual and seasonal specific humidity exhibited increasing trends from the ground to upper air, the increasing trends in the mid to lower layer of troposphere. The annual and seasonal relative humidity decreases significantly on the ground , and increases significantly in the mid layer of troposphere. The positive correlation between free atmospheric specific humidity and surface temperature is significant on annual and seasonal time scales. The negative correlation between free atmospheric relative humidity and surface temperature is significant on seasonal time scales. The correlation between relative humidity in the mid and lower layer of troposphere and precipitation is significant. The increased temperature is played an important role in climate changing to aridity of Northeast China. The increase of upper relative humidity helps add precipitation. The changes of surface temperature and water vapor content have impact the change of drought and humid climate.
Blowouts were the main forms of fixed sand activation in sandy grassland. The results of blowouts sustained activation were lead to expansion of desertified land area and deterioration of the ecological environment. In this article, the morphological characteristics of blowouts towards,length and width were determined with used field method to measurement the 129 activation fixed dune blowouts. The results showed that the morphological characteristics of blowouts in study area were the combined effects of the NW winds, W winds and SW wind. Blowouts toward were WNW-ESE(112.5°), and the 74.5% blowouts toward (100°-120°)were vertical SW wind,or were about 20° angle of the W wind. This relation influenced the blowouts geometry features. Based on the reflected in the geometry of the ratio of the blowouts length and width,the blowouts were divided the ovoid blowout,slong strip blowouts,slim blowouts and with type blowouts. Based on the surface topography difference, the blowouts were divided the dish type blowouts, trapezoid type blowouts, valley type blowouts, cup type blowoutsand slope type blowouts. In the same time,this article discussed the effection for blowouts formation and evolution in process of blowouts development from the aspects of primtive landform,surface feature and human activity factors.
