The national safety evaluation, risk assessment and forecasting of countries along the “Belt and Road” initiative are the foundation and prerequisite for the successful implementation of the “National Initiative” and have become the key issues in the study of political geography. Based on the Global Terrorism Database, an evaluation system of the national security situation including the number of terrorist attacks, the number of deaths, the number of terrorist injuries and degree of property losses in terrorist attacks, was developed. Employing Standard Deviation Ellipse and Nuclear Density Estimation method approach to measure the spatio-temporal characteristics of the national security situation. The results show that: 1) From the analysis of time evolution, the national security situation along the “Belt and Road” became increasing seriously from 1970 to 2017, with significant phase characteristics and experienced 3 stages of “rising-active-falling”; 2) From the perspective of spatial analysis, standard deviation ellipse of national security situation moving northwest, the center of gravity path experienced a shift from the West Asia and North Africa, South Asia to West Asia and North Africa area; The spatial characteristics around the “9.11” incident have changed from the 3 "terrorist active areas" and "U-type terrorist latent circles" to the 2 "turbulent core areas" and 3 "turbulent centers".
With the diversification of the research paradigm and methods of human geography, the research perspectives and methods of geopolitics, as an important branch of human geography, also become diversified. Especially since the 1960s, the structural turn of geopolitics has led to a number of important research results in geopolitics. However, on the whole, the study of geographical structure is too simple and immature. Drawing on the latest progress of structuralism in philosophy and related disciplines, especially the study of social theory on social structure, international relations on international social structure and geography on spatial structure, this article discusses the theoretical basis, concept and analytical framework of geo-structure. The analytical framework of the geostructure consists of 5 parts: structure as a component, structure as a process, structure system, 2 levels of structure and 2 mechanisms of action. The contents that constitute the geo-structure can be roughly divided into 3 kinds, namely, material structure, conceptual structure and spatial structure. The structure as a process focuses on exploring the relationships and their interdependence within the structure, and the impact of these changes on the identities and interests of geo-bodies, which means that the structure itself is changing. The geo-structural system has not been seriously studied. But with the advent of the geo-economic era, the transformation of Hobbes culture to Lockean culture, especially the interdependence under various relations, makes the international anarchic society move towards a structural system composed of politics, military, economy and culture. The 2 levels of the geopolitical structure and the 2 mechanisms are closely linked, reflecting the relationship between geo-bodies and the geopolitical structure in which the geopolitical body is placed. Each part of the geo-structure should form a whole in order to explore its impact. In the end, some problems in using geo-structure and the current international situations are briefly discussed in this study.
Territory is a core concept representing complicated power-space relationship in Political Geography. The concept came from biology and went through a rapid development stage in the past century. Despite of the fact that territory study heads forward multivariate scale, the core viewpoints maintain rarely changed. With the increase of empirical analysis of territory, it seems easy to perceive the discrepancy between the imported theory and the actual situation of Chinese society. The traits of power, border and space of territory are founded on the western discourse system. We put forward that “dipan” is a much powerful and maneuverable indigenous notion in China compared to territory. It consists of two Chinese characters: “di” means land while “pan” stands for bearing the weight of something. Thus, this term can be understood as occupation or control of certain space through objects or special social power, and the latter meaning is more frequently used. Chinese society is a nepotistic society, where reasonable power according with etiquette order speaks louder in daily life. By term analysis of everyday application and literary works, we find that the special social power in “dipan” is closely related to “guanxi”. “Dipan” has 3 features. First of all, it expresses a strong subjective feeling. Being well acquainted with each other, long-term stable relationship and mutual benefit interaction can be formed. The closer the “guanxi” is, the easier it is to cross the standard power boundary. Secondly, power brought by “guanxi” and operated in “dipan” are often irregular. Gatekeeper enjoys varying degrees of autonomous discretion power in the handling of specific affairs. Intimate relationship would be taken into consideration in situation handling process. Thirdly, while territory puts emphasis on boundaries, “dipan” lays stress on fuzzification of boundary. With vague border, various subjects could make use of the resources flexibly. One good turn deserves another; harmony could be achieved and multi-win come into being. This is why “guanxi” occupies an important position in Chinese daily behavior. Therefore, “dipan” can be regarded as the spatial projection of Chinese-style “guanxi”. According to the types of “guanxi”, “dipan” can be divided into 3 types. Emotional “dipan” is usually generated by blood and familial relation, and “courtesy” is the main factor shaping its space; instrumental “dipan” is formed by utilitarian relationship; and the mixed “dipan” is affected by both personal relations and objective factors like spatial distance. “Dipan” system becomes a buffer between my territory and others’ territory, where power and behavior freedom in certain space can be achieved through “guanxi” construction.
China-US relations have always been the most important part of international geopolitical relations. Discovering and analyzing of the attitude of two sides to each other from an international multilateral perspective is of great significance for understanding the internal causes of variations in China-US geopolitical relations. Due to differences in political systems, the analysis of characteristics of the China-US changes from the perspective of the presidency of the U.S. can provide a deeper knowledge of the international geopolitical tendencies. From the time series analysis of China-US relations, we can understand the evolutionary stages of China-US geopolitical relations. An in-depth analysis of the motives of China-US relations changes is of great significance for properly making international geo-strategies. Based on the GDELT data, this paper utilized probability analysis and adaptive fractal analysis methods to analyze the attitudes' differences between China and the U.S. during the US presidential terms since 1979 from the perspectives of cooperation and conflict. Moreover, the persistence of China-US attitudes since the establishment of diplomatic ties was also studied. The results show that: 1) China-US geopolitical relations have experienced three periods: the Cold War period, the transition period and the economic and trade cooperation period. The characteristics of these three periods are that the strategic basis of China-US relations has changed from a joint anti-Soviet to economic and trade relations. 2) The negative attitude of the US toward China developed and improved during the George H.W. Bush and Clinton periods. It eased during the George W. Bush era and the early Obama period, but it became more serious in the later period of Obama. 3) The overall attitude of US toward China persists for about 4 years, and is mainly influenced by negative attitudes. During the current Trump administration, the political and economic factors of China-US geopolitical relations have undergone major transitions. It is recommended that policy-makers and researchers of China-US relations should pay attention to this transformation and seek new thoughts and new pathways to cope with China-US relations in a new stage.
From a social constructionist perspective, borders should not be simply stabilized into fixed lines. Instead, borders are socially constructed. The functions, meanings and features of borders can be continuously (re)constructed through the interactions between political authorities and social subjects. Besides, social subjects are far from a unitary and homogenous group. People of different social identities have accorded abundant and unique meanings to borders. After reform and opening up, the tourism commercialization process of Chung Ying Street between Hong Kong and Shenzhen, China, occupies important positions in the daily border-crossing practices of different social subjects in Chung Ying Street area. Drawing on in-depth interviews, participant observation and textual analysis, this paper chooses the case of Chung Ying Street area. Based on the theoretical insights of social construction, this paper explores both the complex interactions between different social subjects during their everyday border-crossing practices and the control mechanism of the border space. This paper finds out that under the context of institutional transition and social transformation in the 1980s, the tourism commercialization process of Chung Ying Street offered extra chances for residents to participate in cross-border small-scale trading. In this way, the identities of both residents and cross-border small-scale traders in Chung Ying Street were highly integrated. Reasons for such a high degree of syncretism can be summarized as follows: on the one hand, the identity change from residents to formal traders was stopped by interference. On the other hand, it was a simple and practical approach for the residents to become small-scale traders. Furthermore, with a background of the transfer of sovereignty over Hong Kong as well as the set-up of market economy system in the mainland during 1990s, the declining economy of Chung Ying Street precipitated the separate identity of residents and small-scale traders. However, the latter were still able to take advantage of the residents’ cross-border passes to conduct informal economic practices. To sum up, the innovative contributions of this paper lie in two aspects. On the theoretical level, this paper suggests that the identity integration and separation of social subjects implies their agency in response to the changes of border landscapes. During such responses, each individual tends to make every possible use of the border rights embedded in the ‘potential disparity structure’ of identity. The utilization of identity discrepancy becomes a common character shared by different social subjects. On the empirical level, this paper points out that the enactment and implementation of Hong Kong-Shenzhen border control policy should be premised on the understanding of the status quo and evolution process of the ‘potential disparity structure’ of identity in the border space.
Since the 2000s, new town and new district have become important phenomenon in China’s urbanization process. The construction of these new urban spaces is closely related to the transformation of local policies. A major strand of literature has reached a consensus that local governments are playing a pivotal role in Chinese urbanization. However, little has concerned the relationship between capital flows and local government in urban development process. Especially for inland cities lacking foreign capital, it is necessary to explore the interaction between government and capital. Taken Kangbashi New District in Ordos City as a case study, this article puts forward a research framework of “local government-led capital circuit”, and examines the role of local government in capital circulating and capital switching process. The data used in this study mainly come from interviews and secondary data gathered through 4 rounds of fieldwork from April 2011 to August 2016. Semi-structured interviews were carried out with Ordos municipal officials in charge of urban planning and the construction of new district projects. Three circuits of capital flow are identified: 1) Capitalization of coal resources; 2) Capital fixes in urban infrastructure and real estate; 3) Attraction of investments in manufacturing and tertiary industries. This article shows that the local government dominated these 3 circuits of capital accumulation in the new district making through land leasing, support for the investment company, infrastructure provisions and various preferential policies. And, the local government channeled the floating capital accumulated in the primary circuit (from the coal industry) to the built environment of the new district. This study contributes to the existing literature in several ways. First, it enriches Harvey's model of capital switching. Based on the situation of the developed capitalist economy, Harvey points out that the state is only indirectly involved in the process of capital accumulation. However, this study argues that the Ordos Government directly “manipulates” the capital accumulation and capital switching process. In addition, this study also provides a new way to test Harvey's capital switching model through a case study instead of the macro-scale analysis of various pertinent historical data. Second, the case of Ordos adds new knowledge about the new town construction project. New town and new district in China are built as a pool to absorb the floating capital accumulated in the primary circuit, and to further attract investment for local economic development. It has become a popular strategy of the local government. Third, this study advances the understanding of the state-market relations. Market development does not result in the demise of the state regulation in China; rather, the local government dominates the market forces by firmly controlling land leasing, taxation and the provision of many public facilities. The Chinese experience can provide useful information about local state regulations in the post-global financial crisis and post-neoliberalism era.
City network is an important perspective to study cities and regions. In recent years, a large number of studies on city networks involving China have emerged. For the one hand, the case study of China has always been attracting the attention of scholars all over the world for the past decades, and remarkable development has been achieved in city network research on China. For the other hand, while the number of publications is growing really fast, some limitations and challenges of this research has also appeared. Therefore, a systematic review to this large body of literature is needed at present. This article summarizes and reviews the progress of city network research on China from four aspects: 1) Data and methods used in city network research on China; 2) The major findings of this research, including network patterns and formation mechanism on different spatial scales; 3) The main contributions of this field; 4) Some limitations of current studies and the prospect for future research. The findings of this article are provided as follows. City network research on China utilizes various data and methods to construct networks, while Social Network Analysis and Complex Network Analysis are applied to the description of city networks. Major findings of city network research on China covers three spatial scales: global scale, national scale and regional scale, which have revealed the characteristics and formation mechanism of city network on China under different spatial scales. Mainly contributions of city network research on China include: 1) Multi-scale studies on city networks of Chinese cities are important inspirations for city network research worldwide; 2) Avoiding Western Centralism views on studying globalization and making up for the major defects in the research of world cities; 3) Using some original perspectives and data to depict inter-city relations, which has promoted the development of world city network research; 4) Bringing the network logic to the studies of Chinese cities as well as helping promote the academic development of urban geography and economic geography in China. Main limitations and challenges include: 1) A large number of empirical studies dedicate to describe and explain the network structure, paying less attention to theoretical innovations; 2) The data sources and network construction methods used are increasingly convergence, leaving no much room for related innovations in future work. Accordingly, we propose that city network research on China should actively expand the research perspective. Deepening the mechanism research and theoretical innovation should also be highlighted. And strengthening policy studying of city networks on China can benefit the further development of this field, which is almost neglected in current stage.
While China joined to WTO, under the joint action of economic crisis and accelerating the pace of opening up, the evolution process of China’s financial repression level has been changing. This paper takes 30 provincial-level panel data (not including data of Tibet, Hong Kong, Macao and Taiwan) from 2001 to 2015 as the research sample, calculates the regional financial repression level by referring to the existing research results, analyzes its temporal and spatial evolution law by using nuclear density and dynamic degree, and displays its evolution process by using quartile classification method through GIS technology. The research shows that: 1) The economic crisis has a positive impact on the level of regional financial restraining, and the areas under impact are mainly economically less developed areas, and there is a certain "Matthew effect" in the level of regional financial restraining during the period of economic crisis. 2) After the economic crisis, the government policy has gradually restored the level of financial development and gradually relieved the level of financial restraint; however, the government’s policy support for financial development is limited, and the reduction of financial restraining level needs to gradually increase the degree of financial marketization and rely on the market to promote the level of financial development. 3) According to the contrast of the level of financial suppression before and after the economic crisis, it is tried to put forward that the rise of financial restraining level is likely to predict the trend of economic downtrend. On this basis, it puts forward pertinent suggestions for reasonably controlling the level of financial restraint. Firstly, local governments should weigh the advantages and disadvantages of financial restraint and economic development, and implement appropriate financial restraint policies while maintaining healthy and stable economic development. Secondly, after 2012, China’s regional financial restraint level is relatively stable, but the economy has maintained a sustained growth state, so we can appropriately liberalize the supervision of financial institutions and the financial system, gradually reduce the level of financial restraint, steadily promote financial liberalization reform, as an opportunity to reduce the financing of small and medium-sized enterprises. Cost of capital, to achieve the financial services for the real economy, the national economy as a whole to achieve a new round of development. Thirdly, the local financial development can not only rely on the supervision and support of government policies, but also need to play the role of the market; while correctly interpreting the central financial development policy, the local characteristics, government policies and market conditions should be fully combined to develop and play the role of local financial characteristics, to achieve the financial field and the real economy. The fields complement each other and develop at the same time. Fourthly, according to the changes of financial restraint level before and after the economic crisis, this article tentatively puts forward that the financial restraint level can be used as a wind vane to judge the trend of economic operation. The government should grasp the trend of financial restraint as appropriate. When the financial restraint level presents an upward trend, the government should timely understand the trend of macroeconomic operation, through macro view control, prevent and weaken the adverse consequences that may lead to the economic crisis.
Improving urban eco-efficiency is the key to realize the construction of ecologically-civilized city, which also improve harmonious development of regional society, economy and ecology. In this article, we assessed the urban eco-efficiency with Stochastic Frontier Analysis (SFA) in China (not including data of Tibet, Hong Kong, Macao and Taiwan) during 2006-2013, then analyzed the spatio-temporal evolutionary characteristics of urban eco-efficiency by using Kernel density function, dynamic comparative of urban eco-efficiency of different scales in different economic zones also analyzed. Finally, the Tobit regression model was established, we discussed the impact of affecting factors on urban eco-efficiency based on different scales. The main results are as follows: 1) The mean value of urban eco-efficiency in China ranges from 0.807 6 and 0.838 2 during 2006-2013, high value areas present spatial agglomeration trend, the environment input factors such as sulphur dioxide emission, green house gas emission and solid wastes have negative effects; 2) China’s urban efficiency has a fluctuated dynamic change process, the mean eco-efficiency of various scales cities shows increasing tendency, the eco-efficiency of megacities improved fastest among various scales cities, urban eco-efficiency increasing returns to scale shows obvious, urban eco-efficiency becoming universal; 3) The effect of affecting factors on the urban eco-efficiency shows obviously scale difference, the large-scale cities have better economic foundations, industrial structure optimized continuously, an effective resource element allocation mechanism was formed gradually, therefore, there are few significant factors affecting ecological efficiency, however, the eco-efficiency of small-scale cities is more easily affected by various kinds of factors, therefore, it is necessary to take corresponding measures to improve the eco-efficiency of various scales cities.
The efficiency of environmental regulation(EER) is an important way to evaluate the government's ability of environmental regulation. Based on the panel data of three coastal metropolitan agglomerations in eastern China from 2003 to 2016, this article uses the super-efficient SBM model with unexpected output to measure their EER, and combines the coefficient of variation, Gini coefficient, spatial autocorrelation and GLS model to analyze the spatial evolution characteristics of urban agglomerations' EER and explore its driving factors. The results show that: 1) The EER in the Beijing-Tianjin-Hebei urban agglomerations rises most significantly; The EER in the River Delta urban agglomerations declines obviously; The EER in the Pearl River Delta urban agglomerations is higher than other urban agglomerations. 2) The internal differences of EER of the three major urban agglomerations are obvious, and the internal difference of the Pearl River Delta urban agglomerations is higher. 3) The Pearl River Delta urban agglomeration is a spatial agglomerations area with high EER, and the spatial spillover effect is significant; Beijing-Tianjin-Hebei and the Yangtze River Delta urban agglomerations are spatial agglomeration areas with low EER, and their spatial spillover effects are not significant. 4) Economic development level, industrial structure, market environment, urbanization level and opening level are the influencing factors of EER of urban agglomerations.
Based on the headquarter-affiliate enterprises connection data, the urban association matrix is constructed. The social network analysis method is used to analyze the urban network structure characteristics of Liaoning, Jilin and Heilongjiang provinces in the northeastern China from the perspective of network density, in-degree and out-degree of centrality and cohesion subgroups. The characteristics of regional organizational structure are discussed in depth from the perspective of enterprise linkages. The results show that: 1) The development of regional networks is in a stage of gradual improvement. There is a significant difference in network density at the provincial scale. The overall density of Jilin Province is greater than that of Liaoning Province, which is larger than that of Heilongjiang Province. The associations in the province are generally higher and the inter-provincial linkages are relatively insufficient. 2) The centrality of the network shows polarization characteristics, and the regional central city is in a dominant position in the network. Due to the ‘siphon effect’ of the central city, there is a clear ‘wicked under the light’ phenomenon in its surrounding areas. 3) The phenomenon of small groups linked by regional enterprises is prominent. Shenyang, Dalian, Changchun, Harbin, the four major cities are regional contact centers and the development speed is fast. Economic development is slow due to the lack of core in marginal cities .Based on the relationship of parent-subsidiary enterprises, the study considers that the urban networks of Liaoning, Jilin and Heilongjiang provinces in the northeastern China are generally ‘multi-core network’ organizational structure, while on the provincial scale, they show organizational models of ‘dual-nuclei’‘axis-spoke’ and ‘single-core radial’.
The construction of modern industrial system is the key-point of achieving high-quality economic growth in the new era. Based on the macro background of the construction of modern industrial system and the perspective of synergetics, this article uses the provincial panel data (not including data of Tibet, Hong Kong, Macao and Taiwan) to construct the quaternity cooperative index system of tangible economy, science and technology innovation, modern finance and human resources. When the quaternity cooperative index in China is systematically measured, the relative and absolute regional differences of the quaternity cooperative index are deeply analyzed by using Dagum-Gini coefficient and nuclear density method, and its dynamic evolution process is predicted scientifically by Markov Chains method. The findings are provided as follows: 1) Coordination of tangible economy, science and technology innovation, modern finance and human resources in our country has maintained a certain growth trend. However, the overall level of quaternity cooperative index is still at a relatively low level, and the growth rate of provinces and cities varies from region to region and within each region. There are obvious spatial differences among the quaternity cooperation, of which the eastern region is the highest, the middle part is the second, and the western part is the lowest. 2) The relative and absolute regional disparity of the quaternity cooperation is all increasing. The difference within eastern region and difference between the eastern region and the western region are the largest, the difference between the western region and the east-central region is the second, and the difference between the central region and the central-west region is the least. The intensity of the transvariation among regions is the main source of regional gap, but with the change of time, the contribution rate of the intensity of the transvariation among regions decreases gradually while the contribution rate of regional disparity increase gradually. 3) The results of Kernel nuclear density show that the center of the distribution curve of the quaternity cooperation gradually moves to the right, and the main peak value gradually decreases, which indicates that the quaternity cooperation of modern industrial system in China is in an increasing trend. However, absolute regional differences show a trend of further expansion. At the same time, the forecast result of Markov indicates that the evolution of the quaternity cooperation degree is the neighboring evolution, and the probability of transition from the low level to the high level is increasing. The overall development is towards a higher level. The conclusions of this article are of great significance for promoting regional coordinated development and the construction of modern industrial system in the new era.
The concept of compact city provides an efficient urban development model with a fine fabric and organic connection between urban spatial structures. It achieves intensive land utilization pattern by controlling the urban sprawl with urban growth boundary, as well as the linked communities by the advanced public transportation system. In addition, as one of the most recommendable urban development ways advocated by sustainability science, the greatest value of compact city is considered to reduce energy consumption significantly in the process of urban economic and social development. Taking Jiangsu Province as an example, this study selects mass of statistical data from 2007 to 2016, to explore whether a compact city can contribute to reducing power consumption and emission, and testing the quantitative relationship, how does compact urban structure affect energy consumption as well its force direction. Firstly, the urban compactness and energy consumption value are calculated. An assessment index system with five primary indicators (land utilization, economy, population, infrastructure, and public services) and twelve secondary indicators is built, and the urban compactness is measured by the value of these indicators. It should be noted that, subject to the limitation of the complexity of urban energy consumption statistics in China, energy consumption value is obtained by converting the original row data of the whole society’s electricity, total natural gas supply and total liquefied petroleum gas (LPG) supply into the standard coal then adding them together. Such processing method can greatly reduce the error of results. Secondly, the representation of urban compactness and energy consumption value are visualized spatially by prefecture-level city, and then the temporal and spatial evolution of these two variables are observed at four time points. Finally, the correlation between urban compactness and energy consumption is investigated by employing the grey relational analysis method, and the interactive mechanism of them is quantified by using the ordinary least squares method and the first-order difference generalized moment estimation in econometrics. This study finds that both urban compactness and energy consumption in Jiangsu Province have significant characteristics of spatial concentration, and the northern and southern parts of Jiangsu are significantly different by taking the Yangtze River as the boundary. Moreover, urban compactness and energy consumption are strongly correlated. The increase in compactness promotes its inhibitory effect on energy consumption, however, this effect shows typical timeliness and hysteresis. The utility of adjusting urban spatial structure will conduce to the changes of energy utilization structure gradually. Clearly, the results show that compact city plays an important role in the transformation process in terms of urban spatial development from incremental expansion to inventory optimization in the eastern China. Besides, from the perspective of practical application in spatial planning, compact city enhances the integration of production, living and ecological spaces in urban area, and promotes the sustainable and coordinated development.
Reclamation is considered to be an effective measure to solve the problem of land shortage in urban and industrial expansion. However, the extent and intensity of coastal development has caused serious damage to the coastal wetland ecosystem. Analyzing the characteristics and trends of coastal wetland evolution influenced by reclamation activities is of great significance for developing regional ecological coping strategies. Using Remote Sensing (RS) and Geographic Information System (GIS), this study took the northern area of Liaodong Bay as a case study to reveal shoreline changes and to delineate the paths and patterns of coastal wetland landscape succession both outside and inside reclamation areas. Results showed that: 1) The length of the coastline increased and showed a seaward advancing change in the period of research. In 1985-1993 and in 2002-2014, the coastal zone in the Northern Liaodong Bay experienced significant landward erosion and seaward expansion. The natural shorelines in the west banks of Daling River Estuary and Daliao River Estuary turn into artificial shorelines. 2) Reclamation has converted 85% of natural coastal wetlands into artificial coastal wetlands and non-wetland, landscape fragmentation increased. But in the 2002-2014, reed and intertidal salt marsh grew gradually outside reclamation area, the landscape diversity increased. 3) The traditional landscape succession over nearly four decades went from natural coastal wetlands to inland halophytes/reed swamps to aquaculture ponds/cultivated lands and then to built-up areas. Due to advanced reclamation and fast desalination technologies, the successional process was simplified and the time was shortened. 4) The evolution of regional landscape pattern is significantly influenced by different reclamation intensity and way. Strengthening the protection of the reverse succession from aquaculture ponds to inland halophytes on the west bank of the Daliao River and the wetland area on both sides of the Shuangtaizi Estuary is of great significance for the improvement of regional ecological environment.
Firmiana danxiaensis is selected as Critically Endangered (CR) plants in the first volume of the China Species Red List (CSRL, 2004), as well as the Ⅱ grade national key protected wild plants. Field surveys show that F. danxiaensis in the core areas of the Danxia Mountain of the Guangdong Province are not only very rare, but also in very narrow distribution areas. As the increasing influence of the world natural heritage sites of “China Danxia”, abundant activities of human beings and visitors in the Danxia Mountain may influence the survival environments of natural plants. Therefore, it is important to find out the number of F. danxiaensis , and summarize the characteristics of their micro geomorphic environments. The number of F. danxiaensis and their spatial distribution are got by field investigations, and the spatial analysis module of the ArcGIS10.5 are used to overlay at the DEM data of 1 m resolution ratio to analyze their environment characteristics of spatial distribution of the slope and the aspect. The investigations indicate that there are only 772 Firmiana danxiaensis in the core areas of the Danxia Mountain, with the altitudes between 100-300 m, slope above 30°, aspects of northwest and southeast with vertical joints and horizontal beddings, and relatively barren soil of cliffs. From the study, we may speculate that F. danxiaensis is also distributed with similar micro-landforms of Danxia red cliffs outside of this research area. The actual situation needs to be further investigated and verified by UAV (unmanned aerial vehicle) technology. Besides F. danxiaensis , there are special rare and endangered vegetations in the Danxia Mountain, such as Danxiaorchis singchiana, Spiradiclis danxiashanensis, Viola hybanthoides, and Chiritopsis danxiaensis which are the common wealth of all mankind in revealing the origin of the species, system evolution, genetic breeding, reproductive ecology, etc. So it is urgent to monitor, protect and study the 6 concentrated areas of F. danxiaensis of Guaimianshi, Jinguichaosheng, Longjiaoshan, Jinshiyan, Shuangxitai, and Longwangquan-Shaoyinting, and establish ecological redlines of F. danxiaensis in the Danxia Mountain of Guangdong Province, China.
As one of the most severe soil erosion areas and typical fragile eco-environment regions, the soil erosion processes on the Chinese Loess Plateau (CLP) include surface soil erosion and weathering, hydrological transport and biological activities in the catchment, all of which belong to the processes of Earth’s Critical Zone. Nevertheless, the understanding of historical soil erosion flux and its driving mechanism is limited, which significantly restricts the reasonable evaluation of erosion control effect on the CLP since 1950s. The sediment sequences in the check dams and landslide-dammed reservoirs on the CLP, which are composed of different numbers of deposition couplets and annual freeze-thaw layers, are one of the best geological carriers for high-resolution reconstructing historical erosion flux, storm intensity and frequency, eco-environment change and land use. Located at the hilly-gully area of the northern Loess Plateau, Jingbian (JB) landslide-dammed reservoir was the result of natural collapse of loess slope at the left of the gully during the period of 1851-1861, which had conserved erosion sediments and documented natural and human information in the catchment during the past 160 years. Based on a drilled 22.75 m JB sediment sequence, Rb/Zr ratios by XRF core scanning and correlation between Ca/Zr and Fe/Zr were used to plot deposition couplets and identify annual freeze-thaw layers. Meanwhile, couplets and annual (specific) sediment yields were calculated when the chronology of the JB sequence was built by the combination of 137Cs contents, annual freeze-thaw layers, modern and history rainfall records. The results showed that the JB sediment sequence consisted of total 126 couplets with 78 annual freeze-thaw layers, which were formed between 1855 and 2014. The range of couplet sediment yields and specific sediment yields in the JB catchment were 0.27×10 4-22.44×10 4t and 0.09×10 4-7.82×10 4t/km 2, respectively. And the range of annual sediment yields and specific sediment yields were 0.27×10 4-90.73×10 4t/a and 0.09×10 4-23.40×10 4t/(km 2·a), respectively. ENSO events significantly affected soil erosion and sediment yield under heavy rains in the JB catchment. Further, compared with El Ni?o years, the sediments in the JB catchment was more prone to be eroded and deposited in the La Ni?a years and next years of El Ni?o, which may be mainly contributed on the heightened East Asian monsoon along with more precipitations within the JB catchment in these years. These results are helpful for extending the history of soil erosion flux in the small catchments and for understanding the response of soil erosion for ENSO events at the hilly-gully area, which will provide the theory basis for dam construction, soil and water loss management, flood control on the northern CLP.
The variation characteristics of precipitation isotopes and the influence of moisture source on them are analyzed by using precipitation isotope data collected around the No. 4 typhoon, named ‘Haima’, in 2011 at Changsha, which located in the Dongting Lake Basin. The results show that both the slope and the intercept of meteoric water line produced by the typhoon precipitation are smaller than that of summer’s at Changsha, which is consistent with water isotope fractionation theory. Significant deplete in heavy isotopes leads to lowest value of precipitation δ 18O under the typhoon weather system during the study period, while the deuterium excess(d) is less fluctuation than in the rest time, the latter reflects that the moisture source of the typhoon is relatively single. Precipitation d-excess indicates that moisture is transported from the western Pacific Ocean both before and during the typhoon precipitation, while unclear moisture source after the typhoon precipitation. Also the moisture transport trajectory for precipitation in the basin confirms the moisture sources indicated by precipitation d, for example, the water vapor of typhoon precipitation in the basin mainly comes from the northern South China Sea, and huge water vapor over northern South China Sea had been carried by the typhoon from the western Pacific.
The river basin water and ecological issues have become prominent urgent problems and have generated considerable recent research interest around the world, owing to the combined effect of global climate change and human activities. This paper first briefly presented the concept of integrated river basin management. Then we provide the concept and connotation of eco-hydrological regulation for integrated river basin management, it is synthetically guided by theory of sustainable development, theory of ecohydrology as well as nature-based solution to water issues for comprehensive contributing to dual-regulation of a river basin. With the support and participant of government and publics, especially those of mitigation measures (e.g., laws and regulations, water right and water market, ecological engineering, hydraulic engineering), it could efficiently address river basin water and ecological issues and improve benefits from water and ecosystem. Therefore, it could help to achieve a coordinated development between water resources-ecological environment-social economy, and promote the maximum of public welfare in river basin. Furthermore, we systematically elaborated the essential research contents of eco-hydrological regulation for integrated river basin management: 1) the principle and methodology of eco-hydrological regulation; 2) the integrated water resources management for eco-social coordinated and sustainable development in river basin. The results of this paper have a great implication in the enrichment and development of theoretical methods and technical systems of integrated river basin management, which would be beneficial for effectiveness as well as overall level of integrated river basin management.
