Over the past decades, China has made great progress in industrial development, urban construction and information technology, and it leads to tremendous changes in the human settlements. In addition, socio-economic development has introduced the diversified human activities, which brings new challenges to the cognition of traditional human settlements. In this paper, a new division of domestic human settlements have been proposed, it is divided into real human settlements, imagery human settlements and pseudo human settlements (i.e. the “three states” of human settlements) based on the geographical scale. Using the “subjective literature induction + objective literature bibliometrics” approach, this paper reviews and prospects the related studies on human settlements from the geographic scales of “three states”, including its content, data and methods. From the analysis above, the following conclusions are drawn in this paper. ① The studies of human settlements have the tendency to be comprehensive and integrated in terms of themes, disciplines and directions. The studies of human settlements have made great progress in understanding the human-land relationship. An increasing number of studies consider the impact of different geographical scales on human settlements. ② Dataset of human settlements shows a trend towards quality optimization, with increasing resolution and precision. The trend of spatio-temporal integration of data from multiple sources is becoming more and more evident. The combination of “big data” and “small data” is also the characteristic of human settlements. ③ Qualitative studies have made significant advances in investigation forms, analytical tools and methods. Growing numbers of econometric models are being developed for the study of human settlements. At the same time, the aggregation of “big data intelligent analysis + small data sampling survey” is applied to explore the relation between human and environment. In the future, domestic studies of human settlements should deepen the logic analysis principle of “one horizontal + one vertical”. On the one hand, scholars should focus on the spatio-temporal characteristics of different human activities (such as living, working, transportation and recreation) at the horizontal scale. On the other hand, much attention should be paid to the deep structure of human settlements under the trend of “reality- imagery -pseudo” at the vertical scale. Domestic studies should be centered on the “three states” of human settlement and diversified human activities. Finally, the Science of Human Settlements would be gradually evolutionary into the multi-perspective, multi-fields, and systematically integrated discipline group.
Based on a comprehensive theoretic perspective of network externalities and economics of innovation, the main sources of the knowledge pipeline effects of air traffic network are examined, and the influence mechanisms of air transport on urban knowledge production are analyzed. Information of direct flights between cities in 2019 is used to construct the urban network, and the number of patent applications is used to measure the level of urban knowledge production. Then the impacts of network embedding on knowledge production are quantitatively tested by a combination of multiple linear regressions, quantile regressions and geographically weighted models. Two conclusions are drawn. 1) The knowledge pipeline effect of air transport network has become an important factor influencing urban knowledge innovation. On the one hand, in the “space of flows”, the air network acts as a bridge to link diverse knowledge production systems that are geographically dispersed, promoting the flow, matching and combination of complementary knowledge. As a result, the cities with higher ability to use network resources exhibit higher knowledge production efficiency. On the other hand, cities that are the first to be linked by air transport are usually innovation hotspots, which make the knowledge output effect of airline network present a diminishing marginal impact. As a result, the higher the level of knowledge output, the less the city will benefit from the network linkages. 2) The effect of airline network embedding on knowledge output presents sector heterogeneity and spatial heterogeneity. From the perspective of the sector heterogeneity of network effects, sectors with more knowledge sources and more active innovation, such as H and C in the International Patent Classification (IPC) system, will obtain higher benefits from network connections, while sectors whose technical issues are decomposable or technologies are in mature stage, such as F and D in the IPC system, will benefit less. From the perspective of the spatial heterogeneity, due to differences in the scale of knowledge output and the characteristics of leading industries, cities in the eastern China benefit significantly less than those in the central and western China. The results of this article have clear policy implications. The policy makers should improve the layout of airlines to fully release the knowledge pipeline effects of air transport network on urban knowledge innovation, and implement differentiated innovation policies to promote the division and cooperation of different urban knowledge production systems across a larger geographical scope.
The analysis of the characteristics and location of regional high-tech manufacturing industry embedded in global R&D network is one of the frontiers and hot fields of economic geography research. Zhejiang Province, a region with developed shipbuilding industry in China, was taken as an example. Based on patent data and order data, UCINET6.0 and R programming language software were used to describe the geographical characteristics and spatial correlation of shipbuilding network in Zhejiang province, and to identify the technology network embedment of shipbuilding industry in global latecomer regions under the international R&D division. The results show that: 1) the research and development of shipbuilding in Zhejiang mainly focuses on B63B and B63H, and the shipbuilding technology network node mainly concentrates in Zhoushan. The main cooperation areas of shipbuilding research and development are Hangzhou, Shanghai, Beijing, Taizhou, Wenzhou and Ningbo, which are mainly the cities in Zhejiang province. 2) The analysis of order data shows that the status change of Zhejiang shipbuilding technology cooperation in the inter-provincial and international shipbuilding technology network. In 2015, domestic technical partners of Zhejiang were mainly Liaoning, Fujian and Taiwan. In 2018, Shanghai, Guangxi, Hainan and Tianjin were added, and the scope of domestic cooperation expanded and the frequency of cooperation increased. As for the international technical cooperation, the main cooperation partners changed from Italy, Denmark and other European countries in 2015 to Japan, South Korea and Singapore in 2018. 3) Zhejiang shows that there are no obvious advantages in the node of shipbuilding technology cooperation network in the Yangtze River Delta, whose cooperation products focus on the production and research of container ships and bulk carriers with low added value, mainly through the signing of technical cooperation agreements, simple supply and marketing, and the undertaking of maintenance or modification and upgrade orders. Furthermore, multi-scale spatial relation and geographical distance feature of path dependence of shipbuilding industry research and development was clarified in the process of global localization. And it’s suggested the shipbuilding industry in China should integrate national system diversity, market diversity and its own research and development cluster level of shipbuilding, breakthrough shipbuilding research and development value chain space lock from the near to the distant, form a cross-domain and multi-agent collaborative innovation roadmap.
In recent years, with the continuous acceleration of the transformation and upgrading of domestic coastal ports and the cities where the ports are located, as well as the rapid advancement of the integration of port resources and the adjustment of port functions, the relationship between China’s coastal ports and the cities where the ports are located is entering a new stage of development. Therefore, objective analysis of the coordinated evolutionary relationship between coastal ports and port cities, and the role of port-city coordinated development in promoting the economic growth of the port city, is of great significance for guiding the high-quality economic development of coastal ports and port cities. This paper takes 20 major coastal ports and cities where the ports are located as examples. Firstly, build a model for the coordination degree of the port-city complex system, and calculate the synergy degree of the port and the city complex system from 2010 to 2019. Secondly, using the panel data model to test the relationship between port-city synergy and urban economic growth. Thirdly, analyzing the evolution law and driving reasons of the coordination degree of the port-city complex system of China’s coastal ports and cities where the ports are located, as well as the action mechanism of the synergy degree of ports and cities on urban economic growth. Finally, synthesizing the results of the coordination degree and panel data model, put forward suggestions to promote the sustained and high-quality economic development of China’s coastal ports and port cities.
Based on the assumption that a student home address implies a geographic location, this study retrieved the geographic coordinates and spatial distribution of primary school students by using the geocoding APIs provided by AutoNavi Information Technology Co. Ltd after collecting the registered student home addresses in Zhuzhou, Hunan province. Shortest distances through the road network from student home to all schools in the area were calculated based on the Dijkstra algorithm and the spatial accessibility of primary educational resources was assessed by using a two-step floating catchment area method. This study is aiming at providing a new method to obtain the spatial distribution of primary school students and a new viewing angle to assess the spatial equilibrium of educational resources in rural areas. Results show that: 1) the geographic coordinates can be adequately obtained by using registered home addresses and geocoding APIs. 2) The maximum, mean, and medium of shortest distances from student home to their nearest school are 11.83 km, 2.10 km, and 1.81 km in the study area, respectively. Only 55.46% of the shortest distances from student home to their nearest school is less than 2.0 km in the study area, which rises a challenge for achieving a fair and efficient educational resources distribution. 3) In the northern region of the study area, the averaged shortest distance from student home to their nearest school is generally small and the spatial accessibility of primary educational resources is uniformly high because there exist many schools. However, the shortest distances are relatively large and the spatial accessibility is low in the south-eastern region because the number of schools in this region is small. 4) At last, the averaged shortest distance from student home to their nearest school was largely reduced and the spatial educational resources accessibility was highly improved in the south-eastern region of the study area in a scenario of installing three new schools. For example, the averaged shortest distance was reduced from 3784 m and 3520 m to 3116 m and 2636 m, and the spatial accessibility was improved from 0.0492 and 0.0982 to 0.0762 and 0.1496 in Longtan and Longmen, respectively.
During the Bohai period of the Tang Dynasty, the Northeast China was influenced by the culture of the Central Plains and underwent great changes in terms of urban patterns and architectural styles. The change provides a large number of ancient city sites for studying the social development of the Northeast China today. With ArcGIS software and spatial analysis methods, this paper studies on the distribution characteristics of 234 ancient city sites in the Bohai Kingdom of Tang Dynasty in Northeast China, and the relationship between the spatial pattern of ancient city sites and natural conditions. By analyzing 234 ancient city sites with Nearest Neighbor Analysis, this paper argues that Ancient Bohai City relics in Tang Dynasty were mainly concentrated in 4 agglomeration areas, namely the Tumen River-Yalu River Agglomeration Area (A), Mudan River Agglomeration Area (B), Songhua River-Liao River Agglomeration Area (C), Muling River Agglomeration Area (D). Among them, accounting for 47.43% of the total sites, the Tumen River-Yalu River Agglomeration Area is the most significant one located in the south of the study area. This paper also discusses the distribution of Ancient Bohai City relics in the way of from sparse to dense from north to the south, forming an obvious pattern of spatial clusters. In the climatic environment of the time, natural factors such as water and heat conditions became the main factors affecting the city sites. In order to adapt to the cold climate of the northeast, the outer walls of the city buildings were thicker than those in the central plains; sites below 500 m in elevation accounted for nearly 70% of the total number; nearly 80% of the city sites were built in flatter areas below 9°; in order to have better lighting, most of the city sites were chosen to face south on slopes; more than 80% of the sites were chosen to be within 1000 m from the river. These show that natural conditions had an important influence on the choice of the Bohai city site. Human factors such as political, economic, military and transportation locations guided the number and distribution of ancient city sites. These human factors include Bohai agriculture, animal husbandry and handicrafts economic form which made Bohai city site closer to the means of production. Bohai Kindom is also the transportation hub of the northeast of the Tang Dynasty. Transportation routes have an impact on the distribution of the city site. Bohai and surrounding people have been at war, that part of the city site plays an important military defense function. In summary, the distribution of the ancient city sites in Bohai is the result of both natural and humanistic influences, and is an important reflection of human adaptation to nature and the use of nature.
By using social survey, court records, Points of Interest, road networks, and Baidu Location-based Service population dataset in Beijing, this research finds that the densities of theft and violent crime cases have no significant or weak-to-moderate correlation with fear of crime. Furthermore, according to the security situation and level of mismatch between perceived fear and actual crime, we classify each sample into four types: ‘matching and high security’, ‘matching and high danger’, ‘mismatching and more dangerous than it looks’, ‘mismatching and safer than it looks’. It indicates that fear of crime and actual criminal activities are two distinct social phenomenon whose spatial patterns, forming mechanisms, and policy recommendations need to be separately analyzed. The vulnerable features including female, low-income, non-managerial level, and victimization experience make people inclining to overestimate the risk of crime. The female, low-income, immigrant, and married person are also more exposed to actual crime, suggesting some specific prevention measures should be taken for these vulnerable individuals. The permeable environment with densely population, mixed function and compact road networks would result in more dangerous situation than subjective perception, since defensible space theory and street eyes theory are appropriate to explaining crime and fear of crime at the macro spatial scale, respectively. Meanwhile, the stricter access control at the micro spatial scale is beneficial to both the reduction of criminal activities and the relief of fear of crime. In addition, residential instability, physical disorder, and social disorder would lead to the relative safer situation than human perception. But in general, environmental maintenance can simultaneously suppress actual crime and mitigate fear of crime. Rather, the residents dwelling in high-mobility and high-status communities tend to underestimate the risk of crime.
Based on Chinese provincial panel data from 2000-2018, the ‘bottom-up’ method and Super-SBM model were used to measure tourism carbon emission reduction potential of 30 provinces. Besides, the modified gravity model and social network analysis method were applied to explore the spatial correlation network characteristics and its determinants of tourism carbon emission reduction potential in China. The results showed that: 1) The spatial correlation degree of tourism carbon emission reduction potential was strengthened during the study period. In addition, the network density and the number of network relations maintained a fluctuating upward trend, while the network efficiency and network hierarchy declined gradually. 2) The eastern provinces were at the center of spatial correlation network, which had strong ability to control and dominate the elements needed to reduce the tourism carbon emission reduction potential. The western less developed provinces were at the edge position and had difficulty in influencing and controlling other provinces. 3) Beijing, Tianjin, Jiangsu and Shanghai belonged to ‘net benefit spillover’; Guangdong, Zhejiang and Fujian belonged to ‘agent plate’; Jilin and other 22 provinces were classified as ‘net spillover plate’. 4) Spatial adjacency relation, differences in economic development level, industrial structure, technological innovation level and tourist scale drove the formation and evolution of spatial correlation network structure of tourism carbon emission reduction potential in China.
The Indian Ocean Region (IOR) is crucial to China’s economic development and national security, but the vast regional space and complex social environment surrounding the IOR pose many potential risks to Chinese enterprises’ investment, trade and so on. National risk refers to the possibility of economic loss of investment caused by the domestic political, economic, social and cultural environment of the host country or international political and economic factors in the process of the investor’s international investment activities. Based on the relevant data of 49 countries around the IOR from 2005 to 2019, 22 indicators are selected from four dimensions of politics, economy, society and culture to construct the national risk assessment index system around the IOR, using dynamic time warping and map visualization to explore the spatio-temporal evolution characteristics of comprehensive risks in five subregions around the IOR from 2005 to 2019. The results show that: 1) From 2005 to 2019, the comprehensive risk of countries in the IOR showed a declining trend, but the countries in the region are still concentrated in medium risk and higher risk levels. 2) Pakistan-Afghanistan-Iraq-Iran and Egyptian-Sudan-Eritrean-Somalia are the two high value clusters of comprehensive risks in the region. The comprehensive risks of countries around the IOR show obvious ‘regional agglomeration’ characteristics. 3) The dominant risk varies from region to region, political risk is the dominant risk in all regions except Australia and is currently the main source of risk in the IOR.
Cultural heritage has become an essential resource or means in China's modernization projects and social governance. Heritagization is a process in which a historical remnant is officially recognized as ‘heritage’, and protected, developed and managed. However, less attention has been paid to how the heritagization process takes placed in local place and its mechanism. Taking Genglubu—guides written by Hainan fishermen recording navigation routes and other information for fishing in the South China Sea—as a case, this article reveals how Genglubu transforms into ‘intangible cultural heritage’ and its relationship with place, and how different groups engage and interact in the heritagization process. This study is conducted based on fieldwork, including in-depth interviews and participant observation in Qionghai City and Wenchang City, Hainan Province, China during 2017 and 2019. We recruited a total of 72 interviewees, including 24 fishermen and residents in Wenchang and 25 counterparts in Qionghai, two editors, seven national or provincial level and 14 below the provincial level workers of government or public service institutions (e.g. museums). Each interview lasted between 0.5-1.5 h during which interviewees were allowed to answer each open-ended question according to their personal experience and thoughts, and bringing up new topics was encouraged. This research employs the grounded theory approach to analyse the interview data for drawing findings. After the transcription of the recordings, the interviews are coded by three steps: open coding, axial coding, and selective coding, to attain the results. The findings reveal that ‘others’ and Hainan fishermen interact in the heritagization of Genglubu, but the effect of ‘others’ is stronger. The meanings of Genglubu which shifts from defuncted ‘secret guideline’ in the private/domestic space to ‘cultural heritage’ supporting the nation's sovereignty over the South China Sea in the public/national space. The identity of fishermen has transformed into ‘pioneers’ or ‘guardians’ of the South China Sea. The collection of relics and cultural activities promote ‘heritagization’ and make different groups interweave with each other where fishermen can impact the understanding and behaviours of ‘others’ in the heritage work. Genglubu can become tourism resource. However, it has not yet become a strong ‘selling point’ to drive the tourism industry, and the residents are in a weak position in the use of its economic capital. Heritagization helps evoke the faded memories of Genglubu, but ‘individual’ memories has been weaken and the place imagination has been restructured. Genglubu has a stronger rooting and effect in Qionghai than in Wenchang. This paper applies the combination of ‘top-down’ and ‘bottom-up’ approach to reveal the differences and intersection of the cognitions and behaviours between the two, with aims to provide a fresh insight for unravelling the heritagization of local relics transforming into ‘cultural heritage’, and how complicated place elements and social relations entangle in this process.
The spatial distribution characteristics, agglomeration evolution status and distribution direction changes of ski resorts have a profound impact on the development of China’s ski tourism and even the ice and snow industry. Using the principle of geostatistical spatial analysis, through nearest neighbor index analysis, spatial autocorrelation analysis, kernel density analysis, standard deviation ellipse and average center analysis, the spatial characteristics and evolution of China’s ski resorts every 10 years before and after 1990 were synthesized. analysis. The results show that: 1) Before 1990, there were only 7 ski resorts in Heilongjiang and Jilin Province, and their distribution was relatively discrete. 2) From 1990 to 1999, the number of ski resorts increased slightly, and spatially spread to Xinjiang, Hebei and Sichuan. 3) From 2000 to 2009, the ski resorts grew rapidly, and a dual-core driving model of ski resorts with Harbin-Mudanjiang and Beijing-Zhang as the core was formed. 4) 2010-2019 is the 10 years with the fastest increase in the number of ski resorts. In 10 years, 522 new ski resorts have been added. Based on the dual-core model, the main belts of Changbai Mountain and Yanshan-Taihang Mountain have been gradually formed. The spatial structure of ski resorts connecting south and north. On the whole, the Chinese ski resorts in the past 30 years have shown the spatial evolution characteristics of “south exhibition, west expansion, east advancement”. The research results have certain theoretical guiding significance for the future spatial layout, optimization and coordinated development of China’s ski resorts.
This study takes Jilin Province as the study area, and analyzes the occurrence characteristics of group adverse weather conditions in winter and its potential impact on various regions of Jilin Province based on high-dimensional copula function. On the basis of previous studies on the suitability of ice-snow tourism, strong wind (> 5 m/s), extreme low temperature (≤?16℃) and snowing days as adverse weather conditions are selected to analysis the potential impact to ice-snow tourism. High dimensional copula function is optimized in meteorological stations of Jilin Province based on the meteorological data from January, February and December from 1985 to 2015. Based on the high dimensional copula function, this study analyzes the impact of three kinds of adverse weather conditions on winter tourism in Jilin Province. By comparing the families of copula function, the three generic functions of Survival Joe (SJ), Clayton and Farlie Gumbel Morgenstern (FGM) are selected to construct R-Vine Copula distribution. From the analysis of daily meteorological data, it is found that the frequency of single adverse weather conditions in Jilin Province is 0.15-0.30, while the frequency of two adverse weather conditions together is 0.01-0.04. The frequency of adverse weather conditions in the western region is higher than that in the Middle East. In the coupling analysis of multiple adverse weather conditions, if adverse weather events occur for 5 d per year, the mean cumulative joint probability in the western region (0.28) is higher than that in the central region (0.07) and the eastern region (0.04); If adverse weather events occur for 10 d per year, the mean cumulative joint probability in the western region (0.65) is higher than that in the eastern region (0.18) and the central region (0.30). When 5 d adverse weather events occur every year, the potential losses in Changchun, Yanbian, Songyuan, Baicheng and Jilin are greater than 10 million yuan. When all kinds of adverse weather events occur 10 times per year, the potential loss of ice and snow tourism revenue in the these areas will be more than 100 million yuan. The occurrence of adverse weather conditions has obvious temporal and spatial law in Jilin Province. From a single disaster, the occurrence of the three adverse weather conditions has a certain periodicity in the time series. Spatially, the frequency of adverse weather conditions in the west of Jilin Province is higher than that in the Middle East. From the occurrence characteristics of group adverse weather conditions, the group occurrence probability in the western region of Jilin Province is higher than that in the middle east region of Jilin, and the joint occurrence probability of adverse weather events in Baicheng, Songyuan and Siping is higher than other cities. From the potential impact of adverse weather conditions, Changchun, Yanbian, Songyuan, Baicheng and Jilin have severe potential losses. This law is of great significance to the disaster reduction planning, tourism insurance and the implementation of tourism planning of winter tourism in this area.
Due to the human activities, the existing natural ecological areas are not real natural. In this article, 474 national nature reserves, 25 key ecological function zones and 32 terrestrial biodiversity conservation priority areas were selected as the research areas. By constructing human disturbance index, the characteristics of temporal and spatial dynamic changes of human disturbance in important natural ecological areas in China were evaluated. The main conclusions are as follows: 1) The intensity of human activities in the important natural ecological spaces was lower than that in China in 2018, which reflected the effect of categorized and zoned governance was good. Taking the Hu Huanyong line as a dividing line, the intensity of human activities in the west and north of the important natural ecological areas was relatively small, and that in the south and east was relatively obvious; from 1980 to 2018, the human interference index of the important natural ecological spaces increased gradually. Compared with that of China, the increase rate was small. The average annual growth rate of 1990-2000 and 2010-2018 was relatively larger than that of the other period. It was due to policy regulation and economic development; 2) The human disturbance index of national nature reserves was the lowest in the five monitoring years. At the same time, its growth speed was the slowest and the growth rate was the smallest, which showed it achieved certain positive effect in managing and controlling human activities. Otherwise, that of key ecological function zones and terrestrial biodiversity conservation priority areas need to be further strengthened, which reflected gradient difference of managing and controlling human activities in important ecological protection areas. 3) Human disturbance in most of the important natural ecological areas in China has been stable and decreased, which was conducive to the protection of important ecosystems and biodiversity, as well as the maintenance of ecological service functions. However, there are still 22.15% national nature reserves, 32% key ecological function zones and 28.12% terrestrial biodiversity conservation priority areas need to be paid attention to in the future. The human interference index of the areas of returning farmland to forest and Hulunbuir grassland in Daxing'an Mountains decreased. The human interference index of the areas in Xinjiang, Qinghai Tibet Plateau, Hengduan Mountains and other areas to the north and west of Hu Huanyong line was basically balanced, and that of the areas in northeast plain, coastal areas and Xinjiang oasis agriculture areas were rised. 4) The human disturbance index, also the increase rate in the important ecological areas were lower than those in the external unprotected area, which quantitatively reflected the importance and necessity of building important natural ecological areas in China. The farther away from the important natural ecological areas, the more obvious human interference, and the gradual reduction of human activity management and control. To a certain extent, it showed that the construction of important natural ecological areas in China had a positive spillover effect on the human activity management and control in the surrounding areas. In general, the analysis results explained the importance of the construction of important natural ecological areas in China, and clearly described the necessity of regional management and control of China’s land space classification, which can provide scientific basis for the scientific governance of natural ecological areas in China in the future.
The ecological, production and living functions of the Transitional geo-space in the mountainous area are highly complex, and the pattern and structure of the three directly affect the multi-functionality and rationality of the land use. There is a multi-objective trade-off relationship between ecological protection and economic and social development in this area, and it is a key area for land space development and pattern optimization. The study takes Changning County, Yibin City as the research area, and quantifies land use functions on a grid scale based on multi-source data. Through landscape superposition analysis and correlation analysis methods, the spatial differentiation characteristics of land multi-functionality are clarified, and the geographic spatial transitional relationship between land functions and terrain factors is revealed. The results show that: 1) The production, ecological and living functions of the transitional geo-space in the mountainous area have multiple combinations and strong spatial heterogeneity. 2) The multi-functionality of the land presents an increasing trend in the transition from the northern plain to the mountainous area in the south. The land dominated by multiple and dual functions is mainly distributed in the central trough and the southern mountainous area, accounting for more than 50% of the total land area. 3) Terrain factors play a major role in the formation of multi-functional landscapes. The critical value of land use multi-function is 650 m above sea level, 200 m topographic relief and 15° slope. Beyond this critical value, land multi-function will tend to decrease, but ecological function will dominate.
On the basis of the dual perspectives of carbon emissions and non-point pollution emissions, this article construct the ecological efficiency evaluation index system of cultivated land use in the Dongting Lake Plain. Taking 24 counties (districts and cities) in the Dongting Lake Plain from 2007 to 2017 as the research object, using Slacks-Based Measure of Super-Efficiency model (Super-SBM model) and spatial autocorrelation models, spatial measurement models and other methods, this article analyzes the temporal and spatial changes and spatial correlation of the ecological efficiency of cultivated land use in the Dongting Lake Plain, and shows the spatial effects and influencing factors of the ecological efficiency of cultivated land use in the Dongting Lake Plain. The results show that: 1) The ecological efficiency value of cultivated land use in the Dongting Lake Plain from 2007 to 2017 showed a gentle evolution trend of “rising-fall-rising”, and was generally at a medium-efficiency development level. The difference in ecological efficiency of cultivated land use among regional counties gradually shrinking. 2) The ecological efficiency of cultivated land use in the Dongting Lake Plain has significant spatial agglomeration features. High-high agglomeration areas are mainly distributed in the southwest and south of the Dongting Lake Plain, and low-low agglomeration areas are mainly distributed in the north and northwest of the Dongting Lake Plain. The spatial pattern changes mainly occur in high-low agglomeration areas and low-high agglomeration areas. 3) The ecological efficiency of cultivated land use in the Dongting Lake Plain has significant spatial effects. The level of urbanization, regional scientific and technological investment, agricultural technology extension area, per capita net income of farmers, and per capita agricultural output value of farmers have significant positive effects on the ecological efficiency of cultivated land use. Urban and rural differences and fiscal expenditures for agriculture have a negative effect on the ecological efficiency of cultivated land use. In the future, the horizontal linkage mechanism among counties be established to promote the technology and policy spilt over in the high value areas of ecological efficiency of cultivated land use, to drive the linkage development in the low value areas. At the same time, farmland ecological planting subsidies will be further increased to promote farmers’ farmland planting behavior from environmentally unfriendly to environmentally friendly.
Taking upstream district of the Minjiang River as an example, we firstly analyze the temporal and spatial dynamics of forest carbon density from 2007 to 2016. To reveal the geographical variation of the association between road network and forest carbon density, this work studies the impacts of different road scenarios and the indexes of different road network measurement on forest carbon density using conventional and improved road network measurement indicators as well as the buffer analysis method and Geographic Weighted Regression (GWR) model. The results show that: 1) The carbon density of the study area is obviously affected by the road network and the magnitude of impact is in the order of within the road network effect zone < the entire research area < outside the road network effect zone; The carbon density of the overlapping region of multiple road effect zones (26.330 Mg/hm 2) is significantly lower than the carbon density (37.406 Mg/hm2) of the single road effect zone. The carbon density of the different grade road effect zones is in the order of county road > expressway > provincial road > other road > national road > rural road; Road construction and expansion also have a significant impact on the reduction of carbon density during 2007 to 2016. 2) The degree of influence of roads on carbon density changes with the change of sample points showed with the characteristic of “spatial non-stationarity”. Carbon density decreases with increasing road density and increases with increasing distance from the road. 3) The regression coefficients and correlation coefficients in the northwest and middle regions of the study area are large, indicating that the roads in these two regions have large impacts on carbon density and are well explained by the model. Policy makers should pay special attention when formulating forest carbon sink protection strategies.
To reveal the surface-ground water exchange yield in different temporal and spatial scale in Zelinggou Basin, middle reaches of the Bayin River in Qaidam Basin. The SWAT-MODFLOW coupled model was used to simulate the water cycle of the Zelinggou Basin, the monthly stream flow, remotely sensed evapotranspiration data, ground water level data were used to calibrate and validate the model. The results showed that: 1) For the monthly streamflow simulating during calibration and validation period, R2 of the SWAT-MODFLOW coupled model are 0.74 and 0.73, NSE are 0.67 and 0.7, and PBIAS are between ?20% and 20%. While for the actual Evapotranspiration in each sub-basin, all R2 and NSE are greater than 0.91 and 0.85, and PBIAS are between ?20% and 20%. The bias values are within 0.6 m and R2 value is 0.94 between the simulated groundwater level and the measured. 2) The river where surface water to groundwater accounts for 90.31% of the whole length of the river, and the average annual replenishment amount accounts for 50.20% of the total annual exchanged water. Seasonally, the maximum value of recharge is 331043.31 m3/d in July, while the minimum value is 41208.33 m3/d in December. The groundwater discharged yield is relatively stable, it seasonal variation is between ?2.5% and 2.5%, and the annual variation is between ?6.5% and 0.6%. This research can further support the hydrological processes modelling and water resource allocation in data scarce area.
