Accounting for the gains and losses of ecological assets holds scientific significance in sustaining human well-being. Based on related research on ecological assets, we established a county-scale ecological asset accounting technology system by analyzing the temporal and spatial variations of county-level ecological assets in China from 1990 to 2018 and clarified the factors which caused the gains and losses of ecological assets. On these bases, optimization and promotion pathways were proposed. The results show that the number of counties dominated by farmland and forest ecological resources accounted for about 45% and 37% of the total counties, respectively. From 1990 to 2018, the quality of county-level ecological stock assets showed an increasing trend, while the water conservation volume decreased in nearly 70% of the counties. The number of counties with the gains (47%) and losses (37%) of ecological flow assets demonstrated spatial patterns which showed the same segmentation characteristics as the “Hu Huanyong Line”, that is, the counties in the vastness of northwest China experienced significant gains, while decreases were widespread in eastern and southern China. The change of ecological assets in more than 70% of the counties was driven by climate change and human activities. The average degree of impact of human activities driving the ecological asset gains in counties was about 80%, while that of climate change causing the ecological asset losses was about 60%. According to various ecological resource types, gain and loss status, and its driving factors, counties in China can be classified into five types: climate change mitigation, climate change adaptation, ecological resources restoration, ecological resources protection, and ecological resources management. Our results indicate that differentiated optimization and promotion pathways can be adopted to achieve desired ecological asset gains.
This essay combines the Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) nighttime light data and the Visible Infrared Imaging Radiometer Suite (VIIRS) nighttime light data into a “synthetic DMSP” dataset, from 1992 to 2020, to retrieve the spatio-temporal variations in energy-related carbon emissions in Xinjiang, China. Then, this paper analyzes several influencing factors for spatial differentiation of carbon emissions in Xinjiang with the application of geographical detector technique. Results reveal that (1) total carbon emissions continued to grow, while the growth rate slowed down in the past five years. (2) Large regional differences exist in total carbon emissions across various regions. Total carbon emissions of these regions in descending order are the northern slope of the Tianshan (Mountains) > the southern slope of the Tianshan > the three prefectures in southern Xinjiang > the northern part of Xinjiang. (3) Economic growth, population size, and energy consumption intensity are the most important factors of spatial differentiation of carbon emissions. The interaction between economic growth and population size as well as between economic growth and energy consumption intensity also enhances the explanatory power of carbon emissions’ spatial differentiation. This paper aims to help formulate differentiated carbon reduction targets and strategies for cities in different economic development stages and those with different carbon intensities so as to achieve the carbon peak goals in different steps.
Research on the carbon budget and zoning for carbon compensation in major functional zones (MFZs) is important for formulating strategies for low-carbon development for each functional zone, promoting the collaborative governance of the regional ecological environment, and achieving high-quality development. Such work can also contribute to achieving peak emissions and carbon neutrality. This paper constructs a theoretical framework for the carbon budget and carbon compensation from the perspective of the MFZ, uses 157 county-level units of the Beijing-Tianjin-Hebei urban agglomeration (BTHUA) as the study area, and introduces the concentration index, normalized revealed comparative advantage index, and Self Organizing Mapping-K-means (SOM-K-means) model to examine spatio-temporal variations in the carbon budget and carbon compensation zoning for the BTHUA from the perspective of MFZs. The authors propose a scheme for the spatial minimization of carbon emissions as oriented by low-carbon development. The results show that: (1) From 2000 to 2017, the carbon budget exhibited an upward trend of volatility, its centralization index was higher than the “warning line” of 0.4, and large regional differences in it were noted on the whole. (2) There were significant regional differences in the carbon budget, and carbon emissions exhibited a core-periphery spatial pattern, with a high-value center at Beijing-Tianjin-Tangshan that gradually decreased as it moved outward. However, the spatial pattern of carbon absorption tended to be stable, showing an inverted “U-shaped” pattern. It was high in the east, north, and west, and was low in the middle and the south. (3) The carbon budget was consistent with the strategic positioning of the MFZ, and the optimized development zone and key development zone were the main pressure-bearing areas for carbon emissions, while the key ecological functional zone was the dominant zone of carbon absorption. The difference in the centralization index of carbon absorption among the functional zones was smaller than that in the centralization index of carbon emissions. (4) There were 53 payment areas, 64 balanced areas, and 40 obtaining areas in the study area. Nine types of carbon compensation zones were finally formed in light of the strategic objectives of the MFZ, and directions and strategies for low-carbon development are proposed for each type. (5) It is important to strengthen research on the carbon balance and horizontal carbon compensation at a microscopic scale, enrich the theoretical framework of regional carbon compensation, integrate it into the carbon trading market, and explore diversified paths for achieving peak emissions and carbon neutrality.
Research on the spatio-temporal correlation between the intensity of human activities and the temperature of earth surfaces is of great significance in many aspects, including fully understanding the causes and mechanisms of climate change, actively adapting to climate change, pursuing rational development, and protecting the ecological environment. Taking the north slope of Tianshan Mountains, located in the arid area of northwestern China and extremely sensitive to climate change, as the research area, this study retrieves the surface temperature of the mountain based on MODIS data, while characterizing the intensity of human activities thereby data on the night light, population distribution and land use. The evolution characteristics of human activity intensity and surface temperature in the study area from 2000 to 2018 were analyzed, and the spatio-temporal correlation between them was further explored. It is found that: (1) The average human activity intensity (0.11) in the research area has kept relatively low since this century, and the overall trend has been slowly rising in a stepwise manner (0.0024·a-1); in addition, the increase in human activity intensity has lagged behind that in construction land and population by 1-2 years. (2) The annual average surface temperature in the area is 7.18 ℃ with a pronounced growth. The rate of change (0.02 ℃·a-1) is about 2.33 times that of the world. The striking boost in spring (0.068 ℃·a-1) contributes the most to the overall warming trend. Spatially, the surface temperature is low in the south and high in the north, due to the prominent influence of the underlying surface characteristics, such as elevation and vegetation coverage. (3) The intensity of human activity and the surface temperature are remarkably positively correlated in the human activity areas there, showing a strong distribution in the east section and a weak one in the west section. The expression of its spatial differentiation and correlation is comprehensively affected by such factors as scopes of human activities, manifestations, and land-use changes. Vegetation-related human interventions, such as agriculture and forestry planting, urban greening, and afforestation, can effectively reduce the surface warming caused by human activities. This study not only puts forward new ideas to finely portray the intensity of human activities but also offers a scientific reference for regional human-land coordination and overall development.
The Mu Us dune field in China has become a focal region for research of the prevention and control of desertification. Agricultural practices in this area have been modernized in recent years, evidenced by the development of Center Pivot Irrigation (CPI) farmlands. However, the impacts of CPI farmlands on combating desertification remain poorly understood. This study chose the southeastern part of the Mu Us dune field as a study area to investigate the variations of CPI farmlands from 2009 to 2018 and the influencing factors. The results showed growth trends in both the number and the area of these CPI farmland units over the period. The areas of meso- and micro-scale CPI farmland units stabilized over time to mainly 0-0.2 km2 and 0.2-0.4 km2, respectively; Topography, temperature, and geological substratum were preliminarily identified as the major natural factors driving the development of the CPI farmlands. Within the context of varied stakeholders, the potential for soil erosion, and damage to natural vegetation, the current study suggests that strict management of CPI farmland is required through effective long-term planning and land-use policies. The results of this study can assist in realizing the sustainable development of agriculture and its ecological significance in dune field areas.
Functional zoning is an important mechanism for achieving national park planning and management objective. Better functional zoning is of great significance to the protection of ecosystem legitimacy and integrity, the appropriate utilization of resources, community integration, and feasible management. In the present study, the proposed Qinghai Lake National Park is the research object. Based on the critical goal of ecological protection, the importance of ecosystem service functions and the ecological sensitivities were evaluated. The results showed that the ecosystem service functions and the ecological sensitivity of the whole region are high. Among them, lake, river and wetland as the most strictly protected ecosystems account for the highest proportion. Then this study divided the proposed Qinghai Lake National Park into five functional areas through grid calculations, spatial analysis and multifactor trade-off. The results indicated that the goal of functional zoning for national park is to maximize the overall utility of park protection value and its comprehensive functions based on its spatial units with different functions, management and control requirements. The zoning scheme addresses the lack of sustainable development in Qinghai Lake National Park due to ecological environmental changes and single-resource zoning with resource protection as the primary goal. This study can serve as a reference for spatial functional zoning methods of national land parks, nature reserves and other natural protected areas.
Water diversion projects are an effective measure to mitigate water shortages in water-limited areas. Understanding the risk of such projects increasing concurrent drought between the water intake and receiving regions is essential for sustainable water management. This study calculates concurrent drought probability between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project using Standardized Precipitation Index and Copula functions. Results showed an increasing trend in drought probability across both the water intake and receiving regions from 2.67% and 8.38% to 12.47% and 14.18%, respectively, during 1969-2018. The return period of concurrent drought decreased from 111.11 to 13.05 years, indicating larger risk of simultaneous drought between the two regions. Projections from CMIP6 suggested that under the SSP 2-4.5 and 5-8.5 scenarios, concurrent drought probability would increase by 2.40% and 7.72% in 2019-2050 compared to that in 1969-1990, respectively. Although increases in precipitation during 2019-2050 could potentially alleviate drought conditions relative to those during 1991-2018, high precipitation variability adds to the uncertainty about future concurrent drought. These findings provide a basis for better understanding concurrent drought and its impact on water diversion projects in a changing climate, and facilitate the establishment of adaptation countermeasures to ensure sustainable water availability.
Since the Three Gorges Dam (TGD) was put into operation, the flood water level at an identical discharge rate has not displayed a decreasing trend along the middle reaches of the Yangtze River (MYR). The flow resistance variations of the channel and bars in response to the operation of the TGD remain poorly understood, despite the importance of understanding these for water disaster mitigation and water environment regulation. Herein, the impacts of the TGD on the downstream flow resistance of the channel and bars in the MYR were analyzed using systematic surveys of hydrological datasets, cross- sectional profiles, sediment datasets, and remote sensing images, during different periods. Under the actual natural conditions in the MYR, a modified semi-empirical formula, which considered the grain, dune resistance, as well as the topographic features of the riverbed, was proposed to predict the channel resistance. Furthermore, the effect of various dam-control flow and sediment elements on the variation in different flow resistance components, and the corresponding relationships among them were investigated. Results showed a decline in the comprehensive, channel, and bar resistances as the discharge increased, whereas there was a slight increase when reaching the bank-full discharges. Notably, the bar resistance occupied 65%, while the channel resistance, in which dune resistance was much larger than grain resistance, contributed 35% to the comprehensive resistance. In addition, while flow resistance rose over time, there was a decline as the distance from the TGD increased. In conclusion, the increased dune and bar resistances, interpreted by the fluctuated channel longitudinal profile and growing vegetated area on bars, were the dominant factors preventing the flood water level from dropping.
Global warming has caused the Arctic Ocean ice cover to shrink. This endangers the environment but has made traversing the Arctic channel possible. Therefore, the strategic position of the Arctic has been significantly improved. As a near-Arctic country, China has formulated relevant policies that will be directly impacted by changes in the international relations between the eight Arctic countries (regions). A comprehensive and real-time analysis of the various characteristics of the Arctic geographical relationship is required in China, which helps formulate political, economic, and diplomatic countermeasures. Massive global real-time open databases provide news data from major media in various countries. This makes it possible to monitor geographical relationships in real-time. This paper explores key elements of the social development of eight Arctic countries (regions) over 2013-2019 based on the GDELT database and the method of labeled latent Dirichlet allocation. This paper also constructs the national interaction network and identifies the evolution pattern for the relationships between Arctic countries (regions). The following conclusions are drawn. (1) Arctic news hotspot is now focusing on climate change/ice cap melting which is becoming the main driving factor for changes in geographical relationships in the Arctic. (2) There is a strong correlation between the number of news pieces about ice cap melting and the sea ice area. (3) With the melting of the ice caps, the social, economic, and military activities in the Arctic have been booming, and the competition for dominance is becoming increasingly fierce. In general, there is a pattern of domination by Russia and Canada.
Special attention needs to be paid to achieve the world’s poverty reduction goal by 2030 in less than ten-year time. The paper aims to investigate the multidimensional poverty in South Asia in the period 2003-2019. It constructs the Multidimensional Poverty Index (MPI) by selecting ten indicators in the fields of health, education and living standards. The research results show that the MPI of South Asia decreases in the research period. Poor people in South Asian countries are still facing several forms of deprivation while cooking fuel, sanitation, housing, nutrition and years of schooling are the main restrictive factors to poverty reduction in this region. Pakistan, India and Bangladesh face the worst poverty situation in terms of health, education and living standards. Targeted poverty alleviation and resilient poverty reduction are proposed in the paper to improve the poverty reduction efficiency and individual/regional capacity against risks to avoid returning to poverty.
Bangladesh is one of the most vulnerable countries to natural disasters such as droughts in the world. The pre-monsoon Aus rice in Bangladesh depends on rainfall and is threatened by increasing droughts. However, limited information on the changes in Aus rice as well as droughts hamper our understanding of the country’s agricultural resilience and adaption to droughts. Here, we collected all the official statistical data of Aus rice at the district level from 1980 to 2018, and examined the interannual variations of area, yield, and production. The results showed both area and production of Aus rice decreased significantly (61.58×103 ha yr-1 and 17.21 ×103 M. tons yr-1, respectively), while yield increased significantly (0.03 M. tons ha-1 yr-1). We also found a significantly increasing trend of droughts in 88% of area based on the Palmer Drought Severity Index (PDSI) data, especially in those rainfed agricultural areas. Moreover, we found significant positive correlations between PDSI and Aus rice area (production) in 33 (25) out of 64 districts. There is hardly a relationship between PDSI and yield, likely due to the improved management and increasing irrigated areas. Implementing continuous drought monitoring, combined irrigation (surface and groundwater) systems, and conservation and precision agriculture are highly recommended in these drought-prone districts to ensure food security in Bangladesh.
As an important innovation flow, venture capital has been examined in urban network research. However, the segmentation of capital categories and the cross-scale connection of capital remain scarcely analyzed. This study focuses on the structure and industry differentiation of venture capital flows in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and its cross-scale network characteristics. Based on a venture capital database covering capital amount, investment subject address information, and industry information (2000-2018), this article examines the spatial distribution and network structure of venture capital in the GBA by means of a distance-based test of spatial concentration approach and social network analysis. Key findings show that: (1) Venture capital institutions and startups in the GBA present a high-concentration distribution pattern. In the past 20 years, venture capital activities in the GBA have substantially increased, forming a complex urban network structure with Guangzhou, Shenzhen, and Hong Kong as the core of this network. (2) Different types of venture capital show significantly different urban network structures, with manufacturing, the Internet industry, the financial sector, the cultural media industry, and the medical and health industry as the five industry types with the largest capital flow in the GBA. (3) Cross-scale research on the venture capital network reveals the position of the GBA as a capital hub in China, which forms a dense venture capital connection network with major cities on a national scale. (4) The network structure of venture capital in the GBA is influenced by multi-dimensional proximity, institutional factors, urban economy, and path dependence. Along with these three key mechanisms, the GBA has grown into a national-scale and even global-scale venture capital center.
Industrial agglomeration is a highly prominent geographical feature of economic activities, and it is an important research topic in economic geography. However, mechanism-based explanations of industrial agglomeration often differ due to a failure to distinguish properly between the spatial distribution of industries and the stages of industrial agglomeration. Based on micro data from three national economic censuses, this study uses the Duranton-Overman (DO) index method to calculate the spatial distribution of manufacturing industries (three-digit classifications) in the Beijing-Tianjin-Hebei region (BTH region hereafter) from 2004 to 2013 as well as the hurdle model to explain quantitatively the influencing factors and differences in the two stages of agglomeration formation and agglomeration development. The research results show the following: (1) In 2004, 2008, and 2013, there were 124, 127, and 129 agglomerations of three-digit industry types in the BTH region, respectively. Technology-intensive and labor-intensive manufacturing industries had high agglomeration intensity, but overall agglomeration intensity declined during the study period, from 0.332 to 0.261. (2) There are two stages of manufacturing agglomeration, with different dominant factors. During the agglomeration formation stage, the main locational considerations of enterprises are basic conditions. Agricultural resources and transportation have negative effects on agglomeration formation, while labor pool and foreign investment have positive effects. In the agglomeration development stage, enterprises focus more on factors such as agglomeration economies and policies. Internal and external industry linkages both have a positive effect, with the former having a stronger effect, while development zone policies and electricity, gas, and water resources have a negative effect. (3) Influencing factors on industrial agglomeration have a scale effect, and they all show a weakening trend as distance increases, but different factors respond differently to distance.
