Carrying Capacity（CC）was first coined in biology and ecology in the 1920s,and later developed rapidly in related sciences such as natural resources science and environment science. The concept of Resources and Environment Carrying Capacity（RECC）,from theoretical investigation to practical implementation,has become an effective and operational tool to describe development restrictions and quantify regional sustainable development. RECC research has become a hot topic methodologically and theoretically in ecology,geography and natural resource and environment. It primarily focuses on the ultimate limit of population and economic development on earth. After briefly looking at the origin of the concept and early headway,we summarize RECC research from land resource carrying capacity,water resource carrying capacity,and environmental carrying capacity（environment capacity）. The following evaluating methods,including ecological footprint and virtual land （or the biological productive land by ecological footprint）,water footprint and virtual water （or the global flow of virtual water）,emergy analysis and virtual energy（or energy equilibrium）,are considered as important research progresses in the past century. However,there is still lack of a standard set of evaluation theories and methodologies for RECC research in China and globally,leading to much debate over the objectivity and comparability of resultant figures. Concerning this issue,we propose that RECC research in the future should pay more attention to enhancing exploratory studies in basic theories and carrying mechanisms,thresholds determination and synthetical calculation,technological standards/manuals setting,measurable assessment and systematical integration. More effort is needed to promote the standardization,digitalization and systematization of RECC research in China before according with national practical and operational demands.
Tourism stakeholders include many kinds of groups,such as government agencies,community resident and tourism developers. Community residents are the most important stakeholders in tourism destinations and their perceptions and attitudes have attracted increasing attention from the 1970s internationally and from the 1990s within China. Drawing on national and international work in this field published between 1975 and 2015,we describe research on tourism influences in different aspects,factors that influence community residents’ perceptions and attitudes towards tourism,and theoretical and research methods of tourism destination community residents' attitudes towards tourism development and impacts. We found that the relationship between different influence factors and community residents' perceptions and attitudes are determined by tourism development phases and conditions. Researchers based in China need to combine the special conditions of tourism development in China for empirical research;while they have conducted localization research in related fields in recent years,there are few results regarding theoretical constructions. We should promote theoretical abstraction and innovation in the process of examining tourism phenomenon in the future. Quantitative research methods have dominated the study of community residents’ perceptions and attitudes towards tourism,strengthening the use of qualitative research methods would benefit our understanding of the nature behind these phenomenon.
This research aimed to compute the semantic proximity in land-use data. First,this research established a model to express the layer of details of the semantic characteristics in land-use data,started from the basic situation of land-use category and combined with characteristics of ownership. Second,feature-matching was used to gain concrete metric values by computing the matching relationship among ownership,reason of coverage,land cover type,usage,using state,nature of the stem in vegetation,habits of growth in vegetation,usage of vegetation and land use patterns. This research achieves the whole process from semantic modeling to the semantic proximity in land-use data. Third,this experiment takes 38 entities in land-use data as an example to compute semantic proximity among those with the same characteristic in ownership but different characteristic in land use type,and compares the result of the experiment with the judgment of the practical experience to discover that the result of calculations conforms to human cognition and the methods used in calculating the semantic similarity have strong practicability. Finally,the computation results of semantic proximity were transformed into a spatial measurable value to divide the land-use patch into this have the adjacent relationship in spatial position based on the semantic proximity which the area of is smaller than the threshold when the scale is change smaller in the processing of land-use data in order to demonstrate the practical value of the research findings. The results of this research can be directly applied to statistics,processing,planning,management and development of land resources,and in computing semantic proximity in land-use data to calculate semantic adjacent relationships in other related spatial geographic data.
Exploring spatial and temporal pattern evolution and driving factors of urban construction land use efficiency has important theoretical and practical significance for urban sustainable development. Here,31 provinces in China were taken as the research object to measure urban construction land use efficiency using data envelopment analysis. At the same time,ArcGIS was used to explore the spatiotemporal characteristics of urban construction land use efficiency evolution. Driving factors are discussed using grey correlation modeling. We found that from 2009-2013,provincial urban construction land use efficiency increased,but the efficiency value was not high. Spatial differences in urban construction land use efficiency were remarkable. Overall,the use efficiency of urban construction land in China shows significant spatial autocorrelation. The evolution of local spatial patterns was characterized by the following features：comprehensive efficiency of spatial pattern change was small and pure technical efficiency of the overall spatial pattern change was large. The overall spatial pattern of the scale efficiency was consistent with that of comprehensive efficiency,and the overall pattern changed little. The urbanization level,level of economic development,industrial structure,degree of marketization of land,level of science and technology and location conditions all affect urban construction land use efficiency,but the role of these factors in different research issues differed.
Public green plays a significant role in improving living standards. As an important public resource,the service scope of public green must cover a larger area to satisfy the recreational needs of residents and make good use of its social service functions. The commonly used indices for measuring the function of public green ,such as average public green and overall percentage green area can hardly reflect the distribution of public green. Previous studies usually measured accessibility of public green spaces in order to allocate resources but have failed to reveal relationships between demand from population and supply generated by public green,and neglected the influence of range attenuation on supply and need. To discuss spatial equity of public green at resident parcel, this article chooses seven administrative districts in Wuhan as a case study area and uses the gravity two-step floating catchment area method with distance decay. The results show that:(1) the distance can change the pattern of spatial equity and there are existing notable differences in different level of public green when the catchment makes changes. (2) Majority of case area have an oversupply or undersupply service of public green, while some area has insufficient access to public green within the catchment sizes of 0.50h or 0.75h. (3) Within the same catchment size, the local level of public green can provide better services for residents than district public green. (4) The vast area characterized by unbalanced distribution of spatial equity, which have differences at different sub-districts. The primary factors, such as service capacity, amount of population or public green, have effect on the pattern of spatial equity. The article demonstrates that it is necessary to allocate public green considering the demand from residents to utilize public facility effectively.
From the simultaneous perspective of social network and extension services,we aimed to explore these two information channels in the water-saving technology adoption behavior of farmers. Based on survey data from Minqin County,Gansu,China we established structural equation models to analyze how social networks and extension services affect farmers’ water-saving irrigation technology adoption. We found that farmers enthusiasm for water-saving irrigation adoption is generally low; most farmers adopt water-saving technology with weak willingness and across small areas. There is an especially low level of willingness to pay. Social networks and extension services both have positive significant impacts on farmers water-saving technology adoption,indicating they play crucial roles in facilitating technology adoption. Social networks have both direct and indirect effects on water-saving irrigation technology adoption：internal dimensions of social networks have direct effects on promoting farmers water-saving irrigation technology adoption;and social networks also positively affect effectiveness of extension services,thus indirectly contributing to technology adoption. Farmers awareness of water scarcity and cognition of technology usefulness can facilitate technology adoption,and a good community environment can guarantee technology adoption. Appropriate policy recommendations are proposed based on our empirical results,such as providing funding and policy support for adopters,improving the promotional effects of model households,carrying out trading activities for farmers and providing good social environments.
County sewage treatment services have become an important emissions reduction tool;there is however,a wide disparity in emissions reduction efficiency across county areas. In an effort to examine emissions reduction efficiency across county areas,we used data envelopment analysis to calculate efficiency levels in 413 counties using data from the year 2014. Capital,operating costs,labor and energy consumption were chosen as input indices. The actual treatment of sewage,ammonia,COD and BOD5 reduction were utilized as output indices. An evaluation model of the efficiency of county-level sewage treatment services was established to analyze sewage treatment services and the Tobit model was used to identify key influencing factors. The results show that the combined efficiency of all county areas sewage treatment service is 0.637. The technical efficiency is 0.756 and the scale efficiency is 0.835. We found that 73.85% of counties are increasing their returns to scale. Emission reduction efficiency of sewage treatment service varies among regions. Scale,water load rate,location,population density and economic development levels all have a positive impact on emissions reduction efficiency;biological membrane technology is relatively superior. Many factors are useful in order for some of these sewage treatment facilities to improve their efficiency. Giving guidance according to regional characteristics,facilitating a culture of communication among sewage facilities in county areas,expanding or constructing sewage treatment facilities to appropriate size,utilizing local conditions to choose sewage treatment processes,strengthening the supporting pipe network construction and promoting rain and sewage diversion are all necessary to improve the efficiency of sewage treatment services in China.
In accordance with constraints of the strictest water resource management system,the initial water rights allocation among Chinese provinces must embed water quality effects into the process of water allocation. The processes of water allocation also needs to take the effect of water-use efficiency to water quantity and quality into consideration. Combining with interval number theory,governmental strong reciprocator theory and initial two-dimensional water rights allocation theory from the coupling perspective,we designed a strong reciprocator system based on the principle of ‘rewarding efficiency and penalizing inefficiency’ using the special position and role of the governmental strong reciprocator. As a result of the strong reciprocator system,we propose a water quantity-quality coupled model for the provincial initial water rights allocation by embedding water quality effects into the processes of water allocation. The model of provincial initial water rights allocation is applied to Taihu Basin,to get its nine schemes of the provincial initial water rights allocation in 2020 constrained by different water-use efficiency and emission patterns. At the same standards of water-use efficiency,the amount of initial water rights allocation interval in Jiangsu Province and Shanghai City increases with decreasing water emission responsibility; the amount of Zhejiang Province is otherwise. These results,compared with allocation schemes that merely consider water quantity and water-use efficiency,show that the interval quantity from Jiangsu Province and Shanghai City should be reduced,while the interval quantity from Zhejiang Province should be increased as an incentive for the reduction in water pollutants. Water quantity-quality coupled schemes of provincial initial water rights allocation manifested by interval in multiple scenarios are according with the requirement,which is constrained by the strictest water resource management system.
There are redundant crop residual resources in China and so developing crop residues as biomass energy shows great economic and ecological promise. For the efficient utilization of field crop residues,it is necessary to evaluate the potential and regional distribution of commercial production of field crop residues. First,we employed the yields of various crops in different provinces to calculate the theoretical amount of crop residue and the potential for commercial energy production. Remote-sensing data was mobilized to obtain NPP at a 1 km × 1 km grid level and distribution density of crop residue in different grids,and then suitability distribution of bioenergy plants in different regions was achieved. Compared to previous research,we considered the distribution density of crop residue in different regions because this is important to the use of crop residues which face high collection and transportation costs. We also analyzed the development trend of the distribution of crop residues and energy plants by comparing different years. Our results show that China’s total output of crop residues in 2014 amounted to 0.897 billion ton,collectable amount of crop residue amounted to 0.769 billion ton. Based on the consideration of resources density,larger-scale power plants and fuel ethanol plants are suitable for Jilin,Jiangsu,Henan,Anhui and Heilongjiang Provinces. In the future,China’s crop residue resources and energy plants will be concentrated in these areas. Small-scale power plants and fuel ethanol plants are suitable for Northeast China,Northern China,Southwest China,Middle and Lower Reaches of the Yangtze River,Chengdu Plain and Xinjiang. Government should support the energy utilization of crop residues and distribute energy plants according to crop residue density and scale.
Because energy plays an important role in ensuring the safe operation and sustainable development of cities,it is crucial to forecast energy demands according to actual urban development needs and characteristics. Here,we used LEAP model to predict the total amount of energy demand in Changsha from 2015 to 2020 based on historical economic development and energy consumption data. We used scenario analysis to design five types of scenarios to discuss the impact of GDP growth rate,industrial structure and energy-saving object on future energy demand. These scenarios included baseline scenario,different GDP growth rate scenario,different industrial structure scenario,energy saving scenario and comprehensive scenario. The results showed a significant influence of GDP growth rate on total amount of energy consumption and energy intensity and non-significant effect on the energy consumption structure of sectors. Industrial structure had an impact on the energy consumption structure of sectors and not on the total amount of energy consumption and energy intensity. Under an energy saving scenario (a goal of energy intensity reduction by 15% in 2020 compared to 2015), energy consumption reached 40 140 thousand ton coal equivalent (tce)and less 3170 thousand tce than the baseline scenario. This scenario also predicted the effect of energy-saving policies implemented in the industry,building,transportation and residential sectors. When compared with the baseline scenario,the tertiary industry accounted for the largest proportion of energy-saving with a relative energy-saving rate of 13.4% and industry had a lower energy-saving proportion with a relative energy-saving rate of 6.2%. At the same time,the energy-saving proportion of transportation and residential sector also exceeded 4%.
Frequent droughts and floods in the Huaihe River basin have severely restricted crops production capabilities. To evaluate the influence of climate change on crop productivity,the climatic potential productivity (CPP)of wheat,maize and single-season rice were calculated using weather data from 171 stations and crop growth period data from 121 stations from 1971 to 2010 and stepwise correction modeling. The influence of precipitation changes on crop CPP under the background of climate warming was emphatically analyzed. In the last 40 years,in the Huaihe River basin the single-season rice CPP was the maximum,then maize; wheat was the minimum. The inter-annual variation coefficient of each crop’s CPP was more than 10%,among which wheat CPP was more than 20%. However,each did not have an obvious change over time. The ratio of CPP to light and temperature potential productivity (abbreviation：climate ratio)of three crops was also analyzed. Multiyear mean climate ratio of wheat was the lowest,only 49.7%,and the variation coefficient was 25.4%,while that of maize and rice were 67.3% and 66.4% respectively,and the variation coefficients were 12.9% and 16.3%. The influence of precipitation change on wheat CPP is most serious,then maize CPP and that of rice CPP is the lowest. Serious shortages in precipitation during the wheat growing season and high precipitation variation coefficient both restricted wheat CPP. The main reasons limiting maize CPP were more precipitation,fewer precipitation and precipitation variation during the growing season. The climate ratio of single-season rice was only significantly correlated to precipitation during the growing season,thus rice CPP was mainly influenced by the amount of precipitation.
Crop water and heat resource utilization efficiency changes are the foundations for increasing grain yield potential,realizing sustainable development of agriculture,and optimizing crop distribution and responses to climate change. Based on meteorological and statistical data in Jilin,China from 1993 to 2013,according to three crop accumulated temperature requirements,we divided climate planting boundaries and estimated water and heat resource utilization efficiency in an area expanded by climate warming. From 1993 to 2013,the accumulated temperature zone had an obvious eastward enlargement,climatic planting limits of rice and maize expanded eastward to the Dunhua-Jingyu-Linjiang line,and climatic planting limits of soybean expanded eastward to Changbai. The heat resource utilization efficiency of three crops in the sensitive area was lower than in the non-sensitive area,but the water resource utilization efficiency was higher than that in the non-sensitive area. Meanwhile,crop water and heat resource utilization efficiency in sensitive areas had a significant increasing trend and the average annual growth rate was higher than in the non-sensitive area. The water and heat resources yield efficiency of rice and maize in the sensitive area was higher than in the non-sensitive area,but the yield efficiency of soybean in the sensitive area was lower than that in the non-sensitive area. The conclusions were that climate warming had a positive effect on water and heat resource efficiency in the study area. The study area could appropriately expand the planting area of maize and rice to the east,and the irrigation system and technology should be strengthened to reduce water resource constraints on rice. Local residents should avoid blindly planting grain and soybean in the most eastern region in order to reduce the risk of heat resource constraints.
Aerosols can absorb and scatter solar radiation and cause the total solar radiation reaching the surface to drop and the fraction of diffuse radiation to increase, influencing the surface radiation budget. Here, MODIS Aerosol Optical Depth (AOD) was compared with AERONET AOD observations for 2007 and good agreement was found, except when AOD is larger than 0.7 the uncertainty of MODIS AOD increases. Then global surface radiation with and without consideration of aerosols was calculated by the Fu-Liou atmospheric radiative transfer model based on MODIS aerosol products, CERES cloud products and other remote sensing data. The model calculated surface solar radiation with consideration of aerosols was compared to observations made at Baseline Surface Radiation Network (BSRN) sites. Good correlations exist between the calculated and measured total radiation with an R of 0.92, and between the calculated and measured diffuse radiation with an R of 0.84. The aerosol direct radiative effect was calculated based on the two scenarios of aerosols. Our calculations showed that in 2007, aerosols decreased global total radiation by 9.16 W/m2 on average. Large decreases generally occurred in places with high AOD. For diffuse radiation, aerosol-induced changes were either positive or negative. Large increases generally occurred in places with high surface albedo, while large decreases generally occurred in places with high cloud fraction. The global aerosol-induced diffuse radiation change averaged 8.17 W/m2 in 2007. Aerosol direct radiative effects cause photosynthetic active radiation to increase, which may influence the global carbon cycle of terrestrial ecosystems and result in an increase in the carbon sink function of terrestrial ecosystems.
Urban road green space is an important component of urban green space. With the rapid development of traffic,urban road green space is receiving increasing attention due to its ecological function. However,studies into the ecological costs of urban road green space such as resource consumption and environmental pollution are rare. Here,we established urban road green space ecosystem service values,ecological costs and net ecosystem service values evaluation models using prior work on ecosystem service value. We used urban road afforestation engineering in Yongjia county as a case study to evaluate ecosystem service values and ecological costs of urban road green space under different management modes. The results showed that the ecological costs of urban road green space in Yongjia County declined in the eco-management mode,so net ecosystem service values of urban road green space were nearly 50% higher than those under the general management mode. Under the general agricultural management mode,urban road green space in Yongjia provides product value and net ecosystem service values were 16.6% higher than in the general management mode. The rate of ecosystem service value of urban road green space in Yongjia under an eco-agricultural management mode were more than 4.5 times that in the general management mode. In the general management mode,ecological costs of urban road green space were enormous,among those costs,environment pollution caused by chemical fertilizer accounted for more than 60%. We suggest that urban green space should be managed using an eco-agricultural management mode so that people can maximize its ecological benefit.
The spatial flow of ecosystem services has a great impact on human well-being on-site and off-site,especially in watersheds. Taking the Weigan River basin as an example,an assessment model of ecosystem service overflow was built according to the Theory of Field Strength and Breaking Point model. The ecosystem service overflow from upstream to downstream was calculated from 2000 to 2010. The system of indicators for human well-being was established by considering natural,social and economic conditions as well as data availability for the basin. Granger Causality Test and the Grey Correlation models are introduced to analyze how ecosystem service overflow impacts people. We found that there is a spatial overflow effect of watershed ecosystem services. On the spatial dimension,intensity of ecosystem service overflow from upstream to downstream is inversely proportional to distance. The values of ecosystem service overflow decrease first and then increase. The indicator system of human well-being constituted with three level indicators including basic requirements,safety and health and spiritual needs whose importance can be ranked as safety and health > basic demands > spiritual. The spatial differentiation features of human well-being show that Kuqa is the highest level,Baicheng the second,Shaya the third and Xinhe the lowest. Ecosystem service overflow is the Granger reason of human well-being,which has a great influence on basin human well-being. Ecosystem service overflow has an enormous impact on safety and health in the indicator system. Ecosystem service overflow of forest has the highest coupling degree with human well-being. The coupling degree between the desert and human well-being is the lowest. Effective ways that enhance human well-being of watersheds are to integrate natural resource accounting into the national economic accounting system,compensate for farmland protection and carry out payments for watershed ecological services between upstream and downstream.
Vegetation Net Primary Productivity(NPP)is an important parameter when evaluating terrestrial ecosystems and provides a significant reference for research into global carbon cycles. Based on MODIS data and meteorological station data from 2000 to 2014,we used multi-stepwise regression,principal components regression,partial least-squares regression and ridge regression and estimated vegetation NPP and temporal-spatial distribution patterns in the arid region of Northwest China. We found that the multi-stepwise regression model was superior and the model simulation results were coordinated with measured values in the spatial distribution. A multi-stepwise regression model can be used to retrieve NPP in arid and semi-arid areas and reflects vegetation growth and distribution in the study area. There were obvious regional differences in NPP distribution in the arid region of Northwest China; vegetation NPP in the mountains was increased and decreased in the plains. High values were found in the north,northwest and southeast of the arid region and low values in the south and southeast. At an annual scale,NPP in Northwest China slightly increased from 2000 to 2014 at a rate of 0.40 gC/(m2·a). Trends in annual vege-tation NPP are different among areas,vegetation NPP in 58.66% areas increased,13.64% of areas remained relatively stable,and 27.7% of areas slightly decreased from 2000.
In order to realize the effective organization and optimization of low-level features for high resolution remote sensing images,and make feature descriptors more discriminative,we focused on mid-level feature learning based on sparse coding and support vector machine (SVM)classification,and propose a land use / land cover (LULC)classification method based on soft probability cascading and mid-level feature learning model. First,the gray level co-occurrence matrix (GLCM),Dense Scale-Invariant Feature Transform (DSIFT)and spectral feature descriptors are extracted as low-level feature descriptors. Second,sparse coding is adopted to obtain the sparse coefficients of GLCM,DSIFT and spectral features,and then max-pooling methods are used for learning mid-level feature descriptors. Combined with SVM classification with training samples of LULC class types the soft probabilities of different LULC class types are calculated. Three different kinds of soft probabilities belong to each LULC class type,which takes GLCM,DSIFT and spectral features as low-level feature descriptors respectively,and are cascaded for the construction of final feature descriptors. The cascaded feature descriptors are more discriminative than unsupervised mid-level feature descriptors,because it is learned by a supervised way. This method incorporates different low-level feature descriptors effectively. Finally,using the cascaded feature descriptors,the LULC classification map is achieved by the SVM classifier in a supervised way. Taking rural residents in the district area of Wuhan City as an experimental area,our proposed method was verified by aerial high resolution remote sensing images. Experimental results show that the overall accuracy is 88%. Compared with the extraction of a single low-level feature classification method,the algorithm in this paper can effectively improve LULC classification accuracy.
A complicated international environment,arduous domestic reform,development tasks and pressure to stabilize growth during the 13th Five Year Plan,China’s marine economy needs to resist disturbances and maintain stability and development. Based on marine system economic stability,an evaluation index system was established at two levels：immunity and resilience. The stability index of the marine economic system in 11 provinces along the east coast (excluding Hong Kong,Macao and Taiwan)calculated by means of comprehensive evaluation modeling. We found that the stability index of China’s marine economic system between 2011 and 2013 changed slightly,while variation around 2003 and 2009 was obvious. Local differences in China’s marine economic systematic stability is significant. Systematic stability in Guangdong and Shandong is stable while those in Hainan and Guangxi are the least stable. The system in Shanghai and Zhejiang has higher stability; that in Liaoning and Hebei shows lower stability. Systematic stability in Tianjin,Fujian and Jiangsu is moderate. There is a close positive correlation between the stability of China’s marine economic system and marine developing levels. An obstacle degree model was introduced to analyze obstruction factors affecting the stability of China’s marine economic system quantitatively. Pertinent directions for marine economic development are discussed.
Taking biological resource conservation of the Wuyi Mountains as an example,we analyzed public protection preferences for biological resource protection from the angle of public participation. We first applied choice experiment methods to look at biological resource conservation in China and draw two main conclusions. First,the ratio of public participation in biological resource protection in the Wuyi Mountains was about 60%,which was a good signal for protection in this area in terms of public participation. Second,the research calculated marginal WTP for the attributes of biological resources,thus public protection priority was followed by protecting Chinese-specific biological resources,then protecting biological resources with immature breeding technology,then protecting vulnerable biological resources,then protecting endangered biological resources,then protecting biological resources with immature but unpopular applied breeding technology,and then protecting near threatened biological resources. According to these findings,there are two policy implications. First,government and relevant protection organizations should take advantage of the power of the public and guide the public to participate more actively in the protection as an important supplement for biological resource conservation in the Wuyi Mountains. Second,the protection priority of government and protection organizations indicated by their protection policy is partially different from the protection priority of the public according to their protection preference of biological resources. It is of great significance for the government and protection organizations to pay attention to such differences and take measures to encourage the public to participate in biological resource conservation.
