Spatial-temporal changes and driving factors of eco-environmental quality in the Three-North region of China

Eco-environmental quality is a measure of the suitability of the ecological environment for human survival and socioeconomic development.Understanding the spatial-temporal distribution and variation trend of eco-environmental quality is essential for environmental protection and ecological balance.The remote sensing ecological index(RSEI)can quickly and objectively quantify eco-environmental quality and has been extensively utilized in regional ecological environment assessment.In this paper,Moderate Resolution Imaging Spectroradiometer(MODIS)images during the growing period(July-September)from 2000 to 2020 were obtained from the Google Earth Engine(GEE)platform to calculate the RSEI in the three northern regions of China(the Three-North region).The Theil-Sen median trend method combined with the Mann-Kendall test was used to analyze the spatial-temporal variation trend of eco-environmental quality,and the Hurst exponent and the Theil-Sen median trend were superimposed to predict the future evolution trend of eco-environmental quality.In addition,ten variables from two categories of natural and anthropogenic factors were analyzed to determine the drivers of the spatial differentiation of eco-environmental quality by the geographical detector.The results showed that from 2000 to 2020,the RSEI in the Three-North region exhibited obvious regional characteristics:the RSEI values in Northwest China were generally between 0.2 and 0.4;the RSEI values in North China gradually increased from north to south,ranging from 0.2 to 0.8;and the RSEI values in Northeast China were mostly above 0.6.The average RSEI value in the Three-North region increased at an average growth rate of 0.0016/a,showing the spatial distribution characteristics of overall improvement and local degradation in eco-environmental quality,of which the areas with improved,basically stable and degraded eco-environmental quality accounted for 65.39%,26.82%and 7.79%of the total study area,respectively.The Hurst exponent of the RSEI ranged from 0.20 to 0.76 and the future trend of eco-environmental quality was generally consistent with the trend over the past 21 years.However,the areas exhibiting an improvement trend in eco-environmental quality mainly had weak persistence,and there was a possibility of degradation in eco-environmental quality without strengthening ecological protection.Average relative humidity,accumulated precipitation and land use type were the dominant factors driving the spatial distribution of eco-environmental quality in the Three-North region,and two-factor interaction also had a greater influence on eco-environmental quality than single factors.The explanatory power of meteorological factors on the spatial distribution of eco-environmental quality was stronger than that of topographic factors.The effect of anthropogenic factors(such as population density and land use type)on eco-environmental quality gradually increased over time.This study can serve as a reference to protect the ecological environment in arid and semi-arid regions.

Land cover change and eco-environmental quality response of different geomorphic units on the Chinese Loess Plateau

Land cover in the Chinese Loess Plateau has undergone dramatic changes since the late 1980s.Revealing the trend in land cover change and eco-environmental quality response of different geomorphic units in this stage is a realistic requirement for promoting sustainable development of the Chinese Loess Plateau.Based on the data of geomorphic units and land cover in 1990,2000,2010 and 2018 of the Chinese Loess Plateau,we studied the trend of land cover change and eco-environmental quality response of different geomorphic units by using a significance index of land cover change,a proportion index of land cover change and an eco-environmental response model.The results indicated that from 1990 to 2018,the areas of forestland and construction land substantially increased,whereas those of cropland,grassland,wetland and unused land considerably decreased.Land cover change exhibited large geomorphic differences,and the main conversion of land cover was from cropland into other land types.Unstable trend of land cover change in the loess tablelands and sandy loess hills declined,whereas the unstable trends in the other geomorphic units enhanced.Eco-environmental quality varied among different geomorphic units.The expansion of construction land and degradation of forestland,grassland and wetland resulted in the deterioration of eco-environmental quality.The conversion of cropland and unused land into forestland and grassland,and the conversion of grassland into forestland were the main factors that drove the improvement of eco-environmental quality.The findings of this study may provide theoretical reference and support decision making for the optimization of land use structure and the improvement of eco-environmental quality on the Chinese Loess Plateau.

Assessing the impacts of ecological-living-productive land changes on eco-environmental quality in Xining City on Qinghai-Tibet Plateau, China

The Ecological-living-productive land(ELPL)classification system was proposed in an effort to steer China's land pattern to an ecological-centered path,with the development model shifting from a single function into more integrated multifunction land use.The focus is coordinating the man-land contradictions and developing an intensive,efficient and sustainable land use policy in an increasingly tense relationship between humans and nature.Driven by socioeconomic change and rapid population growth,many cities are undergoing urban sprawl,which involves the consumption of cropland and ecological land and threatens the ecological balance.This paper aims to quantitatively analyze the critical effects of ELPL changes on eco-environmental quality according to land use classification based on leading function of ecology,living and production from 1990 to 2015 with a case study of Xining City.Also,four future land use scenarios were simulated for 2030 using the Future Land Use Simulation(FLUS)model that couples human and natural effects.Our results show a decrease in productive land(PL)and an increase in ecological land(EL)and living land(LL)in Xining City.Forestry ecological land(FEL)covered the top largest proportion;agriculture productive land(APL)showed the greatest reduction and urban and rural living land(U-RLL)presented a dramatic increase.The eco-environmental quality improved in 1990-2010,mainly affected by the conversion of APL to FEL and GEL.However,the encroachment of U-RLL into APL,other ecological land(OEL)and FEL was the main contributor to the decline in eco-environmental quality in 2010-2015 as well as the primary reason for the increase area of lower-quality.The Harmonious Development(HD)-Scenario,characterized by a rational allocation of LL and PL and a better eco-environment,would have implications for planning and monitoring future management of ELPL,and may represent a valuable reference for local policy-makers.

Spatiotemporal changes of eco-environmental quality based on remote sensing-based ecological index in the Hotan Oasis,Xinjiang

The rapid economic development that the Hotan Oasis in Xinjiang Uygur Autonomous Region,China has undergone in recent years may face some challenges in its ecological environment.Therefore,an analysis of the spatiotemporal changes in ecological environment of the Hotan Oasis is important for its sustainable development.First,we constructed an improved remote sensing-based ecological index(RSEI)in 1990,1995,2000,2005,2010,2015 and 2020 on the Google Earth Engine(GEE)platform and implemented change detection for their spatial distribution.Second,we performed a spatial autocorrelation analysis on RSEI distribution map and used land-use and land-cover change(LUCC)data to analyze the reasons of RSEI changes.Finally,we investigated the applicability of improved RSEI to arid area.The results showed that mean of RSEI rose from 0.41 to 0.50,showing a slight upward trend.During the 30-a period,2.66% of the regions improved significantly,10.74% improved moderately and 32.21% improved slightly,respectively.The global Moran's I were 0.891,0.889,0.847 and 0.777 for 1990,2000,2010 and 2020,respectively,and the local indicators of spatial autocorrelation(LISA)distribution map showed that the high-high cluster was mainly distributed in the central part of the Hotan Oasis,and the low-low cluster was mainly distributed in the outer edge of the oasis.RSEI at the periphery of the oasis changes from low to high with time,with the fragmentation of RSEI distribution within the oasis increasing.Its distribution and changes are predominantly driven by anthropologic factors,including the expansion of artificial oasis into the desert,the replacement of desert ecosystems by farmland ecosystems,and the increase in the distribution of impervious surfaces.The improved RSEI can reflect the eco-environmental quality effectively of the oasis in arid area with relatively high applicability.The high efficiency exhibited with this approach makes it convenient for rapid,high frequency and macroscopic monitoring of eco-environmental quality in study area.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

Eco-environmental susceptibility in Shangyi County,Northern Hebei Province,China

In this paper,the eco-environmental susceptibility of Shangyi County,Northern HebeiProvince of China has been calculated by using the weighted-addition method based on expert’s giv-ing a mark to each influencing factor according to their knowledge on the influence of all the factorson eco-environmental susceptibility.The eco-environmental classification and distribution map werereached based on the above results,its difference is mainly result from the physical conditions andhuman activity,however the value of eco-environmental susceptibility is only a relative index whichcan not completely reflect the quality of eco-environment.This work provided a basis for control-ling the further development of desertification.

Analysis and assessment of Chinese eco-environmental situation

In order to give out the correct conclusion for evaluating Chinese eco-environmental situation, in this paper, a special assessmental procedure has been used to analyse following 7 basic environmental problems: (1) Natural hazards; (2) Soil erosion; (3) Forest shrinkage and grassland degradation; (4) Water resources shortage; (5) Desertification; (6) Environmental pollution; (7) Farmland decrease. The basic strategies for improving Chinese environmental situation have been suggested.

Research on market-based policy instruments for eco-environmental protection

The selection of policy instruments involves policy efficiency and policy effect.Effective settlement of eco-environment problems in the process of industrialization and implementation of active eco-environment protection depend on the innovation of policy instruments.In this paper,based on a descriptive analysis of the policy instruments for ecoenvironmental protection of our country,combined with the theoretical analysis and the empirical research on current marketization of eco-environmental protection,the authors indicate that eco-environmental problems originate fi'om the damage of eco-environment and the extemalities of eco-service,and that the market-based policy instruments which are helpful to balance the relationship between fight,responsibility and interest in the eco-service are effective measures to eliminate externalities and protect eco-environment.

Universal Index Formula of Parameterized Combination Operator for Eco-environmental Quality Evaluation

[Objective] The aim was to evaluate the regional eco-environmental quality by using the universal index formula of parameterization combination operator based normalized index values.[Method] Through setting reference values and normalized transformation formulae for typical ecological environmental indexes appropriately,the difference among the standard normalized values would become very small after normalized transformation,and the ecological environmental indices expressed by normalized values can be equivalent to normalized indices.Under certain optimization conditions,shuffled frog leaping based on immune evolutionary particle swarm optimization algorithm was applied to optimize the parameters in parameterization combination operator formula,and the universal index formula suited to eco-environmental quality assessment was established finally.[Result] The universal index formula of parameterization combination operator,appropriate for any m(1≤m≤23) ecological environmental indices,was used to assess the eco-environmental quality of towns surrounding Headland Reservoir,and the results were in full accordance with those of unascertained measure method,that is,the eco-environmental quality of five towns around Headland Reservoir was the fourth grade.[Conclusion]The universal index formula of parameterization combination operator,suited to eco-environmental quality evaluation,is simple and intuitive in form,easy in computation and universal in application.

Grey Clustering Evaluation on Regional Eco-environmental Quality Based on Normalized Index Value

[Objective] The aim was to assess regional eco-environmental quality by means of grey clustering method based on normalized index value. [Method] Eco-environmental quality in Chaohu basin was assessed by using grey clustering method based on normalized index value, and the evaluation results were compared with those of unascertained measure method to verify the feasibility of grey clustering method used to evaluate regional eco-environmental quality. [Result] In the grey clustering assessment method based on normalized index value, indices whose standard normalized values in the same grade were close to each other were classified into one class and had the same whitening function, which reduced the number of whitening functions. Grey clustering method based on normalized index value was used to assess eco-environmental quality in Chaohu basin, and the evaluation results were basically in accordance with those of unascertained measure method, namely eco-environmental quality in Hefei, Chaohu and Lu'an belonged to the third (pass), fourth (worse) and fifth grade (bad), except for one grade difference in overall basin, and the results showed that the method had practicality and could be applied to assess regional eco-environmental quality. [Conclusion] The study could provide theoretical foundation for the establishment of comprehensive management countermeasures of regional ecological environment.

Quantitative evaluation and spatial differentiation of eco-environmental livability in Zhejiang Province, China

The scientific analyses of the spatial patterns of regional eco-environment livability,along with the explorations of the correlations between ecoenvironments and population and economic activity distributions,are of major significance in the guidance of the coordinated development between social economies,natural resources,and environments.In this study,the topography,climate,hydrology,land cover,air quality,and the dangers presented by natural hazards in the study area were investigated in order to establish an evaluation model for the regional eco-environmental livability.Then,the observed spatial patterns and regional differences in the eco-environmental livability,as well as their relationships with the distributions of population and economic activities in Zhejiang Province,were investigated.The results showed that the ecoenvironmental livability in Zhejiang Province displayed a gradual decreasing trend from southwest to northeast,as well as from the mountains to the hills,valleys,and plains areas.During the compartmentalization of the eco-environmental livability,it was observed that the lowest livable area covered the largest population,accounting for approximately 29.64%of the total population in the study area.The higher livable areas covered the widest land areas,accounting for approximately 26.15%of the total area.Moreover,it was found that the eco-environmental livability in the mountain areas was higher than that in the plain areas in Zhejiang Province.Furthermore,the ecoenvironmental livability was found to have a significant exponential relationship with the population and GDP densities of Zhejiang Province,with the R^2 of the curve-fittings reaching 0.835 and 0.656,respectively.However,it was determined that the coefficient of the exponential function was negative,which indicated that a strong negative relationship existed between the eco-environmental livability and densities of the population and economic activities.It was assumed that the impacts of anthropogenic factors were the fundamental causes of this negative correlation.This study introduced two new factors(air quality and natural hazards)into the evaluation framework of eco-environmental livability.As a result,a more comprehensive model was established for the evaluation of eco-environmenta livability in certain segments of the study area Additionally,the correlation between ecoenvironment livability and human activities was discussed in-depth,which can potentially provide theoretical and practical guidance for the implementation of eco-livability in China,and possibly even those of other vast developing countries.

The Evaluation of Eco-environmental Sensitivity in Ordos City

This paper aims to reveal the difference of eco-environmental sensitivity and its influencing factors in the study area through carrying out the eco-environmental sensitivity evaluation based on land ecological security for 8 counties of Ordos City. Using fragstats landscape pattern analysis,GIS space method and RS analysis,based on ground investigation,this paper uses information mining and data analysis to extract index data for every village in the study area,carry out comprehensive quantitative evaluation,and finally calculate the comprehensive scores of eco-environmental sensitivity of the areas. The paper concludes that the highly sensitive areas and extremely sensitive areas are mainly concentrated in the eastern region of the eastern hilly and gully region and southern region of the Mu Us Desert in Ordos. The main reasons include severe soil erosion in hilly and gully region and serious desertification in southern Mu Us Desert area. So it is necessary to strengthen ecological environment protection in local areas.

Initial Exploration on Eco-environmental Issues in Tibet “One River and Two Streams” Agricultural Basin during New Period

Agricultural economic development of Tibet Autonomous Region mainly concentrates in the "One River and Two Streams" agricultural production basin. The basin is main concentrated place for agricultural resources development,economic construction and population aggregation,and the region playing the advantages of Tibetan agriculture,corresponding with the practice,and enhancing self development and innovation. In the multi-year development and construction,it develops regional large agriculture,builds irrigation and water conservancy facilities,vigorously changes medium and low-yield land,actively develops animal husbandry and agriculture,and gradually promotes the effective combination of traffic industry and transportation industry,which has made considerable achievements. But in the face of today's increasingly advocated theme of "building beautiful Tibet and constructing ecological home",the construction of environmental problems lacking the systemic research is the prominent and fundamental problem in the "One River and Two Streams" agricultural production basin. Meanwhile,environment construction is an important part of economic development planning,and the solving of environmental protection problem is the historical mission in the contemporary and future generations. Therefore,it is very necessary to study the environment problems in Tibet "One River and Two Streams" agricultural production basin. The "One River and Two Streams" agricultural production basin is preliminarily explored for providing reference for the relevant environmental departments.

Progress and major themes of research on urban shrinkage and its eco-environmental impacts

Urban shrinkage is the process of population loss,industrial and functional decline,and eco-environmental deterioration due to various natural and human factors that occur once a city’s development reaches a certain point.It is an external manifestation of positive or negative changes in an urban economy,society,culture,resource use,and sustainability.Urban shrinkage is a new feature of global urbanization as well as a frontier of international and Chinese research.It has attracted widespread attention from academics in China and overseas,becoming an emerging trend that has spread from developed countries to underdeveloped ones.Research on and responses to urban shrinkage have also become new tasks of China’s new urbanization strategy.Our review of the existing literature reveals that there are significant temporal and spatial differences in research by Chinese and overseas scholars on urban shrinkage.Urban shrinkage studies have paid scant attention to interactions with the eco-environment,with analyses of urban shrinkage mechanisms and factors largely focusing on economic and social development factors;and urban shrinkage index analyses have tended not to include eco-environmental quality and environmental pollution indicators.The key tasks for future urban shrinkage research include the following:to conduct in-depth research on the mechanisms and driving factors of urban shrinkage to reveal the essence of urban shrinkage;to discover the principles behind interactions between urban shrinkage and the eco-environment,as well as to analyze the eco-environmental effects of urban shrinkage;to construct an index system for evaluating the extent,monitoring and providing warnings of,and containing urban shrinkage;and to research urban shrinkage coping strategies under different circumstances and carry out experiments and demonstrations according to local conditions.

Dynamics of the eco-environmental quality in response to land use changes in rapidly urbanizing areas: A case study of Wuhan, China from 2000 to 2018

The dramatic land use changes that occur in rapidly urbanized areas are important inducement to changes in the eco-environmental quality.Investigating urban land use changes and their eco-environmental quality responses can provide theoretical support and a decision-making basis for sustainable and high-quality development in rapidly urbanizing areas.Taking Wuhan,China,as the study area,this paper extracts land use information using Landsat satellite remote sensing images and a support vector machine classification.Based on this,a remote sensing-based ecological index evaluation model including humidity,greenness,dryness and heat is constructed to explore the changes in land use and their eco-environmental quality responses from 2000 to 2018.The results show that(1)the structure,extent and spatial layout of land use in Wuhan from 2000 to 2018 have undergone tremendous changes under rapid urbanization,and the change of construction land is the greatest among all land use types;(2)the overall quality of eco-environment in Wuhan continues to improve as the scale of the improved eco-environment areas is greater than that of the deteriorated areas.The direction and magnitude of the impact of each indicator on the eco-environmental quality are different;(3)the improvement or deterioration of eco-environmental quality is closely related to the changes of different land use types within the study area.The eco-environmental quality shows significant spatial heterogeneity,especially between the main urban areas and the suburban areas.This paper argues that reasonably adjusting the land use structure can serve to maintain or even improve the quality of the regional eco-environment.Finally,this study puts forward suggestions for the coordinated development of land use and the eco-environment in rapidly urbanizing areas.

Estimation methods of eco-environmental water requirements: Case study

Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the cor-responding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2010, 2030, 2050) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluc-tuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×1010m3 to 1.02×1011m3, the suitable water requirement ranges from 6.45×1010m3 to 1.78×1011m3, the water shortage ranges from 9.1×109m3 to 2.16×1010m3 under the minimum water requirement, and it is from 3.07×1010m3 to 7.53×1010m3 under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water re-quirements in the three coming years (2010, 2030, 2050) are 4.49×1010m3?1.73×1011m3, 5.99×10m3?2.09×1011m3, and 7.44×1010m3?2.52×1011m3, respectively.

Eco-environmental water demands for the Baiyangdian Wetland

In recent years,the hydrological characters of Baiyangdian Wetland have changed greatly,which,in turn,influence the biotic component,the structure and function of the wetland ecosystem.In order to determine the demands for water resources of ecological wetland system,a method of ecological water level coefficient was suggested to calculate the water resources demands for wetland environment use.This research showed that the minimum coefficient is 0.94 and the optimal coefficient is more than 1.10.According to these two coefficients,the ecological water level and water quantity can be estimated.The results indicate that the amount of the minimal and optimal eco-environmental water require-ments are 0.87×10^(8) and 2.78×10^(8)m^(3) in average monthly,respectively,with the maximum eco-environmental water requirement in summer and the minimum in winter.The annual change of eco-environment water demand is in accord-ing with the climate change and hydrological characters.The method of ecological water level emphasizes that wetland ecosystem adapts to the hydrological conditions,so it can be used in practice well.

The Non-Linear Effect of China’s Energy Consumption on Eco-Environment Pollution

With the increase of total energy consumption,eco-environmental quality drops sharply,which has attracted concerns from all circles.It has become the top priority of construction of socialist ecological civilization to clarify the influences of energy consumption on the level of eco-environmental pollution.Ecological environmental pollution control cannot be one size fits all.It can avoid resource depletion and environmental deterioration via adjusting measures to local conditions to coordinate ecological environmental pollution and energy consumption problems.In this essay,entropy method is adopted to measure the composite indexes of eco-environmental pollution of 30 provinces and cities in China,based on which kernel density function is used to analyze the dynamic law of eco-environmental pollution.And then,traditional fixed effect model and panel quantile regression model are adopted respectively to analyze the influences of energy consumption on eco-environmental pollution.The research finds that composite index of eco-environmental pollution shows N-shaped curve of“rising-dropping-rising”during the sample period,with the overall difference decreasing gradually and the polarization disappearing gradually;in areas with higher eco-environmental pollution,energy consumption has aggravated ecoenvironmental pollution,while in areas with lower eco-environmental pollution,energy consumption could alleviate eco-environmental pollution to some degree;foreign direct investment could relieve eco-environmental pollution.Therefore,corresponding measures should be taken to improve the quality of eco-environment based on the changes of energy consumption in areas with different levels of eco-environmental pollution.

Quantitative Analysis of the Coupling Coordination Degree Between Urbanization and Eco-environment in Mongolia

Mongolia is an important country in the Economic Corridor of China-Mongolia-Russia, a deep understanding of the coupling relationship between urbanization and the eco-environment in Mongolia is meaningful to achieve green development of the Belt and Road. The entropy method and coupling coordination degree model were integrated to evaluate the coupling coordination degree between urbanization and the eco-environment in Mongolia during 2000-2016. The results showed that the coupling coordination degree between urbanization and the eco-environment in Mongolia was generally at the stage of seriously unbalanced development, and that the main contributor of the urbanization and the eco-environment subsystem were demographic urbanization and eco-environment endowment, respectively. The southern part of Mongolia central zone should be paid more attention due to the lower degree of coupling coordination between urbanization and the eco-environment. To promote the healthy urbanization development in Mongolia, six-layer eco-city establishing green development pattern is proposed to provide scientific support for Mongolia.

Impact of coal resource development on eco-environment and its restoration in west of China

West China has rich mineral resources, especially in coal resources with very good mining conditions. Coal resource development is the one of important tasks in the Chinese “West Development”. Thus, the impact of coal resources development on eco-environment and its restoration is worth studying. This study shows that there are many environmental problems such as land damage, coal wastes, damage of hydro-geological condition and pollution of water resource, airborne effluents (industrial exhausts and methane emission from underground), dust, waste, water. Land damage and land desertification are the most important environmental issue in west China. Therefore, the stress of environmental restoration should be desert presentation and disturbed-land reclamation. To control environmental damages and rehabilitate the eco-environment, environmental restoration techniques are also discussed.