Optimization Of Land Use Structure Research Articles

Study on Optimization of Land Use Structure in Fujian Province Based on Low-Carbon Perspective

Carbon peaking and carbon neutrality strategies are pivotal in addressing climate change. Optimizing land use structure is a fundamental approach to achieving low-carbon development within a given territory. This study focuses on Fujian Province as the research subject, predicting carbon emissions for the next decade by analyzing the correlation between land use types and carbon emissions using the gray model. This analysis is based on land use panel data spanning from 2007 to 2021. The study applies the FLUS-Markov model to simulate Fujian’s land use in 2030. A multi-objective optimization model is developed from a low-carbon perspective, integrating carbon emissions, economic, and ecological factors. The study explores land use under three scenarios: natural development scenario (NS), low carbon scenario (LCS), and comprehensive scenario (CS). Findings highlight the relationship between land use-related carbon emissions, urbanization, and relevant policies in Fujian. The FLUS-Markov simulations suggest that under the NS scenario, carbon emissions in 2030 will reach 77.829 million tons, an increase of 11.013 million tons from 2020. In contrast, the LCS demonstrates that optimizing land use structures can effectively balance carbon reduction, economic growth, and ecological preservation. Under the CS, 2030 emissions could be reduced by 7.2854 million tons while maintaining economic and ecological benefits. Despite variations in construction land expansion across these scenarios, all follow a “one belt, one core” development pattern. The study concludes with policy recommendations, including industrial layout optimization and clean energy promotion. These findings support the alignment of land use optimization with Fujian’s future development needs, offering guidance for land-use planning and policies focused on low-carbon objectives.

Quantifying the contributions of precipitation, topography and human activity and their coupling to the development of permanent gully

Gully erosion poses greater threat to ecological and food security globally. The gully development rate and the contributions of primary influencing factors have not been thoroughly understood, primarily due to the complicated environmental conditions characterized by climate, soil, topography, and human activities. Therefore, this study was conducted to explore the gully development and contributions of its driving factors from 2013 to 2021 based on historical Google Earth images and field investigation in a typical rolling hilly watershed of northeast China. The climatic factors reflected by precipitation, topographical factors related to gully, and anthropological factors reflected by tillage ridge orientation and linear anthropological factors (LAF) including roads and shelterbelts were obtained. The tillage effect index (TEI), LAF effect index (LEI) and the distance from gully to LAF (DL) were calculated to analyze the influence of anthropological factors on gully development. The results showed that the linear, areal and volumetric gully development rates (RL, RA and RV) showed great variabilities in different periods with the average of 5.69 m year−1, 137.37 m2 year−1 and 428.54 m3 year−1, respectively. The accumulated RL, RA and RV increased exponentially or linearly with accumulated precipitation amount (P), erosive rainfall duration (RD), erosive rainfall (ER), maximum 30-min rainfall intensity (I30) and rainfall erosivity (RE) increased (P < 0.001). The slope of the gully head (HS) was identified as the primary topographic factor influencing RL. Both RA and RV showed positive power relationships with the drainage area of the gully (CA) and the upstream gully head (HA). The human activity reflected by tillage ridge orientation, unpaved road and shelterbelts had different effects on RL and RA. The increased orientation angle between gully and tillage ridge (ROA) mitigated headcut retreat for normal precipitation year but it would aggravate headcut retreat in the periods of continuous heavy rainfall. Gully bank with the ROA of 30−90° was more prone to areal development. The TEI, LEI and DL had significantly positive linear, power or exponential relations with gully development rates. The PLSR and VPA analysis indicated that topography, the interaction between topography and human activity, and the coupled effects of precipitation, topography and human activity were the main contributor of RL, RA and RV, respectively, and accounted for 34 %, 50 %, and 40 % of total variability of RL, RA and RA, respectively. This study can provide guidance for the control of gully erosion and the optimization of land use structure in the gully catchment.

Optimization of Land Use Structure Based on the Coupling of GMOP and PLUS Models: A Case Study of Lvliang City, China

Optimization of Land Use Structure Based on the Coupling of GMOP and PLUS Models: A Case Study of Lvliang City, China

The Impact of Future Land Use Change on Carbon Emission and Its Optimization Strategy

Rapidly changing climate issues and increasingly severe carbon emissions are great challenges to the carbon peaking and carbon neutrality strategy. Analyzing the impact of future land use changes on carbon emissions can provide an important basis and reference for scientifically constructing a low-carbon and sustainable territorial spatial planning, as well as realizing the goal of the dual-carbon strategy. Based on land use data, agricultural production activity data, and energy consumption statistics, this study simulated the land use changes of the Yangtze River Delta region (YRDR) from 2030 to 2060 under the natural development (ND) scenario and sustainable development (SD) scenario by using the Patch-generating Land Use Simulation (PLUS) model and analyzed the impacts of future land use changes on carbon emissions. The results showed that: (1) The land use simulation results obtained by using the PLUS model under the sustainable development scenario were highly consistent with the actual land use with an OA value of 97.0%, a Kappa coefficient of 0.952, and a FoM coefficient of 0.403; (2) Based on the simulated land use under the SD scenario from 2030 to 2060, the quantity of construction land was effectively controlled, and the spatial distributions of cropland and forests were found to dominate in the north and south of the Yangtze River, respectively; (3) Anhui Province was the major contributor (accounted for 49.5%) to the net carbon absorption by cropland while Zhejiang Province was the major contributor (accounted for 63.3%) to the net carbon absorption by forest in the YRDR during the period 2020–2060 under the SD scenario; (4) Carbon emissions from construction land were the main source of carbon emissions from land use in the YRDR during the period 2020–2060 with proportions higher than 99% under both the ND and SD development scenarios. These findings underscore the urgent need for the government to take measures to balance the relationships between cropland and ecological protection and economic development, which provides a reference for the optimization of land use structure and policy formulation in the future.

Optimization of land use structure based on an improved multi-objective genetic algorithm: a case study in a large-scale opencast coal mine area, China

Optimization of land use structure based on an improved multi-objective genetic algorithm: a case study in a large-scale opencast coal mine area, China

Impact of Land Use Change on Carbon Storage in Urban Agglomerations in the Guanzhong Plain

It is important to study the impact of land use change on terrestrial ecosystem carbon stocks in urban agglomerations for the optimization of land use structure and sustainable development in urban agglomerations. Based on the patch-generating land use simulation (PLUS) model and integrated valuation of ecosystem services and trade-offs (InVEST) model, a simulation was developed that predicted the land use change and carbon stock of the Guanzhong Plain urban agglomeration in 2040 under different scenarios and further analyzed the impact of land use change on carbon stock. The results showed that:① The land use types of the Guanzhong Plain urban agglomeration were mainly cultivated land, forest land, and grassland, which accounted for more than 90 % of the total study area. ② From 2000 to 2020, the carbon stock in the Guanzhong Plain showed a continuous downward trend, with cropland, woodland, and grassland being the main sources of carbon stock in the Guanzhong Plain, and the overall carbon stock declined by 15.12×106 t, with the spatial distribution presenting the distribution characteristics of "high in the north and south and low in the middle." ③ By 2040, the carbon stock would decrease the most under the urban development scenario, with a total reduction of 27.08×106 t, and the least under the ecological development scenario, with a total reduction of 4.14×106t. The research results can provide data support for the high-quality development and rational land use planning of the Guanzhong Plain urban agglomeration.

Effects of Land Use/Cover Change on Terrestrial Carbon Stocks in the Yellow River Basin of China from 2000 to 2030

Accurately assessing and predicting the impacts of land use changes on ecosystem carbon stocks in the Yellow River Basin (YRB) and exploring the optimization of land use structure to increase ecosystem carbon stocks are of great practical significance for China to achieve the goal of “double carbon”. In this study, we used multi-year remote sensing data, meteorological data and statistical data to measure the ecosystem carbon stock in the YRB from 2000 to 2020 based on the InVEST model, and then simulated and measured the ecosystem carbon stock under four different land use scenarios coupled with the FLUS model in 2030. The results show that, from 2000 to 2020, urban expansion in the YRB continued, but woodland and grassland grew more slowly. Carbon stock showed an increasing trend during the first 20 years, with an overall increase of 7.2 megatons, or 0.23%. Simulating the four land use scenarios in 2030, carbon stock will decrease the most under the cropland protection scenario, with a decrease of 17.7 megatons compared with 2020. However, carbon stock increases the most under the ecological protection scenario, with a maximum increase of 9.1 megatons. Furthermore, distinct trends in carbon storage were observed across different regions, with significant increases in the upstream under the natural development scenario, in the midstream under the ecological protection scenario and in the downstream under the cropland protection scenario. We suggest that the upstream should maintain the existing development mode, with ecological protection prioritized in the middle reaches and farmland protection prioritized in the lower reaches. This study provides a scientific basis for the carbon balance, land use structure adjustment and land management decision-making in the YRB.

Vulnerability assessment of Ukrainian forests as the basis of nature-based solutions for mitigation and adaptation to climate change

A wide range of climatic conditions in Ukraine causes significant regional differences in the vulnerability of forests to the current rapid climate change. The mitigation/adaptation strategy should be based on assessments of their vulnerability at the regional level.&#x0D; Phytoindication model by Prof. Y.P. Didukh was used to assess forest vulnerability. The model provides a quantitative estimation of climate as one of the major environmental factors affecting the distribution, condition and productivity of vegetation on the base of climate-related indicators – continentality, humidity and frost. For these indicators climate suitability scales were calculated. The modeling was carried out for the main forest species: Pinus sylvestris L., Quercus robur L., Fagus sylvatica L., Picea abies (L.) H. Karst, Betula pendula Roth., Alnus glutinosa (L.) Gaertn. and Robinia pseudoacacia L. Climate projections based on the Euro CORDEX time series (up to 2100) and 2 scenarios of the Representative Concentration Pathways (RCP 4.5, RCP 8.5) were used. Using Q-GIS, the maps containing zones of suitability to climate for each of the studied species were created for current climate conditions and future time series.&#x0D; The directions for strengthening the mitigation and adaptive capacity of forests are considered. The mainstream for nature-based solutions is adaptive sustainable forest management, which provides: 1) optimization of land use structure and increasing the forested area; 2) development and implementation of a national forestry program considering the priorities of climate change and low-carbon development; 3) using wood to substitute greenhouse gas intensive-materials and fossil fuels; 4) the best forestry practices through the introduction of modern Climate-Smart Forestry principles.

Land urbanization and urban CO2 emissions: Empirical evidence from Chinese prefecture-level cities

Changes in land use and the resulting human practices in the land urbanization process would lead to variations in the function, intensity, and efficiency of CO2 emissions and greatly influence urban CO2 emissions. Therefore, using Chinese prefecture-level data for a time period ranging from 2003 to 2017, we systematically examine the mechanism of how land urbanization influences CO2 emissions based on land-use intensity regulation, land-use structure optimization, and land-use efficiency improvements. First, the benchmark results show that land urbanization's influence on urban CO2 emissions is significantly positive. This indicates that the consumption effect caused by land urbanization exceeds the agglomeration effect. Furthermore, the results of the nonlinear analysis using the spatial adaptive semi-parametric and semi-parametric spatial dynamic panel models show that the association between land urbanization and carbon emissions demonstrates an inverted U-shaped curve. Simultaneously, land urbanization represents a dynamic cumulative and spatial spillover effect on urban CO2 emissions. Second, a mechanism analysis reveals that effective land urbanization can promote CO2 emission reductions through efficiency improvement, structure optimization and proper control of the land-use intensity. Additionally, we analyze heterogeneity in regional differences. In the line with study findings, the central government in China should promote the optimization of territorial spatial governance, optimize energy consumption structures, make comprehensive use of its funds, tax policies, industrial development support, and market-oriented mechanisms, and further optimize the layout of urban space.

Land Use Structure Optimization and Ecological Benefit Evaluation in Chengdu-Chongqing Urban Agglomeration Based on Carbon Neutrality

Optimizing land use structure in urban agglomerations is essential to mitigating climate change and achieving carbon neutrality. However, the studies on low-carbon (LC) land use in the urban agglomeration based on carbon neutrality are still limited and lack the consideration of the optimized land ecological benefits. To reduce land use carbon emissions (LUCEs) and improve the ecological benefits of urban agglomerations, we constructed the framework of land use structure optimization (LUSO) under carbon neutrality. Then, in view of land use quantity structure and spatial distribution, we compared the results of LUCEs and the ecological benefits of the Chengdu–Chongqing urban agglomeration (the CCUA) in 2030 under different scenarios. The results showed that in 2030, the LUCEs of the CCUA is 3481.6632 × 104 t under the carbon neutral scenario (CN_Scenario), which is significantly lower than the baseline scenario (BL_Scenario) and 2020. In the CN_Scenario, the land use/cover change (LUCC) in the CCUA is more moderate, the aggregation degree of the forestland (FL), grassland (GL), wetland (WL), and water (WTR) patch area deepens, and the overall landscape spreading degree is increased, which is more conducive to play the ecological benefit of carbon sink land. The results can provide a reference for the more efficient use of land resource areas and the formulation of land use and spatial planning.

Simulation of land use trends and assessment of scale effects on ecosystem service values in the Huaihe River basin, China.

Land use demand change in the Huaihe River basin (HRB) and ecosystem service values (ESVs) in watersheds are important for the sustainable development and use of land resources. This paper takes the HRB as the research object, and using remote sensing images of land use as the data source adopts the comprehensive evaluation analysis method of ESVs based on equivalent factors and sensitivity analysis of the performance characteristics of ESV changes of different land use types. The PLUS model is used to predict spatiotemporal land use change characteristics to 2030 combining inertial development, ecological development, and cultivated land development. The spatial distribution and aggregation of ESVs at each scale were also explored by analyzing ESVs at municipal, county, and grid scales. Considering also hotspots, the contribution of land use conversion to ESVs was quantified. The results showed that (1) from 2000 to 2020, cultivated land decreased sharply to 28,344.6875 km2, while construction land increased sharply to 26,914.563 km2, and the change of other land types was small. (2) The ESVs in the HRB were 222,019 × 1012 CNY in 2000, 235,015 × 1012 CNY in 2005, 234,419 × 1012 CNY in 2010, 229,885 × 1012 CNY in 2015, and 224,759 × 1012 CNY in 2020, with an overall fluctuation, first increasing and then decreasing. (3) The ESVs were 219,977 × 1012 CNY, 218,098 × 1012 CNY, 219,757 × 1012 CNY, and 213,985 × 1012 CNY under the four simulation scenarios of inertial development, ecological development, cultivated land development, and urban development, respectively. At different scales, the high-value areas decreased, and the low-value areas increased. (4) The hot and cold spots of ESV values were relatively clustered, with the former mainly clustered in the southeast region and the latter mainly clustered in the northwest region. The sensitivity of ecological value was lower than 1, while the ESV was inelastic to the ecological coefficient, and the results were plausible. The mutual conversion of cultivated land to water contributed the most to ESVs. Based on the multi-scenario simulation of land use in the HRB by the PLUS model, we identified the spatial distribution characteristics of ESVs at different scales, which can provide a scientific basis and multiple perspectives for the optimization of land use structure and socio-economic development decisions.

Assessing the impact of land use and changes in land cover related to carbon storage by linking trajectory analysis and InVEST models in the Nandu River Basin on Hainan Island in China

This study aims to evaluate the effects of the spatiotemporal patterns of land-use and land-cover (LULC) changes on the dynamics of carbon storage in a tropical region of China by linking the trajectory analysis of LULC changes and the InVEST model. Based on remote sensing (RS), geographic information system (GIS) and change trajectories, the spatiotemporal evolution of LULC changes was explored. This evolution could be coupled with the spatiotemporal LULC change trajectories and the InVEST model for the quantitative study of the spatial distribution and temporal variation in regional carbon stocks. The results showed that during the 2000–2020 period, the built-up land continually increased to 206.05 km2 through urban expansion, and forestland became the dominant type of land, with an area of 357.39 km2. In addition to the change in land use, the carbon storage in the study region increased by 4.87 Tg C. The anaphasic trajectory had the largest area ratio at 7.05% in the total area, while the prophasic trajectory contributed to the largest increase in carbon storage, 5.87 Tg C. Moreover, the repetitive trajectories had no impact on carbon sinks and sources, whereas the anaphasic trajectory and the continual trajectory imposed passive impacts on carbon storage. These advances in research underpin scientific efforts to improve the understanding of the relationship between the optimization of land-use structure and patterns and the carbon storage service in the Nandu River Basin.

Spatial-Temporal Pattern and Convergence Characteristics of Provincial Urban Land Use Efficiency under Environmental Constraints in China.

Revealing the spatial–temporal pattern and convergence characteristics of urban land use efficiency has important guiding significance for adjusting and optimizing the regional urban land use structure. Taking the provincial units in China as the research object, the urban land use efficiency evaluation system considering the unexpected output was constructed, and the slack-based measure (SBA) model was used to quantitatively measure the provincial urban land use efficiency from 2000 to 2020. The exploratory spatial data analysis (ESDA) model and spatial convergence index were combined to reveal the spatial–temporal pattern and convergence characteristics of provincial urban land use efficiency. The results showed that the provincial urban land use efficiency has been continuously improving, with regional differences as shown in eastern region > northeast region > central region > western region. Moran’s I of provincial urban land use efficiency was greater than 0, there was a positive spatial correlation, and the clustering feature became increasingly significant. The spatial form of LISA was characterized by “small agglomeration and large dispersion”; the H(High)-H(High) type was clustered in the Yangtze River Delta and Beijing–Tianjin–Hebei, while the L(Low)-L(Low) type was clustered in Xizang, Xinjiang and Qinghai. There was a σ convergence in provincial urban land use efficiency, and there was significant absolute β convergence and conditional β convergence of provincial urban land use efficiency. The results showed that the differences in provincial urban land use efficiency were shrinking, showing a “catch-up effect”, and converging to their respective stable states over time. Based on the analysis of the spatial–temporal pattern and convergence characteristics of provincial urban land use efficiency in China, we could provide a direction for the optimization of the urban land use structure and efficiency improvement in China, in order to narrow the differences in urban land use efficiency in China’s four major regions.

Remarkable improvement of ecosystem service values promoted by land use/land cover changes on the Yungui Plateau of China during 2001–2020

Quantitative evaluation of the relationship between land use/land cover (LULC) change and ecosystem service values (ESVs) is of great significance for the scientific optimization of land use structure and the formulation of sustainable land use policy, However, the responses of ESVs to LULC changes in fragile ecosystem regions over long time scales and large spatial scopes in the context of ecological restoration measures have seldom been studied. In this study, the Yungui Plateau in China was used as the study region. Based on annual Moderate–Resolution Imaging Spectroradiometer (MODIS) land cover datasets (MCD12Q1) from 2001 to 2020, using the equivalent coefficient value of ESVs modified for the specific situation of China, and adopting the Getis-Ord Gi* statistic method and Spearman’s rank correlation analysis, the study estimated the values of 11 types of ecosystem services, and analyzed the dynamics of LULC and its impact on ESVs from 2001 to 2020. The results showed that the LULC pattern in the Yungui Plateau changed dramatically in the past two decades, with a significant increase in forestland. The total ESVs improved remarkably from 638.10 billion yuan in 2001 to 746.99 billion yuan in 2020, and was mainly affected by forest restoration and the conversion of grassland to forestland and farmland to grassland. The distribution of ESVs shows obvious spatial and temporal heterogeneity; ESV hot spots were mainly distributed in the edge regions, while ESV cold spots were concentrated on the central and eastern of Yungui Plateau, and the decline in total ESVs still existed and displayed an increasing trend caused by farmland expansion and forestland degradation. Thus, we conclude that the LULC changes caused by ecological restoration measures have a significant positive effect on the improvement of the total ESVs in the Yungui Plateau and suggest that declines in ESVs in local areas should be of high concern in future land use planning and management.

Water–energy–carbon nexus of different land use types: The case of Zhengzhou, China

The rapid urban expansion of China has led to a large amount of water and energy consumption, and caused drastic growth of carbon emissions. Discovering the water–energy–carbon nexus of different land use types helps explain the interactions between resources capacity and environmental effects of land use activities, as well as provides reasonable options for land use management based on water–energy conservation and carbon emission reduction. In this paper, carbon emission/absorption of different land use types was estimated and the water–energy–carbon nexus of different land use types in Zhengzhou was analyzed. Through the SD model, the future carbon emissions of different scenarios were predicted under water, energy, and land constraints. It showed that total carbon emission increased and carbon absorption reduced along with the land use change during the rapid urbanization process of Zhengzhou city. The water and energy consumption and carbon emissions of different land use types were determined by the different intensities and their spatial patterns of human activities. Therefore, carbon emission and its intensity varied with land use types and water–energy–carbon nexus was closely related to land use types. The carbon emission prediction showed that the carbon emission reduction potential was the highest and the peak carbon emission (40.18 × 106 t) occurred in 2025 under a comprehensive scenario, which was designed with water–energy saving and optimization of land use structure. This study could provide references for policy–makers to formulate differentiated strategies for different land use activities, and contribute to realize water–energy saving and efficient utilization of land and the emission reduction of Zhengzhou city.

Effects of urban land use transitions on ecosystem services: Implication on Chinese urban planning

Urban land use transitions along with the rapid urbanization development cause obvious negative effects on the local ecological system. This paper explored the dynamic patterns of land use in central China’s largest city Wuhan, using high-resolution Landsat Thematic Mapper (TM) data in 1990, 2000 and 2010. The aggregate ecosystem services value, its dynamics, and spatial features were discussed based on the equivalent value per unit area approach, with the revision of Xie et al.’s (2015) unit parameters, adapted to Wuhan’s local situation. The results indicated that Wuhan’s ecosystem services value had been experiencing a continuous decrease during 1990 and 2000 and the following decade. The decrease was mainly due to urban expansion. However, Wuhan’s ecosystem services value decreased less between 2000 and 2010 with a much faster urban expansion pace than those in the former decade. The results illustrated that urban development severely affected ponds, rivers/lakes in their contribution to the ecosystem services that they naturally provided. Ponds and rivers/lakes contributed importantly to urban ecosystem services, even with a small proportion of area. Farmland contributed highly to urban expansion space as well as highly to the loss of related ecosystem services such as food provision and nutrient cycle maintenance. Forest land followed with an important contribution to climate regulation, soil conservation and waste regulation. The optimization of land use structure and configuration could improve urban ecosystem services. The authors conclude that even though the awareness of ecological resources conservation and sustainable development planning is emphasized, the practices are still in a challenge. The integration of ecosystem services dynamics to urban planning is an essential way that the large cities of China can realize sustainable development during its rapid urbanization.

Optimization of land use structure to balance economic benefits and ecosystem services under uncertainties: A case study in Wuhan, China

Rapid economic growth and urbanization in China have led to significant changes in land use structure and seriously threatened the sustainability of urban ecosystems. A Fuzzy Multi-Objective Linear Programming (FMLP) model is developed in this paper to determine an optimal land use structure with social, economic and ecological benefits of lands considered comprehensively. Ecosystem service assessment is integrated into the FMLP model for emphasizing the ecological benefits of land use, and the uncertainty in the optimization process have been addressed. Wuhan is selected as a case study. The results indicate that (1) the relative equilibrium between economic and ecological benefits can be achieved by establishing the FMLP model. (2) The optimized land use structure can increase the ecosystem service value (ESV) at a lower cost of economic benefits. (3) The optimal land use allocation can contribute to a growth of ecological benefit by 1.51 billion RMB and economic benefit by 348.6 billion RMB compared to the government's land use planning. (4) The ESVs of 11 types of ecosystem service functions are all increased in varying degrees through land use structure optimization. (5) There are huge differences in economic and ecological benefits between the central and remote urban areas of Wuhan. The economic benefit is 603 folds of the ecological benefit in central urban area while the ESV in remote urban area is 25 folds of that of the central urban area in Wuhan. These findings could provide valuable decision-making support for the sustainable land use planning in Wuhan. The FMLP model is proven to be feasible and applicable for land use planning under uncertain conditions and thus could be applied to other cities with unbalanced land use structure.

青弋江流域生态系统服务评估与权衡研究

研究生态系统服务价值变化特征及多种服务之间的权衡协同关系，对平衡经济发展与环境保护具有重要意义。基于修订的当量因子表，结合2000、2009、2018年3个时期遥感解译获取的土地利用数据，运用生态系统服务权衡协同度模型、敏感性分析、空间自相关、土地利用程度综合指数模型等分析了青弋江流域生态系统服务价值（Ecosystem Services Value，ESV）的时空演变特征及9种生态服务之间的权衡协同关系。结果表明：（1）2000、2009及2018年的生态系统服务价值分别为285.19、351.26和294.68亿元，价值总量呈先增后减的变化趋势，其中2009-2018年间总ESV下降了16.1%，生态服务趋于退化。整个研究时段内，林地对ESV的贡献量最大，其次是耕地和水域。（2）2000-2009年，单项生态系统服务间以协同关系为主导，协同率为77.8%，食物生产服务与本研究中的其他服务之间均为权衡关系；2009-2018年间生态系统服务间的关系与前9年基本一致，但食物生产服务与其他服务功能之间的权衡度呈增强的趋势。（3）敏感性分析表明，各时期的敏感性指数（CS）值均小于1，表明基于修订的当量因子表计算获得的生态系统服务价值系数符合青弋江流域的实际情况，计算结果可靠。（4）生态系统服务价值存在较强的正向空间自相关，但集聚程度有下降的趋势。双变量空间自相关分析表明当土地利用程度增强时，生态系统提供的总服务价值或单项服务价值均会降低。研究结果可为青弋江流域土地利用结构的优化调整及生态环境保护提供参考信息。;It is of great significance for balancing economic development and environmental protection to study the characteristics of ecosystem services value (ESV) and the trade-offs and synergies between multiple services. Based on the revised equivalence factor table, combined with the land use data from remote sensing interpretation in 2000, 2009 and 2018, the ecosystem services trade-offs and synergies model, sensitivity analysis, spatial autocorrelation and comprehensive index model of land use degree were used to analyze the spatio-temporal evolution characteristics of ESV in Qingyijiang River Basin and the trade-off relationship among nine kinds of ecological services. As the results showed, firstly, in 2000, 2009 and 2018, the ESV of Qingyijiang River Basin was 28.519 billion yuan, 35.126 billion yuan, and 29.468 billion yuan respectively, while the total value showed a trend of first increase and then decrease. Among them, the total ESV decreased by 16.1% from 2009 to 2018, and the ecological services tended to be degraded. Secondly, from 2000 to 2009, the single ecosystem service was dominated by synergy, with the synergy rate of 77.8%. There was a trade-off relationship between food production service and other services in this study. The relationship between ecosystem services in 2009-2018 was almostly same as that in the previous nine years, but the trade-off between food production service and other services was increasing. Thirdly, the sensitivity analysis showed that the coefficient of sensitivity index (CS) values of each period were less than 1, which indicated that the ESV coefficient calculated on the basis of the revised equivalence factor table was consistent with the actual situation of Qingyijiang River Basin, and the calculation results were reliable. Fourth, there was a strongly positive spatial autocorrelation of ESV, but the degree of agglomeration had a downward trend. Bivariate spatial autocorrelation analysis showed that the total service value or individual service value of ecosystem would decrease when the land use degree increased. The results can provide reference information for the optimization and adjustment of land use structure and ecological environment protection in the Qingyijiang River Basin.

Zonation on non-point source pollution risk in the lower reaches of Zijiang River based on the "source-sink" theory

Non-point source pollution risk assessment and zonation research are of great significance for the eco-environmental protection and optimization of land use structure. We identified the "source" and "sink" landscape using the "source-sink" landscape pattern theory based on the two phases of land use data in the lower reaches of Zijiang River in 2010 and 2018. We comprehensively considered the non-point source pollution occurrence and migration factors, and used location-weighted landscape contrast index (LCI) and non-point source pollution load index (NPPRI) to analyze non-point source pollution risk spatio-temporal characteristics in the study area. Zonation on non-point source pollution in the lower reaches of Zijiang River was studied by identifying the key factors of non-point source pollution risk. The results showed that the overall risk of non-point source pollution was relatively low. The sub-basin with "sink" landscape was the main type, accounting for 61.2%. Non-point source pollution risk was low in the southwest and was high along the banks of Zhixi River, Taohua River and main stream of Zijiang River, as well as plain in the northeast of the lower Zijiang River. The risk of non-point source pollution from 2010 to 2018 showed an increasing trend. The changes in landscape pattern, especially the expansion of rural settlement, arable land and the shrinkage of forest land had positive and negative responses to the risk of non-point source pollution, respectively. LCI, slope, and distance were the key factors affecting the change of the risk index of non-point source pollution. The lower reaches of the Zijiang River could be divided into four control regions: pollution treatment area near river, low slope pollution control area, ecological restoration-risk prevention and control area, and ecological priority protection area.

Analyzing land use structure efficiency with carbon emissions: A case study in the Middle Reaches of the Yangtze River, China

China has a large population and limited land resources. The dearth of available land poses considerable challenges for economic development and environmental protection. In order to realize maximum benefits through the optimization of land use structure, land use structure efficiency (LUSE) becomes an important planning guideline for the sustainable development of a region. This paper conducts a case study in the Middle Reaches of the Yangtze River (MRYR) and investigates the LUSE of the region considering the effect of carbon emissions from 1995 to 2018 by using the slack-based measure with undesirable output (SBM-Undesirable) model and Markov transition probability matrix with spatial effect. The results show that: (1) the average LUSE in the study area is 0.652 when the carbon emissions are not considered, compared with that of 0.569 when the carbon emissions are factored in. The comparative result indicates that carbon emissions have a great impact on the LUSE; (2) the LUSE has a rising trend during the study period (except for 2010) starting with a value of 0.463 in 1995 and ending with a value of 0.671 in 2018. Furthermore, the spatial pattern of the LUSE in the study area has been through a drastic change, with the high-value areas clustered at a single center in 1995 evolving to a multiple-center pattern in 2018; (3) High LUSE areas have a positive spillover effect on its neighboring areas, while low LUSE areas have negative spillover effects. The results can provide insights into the optimization of land use structure and the efficient utilization of land resources. This study also suggests that policy makers should optimize the industrial structure and propose policy initiatives oriented towards goals of energy-saving and emission reduction to facilitate regional planning and sustainable development.