Spatiotemporal variations in ecosystem services and their trade-offs and synergies against the background of the gully control and land consolidation project on the Loess Plateau,China

Studying the spatiotemporal variations in ecosystem services and their interrelationships on the Loess Plateau against the background of the gully control and land consolidation(GCLC)project has significant implications for ecological protection and quality development of the Yellow River Basin.Therefore,in this study,we took Yan'an City,Shaanxi Province of China,as the study area,selected four typical ecosystem services,including soil conservation service,water yield service,carbon storage service,and habitat quality service,and quantitatively evaluated the spatiotemporal variation characteristics and trade-offs and synergies of ecosystem services from 2010 to 2018 using the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model.We also analysed the relationship between the GCLC project and regional ecosystem service changes in various regions(including 1 city,2 districts,and 10 counties)of Yan'an City and proposed a coordinated development strategy between the GCLC project and the ecological environment.The results showed that,from 2010 to 2018,soil conservation service decreased by 7.76%,while the other three ecosystem services changed relatively little,with water yield service increasing by 0.56% and carbon storage service and habitat quality service decreasing by 0.16% and 0.14%,respectively.The ecological environment of Yan'an City developed in a balanced way between 2010 and 2018,and the four ecosystem services showed synergistic relationships,among which the synergistic relationships between soil conservation service and water yield service and between carbon storage service and habitat quality service were significant.The GCLC project had a negative impact on the ecosystem services of Yan'an City,and the impact on carbon storage service was more significant.This study provides a theoretical basis for the scientific evaluation of the ecological benefits of the GCLC project and the realization of a win-win situation between food security and ecological security.

Evaluation and Driving Force Analysis of Cultivated Land Quality in Black Soil Region of Northeast China

Cultivated land is an important natural resource to ensure food,ecological and economic security.The cultivated land quality evaluation(CQE)is greatly significant for protecting and managing cultivated land.In this study,320 counties in the black soil region of Northeast China(BSRNC)represent the research units used to construct the CQE system measuring the soil properties(SP),cultivated land productivity(CLP),ecological environment(EE)and social economy(SE).The total of 19 factors were selected to calculate the integrated fertility index(IFI)and divided into grades.Simultaneously,we used the coupling coordination degree model to comprehensively analyze the spatial pattern of the cultivated land quality(CLQ)in the BSRNC,and use the structural equation model(SEM)to analyze the driving mechanism.The results show the following:1)The CLQ of 262 counties in the BSRNC is in a state of coupling and coordination,and the coupling and coordination degree presents a spatial distribution pattern of‘high in the southwest and northeast,low in the northwest and southeast’.The coordinated development degree of 271 counties is between 0.4 and 0.6,which is in a transitional state between coordination and disorder.2)The CLQ in the BSRNC is generally good,with an average grade of 3.High-quality cultivated land accounts for 58.45%of all counties,middle-and upper-quality cultivated land accounts for 27.05%,and poor-quality cultivated land accounts for 14.49%.3)The SEM analysis shows that the SP,CLP,EE,and SE all influence the CLQ.Among them,the SP has the largest driving force on the CLQ,while the SE has the smallest driving force on it.The results confirm that the main factors affecting the evaluation results are crop productivity level,normalized difference vegetation index,ratio vegetation index,difference vegetation index,and organic carbon content.When implementing protection measures in counties with a low CLQ,considering a balanced coordination of multiple systems and reasonably controlling the quality degradation are important.This study provides the current situation and driving factors of the CLQ in the BSRNC and will play an important role in black soil governance and utilization.

Arrangement of High-standard Basic Farmland Construction Based on Village-region Cultivated Land Quality Uniformity

As an important constitute of land consolidation, high-standard basic farmland construction is an important means to protect the quantity, quality and ecological environment of cultivated land. Its target not only lies in the increase of cultivated land quantity, but also the improvement of cultivated land quality, agricultural production conditions and ecosystem environments. In the present study, the quality evaluation method and construction arrangement of cultivated land were explored to facilitate the process of decision-making and implementation for high-standard basic farmland construction(HSBFC) with administrative village as the unit. Taking the land comprehensive improvement project area in Quzhou County, Handan City, Hebei Province as a case study, the whole process of the study comprised of three steps: 1) establishment of the evaluation model of cultivated land quality uniformity based on regional optimum cultivated land quality, and construction of the uniformity evaluation index system from the aspects of soil fertility quality, engineering quality, spatial quality and eco-environment quality, according to the new concept of cultivated land quality; 2) calculation of cultivated land quality uniformity by grading indicators, assigning scores and weighting sums, exploring the local homogenization characteristics of regional cultivated land quality through spatial autocorrelation analysis, and analyzing the constraints and transformative potential of barrier factors; 3) arrangement of HSBFC according to the principle of concentration, continuity and priority to the easy operation. The results revealed that the value of farmland quality uniformity for the administrative villages in the study area was between 7.76 and 21.96, and there was a difference between various administrative villages. The regional spatial autocorrelation patterns included High-High(HH), Low-Low(LL), High-Low(HL) and Low-High(LH). These indicate that regional cultivated land quality has local homogenization characteristics. The most restrictive factors in the study area were the medium and low transformation difficulty indexes, including soil organic matter content, farmland shelterbelt network density, field regularity and scale of the field. In addition, there were also high transformation difficulty indicators in some areas, such as sectional configuration. The project area was divided into four partitions: major construction area, secondary construction area, general construction area, and conditional construction area. The cultivated land area of each subarea was 1538.85 ha, 1224.27 ha, 555.93 ha, and 1666.63 ha, respectively. This comprised of 30.87%, 24.56%, 11.15% and 33.42% of the total project area, respectively. The evaluation model and index system could satisfy the evaluation of farmland quality and diagnosis of obstacle factors to facilitate the subsequent construction decision. The present study provides reference for the practice of regional HSBFC, and a new feasible idea and method for related studies.

Update of Cultivated Land Quality Grade Based on GIS—A Case Study of a County in Guangxi

The quality of cultivated land has an important influence on agricultural output, food security, sustainable development and the ability of using cultivated land resources. As the trend of cultivated land quality is getting more and more attention, in order to strengthen the management of cultivated land quality, improve the precision of cultivated land quality and other achievements, and maintain the current situation of cultivated land quality and other achievements. For this paper, taking A county of Guangxi Zhuang Autonomous Region as an example, with the support of GIS, the paper studies the grade and grade renewal of cultivated land by using the superposition method, studies the grade and grade change of regional cultivated land and its spatial distribution, grasps the status quo change of cultivated land and the grade and grade change of cultivated land caused by the quality construction of cultivated land in the year, and then provides scientific data for land use plan, land consolidation and cultivates land protection.

Progress in Researches on Evaluation of Quality of Cultivated Land Consolidated from Coal Mining Subsided Land

The evaluation of consolidated cultivated land quality can provide basic information for how to perfect the program of land consolidation,as well as a reference for the dynamic monitoring of farmland quality in mining area. Based on the consultation and analysis of related literature,we can conclude that: firstly,most scholars focus on soil consolidation,while consider little about land use and economic condition. Secondly,foreign scholars usually use crop yields to judge the success of land consolidation,while domestic scholars have been evaluated the quality of consolidated cultivated land synthetically from several aspects,such as soil fertility,soil environmental quality,and farmland infrastructure conditions. Specifically,most of the evaluations are static,and indicators are different. Besides,the quality of consolidated cultivated land is generally low,and it lacks systematic research on technologies for improving quality of cultivated land consolidated from coal mining subsided land. It is concluded that future researches should focus on establishing scientific and feasible evaluation system to realize comparison of quality change in the dynamic course of " undisturbed-subsided-consolidated" cultivated land in coal mining areas,as well as technologies for improving quality of cultivated land consolidated from coal mining subsided land.

Improvement of Evaluation Methods for Cultivated Land Quality

As the existing cultivated land quality evaluation index system is unable to accurately evaluate the quality of cultivated land after land remediation,a modified land use coefficient method was established in this study to calculate the land use coefficient of cultivated land after land remediation. An evaluation index system was first established for the land utilization level of cultivated land in the remediation areas.After that,the land utilization level index before and after the remediation was evaluated separately. The ratio of the two was used as the correction factor to correct the original land use coefficient. The corrected land use coefficient was used to evaluate the quality of cultivated land. The quality evaluation and verification of the land remediation areas in Yuzhou City were conducted. It was found that the land use coefficient corrected by the modified method was more consistent with that calculated by production method 5 years after the project acceptance. It suggests that the modified land use coefficient method reflects the impact of land remediation on the quality of cultivated land,and it is more suitable compared with the production method for the quality evaluation of cultivation land in remediation areas.

Research of Farmland Quality Evaluation Based on Land Consolidation——A Case Study of Land Consolidation Project in Mofang Village,Daixian County,Shanxi Province

Taking land consolidation project in Mofang Village of Daixian County as an example,on the basis of counting natural and utilization grades before and after farmland consolidation,farmland quality in the project region after the consolidation is evaluated.

Research on Monitoring Area Division of Quality Grade Changes in County Cultivated Land and Technology of Deploying Monitoring Point

It is an important means in management of improving both the quality and quantity of cultivated land to monitor grade changes in cultivated land quality. How to deploy monitoring network system and its point reasonably and roundly are the key to the technology of monitoring grade changes in cultivated land quality by monitoring grade changes in cultivated land quality dynamically in order to obtain the information to the index of cultivated land quality and its changes based on the existing achievements of farmland classification and grading. Spatial analysis method is used to demarcate monitoring area and deploy monitoring point according to ARCGIS,of which the result can meet the demand for monitoring grade changes in cultivated land.

Site Selection of Land Consolidation Project Based on Farmland Quality Evaluation in Yanjin County of Henan Province

In order to explore the effects of farmland quality evaluation on site selection of land consolidation projects,the methods of agricultural land use classification were used. Taking several project areas in Yanjin County of Henan Province as examples,the farmland quality before and after land consolidation projects was evaluated. The results indicate that under the conditions of reasonable site selection,the implementation of land consolidation projects can effectively improve the farmland quality and increase the grain productivity. Therefore,before the site selection for land consolidation projects,it is recommended to carry out pre-evaluation of farmland quality,and guide the project implementation according to the evaluation results. Besides,it is recommended to focus on medium and low level farmland with large centralized area,excellent original production conditions,but low level of development and use.

Early Warning of Cultivated Land Quality Based on Multiple Indicators

At present,the quality protection and early warning of cultivated land in China are actually based on the increase and decrease of the quantity of cultivated land and the change of its quality.The early warning of cultivated land quality based on this is easy to cause the problem of missing and wrong alarm.Based on the quality and productivity change of regional cultivated land,early warning on the regional cultivated land quality is conducted in this study respectively,and the results of the two early warning are compared.Moreover,a multi-indicator cultivated land quality early warning based on the quality change,productivity change and auxiliary indicators is proposed.The results show that:early warning of cultivated land quality based on quality and productivity change of cultivated land has certain limitations.Based on multi-indicator early warning,the number of counties with heavy,medium and light warnings in Henan Province is 52,8 and 11 respectively.The multi-indicator early warning result of cultivated land quality is more accurate,which can provide a basis for cultivated land protection and management assessment,and has great application value.

Study on Division Method of Quality Monitoring Control Area Based on Comprehensive Cultivated Land Attribute

The quality change of cultivated land resources requires the scientific deployment of monitoring areas.In this study,Yuzhou City is taken as an example to divide the quality monitoring control areas through the study of natural quality,utilization level,income level,and utilization characteristics,etc.Compared with the traditional administrative unit division or cultivated land quality division method,the regional homogeneity of this study is stronger,and there are quality differences between regions.It provides precondition and precision guarantee for the monitoring of cultivated land quality.

Research on Dynamic Change of Regional Cultivated Land Quality and Its Influence Factors

According to the reason of quality change,cultivated land is divided into four change types: decrease,increase,land construction project and gradual change. Farmland grading factor method is used to evaluate the quality of cultivated land in Zhengzhou City. The results show that(1) the quality of cultivated land in Zhengzhou City has slightly increased during the study period. Due to the decrease in the amount of cultivated land,the production capacity has declined.(2) The impact of different types of cultivated land change on the quality of regional cultivated land is in the order of gradual change> decrease > increase > land construction project.(3) Zhengzhou City is able to maintain the quality of regional cultivated land through new cultivated land and project construction,but fails to maintain the production capacity. By analyzing the mechanism of regional cultivated land quality change in different types,the relationship between quality changes in various types of areas and overall quality changes could be analyzed,and it could provide policy recommendations for managers to formulate farmland quality and capacity protection,with significant application value.

Analysis on the Application of Quality Classification of Cultivated Land Resources in Municipal Land Space Planning:A Case Study of Chongzuo City

Cultivated land is the most important strategic resource to ensure food security.The newly constructed quality classification system of cultivated land resources considers the cultivated land health index for the first time.How the new classification and grading index system and the quality classification results of cultivated land resources to effectively guide the preparation of municipal land space planning has become a key research direction.This paper expounds the overall design idea for quality classification of cultivated land resources and classification index system.Taking Chongzuo City as an example,through the analysis of the quality classification results of cultivated land resources in the study area,using GIS spatial analysis and factor pairwise comparison method,this paper explores the application ideas and methods of quality classification research results of cultivated land resources in the formulation of cultivated land retention target,the delineation of dominant areas of cultivated land protection,the delineation of three control lines,the comprehensive improvement of land,and ecological restoration zoning in the municipal land space planning.

Compounding soils to improve cropland quality:A study based on field experiments and model simulations in the loess hilly-gully region,China

Increasing the quantity and improving the quality of cropland can alleviate the human-land contradiction and promote the sustainable development of agriculture especially in mountainous areas.With the support of the central government’s policies,Yan’an,Northern Shaanxi,China implemented a major land consolidation engineering project in the loess hilly-gully region from 2013 to 2018,achieving 33,333.3 ha of new cropland.However,the poor quality of some newly-constructed cropland at the initial stage hindered its efficient utilization.In order to overcome this problem,red clay and Malan loess were compounded in different volume ratios to explore the method to improve the cropland quality.The Root Zone Water Quality Model was used to simulate the effects of different soil treatments on soil water,nitrogen and maize growth.Experimental data were collected from 2018 to 2019 to calibrate and validate the model.The root mean square error(RMSE)of soil water content,nitrate nitrogen concentration,above-ground biomass,leaf area index were in the range of 11.72-14.06 mm,4.06-11.73 mg kg^(-1),835.21-1151.28 kg ha^(-1)and 0.24-0.47,respectively,while the agreement index(d)between measured and simulated values ranged from 0.70 to 0.96.It was showed that,compared with land constructed with Malan loess only(T1),the soil structure and hydraulic characteristics of land with a volume ratio of red clay and Malan loess of 2:1(T3)was better.Simulation indicated that,compared with T1,the soil water content and available water content of T3 increased by 14.4%and 19.0%,respectively,while N leaching decreased by 16.9%.The aboveground biomass and maize yield of T3 were 7.9%and 6.7%higher than that of T1,respectively.Furthermore,the water productivity and nitrogen use efficiency of T3 increased by 21.0%and 16.6%compared with that of T1.These results indicated that compounding red clay and Malan loess in an appropriate ratio was an effective method to improve soil quality.This study provides a technical idea and specific technical parameters for the construction or improvement of cropland in loess hilly-gully region,which may also provide reference for similar projects in other places.

Design of Trinity Framework for Cultivated Land Protection

Starting with the goals and tasks of quantity,quality and ecological protection in different scales,this paper constructs a"trinity"framework of cultivated land protection system,and puts forward the key points of cultivated land protection in different scales.Finally,a preliminary evaluation is made on the quantity,quality and ecological protection of cultivated land on a macro scale in China.

Impact of land use change on water quality in the Dianchi Lake watershed, Yunnan, China, 1988-2008

Land use changes occurring in China during the time period of rapid economic development are linked to the degradation of water quality in streams and lakes. This paper examines these linkages in the Dianchi Lake watershed in Yunnan in southwest China based on a twenty-year data set from 1988 to 2008. Pearson correlation analysis and simple linear regression analysis are employed to explore the relationships between land use change and water quality of two sub-basins, the Caohai Lake basin and the Waihai Lake basin, within the Dianchi Lake watershed. Land use categories more strongly correlate to water quality in the Caohai Lake basin than that in the Waihai Lake basin. The different structure of land use categories, spatial distribution of land cover, and scales of buffer zones could be the factors resulting in the dissimilarities between these two lakes. The research can provide valuable insights for policymakers into land use management in order to curb further water degradation in Dianchi Lake.

County scale spatial differential characteristics of cultivated land use grade: A case of Binchuan County

Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial analysis and statistical analysis unifies, to explore the quality of cultivated land in Binchuan County using level, and explain the utilization level of county cultivated land quality spatial differentiation characteristics. The results showed that:(1) in the quantity of cultivated land quality and utilization level, the average utilization of paddy land was greater than that of dry land, and the comprehensive utilization of cultivated land and so on. Among them, the paddy land ranged from grade 6 to 15, the average utilization was grade 11.6; dry land ranged from grade 2 to 11, the average utilization was grade 5.9; comprehensive range of cultivated land is grade 2 to 15, the average utilization was grade 8.1;(2) the quality of cultivated land utilization spatial differentiation. Paddy field, dry land and cultivated land and large value distribution in the central and southern, inverted V shape distribution; the smaller the value distribution in the East and West, a dumbbell shaped distribution. Among them, they don't use a larger value of paddy land distributed in the central, South and southwest, the maximum value is 14.3, the smaller the value distribution in the West and East, the minimum value is grade 7; the larger the value distribution by the dry land in the South and West, the maximum value is grade 10.2, the smaller the value distribution in the West and East. The minimum value is grade 2.3; the comprehensive utilization of cultivated land don't distributed larger value in the central, South and south-west, the maximum value is grade 12.7, the smaller the value distribution in the West and East, the minimum value is grade 3.5. This paper can provide scientific basis for the dynamic monitoring of cultivated land quality, the transformation of low yield farmland and the early warning of cultivated land pressure.

Research on Grade Renewing of Cultivated Land at County Level:A Case Study of Daxing District,Beijing

To create a scientific way to renew the grades of cultivated land at county level, monitoring points were set up according to the monitoring control regions and grade types of cultivated land in Daxing District, Beijing, and soil samples were collected to carry out chemical analysis. Afterwards, the input and output data of cultivated land in each village were surveyed to renew the grades of cultivated land. The results indicate that the average natural grade of cultivated land was 8.4, which was equal to that of 2004; the average utilization grade was 8.1, which was slightly higher than that of 2004; the average economic grade was 9.9, which was lower than that of 2004. It is concluded that it is scientific to renew cultivated land grades through scientifically setting monitoring points according to the monitoring control regions and grade types of cultivated land.

Exploring differentiated improvement strategies of cultivated land quality in China

Quality is the core feature of cultivated land. In the face of deteriorating cultivated land quality and growing food demand, improving cultivated land quality is a top priority for guaranteeing the sustainable use of resources and national food security. Cultivated land quality in the new era can be considered in four dimensions: suitability, contiguity, resistance and ecological stress. Cultivated land suitability in China shows a decreasing trend from east to west, cultivated land contiguity is high in the north-east and low in the south-west. In terms of cultivated land resistance, the number of strongly and weakly resistant cropping fields is small and spatially clustered. Cultivated land with ecological stress is mainly located in the northern region. Based on the current situation of cultivated land quality and the strategic needs of national high-quality development, China's future goals for improving cultivated land quality include four aspects: promoting the sustainable use of resources,improving the economic benefits of farming, coping with extreme meteorological disasters and meeting the transition of the food system.Against the backdrop of a volatile international environment and high domestic demand for food, China should guarantee a safe supply of staples, a stable supply of animal feed and a moderate supply of high-nutrient food. In the future, China should create three major food production spaces: highstandard, low-to medium-yield, and marginal cultivated land. China urgently needs to construct three paths to implement the goal of improving cultivated land quality, namely the development of high-standard cultivated land with the core of spatial optimization, resilience enhancement and scale coupling,the transformation of low-to medium-yield cultivated land with the core of obstacle elimination, tenure adjustment, ecological sustainable, and the conservation development of marginal cultivated land with a focus on sustainable use.

基于GlobeLand 30的耕地资源损失过程研究——以环渤海地区为例

研究目的:认识和理解耕地资源损失过程。研究方法:基于中国成功研制出的世界上首套30 m分辨率2000—2010年GlobeLand 30数据,利用GIS空间分析方法,综合分析环渤海地区耕地资源损失流向、质量和空间特征。研究结果:2000—2010年,环渤海地区土地利用/覆盖变化剧烈,耕地资源明显减少,主要损失流向为人造覆盖、草地、水体和森林;耕地资源损失区域主要位于降水量较少、海拔较高等耕作条件较差的地区;耕地资源重心总体向东南方向移动,破碎化程度日趋严重。研究结论:基于GlobeLand30数据的耕地资源损失过程研究能有效揭示耕地资源损失流向、质量和空间特征,为区域耕地资源利用与保护提供了积极借鉴和参考。