Spatiotemporal patterns and drivers of cultivated land conversion in Inner Mongolia Autonomous Region,northern China

Protection and optimization of cultivated land resources are of great significance to national food security.Cultivated land conversion in northern China has increased in recent years due to the industrialization and urbanization of society.However,the assessment of cultivated land conversion in this area is insufficient,posing a potential risk to cultivated land resources.This study evaluated the evolution and spatiotemporal patterns of cultivated land conversion in Inner Mongolia Autonomous Region,China,and the driving factors to improve rational utilization and to protect cultivated land resources.The spatiotemporal patterns of cultivated land conversion in Inner Mongolia were analyzed using the cultivated land conversion index,kernel density analysis,a standard deviation ellipse model,and a geographic detector.Results showed that from 2000 to 2020,the trends in cultivated land conversion area and rate in Inner Mongolia exhibited fluctuating growth,with the total area of cultivated land conversion reaching 7307.59 km^(2) at a rate of 6.69%.Spatial distribution of cultivated land conversion was primarily concentrated in the Hetao Plain,Nengjiang Plain,Liaohe Plain,and the Hohhot-Baotou-Ordos urban agglomeration.Moreover,the standard deviational ellipse of cultivated land conversion in Inner Mongolia exhibited a directional southwest-northeast-southwest-northeast distribution,with the northeast-southwest direction identified as the main driving force of spatial change in cultivated land conversion.Meanwhile,cultivated land conversion exhibited an increase-decrease-increase change process,indicating that spatial distribution of cultivated land conversion in Inner Mongolia became gradually apparent within the study period.The geographic detector results further revealed that the main driving factors of cultivated land conversion in Inner Mongolia were the share of secondary and tertiary industries and per-unit area yield of grain,with explanatory rates of 57.00%,55.00%,and 51.00%,respectively.Additionally,improved agricultural production efficiency and the coordinated development of population urbanization and industry resulted in cultivated land conversion.Collectively,the findings of this study indicated that,from 2000 to 2020,the cultivated land conversion in Inner Mongolia was significant and fluctuated in time,and had strong spatial heterogeneity.The primary drivers of these events included the effects of agriculture,population,and social economy.

Estimation of Land Production and Its Response to Cultivated Land Conversion in North China Plain

Food safety and its related influencing factors in China are the hot research topics currently,and cultivated land conversion is one of the significant factors influencing food safety in China.Taking the North China Plain as the study area,this paper examines the changes of cultivated land area using satellite images,estimates land productivity from 1985 to 2005 using the model of Estimation System for Land Productivity(ESLP),and analyzes the impact of cultivated land conversion on the land production.Compared with the grain yield data from statistical yearbooks,the results indicate that ESLP model is an effective tool for estimating land productivity.Land productivity in the North China Plain showed a slight decreasing trend from 1985 to 2005,spatially,increased from the north to the south gradu-ally,and the net changes varied in different areas.Cultivated land area recorded a marginal decrease of 8.0 × 105 ha,mainly converted to other land uses.Cultivated land conversion had more significant negative impacts on land produc-tion than land productivity did.Land production decreased by about 6.48 × 106 t caused by cultivated land conversion between 1985 and 2005,accounting for 91.9% of the total land production reduction.Although the land productivity increased in Anhui and Jiangsu provinces,it can not offset the overall adverse effects caused by cultivated land con-version.Therefore,there are significant meanings to control the cultivated land conversion and improve the land pro-ductivity for ensuring the land production in the North China Plain.

ANALYSIS AND MODELING ON CULTIVATED LAND CONVERSION——Case Study of Hebei Province

： With the acceleration of thc urbanization and industrialization of China, it is inevitable that cultivated land convcrts to built-up land for industrial, commercial and residential uses, which would impose pressure both on food security and on the sustainability of urbanization itself tbr such a country with large population and few cultivated land. Based on thc three-time Landsat Thematic Mapper （TM） digital imagcs and statistic data of Hebei Province, the general facts of cultivated land conversion and its driving forces were analyzcd by establishing econometric model in this papcr. Some conclusions werc drawn as the following： during 1985 2000, the rate of cultivated land converting to built-up arca in Hebei was 4.01% or 0.27% pcr year. Of all the converted cultivated land, 20.96% was converted to built-up area and of all the new built-up areas, 83.4% was converted from cultivated land; meanwhile the conversion is uneven not only in time but also in space; factors such as edgc length shared by cultivated land and built-up land, agricultural value per hectare, non-agriculture value per hectarc, GDP, total population, farmer＇s net income per capita and time had significant effects on this conversion.

Analysis on the Influencing Factors and Control Measures of "Non-Grain Conversion" of Cultivated Land in Agricultural Land Transfer

Through the method of literature analysis,this paper analyzes the present situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land in China,summarizes the influencing factors and consequences of the phenomenon of"non-grain conversion"of cultivated land in the transfer of agricultural land,and finally puts forward some measures.The study found that costs and benefits are the fundamental factors affecting the"non-grain conversion"of cultivated land in agricultural land transfer,and other main factors include government and policy guidance,industrial and commercial capital to the countryside,labor transfer and so on.The"non-grain conversion"of cultivated land in the transfer of agricultural land is a serious threat to China s food security,leading to the decline of the quality of agricultural land and the destruction of the ecological environment,as well as the risk of breach of contract in"industrial and commercial capital to the countryside".Based on the understanding of the influencing factors of non-grain conversion,this paper puts forward the following measures:strengthening the control of the use of cultivated land in agricultural land transfer;implementing accurate subsidies for grain cultivation and ensuring the benefit of grain growers;adopting grain planting incentive mechanism to increase grain enthusiasm;strengthening media publicity and education to enhance food security awareness.The improvement of the current situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land will be of great significance to the protection of agricultural land and food security in China.

Mutual Conversion of Land Use between Urban and Rural Area in the Process of Urbanization: A Case Study of Shandong Province

Urbanization is one of the driving forces for the land use change in type and structure, and its prominent effect is to convert rural land to urban land. This paper takes Shan-dong Province as an example to analyze the current situation of the mutual conversion between the urban and rural areas from the aspects of the structure of land use, the decreasing tendency of the cultivated land, the changes of land use in urban and rural residential areas. It points out that cultivated land is converted to residential area land, industrial and/or mining area land. The relationship between the urban area land and the cultivated land is more direct; meanwhile, the changes of rural residential area lag behind obviously. The decrease of the cultivated land and the decline of soil quality will be the two difficult problems in the process of urbanization.

Impacts of Cultivated Land Conversion on Environmental Sustainability and Grain Self-sufficiency in China

Using provincial data, the present paper examines the impact of cultivated land conversion on agriculture and the environment. It is found that the grain production center is gradually moving towards more fragile and water scarce areas, putting more pressure on the environment. Land conversion caused large losses in ecosystem service values in the 1990s, but large scale ecological restoration programs have been implemented since 2000 to compensate for such losses. The ecological restoration programs are concentrated in regions with relatively low land productivity, whereas cultivated land conversion usually takes place in areas with relatively high land productivity. Newly-cultivated land, especially that in areas marginally suit for agricultural production, is likely to have much lower productivity levels than the original cultivated land. Because the stock of potentially cultivable land is almost exhausted, China＇s grain self-suffiency policy can only be maintained by preserving the available stock of arable land and increasing its productivity in a sustainable way.

下辽河平原区耕地非农化时空演变特征及驱动机制

探索耕地非农化的时空演变特征及其驱动机制是耕地保护的前提,分析下辽河平原区2000—2020年耕地非农化的时空演变特征及驱动机制,可以为该地区耕地保护政策的制定与防止耕地非农化提供理论依据。本文基于2000年、2005年、2010年、2015年和2020年5个时期的土地利用数据,以下辽河平原区为研究区域,结合社会经济数据,运用ArcGIS 10.2空间叠加分析,计算耕地非农化面积,采用重心迁移模型、核密度分析、地理探测器等统计学和地理信息系统的空间分析方法,揭示下辽河平原区耕地非农化特征及其演变趋势,并探讨其耕地非农化的驱动因素。研究结果表明:1)在时间上,下辽河平原区耕地非农化面积和非农化率呈现周期性波动,耕地非农化总面积为2201.52 km^(2),耕地非农化率为7.11%。2)在空间分布上,耕地非农化的重心主要从辽中区向东北方向迁移至于洪区,下辽河平原区耕地非农化东部地区高于西部地区,核密度最大值1657.3,主要在于洪区、浑南区、沈北新区、苏家屯区附近;耕地非农化的次集中区域为新民市和昌图县,其核密度最大值分别为1033.18和1018.49。3)在驱动因素上,耕地非农化驱动因素影响依次为农业机械总动力>户籍人口>城镇人口>固定资产投资>第三产业增加值>GDP>粮食产量>第二产业增加值,交互作用探测器表现为双因子增强或非线性增强关系。综合来看,耕地非农化是社会、经济因素综合作用的复杂结果。鉴于此,本文建议通过严格控制城市建设用地占用耕地的规模、挖掘农村居民点利用潜力、转变经济发展方式、推动农业产业结构调整等措施治理耕地非农化。

县域耕地非农化时空演变特征及动态趋势研究——以安徽省为例

耕地是国家粮食安全的物质基础,把握耕地非农化的时空演变规律及动态趋势,对保障粮食供给和可持续发展具有重要意义。以安徽省为研究对象,基于ArcGIS、GeoDa和Matlab软件,提取安徽省1995—2020年耕地非农化数据,在县域尺度上,采取探索性空间数据分析方法研究耕地非农化时空演变特征,运用MarKov链分析耕地非农化的动态演变趋势,为合理管控耕地非农化提供科学依据。结果表明,安徽省耕地非农化面积高值区主要位于安徽省中部(合肥都市圈)重点发展区,低值区主要集中在安徽省北部和南部一些经济欠发达地区,空间集聚性呈先减后增再减趋势,集聚效应逐渐减弱,冷热点区在空间上形成了“块状热点集群”和“点状冷点集群”。安徽省县域耕地非农化水平的趋势主要表现为:不同等级间不够稳定,易发生转移;等级转移基本发生在相邻类型之间,较少出现“跳跃式”转移;考虑空间因素后发现,相邻县区差异化的耕地非农化水平对本县区发生等级转移的概率有不同程度的影响,随着空间溢出效应增强,维持原等级的概率越低,更易发生转移;等级转移的概率同时受空间滞后类型和初始等级的影响。

1990—2020年滇中城市群耕地非农化时空变化特征及驱动机制

[目的]通过分析滇中城市群30年耕地非农化的演变路径、时空变化特征及驱动机制,为滇中城市群耕地资源的保护及精准管理提供理论依据。[方法]基于滇中城市群土地利用数据和统计年鉴数据,运用重心迁移模型、变化轨迹模型、空间自相关分析、主成分分析等方法揭示1990—2020年滇中城市群耕地非农化过程、空间分布特征及主要驱动因素。[结果](1)从时间上看,滇中城市群耕地非农化面积呈波动下降趋势,2000年前后由年均增加约6.88×10^(3)hm^(2)转变为年平均减少约2.66×10^(4)hm^(2),受政策、经济和城市化影响导致其变化最剧烈。从空间上看,耕地非农化集中分布于滇中城市群的中部、东部、东南部和东北部地区。(2)30年来,滇中城市群耕地非农化在空间分布上趋于均衡,区域间耕地非农化差异变小,空间格局趋于稳定。(3)滇中城市群耕地主要转出为林地和草地,少部分转化为建设用地,变化型耕地中有54.60%与草地相关,29.33%与林地相关,4.64%与建设用地相关,主要发生在滇中城市群的中部、北部、东南部和西北部的局部区域。(4)滇中城市群耕地非农化存在显著的空间聚集效应,以高—高聚集和低—低聚集为主,高—高聚集主要分布在中部、北部和东南部,低—低集聚主要分布在西北部、西部和西南部。(5)滇中城市群耕地非农化受社会经济和自然条件共同影响。社会经济中的农业人口、国有固定产投资和城市化率是耕地非农化最主要的驱动因素,影响系数分别为-0.18,0.11,0.10;而自然因素年平均降水量和年平均气温在耕地非农化空间分布和扩张过程起着关键性的作用,影响系数分别为0.17,-0.15。[结论]研究结果揭示30年来滇中城市群耕地非农化的时空变化特征、演变路径及驱动机制。对合理利用和保护耕地资源,保障云南省粮食安全具有重要作用,在一定程度上可为滇中城市群的耕地保护和耕地布局优化提供决策参考。

耕地非农转换空间非均衡测度及空间扩散路径分析——以武汉城市圈为例

基于武汉城市圈48个区(县)2000—2020年5期土地利用变化数据,采用洛伦兹曲线、基尼系数测算武汉城市圈耕地非农转换空间非均衡程度,并利用重心模型绘制基于耕地非农转换速度的分级重心曲线,分析耕地非农转换空间分布特征及时空扩散路径。结果表明:(1)武汉城市圈耕地非农转换速度呈现中部高,四周低的总体特征。(2)耕地非农转换速度空间分异特征明显,不同时期耕地非农转换最快的区域均集中于武汉市及黄石市下辖区县。(3)武汉城市圈耕地非农化在县域尺度上空间分布极不均衡,且非均衡程度有先下降后逐步上升的趋势,其中2005—2010年非均衡程度最低。(4)2000—2020年不同时期耕地非农转换速度分级的重心集中分布于武汉市洪山区、蔡甸区、江夏区、江岸区以及鄂州市的鄂城区。(5)武汉城市圈耕地非农化重心空间迁移方向为西北—东南—西北,其空间扩散路径整体呈现回旋状。该研究实现了武汉城市圈在县域尺度耕地非农转换方向和均衡性的动态可视化,为协调土地非均衡发展和促进区域均衡发展提供了一定科学依据。

新形势下耕地资源质量分类与等别转换的应用研究——以济南市为例

以济南市为研究区域,在2021年度耕地资源质量分类成果的基础上,运用改进的灰靶模型和指标赋分求和法2种等别转换方式将济南市耕地资源质量分类成果转换为等别数据。结果表明:改进的灰靶模型兼顾了耕地的自然本底特征和耕地的粮食产能,在赋权和评价过程更为客观、科学,转换后的等别成果更为合理,济南市质量较好的耕地主要位于中部和北部平原地区以及沿黄地区,等别主要为3等和4等地,占总耕地面积的77%,符合济南市实际情况;采用指标赋分求和法转换的等别整体较为合理,但主观性较强,评价结果区域内部差异性较小。因此,改进的灰靶模型在耕地资源质量分类与等别衔接研究中应用性更强,转换成果可为耕地占补平衡与进出平衡等实践应用提供参考。

土地资源管理中县级国土空间总体规划编制问题及对策

针对南华县国土空间总体规划中耕地“非农化”“非粮化”、用地布局缺乏科学性等问题,通过采取工程措施与调出补划相结合的方式,调整规划分区规则以及分类型、分区域布局新增建设用地等措施,使永久基本农田中的“非耕地”面积减少了149.02 hm^(2),农田保护区面积增加了9 607.35 hm^(2),城镇开发边界和村庄建设边界外的新增建设用地规模由6 044.02 hm^(2)下降到417.83 hm^(2)。

喀斯特山区耕地“非粮化”空间分布特征及驱动机制研究--以平塘县为例

基于平塘县2012年和2022年的土地利用数据,探究耕地“非粮化”的空间分布特征并分析耕地坡度、耕地质量、道路距离、居民点距离、水源距离5个因子对耕地“非粮化”的驱动作用。结果表明:(1)平塘县现状耕地为30946.67 hm^(2),耕地“非粮化”面积为20046.68 hm^(2),耕地“非粮化”率为39.31%;中国天眼5 km范围内耕地“非粮化”率达到63.70%,远高于全县耕地“非粮化”率;(2)耕地“非粮化”变为林地的面积为17080.00 hm^(2),变为园地的面积为2826.66 hm^(2),两者共占耕地“非粮化”面积的99.30%;(3)随着耕地坡度增加,耕地质量降低,离居民点、道路、水源距离增加,耕地“非粮化”率均显著上升。耕地坡度、耕地质量、居民点距离、道路距离、水源距离5个因子对耕地“非粮化”的影响权重分别为0.34、0.26、0.17、0.13、0.10,其中自然条件因素对耕地“非粮化”的影响权重达0.60,是引起耕地“非粮化”的主要原因。

农地非农化经济驱动机制的理论分析与实证研究

协调好经济发展和农地保护的矛盾是实现我国社会经济可持续发展战略的重要基础,而农地非农化又是这一矛盾的焦点,合理调控农地非农化需要掌握其驱动因素的作用机理,辨识主导因素。论文从影响土地资源部门配置的社会经济因素出发,构建了一个农地非农化经济驱动机制的理论分析框架,并应用1995～2001年省级数据进行实证分析。初步分析结果表明,人口增长、固定资产投资是农地非农化的主要推动因素;土地利用的比较效益和耕地资源禀赋是农地非农化的基础因素;地方政府的收益以及地方政府的管制应对行为与农地非农化呈正相关关系,而土地的市场化配置程度与农地非农化的面积呈负相关关系。根据上述的研究结果,文章提出了相应的政策建议。

农用地等级折算成果在耕地占补平衡中的应用

"耕地占补平衡"制度是实现中国严格保护耕地的一项基本制度,耕地占补平衡即包括数量平衡又包括质量平衡。该研究以辽宁省为例,在农用地分等定级成果基础之上,进行了辽宁省耕地各等级之间的折算系数测算,建立了耕地各等级之间的折算系数关系,在此基础上,提出了农用地等级折算成果在耕地占补平衡应用中应注意的两个问题,一是要注意各等级折算系数间的变化规律,二是要注意耕地各等级系数间的变化梯度,本研究最后提出在依据农用地等级折算系数进行补充耕地时,有必要建立所补充耕地的质量标准体系,真正实现耕地占补平衡中的质量平衡。

数量质量并重管理的耕地保护政策研究

研究目的:研究中国耕地保护的现状,构建数量质量并重的耕地保护体系。研究方法:文献资料法和因果分析法。研究结果:(1)中国耕地保护的现状是耕地面积逐年减少、等级不高、分布细碎、后备资源少;(2)数量质量并重管理的耕地保护体系是严守耕地红线、提升耕地等级、稳定耕地布局、严格耕地占补。研究结论:农用地分等成果是耕地质量保护的有力技术支撑。

中国耕地供需变化规律研究

研究目的:探讨中国城市化—工业化用地需求和满足粮食安全的耕地供给之间的消长关系及变化规律,以期为国家土地利用政策提供科学依据。研究方法:首先提出关于最小人均耕地面积(即满足粮食安全的人均耕地需求)和耕地非农化逻辑斯蒂的假设。然后对历年中国耕地的统计数据进行订正,重建1980—2006年耕地数据序列。据此计算了同期的最小人均耕地面积和耕地压力指数(反映耕地需求和供给的对比关系),并验证耕地非农化逻辑斯蒂假设。研究结果:保障粮食安全的人均耕地需求数量逐渐降低,耕地压力指数虽先降后升但总体呈下降趋势。中国在基本满足城市化—工业化用地需求和生态退耕,因而满足粮食安全需求的耕地供给不断减少,同时人口又不断增加的情况下,粮食安全状况非但没有恶化,反而有所改善;耕地压力指数非但没有加重,反而有所减轻,根本原因在于土地生产率的不断提高。耕地非农化逻辑斯蒂增长过程的推导和证明,显示了两个拐点分别出现在1980年和2050年,前者是从缓慢到加速的转折点;后者是从增长到停滞的转折点,保证粮食安全的耕地供给将趋于稳定。其间还有一个由加速到减缓的拐点将出现在2015年。研究结论:城市化—工业化用地需求和粮食安全用地需求可以兼顾。

县域耕地后备资源与规划期内数量质量并重的占补平衡分析

耕地后备资源是耕地的重要补充来源,在耕地占补平衡中具有重要作用,但在补充耕地能力上长期存在偏主观、重数量等情况。利用国土部新一轮耕地后备资源调查评价试点县成果,在新增耕地系数和等级折算系数的基础上提出了耕地数量与耕地数量质量并重的平衡测算方法,分析县域规划期内实现耕地占补平衡的能力。以湖南省沅江市为例,测算至2020年实现数量平衡和数量质量平衡需开发的耕地后备资源面积。结果显示,满足耕地数量平衡需开发耕地后备资源面积为1 083.37 hm2;满足数量质量并重平衡,最低需开发耕地后备资源面积1 083.37 hm2,最高需开发1 351.65 hm2。通过测算,沅江市耕地后备资源开发可满足县域耕地占补数量、质量平衡的需要,但存在较大压力,尤以数量质量并重平衡为甚。因此,明晰县域耕地后备资源补充耕地的能力有利于合理安排新增建设项目,确保实现土地利用总体规划保护耕地的目标。

耕地利用效益体系与耕地保护的经济补偿机制重构

基于耕地功能的多样性以及在社会经济整体发展中的地位和作用,重构了耕地利用的效益体系,并在此基础上分析了耕地利用生态社会效益外部性下的耕地非农化机制。分析表明,耕地利用生态社会效益的外部性是耕地非农化的根本原因,而构建耕地保护的经济补偿机制则是抑制耕地非农化的根本途径。最后提出了耕地保护的区内经济补偿和区际经济补偿运行机制、补偿体系和实施措施。

区域土地开发整理新增耕地潜力及其贡献分析

为了指引重庆市土地开发整理项目的时空配置,保障区域"耕地数量和质量占补平衡",从单位可整理面积新增耕地潜力出发,应用等级折算系数法,分别测算了耕地整理、农村居民点整理、未利用地开发和土地复垦新增耕地潜力,并借助分层聚类法划分出单位新增耕地潜力区,阐明了不同土地开发整理类型对区域新增耕地总潜力的贡献率。结果表明:重庆市不同土地开发整理类型按等折算单位可整理面积新增耕地潜力存在显著区域差异。耕地整理单位潜力Ⅰ、Ⅱ级区主要分布在渝东北中山区和渝东南低、中山区;农村居民点整理单位潜力Ⅰ、Ⅱ级区主要分布在渝西方山丘陵区;未利用地开发单位潜力Ⅰ、Ⅱ级区主要分布在渝西方山丘陵区和渝中平行岭谷低山丘陵区;土地复垦单位潜力Ⅰ级区全部分布在渝西方山丘陵区,Ⅱ级区集中在渝东南低、中山区和渝东北中山区。按等折算单位可整理面积新增耕地潜力既将新增耕地数量和质量紧密与各区县被占用耕地等级挂钩,有利于区域耕地占补平衡从数量到质量的真正落实,又削弱了各区县不同类型土地开发整理可整理面积本身存在的差异对新增耕地潜力测算结果的影响,分级结果更具实际意义,有利于从区域实际出发,高效地安排不同土地开发整理类型项目启动时序及空间配置,获得资源优势的空间互补。