Spatial and temporal variability of farm size in China in context of rapid urbanization

During the last 30 years,China has witnessed rapid economic growth and dramatic urbanization,with about 1.2 × 107rural people migrating annually into urban areas.Meanwhile,especially since 1995,the rural population has been declining,which is closely linked to land circulation and the increase in farm size in many villages.Increasing scale of farming operations is often regarded as a key to avoiding the abandonment of farmland and to increasing the income of rural farmers.However,until now,there has been little research on the spatial and temporal variability of farm size at the national level in China.Using data from the national agricultural census and rural household surveys,this study examines the characteristics of land use circulation and the consequent changes in the area of farmland per household.The results show that: 1) 12.2% of rural households were involved in land circulation at the national level.The highest amounts of land circulation have occurred in those provinces where the farmland per capita is more than 0.2 ha or less than 0.1 ha;2) over 80% of households operate less than 0.6 ha of farmland;3) the proportion of mid-sized farms(between 0.2 ha and 0.6 ha per household) has decreased while the smallest and the largest farms have increased.This bears some similarity with the phenomenon known as the ′disappearing middle′,referring to the changes in farm size.This study establishes a framework for interpreting the factors affecting the changes in farm size in China,which include two promoting factors(urbanization and agriculture) and four hindering factors(agricultual land system,household registration,stable clan system,and farmland loss).     

乡村振兴背景下镇域高标准农田建设分区研究——以山东省滨州市阳信县商店镇为例

在乡村振兴战略背景下,在镇域尺度上构建适宜性评价指标体系,划定高标准农田建设分区,用以指导商店镇高标准农田项目的建设方向。以适宜性评价、障碍度模型为研究方法,研究结果显示商店镇高标准农田建设适宜性一级区主要分布在镇域的中南部地区,二级区基本环绕在一级区外侧,三级区分散于镇域各地,以镇域北部居多,有城镇发展的需求,较不适宜建设高标准农田。商店镇高标准农田建设的障碍因子主要包括耕地连片度、灌溉保证率、盐渍化、有机质含量以及乡镇建设需求。耕地连片度、盐渍化、有机质含量以及乡镇建设需求这4个建设障碍问题在镇域北部都明显存在;镇域东部主要表现为盐渍化问题与耕地连片度,在东部地区高标准农田建设时需重点解决;南部主要存在耕地连片度与灌溉保证率的问题,需加大农田基础设施建设。商店镇高标准农田建设可划分为优先建设区、重点发展区与后备保留区,基于障碍因素进一步细化为12个分区,总体来说,商店镇高标准农田建设南部以完善农田基础设施建设、改良土壤为主,北部地区整治方向为规模化整治、促进农业产业化发展。     

Livelihood Diversification of Farm Households and Its Impact on Cultivated Land Utilization in Agro-pastoral Ecologically-vulnerable Areas in the Northern China

The relationship between livelihood diversification of farm households and cultivated land utilization has become a core research topic related to global environmental change. Agro-pastoral ecologically-vulnerable areas face challenges such as insufficient ecosystem conservation, low agricultural production, and weak economies. In this study, 215 farm households from Zhengxiangbai Banner, Taibus Banner, and Duolun County of Inner Mongolia were surveyed. The sustainable livelihoods framework of the United Kingdom(UK) Department for International Development(DFID) was used to measure the livelihood capital of these farm households. A one-way analysis of variance(ANOVA) was applied to examine the differences in the livelihood capital of different types households, and a correlation analysis was applied to analyze its impact on cultivated land utilization. Results showed that households with non-farming activities accounted for 64.7% of the total surveyed households, and non-farming employment was becoming more prevalent. Physical and financial capital was the driving factors for livelihood diversity. Each livelihood capital had key factors that affected household farmland use behaviors, such as the age of householder, the labor ratio, proportion of income, farmland scale, number of machines, and these had a significantly positive or negative influence on farmland use. Full-time farming households were more likely to transfer the land into cultivation and invest more labor, while non-farming households with high income were likely to transfer farmland out and invest more money to develop efficient farming or improve the employment skills. The results of this study suggest that policymakers need to fully consider livelihood changes of local households. It is effective to strengthen labor training, create farmland market and improve the efficiency of farmland utilization. We hope to achieve a win-win scenario to improve local economies and ecosystem conservation.     

Conflict between wild boars(Sus scrofa) and farmers:distribution,impacts,and suggestions for management of wild boars in the Three Gorges Reservoir Area

Economic losses caused by wild boars(Sus scrofa)continue to increase in the Three Gorges Reservoir Area.We selected 206 farmers in Wuqiaohe Basin as survey respondents using random stratified sampling.The distribution and impacts of wild boars were examined using a questionnaire survey and spatial analysis.The results showed that:(1)The density of farmer settlements is low and most peasants'households are located on the forest edge.Due to large-scale labor migration,a high proportion of farmland(25.85%)has been abandoned and an even higher proportion of farmland(40.48%)has been returned to forest.(2)The probability of wild boar damage to peasant households was 67.96%.Yields of corn and sweet potato decreased by 24.87%and 28.24%,respectively,with a total economic loss of approximately 2,590,100 RMB/yr in the Wuqiaohe basin.Sixty-five percent of the affected cultivatedlands were located within approximately 150 m of the forest edges.(3)The wild boar damage coefficient was significantly and negatively correlated with the distance between the peasants'household and the forest edge,the density of the settlements,and the area of cultivated land.The wild boar damage coefficient shows a significant positive correlation with the area of farmland returned to forest.(4)The damage activity caused by wild boars began to occur7-8 years ago,and the destruction has been more frequently and seriously observed in the last 4-5 years.(5)We make suggestions for wild boar control and management measures including developing a compensation policy.The compensation standard is related to the land area returning from farmland to forests and the actual cultivated land area.     

平阴县孝直镇关于大村制新型农村社区建设的探索和实践

平阴县孝直镇属偏远的农业大镇,为解决村庄规模偏小、布局分散和"空心村"等问题,充分利用国家城乡建设用地增减挂钩政策,以土地综合整治为平台,积极推进大村制建设,合村并点建设新型社区,从根本上改变农村面貌,加速城镇化和城乡一体化进程。     

北京城市人口空间分布特征的GIS分析

城市人口空间分布特征分析是城市化影响下的局地尺度人类-环境(Human-Environment)相互作用研究的一个重要内容.本研究以第五次人口普查数据,采用GIS网格计算方法,模拟北京市2000年人口空间分布,并从宏观、微观、中观3个不同层次分析其空间分布与变异特征.研究表明,从宏观角度分析,各环路间人口密度具有较大的...     

融合多源空间数据的城镇人口分布估算

精细尺度的城镇人口空间分布是分析人类-资源-环境相互关系的重要指标。本文提出了一种融合地理空间大数据和高分辨率遥感数据估计精细尺度城镇人口分布的方法。通过对比各指标与人口相关性,选取R2>0.7的建筑面积、到道路距离、夜间灯光强度、商服中心、EAHSI指数、幼儿园、公园、小学、加油站、医院、公交车站、长途汽车站作为影响人口分布的变量因子。结合城市功能区数据确定人口分布区域,利用随机森林模型对宁波市2018年人口数据进行了500 m格网空间化,从而得出宁波市城镇人口空间分布图。最后,基于随机森林模型的变量因子重要性分析宁波市人口空间分布的影响因素。研究结果表明,本文所提出的城镇人口分布模型在街道尺度的估算精度为81.2%,平均相对误差MRE为0.29、RMSE为3279.89;网格级别的MRE为17.16,RMSE为1149.9,因此模型能精确地反演城镇内部街道人口分布信息。通过对变量因子重要性进行比较,发现建筑面积重要性约为0.22,对宁波市人口估算影响最大;到道路的距离、夜间灯光强度、商服中心、EAHSI（Elevation-Adjusted Human Settlement Index）、幼儿园、公园对宁波市人口估算具有重要作用。本文在格网级别进行的人口分布精度验证对于研究城市精细人口分布具有重大意义。     

日照市西赵村崩塌地质灾害评估及治理方法

目前,日照市因废弃矿山引发的地质灾害主要表现在崩塌、滑坡等方面,对废弃矿山进行地质灾害预测并根据实际情况制定治理方案,不但能有效避免因地质灾害造成的损失,又能绿化生态环境,消除视觉污染。通过对日照市岚山区巨峰镇西赵村崩塌体的基本特征及现状进行影响评估,并就西赵村崩塌地质灾害的治理方案进行了初步分析探讨,为日照市因废弃矿山普遍引发崩塌地质灾害的防治提供了理论基础资料。     

Effects of land-use types on soil organic carbon stocks: a case study across an altitudinal gradient within a farm-pastoral area on the eastern Qinghai-Tibetan Plateau,China

A crucial region for China's ‘Grain-forGreen Policy' is located within a traditional farmpastoral area, between 2000 to 3000 m above sea level, on the eastern Qinghai-Tibetan Plateau.However, the responses of soil organic carbon(SOC) to different land-use patterns in this region are unclear. Here, we determined the SOC(0–20 cm) content of grasslands and forests that are being converted from farmlands, as well as in abandoned arable land and arable land in this region. The factors influencing the reclaimed lands were analyzed along altitudes from 2030 to 3132 m. Our results showed that SOC content was higher for grassland and abandoned arable land than forest and arable land. The SOC content increased with the increase in altitude for total land-use patterns. Further, the grassland and abandoned arable land had higher SOC content than the forest with almost parallel trends along the increase in altitude. However, the proportion of regulated factors of altitude and species richness varied among forest, grassland, and abandoned arable land. Our results indicated that the land-use pattern of returning farmland to grassland and abandoned arable land was more effective in terms of the SOC storage in the superficial layer in this altitude range in the Qinghai-Tibetan Plateau, thereby being beneficial to optimizing land management in this region.     

Impact of labor transfer on agricultural land use conversion at rural household level based on Logit model

Since land and labor force are primary resources to be used and controlled by rural households, the allocation of labor forces will influence land uses, and further lead to land use conversion. The present study used the Binary Logit model to investigate the influence of labor force transfer, characteristics of rural households, location, and land market on agricultural land use conversion at rural household level. This study was conducted based on 329 valid questionnaires, which were obtained in Changshu, Rudong, and Tongshan counties, respectively representing the southern, middle and northern areas of Jiangsu Province. The results showed that land market participation, location, zonal difference and labor transfer had strong influences on agricultural land use conversion. The participation of land market had a strong positive effect on land use conversion, especially for the farmland converted to the fishpond. The nearer to the county seat, the more conversion of land use occurred. Particularly, the labor force transfer caused by wage employment decreased this conversion probability, while the labor transfer caused by self-employment led to more conversion; and the increasing of income from labor transfer increased the conversion. Moreover, land use conversions demonstrated zonal difference, which were more in Rudong and Changshu counties than in Tongshan County, and the factors influencing this conversion were different in the three regions.     

GF-2在城市绿地分类及景观格局度量中的应用

城市植被是维护城市生态系统平衡的重要组成元素,不同类型的植被具有不同的生态服务效益,然而基于植被精细分类的城市绿地景观格局度量研究较少。因此本文以北京城市副中心为研究区,使用夏、冬两季GF-2卫星遥感影像,基于随机森林特征优选和面向对象分类,划分了植被类型,并在此基础上使用景观指数法和移动窗口法分别度量了功能区尺度和栅格尺度绿地景观特征。研究结果表明：针对GF-2数据,使用多尺度分割后影像对象的光谱、纹理特征可以有效地提取植被信息;不同时相的影像能反映各类型植被的物候特征,相比于单时相数据,其分类精度更高,达到了87.7%;各功能区绿地景观格局特征差异较大,城市绿心拥有最丰富的植被且分布集中,商业区植被覆盖度和多样性均较低,绿地景观破碎;北京城市副中心景观多样性及各类型植被分布特征的空间差异显著,当前副中心绿地景观格局已形成规划的基本轮廓,但城市绿心和老城区公共绿地的建设仍有不足。研究探明了北京城市副中心绿地建设现状,证明了国产GF-2卫星在城市生态环境监测中具有较高的应用价值,有助于推动GF-2在城市生态环境领域的应用,并为副中心建设中的绿地系统监测和优化提供参考。     

南京市老城区城市建筑点格局研究

城市建筑是城市形态的重要组成部分,而建筑高度对城市三维空间形态有重要的影响。目前,对城市二维形态的研究较为丰富,而对城市三维起伏形态特征及其空间分布格局方面研究较少,对城市上空利用程度及发展规律认识仍相对缺乏。本文以南京市老城区为例,基于城市数字高程模型数据,将城市建筑抽象为三维点要素,运用点格局分析法研究城市建筑三维宏观特征及建筑类型的空间分布规律。结果显示：（1）南京老城区建筑呈集聚分布,聚集性顺序是低层建筑>高层建筑>多层建筑>超高层建筑。除超高层建筑外,低层、多层和高层建筑的聚集程度,随着空间尺度先增后减,均在1.5 km尺度聚集性最大;显示1.5 km的街区单元应是城市规划管理的最适宜单元。（2）南京老城区建筑高度空间分布表现为“三高一低”,即3个高值区（新模范马路、新街口和珠江路区域）和1个低值区（集庆门区域）,它们与不同时期城市中心具有较好的对应关系;不同类型建筑与城市基准地价的相关分析显示,建筑高度的分布与城市基准地价呈现一定相关性。结果表明,点格局分析方法能有效地分析城市建筑在平面及三维的空间格局特征,进一步深化对城市形态特征的认识。     

A method for spatial heterogeneity evaluation on landscape pattern of farmland shelterbelt networks: A case study in midwest of Jilin Province,China

On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this paper. The distance coefficients of reasonable and existing landscape indexes of farmland shelterbelt networks were computed, and then through the classification of the distance coefficients, and the establishment of evaluation rules, the spatial heterogeneity of farmland shelterbelts was evaluated. The method can improve the evaluating system of previous studies on shelterbelts distribution, resolve the disadvantages of lacking spatiality of overall evaluation, and make the evaluation results have more directive significance for shelterbelt management. Based on this method, spatial heterogeneity of shelterbelt networks was evaluated in the midwest of Jilin Province, China. The results show that the regions with fewer shelterbelts and no closed network account for 34.7% of the total area, but only 4.9% of the area has relative reasonable pattern of shelterbelt networks. Many problems exist in the distribution pattern of shelterbelts, therefore, much attention should be paid to construct farmland shelterbelts in the study area.     

地下水循环结构的动力学研究进展

由地下水补给、径流和排泄过程构成的地下水循环运动,是水文循环的重要组成部分,也是水文地质学的基本研究对象。地下水循环在空间上表现为不同结构单元的组合,存在以含水层特性为依据的介质结构和以渗流场为依据的动力结构2种划分方法。地下水流系统是动力结构意义上的地下水循环单元。近10年来,区域地下水流系统理论取得了显著进展,更加全面深入地揭示了地下水循环结构的动力学特性。通过对河间地块地下水流系统的研究,发现潜水面最高点并非地下水分水岭的准确位置。在盆地尺度上,系统研究了沟谷地貌、降水入渗强度、渗透性随埋深变化和盆地厚度等因素对潜水面波形与地下水循环动力结构的影响,初步发现了动力结构的周期性或趋势性演化特征。通过大规模流线路径的精细识别或驻留时间的统计分析,提出了三维地下水循环单元的划分方法。在水文地质效应方面,发现地下水循环的动力结构对地下水年龄的分布有重要影响。地下水循环的动力结构反映了不同补给区和排泄区之间的水力联系,在盆地尺度地球化学过程、流域尺度生态水文过程中发挥着关键作用,未来的研究重点是三维地下水循环的动力特性和演变规律。     

“股份+合作”土地流转模式的实践和启示——以宁阳县蒋集镇郑龙村为例

近年来,宁阳县蒋集镇郑龙村对土地流转进行了积极探索,形成了"股份+合作"的土地流转模式,这种模式有一套完整机制,取得了合作多赢的成效,并给国土资源工作一定的启示。这一模式得到国家农业部及省市有关专家充分肯定,认为是全国土地流转成功模式之一。     

Modeling of spatial distributions of farmland density and its temporal change using geographically weighted regression model

This study used spatial autoregression（SAR） model and geographically weighted regression（GWR） model to model the spatial patterns of farmland density and its temporal change in Gucheng County,Hubei Province,China in 1999 and 2009,and discussed the difference between global and local spatial autocorrelations in terms of spatial heterogeneity and non-stationarity. Results showed that strong spatial positive correlations existed in the spatial distributions of farmland density,its temporal change and the driving factors,and the coefficients of spatial autocorrelations decreased as the spatial lag distance increased. SAR models revealed the global spatial relations between dependent and independent variables,while the GWR model showed the spatially varying fitting degree and local weighting coefficients of driving factors and farmland indices（i.e.,farmland density and temporal change）. The GWR model has smooth process when constructing the farmland spatial model. The coefficients of GWR model can show the accurate influence degrees of different driving factors on the farmland at different geographical locations. The performance indices of GWR model showed that GWR model produced more accurate simulation results than other models at different times,and the improvement precision of GWR model was obvious. The global and local farmland models used in this study showed different characteristics in the spatial distributions of farmland indices at different scales,which may provide the theoretical basis for farmland protection from the influence of different driving factors.     

Analyzing land use characteristics of rural settlements on the urban fringe of Liangjiang New Area,Chongqing, China

The objective of this paper is to analyze land use characteristics of rural settlements in urban fringe so as to provide references for optimizing the regional distribution of rural settlements, consolidating rural settlements, and coordinating urban-rural integrated development. The methods of spatial statistical analysis, buffer analysis, Ripley’s K function, kernel density analysis based on GIS (Geographic Information System) were used to analyze the characteristics of scale, spatial differentiation and spatial patterns of the rural settlements in Liangjiang New Area in Chongqing Municipality of China. The fractal dimension formula was also developed to reflect fractal feature of the rural settlements. The results show that, the scale of rural settlements in Liangjang New Area takes on distinct characteristics of spatial differentiation along with changes in elevation, gradient, location, geo-hazards distribution, and the like. The fractal characteristic of rural settlements has obvious regional variations subject to the 6 factors of location in the Liangjiang New Area. Overall, the worse the terrain conditions are, the larger the fractal dimension values become. The better the location conditions, the larger the fractal dimension values are. The spatial pattern in the township scale presents three kinds of distribution as being aggregated, uniform and random. In contract, the spatial pattern in the plaque scale displays a banding distribution from a general view with several aggregation zones centering on each town center. From the results, we can see that the characteristics of rural settlements in urban fringe are more complicated. For such kind of rural settlements in special regions, in the rural land consolidation more attention should be paid to improve the rural living environments and public services, as well as to promote the harmonious relationship between the urban and rural areas.     

2001-2017年中国不同耕作区重建MODIS LAI时空动态

叶面积指数Leaf Area Index(LAI)作为植被生物量指标之一,耕作区LAI不仅能反映作物的长势动态,且与农业生态、作物产量密切相关.本文通过对2001-2017年中国农田区域的MODIS-LAI长时序数据进行重建,利用Mann-Kendall检验、变异系数、重心迁移模型等方法分析了中国耕作区LAI的时空变化...     

基于累计机会可达性的北京城市公共服务设施复合功能识别

城市时空大数据技术的快速发展和应用,为城市功能区识别提供了新的数据基础和技术手段,但专门关于城市公共服务设施复合功能的研究还相对较少。基于北京市9大类公共服务设施的空间点数据,综合考虑不同类型公共服务设施等级和品质特征,采用累计机会方法对1 km×1 km格网尺度的北京城市公共服务设施可达性进行了综合评价,在此基础上重点分析了北京城市公共服务设施复合功能特征与影响因素。研究表明：① 北京城市公共服务设施累计机会空间分布存在明显的中心集聚特征,但不同类型公共服务设施的空间分布模式和覆盖范围却有所区别;② 北京城市公共服务设施功能区可以划分为单一功能、单一化的复合功能、2种复合功能、3种复合功能和均衡化的复合功能等5大类型;③ 人口密度、距市中心距离、土地价格和经营性为主设施的累计机会可达性是影响北京城市公共服务设施复合功能的重要因素。研究结论对进一步细化城市功能区研究和促进北京城市公共服务设施空间结构优化具有科学启示作用。     

Changes and development plans in the mountain villages of South Korea: Comparison of the first and second national surveys

Owing to the geographic disadvantages of mountain villages, the social, cultural, and economic conditions of mountain villagers are inferior to those of urban dwellers in South Korea. Thus, in 1995, the The government of South Korea launched a mountain village development support program to promote agriculture and forestry, balance national land development, and preserve cultural heritage. The program was effectively implemented, improving the income, population size, and living conditions of villagers in addition to setting up a system for stable project implementation. However, concerns were raised about long-term development planning, the creation and marketing of specialty brands, facility management/operation, and follow-up support. The government conducted surveys of mountain villagers in 2003 and 2014, obtaining basic data to address these issues. This study evaluates the outcomes of these two surveys, suggesting areas requiring focused action, concentrating on village development projects, forest resource distribution and use, demographic trends, the economy, exchange with urban areas, green tourism, and master planning. We find that despite growth in the forest labor force, forest ownership is diminishing in terms of the number and scale of holdings. Consequently, it is necessary to commercialize forest resources, establish favorable settlement conditions, and expand government support for village-run projects. In addition, systematic forest management for older tree age classes would benefit the public and provide assets for future mountain village development. Our results are expected to provide baseline information for the establishment and efficient implementation of mountain village development policy.