黄土丘陵沟壑区现代沟道农业及其可持续发展

现代沟道农业是黄土丘陵沟壑区人地耦合发展形成的一种新兴农业地域类型,其可持续发展对于区域农业高质量发展、“三生”空间优化和乡村振兴具有重大现实意义。从人地系统科学认知出发,对现代沟道农业的内涵、可持续发展方向、典型发展模式和保障体系进行了探讨,并进行了相关研究展望,为系统认识黄土丘陵沟壑区沟道农业模式,推进农业可持续发展提供了理论参考。主要结论:①沟道农业是乡村地域系统的重要功能类型,具有多尺度、多层次的特点,其可持续发展应从微观、中观和宏观3个层面,协同解决土壤生态系统、农田生态系统和农业地域系统的可持续发展问题。②保障粮食安全和生态安全,积极推进农业结构调整,发展多功能农业,通过“3C”模式,即农业自身内循环、农业外循环、基于农业多功能的农业大循环,实现生产结构优化、产业链条延伸和城乡功能互补。③创新推广土地综合整治带动模式、农业结构调整带动模式、特色资源综合开发模式和土地流转规模生产模式,有助于农业提质增效和农业高质量发展。④拓展地理学与其他学科的交叉研究,深化“理论−实践”贯通式研究,探索建立涵盖技术研发与应用、人才培养、政策制度支撑等内容于一体的农业生产保障体系,全面提升沟道农业资源利用效率和综合生产效益,推动沟道农业现代化。

黄河流域人地系统协调与高质量发展

科学解析黄河流域人地系统协调机理,寻求可持续发展途径,成为促进区域生态环境保护和高质量发展的关键。在新时代“一带一路”与黄河流域国家战略背景下,充分发挥多学科交叉综合优势,实施黄河流域人地系统协调与高质量发展科学计划,具有重要的理论价值和现实意义。该文梳理黄河流域人地系统面临主要问题,解析黄土高原“三生”空间演化及其耦合特征,探讨人地系统科学研究的重点领域和主要内容,提出了黄河流域人地系统研究范式和“土”字样带。通过黄河流域人地系统智能化模拟、高质量发展情景分析,揭示黄河流域人地系统结构功能时空格局及其演变规律,阐明国土空间生态保护与生态安全的关键因子及其驱动机制,为全面构建黄河流域资源能源节约与集约利用技术体系,深入推进生态环境保护和高质量发展战略决策提供参考依据。

罗霄山区生态用地时空演变及其生态系统服务功能的响应——以井冈山为例

生态用地的可持续利用对人类生存至关重要,而山区生态用地变化及其引起的资源环境效应是山区地域人地关系变化的反映,认识和探讨山区生态用地时空分布和形成机理对维持区域生态平衡和引导经济社会可持续发展具有深远意义。运用土地利用空间分析模型和Meta分析方法,分析井冈山的生态用地变化空间格局及其生态服务价值损益;利用Logistic回归和地理探测器,诊断生态用地的空间指向特征和时间演化过程。结果表明:(1)1990—2015年,井冈山生态用地变化显著,呈不断减少趋势,其中近城区表现最明显;生态用地转移的主要对象为城乡建设用地。1990—2000年间,井冈山生态用地的总体转移速率远远大于2000—2015年间的转移速率;林地的转移面积及占比最大,转移部分大于新增部分,属于生态用地减少型地类,而草地和水域属于生态增加型用地,且转移速率较大,是井冈山市较“活跃”的生态用地类型。(2)生态用地的时间演化过程的主导驱动因素包括人口数量和产业结构,空间演变格局中的主导驱动因素为到河流的距离和到地域中心的距离。(3)1990—2015年,生态系统服务价值不断降低但减少速率逐渐放缓,19902000年的年均减少量大于2000—2015年的年均减少量。其中,林地对生态服务价值的贡献最大。山区乡村振兴应以生态系统服务价值目标导向,实现农民生计和生态安全的协同优化,利用山区地域资源优势,强化三产融合,推进山区“乡村振兴”。

土层复配方案对治沟造地新增耕地土壤肥力的影响

新增耕地质量的提升对于延安“治沟造地”项目实施后耕地的有效利用意义重大。为探索一种快速改良“治沟造地”新增耕地质量的有效方法,该研究在延安羊圈沟流域((109°31′~109°71′E,36°42′~36°82′N))开展了为期4 a的新造耕地土层复配试验。试验基于红黏土(Red Clay,RC)和马兰黄土(Malan Loess,ML)结构上的互补性,利用不同比例的RC和ML对新造地块0~30 cm的土层进行复配重构(T0,未复配的原状土;T1,100%的RC;T2,83.3%的RC和16.7%的ML;T3,66.7%的RC和33.3%的ML;T4,50%的RC和50%的ML;T5,33.3%的RC和66.7%的ML;T6,16.7%的RC和83.3%的ML;T7,100%的ML),通过对土壤的理化性质和作物生长情况的分析,结合主成分分析,探索了不同土层复配方案对土壤肥力和作物产量的影响。结果表明:T2和T3处理>0.25 mm水稳性团聚体分别较对照组T0显著提高了13.7、15.2倍;T3处理>0.25 mm水稳性团聚体的几何平均直径(Geometric Mean Diameter,GMD)和平均重量直径(Mean Weight Diameter,MWD)较T0处理分别增大20.9%和29.1%,而容重较T0处理减小11.1%,孔隙度增大15.3%。T3处理有机质和硝态氮含量较T0处理分别增加了24.5%和100%;T2、T3处理有效钾较T0处理分别增加了29.3%和17.6%。主成分分析结果显示,土体结构是土壤肥力形成的结构基础,土壤养分是土壤肥力的重要组成部分,二者共同决定土壤的肥力状况;综合评价结果显示各处理土壤肥力综合得分由高到低依次为T3、T2、T1、T5、T6、T4、T7、T0。T3处理玉米具有最大地上生物量和千粒质量,且玉米产量也相对较高。综合土壤肥力和玉米生长状况,认为当RC为66.7%,ML为33.3%时,复配方案相对较优,能提高土壤的肥力。试验初步表明土层复配是一种可行的快速营造高质量土壤的技术方法,研究为提升“治沟造地”工程新增耕地质量及今后类似土地整治工程的实施提供实践参考。

1978-2017年中国农业污染物影子价格及污染成本测算

农业污染物影子价格及污染成本估算是制定农业污染减排政策的基础性工作。该研究以1978-2017年中国农业部门的省级面板数据为研究单元,利用二次型方向性距离函数和收益函数的对偶关系估算了农业污染物的影子价格,并测算了农业生产的污染成本。研究发现:1978-2017年,中国农业污染物总氮(TN)、总磷(TP)和化学需氧量(COD)的影子价格总体呈下降趋势,分别下降了26.8%、35.9%、59.7%,并大致经历了自由发展、改革推动、市场调控与政策激励4个阶段。由于受自然资源条件与社会经济条件的影响,农业污染物的影子价格存在明显的区域差异,表现为东北地区TN的影子价格最低,西南地区TN和TP的影子价格最高而COD的影子价格最低,华东地区TP的影子价格最低而COD的影子价格最高。中国农业生产年均污染成本为760.6亿元,占全国年均农业总产值的10.8%,尤其是宁夏、贵州、河北、山东的污染成本占各省年均农业总产值的比例高于14%,表明农业污染成本巨大。中国农业污染物影子价格的长期演变趋势及其污染成本分析表明,农业政策的制定应避免掉入"逐利政策"陷阱,并积极转变农业生产方式与探索农业管理新模式。

京津冀地区农业农村发展及城镇化影响研究

从地理学的视角,基于城乡地域系统理论,分析京津冀地区农业农村发展的时空格局及城镇化对农业农村发展的影响。结果表明:(1)时间上,京津冀地区农业农村发展的人口系统发展水平逐渐降低,经济系统波动性降低,社会系统逐步升高,资源环境系统发展趋于稳定,农业农村发展水平逐渐提升。空间上,京津冀地区的县域农业农村发展水平由高到低依次为中部地区、东南地区、西北地区。(2)人口、经济城镇化与农业农村系统耦合水平较高,土地城镇化与农业农村系统耦合水平较低。城镇化对农村人口系统呈现负向效应,而对社会系统呈现正向递增效应,对环境系统具有明显的南北区域差异,经济与土地城镇化对经济系统具有正向递增效应,人口与土地城镇化对农村的资源系统具有正向递减效应。(3)城镇化对农业农村发展具有典型的阶段性和空间差异性特征。

中国乡村聚落建筑面积时空变化分析

基于土地覆盖数据集(CLCD)产品和轮廓提取算法,系统开展了1990―2020年中国乡村聚落建筑形态、面积扩展及其时空变化研究。通过深入分析乡村聚落时空变化特征发现:在快速城镇化进程中,中国乡村人口不断减少的同时,乡村聚落呈现持续扩张的态势。2020年中国乡村聚落面积约是1990年的2倍。小面积的乡村聚落拥有更快的扩张速度,在面积到达特定阈值后开始逐渐放缓。乡村聚落扩张速度具有明显的空间差异性,西部地区的扩张速度快于东部地区。乡村聚落的持续扩张和规模扩大,一方面反映了中国城乡平衡发展取得了可喜进展,另一方面也反映了城乡建设用地“双增长”可能对农业及生态用地产生负面影响,对此应当引起高度重视。

Spatio-temporal analysis of land-use conversion in the eastern coastal China during 1996-2005

Based on the acquaintance of the regional background of urban-rural transformational development and investigations on the spot,this paper discusses the holistic situation, dominant factors and mechanism of arable land loss and land for construction occupation in the coastal area of China over the last decade,with the aid of GIS technology.Conclusions of the research are summarized as follows：（1）the arable land had been continuously decreasing from 1996 to 2005,with a loss of 1,708,700 hm^2 and an average decrement of 170,900 hm^2 per year;（2）land for construction increased 1,373,700 hm^2 ,with an average increment of 153,200 hm^2 per year;（3）total area of encroachment on arable land for construction between 1996 and 2005 was 1,053,100 hm^2 ,accounting for 34.03%of the arable land loss in the same period,the percentages of which used for industrial land（INL）,transportation land（TRL）,rural construction land（RUL）and town construction land（TOL）are 45.03%,15.8%,15.47%and 11.5%,respectively;and（4）the fluctuation of the increase of construction land and encroachment on arable land in the area were deeply influenced by the nation＇s macroscopic land-use policies and development level of regional economy.The growth of population and advancement of technology promoted the rapid industrialization, construction of transportation infrastructures,rural urbanization and expansion of rural settlements in the eastern coastal area,and therefore were the primary driving forces of land-use conversion.

Rocky Land Desertification and its Driving Forces in the Karst Areas of Rural Guangxi,Southwest China

With a subtropical climate,Guangxi Zhuang Autonomous Region has a typical karst landscape.Rocky desertification has become a serious environmental issue due to its high vulnerability caused by the joint effect of natural settings and human activities,because of which its eco-environment has been deteriorated in recent years,and farmland has been disappearing sharply at the same time.This,in turn,has exacerbated the poverty level in the rural areas of the region.In this study,we monitored the spatial distribution of rocky land desertification and its temporal evolution using Landsat TM/ETM images of 1985,1995,2000 and 2005.We also analyzed the driving forces of the desertification and its expansion.Through constructing regression models by using all the relevant variables and considering the lagged effects as well as fixed effects,we quantified the exact role of different factors causing rocky land desertification in the study area with some new findings.The new findings in this study are greatly helpful for preserving,restoring and reconstructing the degraded mountain environment in Guangxi and other karst areas in Southwest China,and also for alleviating poverty in the rural areas in the future.

Hollow Villages and Rural Restructuring in Major Rural Regions of China: A Case Study of Yucheng City, Shandong Province

The agricultural land resources of China are relatively limited because of its large population.Therefore,balancing the land use for industrialization,urbanization,and food security is a big challenge.In recent years,rural hollowing in China has resulted in numerous of abandoned rural houses,and the areas with abandoned houses need to be restored into agricultural land with effective land consolidation techniques.This study used the method of benefit-cost analysis and the data collected through field surveys conducted in Yucheng City in the northwest of Shandong Province in March 2009,to examine how hollow villages (HVs) to be created and how to solve the problem.The qualitative and quantitative analyses indicate following results.1) The situation of HVs is becoming increasingly severe under rapid industrialization and urbanization in Yucheng City.2) Poor infrastructure in rural areas and incomplete urbanization are the main factors that have led to the rural hollowing in many major rural regions of China.3) In order to resolve the problem caused by HVs and increase agricultural land,reconstructing rural communities in the countryside is necessary.4) A new mechanism in the provision of compensation funds by developed regions to the villages in less-developed regions must be established.

Characteristics and Mechanism of Agricultural Transformation in Typical Rural Areas of Eastern China:A Case Study of Yucheng City,Shandong Province

Rural off-farm employment,rapid loss of agricultural land,and advanced technology popularization had led agricultural production in Chinese typical rural areas come at a critical transformation and upgrade stage.Based on sample survey data gathered from 401 households in Yucheng City,Shandong Province,this paper focuses on the characteristics and mechanism of agricultural transformation in typical rural areas of the eastern China.It was found that 74.3% of households surveyed kept at least one member engaging in off-farm employment,and 57.1% looked forward to expanding the operational scale of arable land,while just 13.7% had actually transferred their agricultural land.Since growing off-farm employment does not result in the collapse of traditional subsistence agriculture,therefore,agricultural production in Yucheng City is at an incomplete transformation phase from traditional small-holder farming to modern scale economy.It is caused by both macro environments and family characteristics,while urban-rural dual structure,imperfect rural development policy and agricultural technology popularization make peasant economy strengthen upon maintenance,and small-holder farming becomes peasant's natural response owing to pluriactivity,local off-farm employment,reverse elimination,etc.In order to achieve smooth agricultural transformation of typical rural areas in the eastern China,it needs to promote professional differentiation among peasants,under clear policies adopted by central government.Providing comprehensive services for agricultural production and improving production skills and knowledge of farmers who are still living in the countryside will effectively stimulate the process of agricultural transformation.

Method for Evaluating the Degrees of Land Use Sustainability of Mountainous County and its Application in Yunnan Province,China

The evaluation of sustainable land use is the key issue in the field of studying the sustainable land utilization. In general analysis, the sustainable land use is evaluated respectively from its ecological sustainability, economic sustainability and social sustainability in China and other countries in recent years. Although this evaluation is an important work, it seems insufficient and hard to comprehensively reflect the whole degree of land use sustainability. Thus, to make up this deficiency, this paper brings forward the evaluation indexes, which make it possible to quantitatively reflect the whole degree of land use sustainability, namely, the concept of ＂degrees of overall land use sustainability＂ （Dos）, and research and measurement development of the method of and calculation in Dos. Taking the evaluation of the degree of land use sustainability in county regions of Yunnan Province as the actual example for analysis, results are basically as follows： 1） The degree of land use sustainability （Dos） is the ration index to organically and systematically integrate the degree of ecological friendliness （DeF）, the degree of economic viability （Dev） and the degree of social acceptability （Dsa）, able to comprehensively reflect the whole sustainability degree of regional land use 2） Based on the value of Dos, the grading system and standard for the sustainability of land use may be established and totally divided into five grades, namely, the high-degree sustainability, middle-degree sustainability, low-degree sustainability, conditional sustainability and non-sustainability. Meanwhile, the standard for distinguishing sustainability grades has also been confirmed so as to determine the nature of sustainability degrees in different grades. This makes the possibility for the combination of nature determination with ration in research result and provides with the scientific guideline and decision-making gist for better implementation of sustainable land use strategy. 3） The practice in evaluation of sustainability degree in county regional land use in Yunnan shows that the value of the degree of land use sustainability （Dos） of whole Yunnan Province is only 58.39, belonging to the grade of low-degree sustainability. Two thirds of counties in the whole province represent the grade of ＂conditional sustainability＂ and ＂non-sustainability＂ in the sustainability of land use. Among these counties, 11.11 % shows ＂non- sustainability＇. The lowest degree of land use sustainability appears especially in the middle plateau mountain region of Northeast Yunnan, where the value of Dos in most counties （districts） is below 40 %, belonging to the grade of ＂non-sustainability＂. The sustainability degree in the karst mountainous region in lower-middle plateau mountain region in Southeast Yunnan is generally low and the value of sustainability degree （Dos） in most of the counties （cities and districts） is below 55. The value of sustainability degree （Dos） in most of the counties （cities and districts） in the north, west, northwest and southwest parts of Yunnan is below 55. This article also analyzes the reasons of low degree of sustainability in land use in Yunnan and puts forward the countermeasures to increase the degree of sustainability in land use in the whole province.

Dynamic Evolvement of Agricultural System and Typical Patterns of Modern Agriculture in Coastal China:A Case of Suzhou

Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.

Rehabilitation and Sustainable Use Pattern of Rocky-desertified Land in Southwest China’s Poverty-stricken Karst Mountainous Areas——A Case Study in Benggu Township, Xichou County, Yunnan, China

The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County, Yunnan declared a war against rocky desert in an attempt to ask the fields for more yields. They invented a distinctive land rehabilitation and sustainable use pattern called “transforming heavenand earth” that had been practiced in Southwest China’s karst areas. The key mechanism of the pattern was to develop terraced fields with well conserved soil, water and fertility by exploding rocks in the fields, building stone walls, gathering more soil, and improving soil quality and productivity for the fields in combination with building of irrigation facilities and roads, as well as with forestation and agriculture structure adjustment. The purpose of the pattern was to alleviate poverty in the karst areas by improving soil productivity and promoting agriculturaldevelopment. A typical area was studied with the help of Participatory Rural Appraisal (PRA) and the pattern was carried out there for fifteen years, have produced excellent ecological benefits and good economic benefits. Its application in the area approved that it was a sustainable land use pattern for rocky desert areas.

The causes of land landscape changes in semi-arid area of Northwest China: a case study of Yulin city

Rapid land landscape change has taken place in many arid and semi-arid regions such as the vulnerable ecological area over the last decade. In this paper, we quantified land landscape change of Yulin in this area between 1985 and 2000 using remote sensing and GIS. It was found that fallow landscape decreased by 125,148 hm^2 while grassland and woodland increased by 107,975 hm^2 and 17,157 hm^2, respectively. The major factors responsible for these changes are identified as the change in the government policy on preserving the environment, continued growth in mining, and urbanization. The efforts in restoring the deteriorated ecosystem have reaped certain benefits in reducing the spatial extent of sandy land through replacement by non-irrigated farmland, woodland and grassland. On the other hand, continued expansion of mining industry and urbanization has exerted adverse impacts on the land landscape. At present regional economic development conflicts directly with the protection of the natural environment. Such a conflict has caused the destruction to the land resources and fragmentation of the landscape accompanied by land desertification, the case is even serious in some localities.

Spatio-temporal Dynamic Patterns of Rural Area Development in Eastern Coastal China

The aim of this study is to evaluate the current state of rural area development at the county level in the eastern coastal China. An evaluation index system including 18 factors was developed, and a rural development index (RDI) was constructed to evaluate rural development state in 2000, 2004, and 2008. The quantitative evaluation indicated the following results. 1) This study derived four dominating components by means of principal component analysis, which can explain 78.2% of the total information, namely agricultural production input, the basic condition of agriculture, the comparative effectiveness of grain production, and the household′s own basic conditions. 2) Since the turn of the new millennium, the rural area in the eastern coastal China has experienced a rapid development in general. Well developed, developed, moderately developed and undeveloped rural areas respectively occupied 29.32%, 22.33%, 21.91%, and 10.51% in 2008. 3) The countryside had maintained a sound momentum of developing trend between 2000 and 2008, while the rural development in the eastern coastal China lacked sustainability. And 4) industrialization, urbanization, original economic basis, and location are four major driving forces of the disparity of rural area development in the eastern coastal China. Given these results, the strategies and policies for the improvement of each rural group were put forward.

GIS-based Effect Assessment of Soil Erosion Before and After Gully Land Consolidation: A Case Study of Wangjiagou Project Region, Loess Plateau

The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.

Quantitative Appraisement on Ecological Carrying Capacity in Coastal Rapid Developing Region of Hainan Province

The ecological carrying capacity,an important indica- tor to evaluate the sustainable development of the ecosystem, means the potential ability of the natural ecosystem to carry so- cioeconomic development while the ecosystem is healthy.It is limited by the carrying capacity of natural resources and environ- ment and the elasticity of the ecosystem.It will be greatly signifi- cant to study the ecological carrying capacity of Hainan Province, the first ecological province admitted by the State Environmental Protection Administration in China.Not only is the natural eco- system reflected,but also the effects of human activities are em- phasized by integrating the ecosystem health analysis into the ecological carrying capacity research.The research results,using the Factor Analysis tools of software SPSS,indicate that the eco- logical carrying capacity of Hainan Province fluctuated obviously from 1996 to 2005.The level of the ecological carrying capacity of Hainan Province was relatively high in 1996,and reached into trough from 1997 to 1999.It has steadily ascended to be above the middle level since the 21st century.The results also show that policy factors,especially the implementation of the 'Ecological Province' strategy,were important driving forces to influence the ecological carrying capacity.With the population rapidly increas- ing,the land and water resources per capita have decreased quickly.The amount of the ecological carrying capacity was pro- moted remarkably by socioeconomic development especially economic growth and technology applications.All of these will provide useful suggestions to establish and enact regional devel- opment policies,especially for protecting and reconstructing the ecology and environment of Hainan Province.

Evaluation of Intensive Urban Land Use Based on an Artificial Neural Network Model:A Case Study of Nanjing City,China

In this paper, the artificial neural network(ANN) model was used to evaluate the degree of intensive urban land use in Nanjing City, China. The construction and application of the ANN model took into account the comprehensive, spatial and complex nature of urban land use. Through a preliminary calculation of the degree of intensive land use of the sample area, representative sample area selection and using the back propagation neural network model to train, the intensive land use level of each evaluation unit is finally determined in the study area. Results show that the method can effectively correct the errors caused by the limitations of the model itself and the determination of the ideal value and weights when the multifactor comprehensive evaluation is used alone. The ANN model can make the evaluation results more objective and practical. The evaluation results show a tendency of decreasing land use intensity from the core urban area to the periphery and the industrial functional area has relatively low land use intensity compared with other functional areas. Based on the evaluation results, some suggestions are put forward, such as transforming the mode of urban spatial expansion, strengthening the integration and potential exploitation of the land in the urban built-up area, and strengthening the control of the construction intensity of protected areas.

Use of Intensity Analysis to Measure Land Use Changes from 1932 to 2005 in Zhenlai County, Northeast China

Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932–1954 and 1954–1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976–2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters.