A Methodology Framework for Regional Land-use Change Studies based on Landsat TM images: A Case Study in Northeast China

Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. This paper analyzed the land-use change in Northeast China during 1985-2000 based on Landsat TM images. It divides Northeast China into five land-use zones based on the dynamic degree model of land-use: woodland/grassland-arable land conversion zone, dry land-paddy field conversion zone; urban expansion zone, interlocked zone of farming and pasturing and reclamation and abandon zone. The findings include the obvious increase of cropland area, paddy field and dry land increased by 75 and 276 thousand hm2 respectively; urban areas expanded rapidly, areas of town and rural residence increased by 76.8 thousand hm2; areas of forests and grassland decreased sharply with the amounts of 1399 and 1521 thousand hm2 respectively; areas of water body and unused land increased by 148 and 514 thousand hm2 respectively. This paper also discusses the driving     

基于空间贝叶斯识别城市扩张与生态保护潜在的兼容区和冲突区——以鄱阳湖生态经济区为例

快速城市扩张在提高社会经济水平的同时,伴随着一系列的生态问题,如何合理协调城市扩张与生态保护之间的矛盾是当前我国新型城镇化建设中的一项重要任务。科学识别城市扩张与生态保护的冲突是其基础。以鄱阳湖生态经济区为研究区域,采用空间贝叶斯方法识别城市扩张与生态保护潜在的兼容区和冲突区。研究结果表明:(1)城市扩张适宜性区域分布较为集中,最适宜区域主要分布在南昌市主城区周边县域、余江县和乐平市,较适宜区域主要分布在新建区、瑞昌市、高安市和都昌县,较不适宜区域主要分布在武宁县以及鄱阳湖东岸,不适宜区域主要分布在鄱阳县、浮梁县与武宁县。(2)生态保护适宜性区域分布较为分散,最适宜区域主要分布在武宁县、瑞昌市、鄱阳县和浮梁县,较适宜区域主要分布在主城区东北部、东南部、余江县和湖口县,较不适宜区域主要分布较为分散,各区(市)县均有分布,不适宜区域主要分布在南昌市周边区域和鄱阳湖东岸。(3)综合分析城市扩张和生态保护适宜性评价结果得到的冲突区主要分布在瑞昌市、南昌县和新建区;兼容区中城市发展适宜性高的区域主要分布在南昌市的东南部以及永修县、星子县、余江县,生态保护适宜性高的区域主要分布在鄱阳湖东岸和武宁县;城市扩张和生态保护适宜性都较低的区域主要分布在鄱阳县、余干县、都昌县。研究结果可为土地利用规划与生态安全保护提供参考和借鉴。     

A Methodology Framework for Regional Land-use Change Studies based on Landsat TM images: A Case Study in Northeast China

Abstract

Land-use change is an important aspect of global environment change. It is, in a sense, the direct result of human activities influencing our physical environment. This paper analyzed the land- use change in Northeast China during 1985–2000 based on Landsat TM images. It divides Northeast China into five land-use zones based on the dynamic degree model of land-use: woodland/grassland-arable land conversion zone, dry land-paddy field conversion zone; urban expansion zone, interlocked zone of farming and pasturing and reclamation and abandon zone. The findings include the obvious increase of cropland area, paddy field and dry land increased by 75 and 276 thousand hm² respectively; urban areas expanded rapidly, areas of town and rural residence increased by 76.8 thousand hm²; areas of forests and grassland decreased sharply with the amounts of 1399 and 1521 thousand hm² respectively; areas of water body and unused land increased by 148 and 514 thousand hm² respectively. This paper also discusses the driving forces in each land-use dynamic zone and finds that some key biophysical factors affect conspicuously the conversion of different land-use types. The relation between land-use conversion and DEM, accumulated temperature (≤10°C) and precipitation was analyzed and represented. The land-use changes In Northeast China resulted from the changing macro social and economic factors and local physical elements. Rapid population growth and management changes can explain the shaping of woodland/grassland-cropland conversion zone. The conversion from dry land to paddy field in the dry land-paddy field conversion zone, apart from the change of physical elements promoting the expansion of paddy field, results from two reasons: one is that the implementation of market economy in China has given farmers the right to decide what and how they plant their crops, the other factor is originated partially from the change of the dietary habit along with the social and economic development. The conversion from paddy field to dry land is caused primarily by the shortfall of irrigation water, which in turn is caused by poor water allocation managed by local governments. The shaping of the reclamation and abandon zone is partially due to the lack of environment protection consciousness among pioneer settlers. The reason for the conversion from grassland to cropland is the relatively higher profits of farming than that of pasturing in the interlocked zone of farming and pasturing. In Northeast China, the rapid expansion of built-up areas results from two factors: the existence of a small number of towns and the huge potential for expansion of the existing towns and cities. The urban land expanded mainly in areas with a gentle topographic relief and low population density.     

Commodity production as restoration driver in the Brazilian Amazon? Pasture re-agro-forestation with cocoa (<Emphasis Type="Italic">Theobroma cacao</Emphasis>) in southern Pará

The increasing demand for agricultural commodities is a major cause of tropical deforestation. However, pressure is increasing for greater sustainability of commodity value chains. This includes the demand to establish new crop plantations and pasture areas on already deforested land so that new forest clearing for agriculture is minimized. Where tree crops are planted as part of agroforestry systems on deforested land, this amounts to a form of re-agro-forestation which can generate environmental benefits in addition to crop production. Here, we discuss a case where agroforestry systems based on cocoa (Theobroma cacao) are being established on crop and pasture land in the south of Pará state, Brazilian Amazon. The adoption of cocoa by farmers and ranchers of the region is stimulated by the coincidence of (1) favorable prospects for cocoa on the national and international markets including the expectation of a global cocoa supply gap; (2) environmental policies obliging land owners to reforest excess cleared land with native trees, with agroforests based on the native cocoa tree being an economically attractive option; and (3) biophysical conditions (especially soil fertility) favorable for growing cocoa in part of the region. We show that in the state of Pará at least 1.26 million hectares of naturally high-fertility soils in deforested areas outside legally protected and indigenous lands are potentially suitable for cocoa production with low agrochemical inputs, sufficient to make a significant contribution to closing the predicted supply gap. Their actual suitability depends on their state of degradation after years of pasture use and the availability of technologies and finance to convert them into tree crop agroforests. We discuss the significant environmental benefits of pasture re-agro-forestation with cocoa-based systems, including reduced emissions of up to 135 Mg of carbon per hectare compared to the historically common scenario of planting cocoa after forest clearing. We identify important research questions related to the scaling up of this practice and the maximization of its environmental benefits. We conclude that the coincidence of the afore-mentioned factors could drive a re-agro-forestation frontier in this part of the Amazon, with potential for positive outcomes in terms of commodity production while generating social and environmental benefits.     

三峡库区坡耕地利用与水土保持种植制

三峡库区耕地资源十分有限,且坡耕地占有相当大的比重,陡坡地多,在不良的耕作方式下肥力低下,水土流失十分严重在分析三峡库区自然条件与坡耕地资源特点的基础上,讨论了坡耕地种植制度与土壤侵蚀的关系,提出通过合理搭配作物种类进行多熟制间套作,一年生农作物与多年生经饲作物间作及农作物与木本植物等高间作等手段来建立坡耕地水土保持种植制,从而达到减轻土 蚀之目的。     

The responses of agriculture in Europe to climate change

Human activities are projected to lead to substantial increases in temperature that will impact northern Europe during winter and southern Europe during summer. Moreover, it is expected that these changes will cause increasing water shortages along the Mediterranean and in the south-west Balkans and in the south of European Russia. The consequences on the European agricultural ecosystems are likely to vary widely depending on the cropping system being investigated (i.e. cereals vs. forage crops vs. perennial horticulture), the region and the likely climate changes. In northern Europe, increases in yield and expansion of climatically suitable areas are expected to dominate, whereas disadvantages from increases in water shortage and extreme weather events (heat, drought, storms) will dominate in southern Europe. These effects may reinforce the current trends of intensification of agriculture in northern and western Europe and extensification and abandonment in the Mediterranean and south-eastern parts of Europe. Among the adaptation options (i.e. autonomous or planned adaptation strategies) that may be explored to minimize the negative impacts of climate changes and to take advantage of positive impacts, changes in crop species, cultivar, sowing date, fertilization, irrigation, drainage, land allocation and farming system seem to be the most appropriate. In adopting these options, however, it is necessary to consider the multifunctional role of agriculture and to strike a variable balance between economic, environmental and economic functions in different European regions.     

Bioeconomic modeling of farm household decisions for ex-ante impact assessment of integrated watershed development programs in semi-arid India

The increasing population and urbanization have serious implications for sustainable development in less-favoured areas of developing countries. In an attempt to sustain the long-term productivity of natural resources and to meet the food and non-food demands of growing population in the semi-arid tropics, the Indian government invests and promotes integrated watershed development programs. A comprehensive tool to assess the impacts of watershed development programs on both social well-being and sustainability of natural resource is currently lacking. In this study, we develop a watershed level bioeconomic model to assess the ex-ante impacts of key technological and policy interventions on the socioeconomic well-being of rural households and the natural resource base. These interventions are simulated using data from a watershed community in the semi-arid tropics of India. The model captures the interaction between economic decisions and biophysical processes and using a constrained optimization of household decision model. The interventions assessed are productivity-enhancing technologies of dryland crops and increased in irrigable area through water conservation technologies. The results show that productivity-enhancing technologies of dryland crops increase household incomes and also provided incentives for conserving soil moisture and fertility. The increase in irrigable area enables cultivation of high-value crops which increase the household income but also lead to an increase in soil erosion and nutrient mining. The results clearly indicate the necessity for prioritizing and sequencing technologies based on potential effects and trade-offs on household income and conservation of natural resources.     

退耕还林工程经济补偿机制研究——以雅安市雨城区为例

本文通过对4个乡镇8个村,120户农户的调查,取得第一手资料,分析退耕还林对退耕农户利益的影响,针对西部退耕还林经济补偿机制运行中存在的问题进行了初步探讨,并提出了建立和完善西部退耕还林经济补偿机制的建议,从而对进一步调动农户参与生态建设的积极性,巩固还林成果,持续开展退耕还林工程具有重要意义。     

The oil palm boom: socio-economic implications for Q’eqchi’ households in the Polochic valley,Guatemala

Oil palm (Elaeis guineensis) has become one of the most rapidly expanding crops in the world. Many countries have promoted its cultivation as part of a broader rural development strategy aimed at generating paid work and producing both export commodities and biofuels. However, oil palm expansion has often occurred at the expense of ecosystems and subsistence agriculture, and on lands riddled with tenure conflicts. In this article, we analyse the implications of the combined effect of labouring in oil palm plantations and land access on households, and we discuss how these implications affect human well-being in two indigenous communities of the Polochic valley, Guatemala. Combining participant observation, semi-structured interviews, and land-time budget analysis at household level, we reveal how oil palm cultivation increases incomes for plantation workers’ households, but decreases the productivity of maize cultivation, reduces the time that household members have available for other activities and, particularly, reduces women’s resting time. In contrast, households that focus more intensively on maize cultivation show higher degrees of food security and women can allocate more time to social activities. However, our results also show that maize consumption per capita has not decreased in households working in oil palm plantations since such crop is considered sacred by the Q’eqchi’ and plays a central role in their diet and culture. In conclusion, we argue that while working for an oil palm cultivation can increase specific elements of the basic material conditions for a good life, other aspects such as food security, health, freedom of choice, and social relationships can become deteriorated.     

Habitat suitability and potential distribution of <Emphasis Type="Italic">Laudakia nupta</Emphasis> (De Filippi, 1843) (Sauria: Agamidae) in Iran

In the present study, Laudakia nupta were selected as a case study and were examined using the Maxent method to evaluate the potential distribution and most suitable areas. All occurrence records of the species have been gathered from literature and recent updated checklists of lizards of Iran. The final model of L. nupta showed a good performance (AUC = 0.962; SD = 0.011) indicating that the most suitable areas are situated in the western Zagros Mountains in Iran. The situation of the suitable areas in the western Zagros, while the remaining southeastern areas are of low suitability, is controversial and needs more investigation with different criteria such as molecular and other systematic methods. Precipitation of the wettest quarter is the most effective factor for the species presence and I can assume this importance is directly related to the growth of plant in the habitat as main source of food.     

四湖地区涝渍地农用土地适宜性评价

分析了四湖地区土地利用现状,其宜农耕地最多,作物种类繁多,耕作制度也多样,水域面积大,可养殖面积占水域的一半以上,其养殖潜力很大;宜林、宜放牧土地少;后备土地资源较少。土地利用的主要障碍因子是水文与排水。存在的主要问题是：土地利用的产出效率低;种植业结构欠合理;掠夺式经营,土壤肥力减退,污染加重;滥占耕地现象日趋严重;过渡围湖造田导致生态恶化。同时,从气候等方面分析了四湖地区涝渍特征,又着重对现有六种主要种植制度作了简要的适宜性评价。据此,按照系统工程整体性、关联性、有序性的原则,对未来该地区农业总体发展走向、土地利用规划给予了展望。四湖地区农业总体发展走向应是：稳定发展种植业,突破性地发展水产养殖业与畜牧业、积极发展林果业,有重点地发展农副产品加工业。在土地利用规划上,应根据低丘岗地、沿江高亢平地、湖烷洼地、河湖水域等不同地形地貌分异,进行合理布局。并提出了相关对策。     

基于GIS和生态位适宜度模型的园地适宜性评价——以湖北宜昌市夷陵区为例

生态位适宜度是对经典生态位理论和方法的深化与发展,在合理优化和发挥作物、环境最大共生效应,及农业结构调整和布局中具有重要的理论和实际意义。以宜昌市夷陵区园地为研究对象,将生态位适宜度模型引入到适宜性评价研究中,构建了5个因素12个因子的指标体系并提出了语言型、阈值型和空间型指标的量化方法,采用加权求和与限制因子模型对各评价单元柑橘的生态位适宜度值及限制因子进行了定量分析。结果表明：研究区生态位适宜度值整体较高,最大值达0.893,生境条件基本能满足柑橘的生长发育需求;园地适宜性评价结果以2级为主,所占面积达41.34%,1级地也达到21.58%;限制该地区园地生产潜力的生态因子主要为：土壤质地、冷月平均气温和道路通达度。同时,丰富了土宜评价的理论和方法体系,能直接指导农业生产实践、促进园地的合理开发利用与管理     

城市土地生态适宜性分区划分研究

在新型城镇化与生态文明建设背景下,城市发展迫切需要合理布局以实现城市土地的节约集约利用,降低城市化过程中因建设用地肆意蔓延所导致的土地资源浪费与生态环境破坏影响。以常州市武进区为例,采用地形地貌、生态环境、交通设施、建设密度4类因子建立景观过程阻力赋值体系,结合GIS空间分析技术,以垂直生态过程的多因素多因子综合判别得到的生态保护用地扩张和城镇用地扩张阻力基面为基础,再以描述水平生态过程的最小累积阻力模型计算两种扩张过程的最小累积阻力值,并依据二者的最小累积阻力差值表面,从空间上将武进区划分为4个等级的城市土地生态适宜性分区,分别为优先建设区118.39 km²、适宜建设区233.60 km²、生态缓冲区777.91 km²、生态控制区115.90 km²,明确指出了各分区的空间布局,提出了相应的发展建议,以期为武进区未来城市发展提供科学合理的空间布局参考。同时考虑了垂直生态过程和水平生态过程,一定程度上弥补了传统方法只从景观单元垂直过程研究的不足之处,为生态适宜性分区划分的方法研究提供了有益的尝试和补充。     

Land-use and land-cover effects on regional biodiversity distribution in a subtropical dry forest: a hierarchical integrative multi-taxa study

Latin American subtropical dry ecosystems have experienced significant human impact for more than a century, mainly in the form of extensive livestock grazing, forest products extraction, and agriculture expansion. We assessed the regional-scale effect of land use and land cover (LULC) on patterns of richness distribution of trees, birds, amphibians, and mammals in the Northern Argentine Dry Chaco (NADC) over c. 19 million hectares. Using species distribution models in a hierarchical framework, we modeled the distributions of 138 species. First, we trained the models for the entire Argentinean Chaco with climatic and topographic variables. Second, we modeled the same species for the NADC including the biophysical variables identified as relevant in the first step plus four LULC-related variables: woody biomass, distance to crops, density of livestock-based rural settlements (puestos), and vegetation cover. Third, we constructed species richness maps by adding the models of individual species and considering two situations, with and without LULC variables. Four, richness maps were used for assessing differences when LULC variables are added and for determining the main drivers of current patterns of species richness. We found a marked decrease in species richness of the four groups as a consequence of inclusion of LULC variables in distribution models. The main factors associated with current richness distribution patterns (both negatively) were woody biomass and density of livestock puestos. Species richness in present-day Semiarid Chaco landscapes is strongly affected by LULC patterns, even in areas not transformed to agriculture. Regional-scale biodiversity planning should consider open habitats such as grasslands and savannas in addition to woodlands.     

基于MCR的建设用地扩展边界划定研究

在生态文明建设背景下,科学划定建设用地扩展边界是提高城镇化质量、协调人地关系、改善城市生态环境的关键。基于最小累计阻力模型(MCR),将建成区和生态保护用地作为两类扩展源,通过构建自然、区位、环境和政策4个阻力因子体系,采用层次分析法(AHP)获取各个因子阻力系数,得到两类用地扩展的最小累计阻力值,根据阻力差值划分适宜性分区,并利用Hydrology扩展模块确定建设用地适宜扩展路径和隔离带。结果表明：(1) 越靠近扩展源,其阻力值越小,建设用地源与生态用地源由于空间分布不一致,各阻力值之间差异较大;(2) 基于MCR模型对两类用地扩展的阻力面差值进行建设用地适宜性划分,可分为重点建设区(65 771.64 km²)、优化建设区(51 103.28 km²)、限制建设区(21 001.54 km²)、禁止建设区(17 150.01 km²)和生态恢复区(11 894.70 km²),不同适宜性分区对土地开发建设的要求不一样;(3) 应用Hydrology扩展模块得到的“谷线”可引导建设用地优化开发,避免盲目的“摊大饼”式蔓延格局; “脊线”可控制建设用地扩展的隔离带,从而打破适宜性区域集中连片的扩展态势。研究结果可为建设用地的科学规划和合理布局提供建议,促进城市建设和环境保护的协同发展。     

Biophysical suitability,economic pressure and land-cover change: a global probabilistic approach and insights for REDD+

There has been a concerted effort by the international scientific community to understand the multiple causes and patterns of land-cover change to support sustainable land management. Here, we examined biophysical suitability, and a novel integrated index of “Economic Pressure on Land” (EPL) to explain land cover in the year 2000, and estimated the likelihood of future land-cover change through 2050, including protected area effectiveness. Biophysical suitability and EPL explained almost half of the global pattern of land cover (R ² = 0.45), increasing to almost two-thirds in areas where a long-term equilibrium is likely to have been reached (e.g. R ² = 0.64 in Europe). We identify a high likelihood of future land-cover change in vast areas with relatively lower current and past deforestation (e.g. the Congo Basin). Further, we simulated emissions arising from a “business as usual” and two reducing emissions from deforestation and forest degradation (REDD) scenarios by incorporating data on biomass carbon. As our model incorporates all biome types, it highlights a crucial aspect of the ongoing REDD + debate: if restricted to forests, “cross-biome leakage” would severely reduce REDD + effectiveness for climate change mitigation. If forests were protected from deforestation yet without measures to tackle the drivers of land-cover change, REDD + would only reduce 30 % of total emissions from land-cover change. Fifty-five percent of emissions reductions from forests would be compensated by increased emissions in other biomes. These results suggest that, although REDD + remains a very promising mitigation tool, implementation of complementary measures to reduce land demand is necessary to prevent this leakage.     

基于最小累积阻力模型的农村居民点用地生态适宜性评价——以都江堰市为例

农村居民点用地是乡村聚落景观的重要组成部分,其新建或重建过程从空间上来看是其与内部和周围环境之间相互竞争控制与覆盖的过程。在我国城市化加速推进的背景下,农村居民点用地却不降反升,其空间布局与扩张对自然生态环境的影响及反馈还考虑不足。借鉴景观生态格局的相关理论与方法,运用最小累积阻力模型,以都江堰市为例进行农村居民点用地的生态适宜性评价与分析。结果表明：（1）近十年来,研究区各土地生态适宜性分区空间分布相对集中,生态较适宜与高度适宜区域有一定程度的收缩,而较不适宜与不适宜区域则扩张明显,“一减一增”的鲜明对比表明人类活动对当地景观生态格局的干扰在明显增强;（2）不同时间段农村居民点用地的生态适宜性变化存在明显差异,在生态不适宜区,农村居民点的数量与面积始终保持了较高的增长势头,而中等适宜及以上等级区域的农村居民点数量与面积则经历了先增加后减少的变化趋势;（3）农村居民点用地的生态适宜性处于不断变化之中,2005~2010年和2010~2015年,分别有559.39和781.11 hm2的农村居民点生态适宜性等级发生了变化。研究结果对于加强当地重要生态景观单元的保护,协调人与土地、人与自然之间的矛盾,提高农村土地资源的利用效率和制定村庄建设发展规划等具有一定的实践指导意义。     

粮食安全:气候变化与粮食产地转移

基于1985-2008年中国雀际面板数据,实证检验了气候变化对粮食种植规模与单位产量的作用机制,进而分析了产地转移对国家粮食总供给的影响.结论表明:①中国的稻谷、小麦、玉米产业正分别向黑龙江、河南、内蒙古等气候资源匮乏地区转移或集聚;②粮食产地转移的主导因素在于粮食作物与经济作物、种植业与畜牧业、农业与非农的成本收益比较,而气候变化因素仅处于附属地位;③基于规模效应、牧入效应以及回弹效应的作用机制,东北三省、河南、内蒙古等地区的增长潜质往往优于其他地区;④落后地区应对气候变化的生产与政策成本,往往要低于发达地区保留粮食生产的机会成本,粮食生产向欠发达地区转移应具有可持久性.粮食产地转移过程中,并未呈现粮食供给安全的“个体理性”与“集体理性”的冲突.中国应该在气象预报、水利设施、抗灾能力、中低产田改造等方面加大投入,摒弃区内平衡的传统观念,在全国范围内优化资源配置,并辅以国家粮食储备战略应对特大灾害的供给风险.     

基于MCR模型的农村居民点布局适宜性分区及优化模式研究——以南京市六合区金牛湖街道为例

农村居民点布局适宜性分区是实现布局优化的基础,也是改善农村生产生活条件、实现耕地占补平衡、统筹城乡发展的重要途径。以南京市六合区金牛湖街道为例,利用GIS技术分析了研究区农村居民点分布现状,采用最小累积阻力模型（MCR）实现了农村居民点布局适宜性分区,从而为农村居民点整理项目实施和村镇建设规划提供了科学依据。研究结果表明：（1）金牛湖街道农村居民点现状在整体上存在“布局松散、面积零碎”的问题;各村（社区）之间地域差异明显、分布不均衡;在空间布局上呈现出沿“低坡度、低高程、交通便利”地带分布的显著特征;（2）按农村居民点布局适宜性程度,可将金牛湖街道划分为5种适宜性分区。其中,高度适宜区占街道总面积的165%,总体上能满足农村居民点用地需求;（3）基于农村居民点现状分析及适宜性分区结果,将各村（社区）划分为“就地城镇化”、“内部整改”、“逐步迁村并点”3种优化模式,并从宏观层面上提出优化路径     

基于CLUE-S模型的千岛湖镇土地利用动态模拟分析

基于1993、2004年两期土地利用数据和1〖DK〗∶250000DEM,运用GIS技术,通过Logistic逐步回归分析,在地形、高程、水系、道路交通、城镇和居民点等多种自然和社会经济因素中,筛选出不同时期对千岛湖镇主要土地利用类型空间分布及其变化具有决定作用的驱动因子,并对所得结果进行ROC检验,同时生成相应的土地利用空间分布概率适宜图,然后采用CLUE-S模型,对其2004年的土地利用变化格局进行模拟;并用2004年的土地利用现状图对模拟结果进行检验,结果显示,在基本单元（90 m×90 m栅格）的水平上,模拟的正确率为8471%,Kappa值达到了0825。在此基础上,针对两种政策情景,应用相同模型模拟预测了千岛湖镇2015年的土地利用时空变化。与2004年相比较,变化明显的是城镇工矿用地的扩张和林地的减少,并且城镇工矿用地的扩张多是在原有城镇及工矿用地的基础上向四周扩展,侵占的多是周边的耕地、林地、未利用地。