区域土地利用/覆被时空动态变化研究——以四川省金堂县为例

土地利用/覆被变化动态监测是掌握土地资源数量、进行土地利用评价的重要依据。基于遥感和GIS技术提取金堂县2001、2007、2010和2013年4期土地利用变化信息,并应用模型对研究区土地利用时空变化进行分析。结果表明:(1)土地利用类型以耕地和林地为主,建设用地和林地的单一土地利用动态度为正,面积显著增加;耕地、草地、水体和其他的土地利用动态度为负,面积减少;综合土地利用动态度由6.12%增加到13.81%,土地利用变化强烈。(2)土地利用空间变化显著,土地利用空间变化主要发生在金堂县城、赵镇、三星镇和淮口镇等地;土地利用转化明显,耕地和建设用地的变化最强烈,建设用地、耕地和林地之间的相互转化尤其显著。(3)地形因子对土地利用变化具有较大影响,土地利用变化随高程、坡度的增加而减少,且表现较强的相关性,符合二次变化曲线的特征;阳坡较阴坡对土地利用变化的影响大。这一研究结果为区域土地利用评价提供重要依据,有利于实现土地利用的合理布局和调控管理,对区域土地资源的合理开发利用具有重要意义。     

Implications of land use transitions and climate change on local flooding in urban areas: An assessment of 42 Indian cities

Urban development induced land transitions affect urban hydrology, resulting in increased flooding risks. Climate change-related precipitation changes are an added complexity to the flood risks of cities. This study examines the role of land use changes in determining the occurrence of urban flooding events across 42 Indian cities under current and future climate change scenarios. Landsat images for 1990, 2000, 2010, and 2017 have been processed using a hybrid classification technique to determine the land use shares for all cities. A typical event-count study using newspaper archives has been conducted to create a flooding event database. A multilevel model employing logistic mixed-effects approach was used. Future projections of the occurrence of flooding events for nine models under three climate change-related Representative Concentration Pathways (RCPs)—2.6, 4.5, and 8.5—and three urban development scenarios have been carried out. The results suggest that cities should preserve the land uses that act as a sponge—the green, open and blue spaces. As these spaces decrease, the projected flooding events increase. Under the RCP 2.6 scenario, the number of flooding events is significantly lower (95 % confidence) than under RCPs 4.5 and 8.5. The expected flooding occurrences between RCP4.5 and RCP8.5 are not significantly different (95 % confidence) for many scenarios, suggesting that Indian cities should aim for a world temperature increase of below 2 °C, or devastating consequences are imminent. This study highlights the need for Indian cities to undertake integrated spatial planning measures for a resilient, sustainable urban future.     

Changes in land use, land tenure, and landscape fragmentation in the Tijuana River Watershed following reform of the ejido sector

Changes in land use and land tenure can influence both physical fragmentation and ownership fragmentation of landscapes, with implications for biodiversity. In this study, we evaluated changes in land use and land tenure in the Tijuana River Watershed, a region of high biodiversity and endemism, following the implementation of a new Agrarian Law which allowed for privatization and sales of communal land (ejidos) beginning in 1992. In order to understand changes in land use and cover, we constructed maps from aerial photographs and Aster images and measured changes between 1994 and 2005. In order to understand changes in land tenure, we collected data from Mexican government sources on ejido land size, ownership, and sales, and we conducted 55 structured interviews with ejidatarios in the watershed. Our results demonstrate that land-use/cover change between 1994 and 2005 was dominated by an increase in urban area and grasslands, and a decrease in coastal sage scrub, chaparral, and, to a lesser degree, agriculture. In particular, the conversion of coastal sage scrub has left a far more fragmented landscape than existed in 1994. In addition, most of the ejidos in the watershed, as well as individuals interviewed, had participated in some stage of the land certification and titling process allowed by the new Agrarian Law, resulting in substantial changes in land tenure. However, land tenure security appeared to play a larger role than a desire to sell land and, contrary to studies from other regions, full title to the land was obtained in a range of urban and rural settings, rather than primarily on land closest to urban zones. Our results suggest that past predictions regarding future urban growth and fragmentation of native vegetation in the region have proven accurate and highlights regions of change that merit further study.     

Stakeholder perceptions and governance challenges in urban protected area management: The case of the Las Piñas – Parañaque Critical Habitat and Ecotourism Area,Philippines

The conservation and management of protected areas in urban settings has become increasingly challenging with dynamics over land use change in adjacent urban areas being highly relevant to, but at times conflicting with, the protected area. This study seeks to better understand the implications of land use change processes to urban protected area management through the case study of the Las Piñas – Parañaque Critical Habitat and Ecotourism Area (LPPCHEA) in Metro Manila, Philippines. Factors and processes influencing land use change and protected area management and the impact of stakeholders’ perceptions on protected area were analyzed. The urban protected area in itself has limited influence on its surrounding urban areas, as land use change in these areas is shaped more by social, economic and policy/institutional factors occurring within the context of urban-regional development. The study also found that land use conflict is evident in an urban protected area due to the competing ecosystem services derived by various stakeholders. This discord is deepened by the lack of coordination between land use planning and protected area management. Integrating protected area management with land use planning through legally binding instruments, specific timeframes and clear internal procedures can help resolve land use conflict for an urban protected area at the strategic or policy level.     

Land use conversion in metropolitan areas and the permanence of agriculture: Sensitivity Index of Agricultural Land (SIAL), a tool for territorial analysis

In the past few years, urban growth has affected vast agricultural areas, especially in some European regions (EEA, 2006). In peri-urban areas, land consumption is particularly intense, exposing agriculture to the risk of land loss. Assuming the action of different factors, both exogenous and endogenous, on the agricultural system, the potential risk of land use conversion is measured by the Sensitivity Index of Agricultural Land (SIAL), an innovative tool for territorial analysis. In the following paper, the SIAL will be presented with an application for a metropolitan area. In this case study, the exogenous variables of urban proximity seem to be those most involved in the processes of conversion from agricultural to urban land use.     

Assessing urban growth and rural land use transformations in a cross-border situation in Northern Namibia and Southern Angola

The Okavango catchment is a hot spot of accelerating land use change. In particular, climate predictions, demographic developments and a growing utilization of ecosystem services and functions are expected to increase pressure on resources and land. Land use conflicts, the sustenance of precarious livelihoods, deforestation of woodland savannahs, upstream–downstream water issues and human–wildlife conflicts are among the processes that are characteristic of policy and management challenges in the region. In the Eastern and Western Kavango regions of Namibia and the Cuando-Cubango province of Angola, a unique cross-border situation exists that allows assessing how the combination of local traditions, regional land management and national policies determines spatial patterns of land use and land cover transformation processes.To map major land use types and change processes we used a set of multi-temporal Landsat-5 TM and Landsat-7 ETM+ data sets, support vector machine (SVM) classification and iterative spectral mixture analysis (ISMA) on images covering the period from 1990 to 2010. Integrating satellite imagery with literature reviews, interviews, census and household survey data, we assessed the contrasting development of resource utilization on both sides of the Okavango River. We investigated if and how policies and regulations at different levels drive land use decisions, and how these decisions manifest spatially.We found a strong and interconnected urban growth on both sides of the river. The area around Rundu has constantly been evolving to become Namibia's second largest city, also functioning as a hub of development and transborder commerce with opposing Calai. This trend was found to affect adjacent settlement areas and cause widespread conversion of woodland savannahs to agricultural land or their utilization for timber extraction. The conversion of woodland savannah to arable land was by far the dominant land use change process on both sides of the river, with a total conversion area of 460 km² (Namibia) and 293 km² (Angola) observed during the observation period. Strong spatial change gradients occurred in relation to determining factors, such as accessibility, proximity to water, urban centres, etc., while relations to settlements where less obvious. Assessing results by country illustrated the difference in land use intensity and resource consumption between Angola and Namibia, which relate directly to historical developments, with a long period of stability in Namibia standing opposed to the recent and ongoing recovery from civil war in Angola. These are added to by statutory and traditional policy frameworks, the national endowment with natural capital (e.g. oil, uranium, diamonds, zinc) and the integration into global markets, which strongly affects national economies of both countries at large.Underlying land use decisions were found to be largely driven by individualized perspectives on growth ideologies, consumerism and wealth-aspirations connected to globalization processes. However, at present the result of these perspectives is still mainly a small-structured conversion to rainfed agriculture as a component of subsistence strategies of local livelihoods, and thus stands opposed to other regions of the world, where change processes are much more driven by large companies or follow national regulations and result in more intensive uses.     

Understanding the influence of farmer motivations on changes to soil erosion risk on sites of former serious erosion in the South Downs National Park,UK

Serious soil erosion occurred in the South Downs National Park, southern England in the years 1982–2006 and details of around 400 sites are contained in a database. In 2010 we revisited 85 of the most serious sites where erosion of >10 m³ ha⁻¹ y⁻¹ had been recorded in order to assess land use change and any conservation measures undertaken. At 79% of the sites land use change had resulted in a reduction in the risk of erosion, most notably at 28 sites with a shift to permanent grass from winter cereals. At only 21% of sites was the risk of erosion unchanged. Twenty two farmers responsible for 66 of the sites were interviewed. Land management practices had changed on all of the fields of interest to this study since the time of the serious erosion events, to those which have the potential to lower soil erosion risk. Sixteen interviewees claimed that erosion was a motivating reason for changing their practices, due to either experiencing on or on- and off-farm impacts firsthand (12), having knowledge or suspicion of serious erosion having occurred on their land prior to their management (three), or having no knowledge of any serious erosion on their land but just wanting to reduce overall erosion risk (one). Amongst the main changes reported are changes of land use from winter cereals to grass or to overwinter stubble which have undoubtedly reduced the risk of erosion. However, some changed practices claimed by farmers, such as along-the-contour-working, earlier sowing and the use of rollers may be of little value. Furthermore, deeper analysis of farmers’ motivations regarding changes in land management practices suggests a complex picture in which a range of socio-economic influences come into play over time including financial incentives offered by agri-environmental schemes which were found to be an important driver of change. Future changes in farming economics may therefore undermine the reduction in erosion risk in the longer term.     

A quantitative assessment of policy options for no net loss of biodiversity and ecosystem services in the European Union

The Biodiversity Strategy of the European Union includes a target to “ensure no-net-loss of biodiversity and ecosystem services by 2020”. Many policy options can be envisioned to achieve such a no-net-loss target, mainly acting on land use and land management. To assess the effectiveness of such policies at a European Union (EU) scale, we simulated land use changes and their impacts on biodiversity and ecosystem services indicators. We analysed a Business–as-Usual scenario, and three no-net-loss scenarios. The no-net-loss scenarios included measures that aim to reduce negative impacts of land use change on biodiversity and ecosystem services, by better implementation of existing biodiversity conservation measures (Scenario 1); and enhancement of existing measures (Scenario 2); and offsetting residual impacts on areas of high biodiversity and ecosystem service value (Scenario 3).Results show that none of the scenarios achieved overall no-net-loss. Compared to a Business-as-Usual scenario, the no-net-loss scenarios reduced the overall degree of land cover change at EU level, hence reducing impacts on biodiversity and ecosystem services in large parts of the EU. The more comprehensive no-net-loss scenarios resulted in a gain of natural land cover. Moreover, natural areas became better connected, especially in peri-urban areas as a result of impact avoidance and offsetting. Richness of farmland bird species was projected to increase. Measures included in the no-net-loss scenarios had net positive effects on pollination and carbon sequestration, neutral effects on crop production, erosion prevention and flood regulation, and negative effects on nature-based recreation, compared to Business-as-Usual. In particular circumstances policy measures invoked displacement effects in land use allocation, reducing the effectiveness of the measures. This was primarily the case for flood regulation services throughout the EU.This study differentiates the potential effectiveness of a no-net-loss policy framework in three manners: (i) considering biodiversity and ecosystem services simultaneously; (ii) in the light of existing policies and land use pressures; and (iii) in different land use contexts across the EU. Taken together, we conclude that achieving no-net-loss for biodiversity and ecosystem services throughout the EU remains challenging given high land use demands. Nevertheless, in large parts of Europe there appears room for improvement for certain kinds of biodiversity and ecosystem services compared to Business-as-Usual, while still meeting other land use demands.     

Land‐use change trajectories up to 2050: insights from a global agro‐economic model comparison

Changes in agricultural land use have important implications for environmental services. Previous studies of agricultural land‐use futures have been published indicating large uncertainty due to different model assumptions and methodologies. In this article we present a first comprehensive comparison of global agro‐economic models that have harmonized drivers of population, GDP, and biophysical yields. The comparison allows us to ask two research questions: (1) How much cropland will be used under different socioeconomic and climate change scenarios? (2) How can differences in model results be explained? The comparison includes four partial and six general equilibrium models that differ in how they model land supply and amount of potentially available land. We analyze results of two different socioeconomic scenarios and three climate scenarios (one with constant climate). Most models (7 out of 10) project an increase of cropland of 10–25% by 2050 compared to 2005 (under constant climate), but one model projects a decrease. Pasture land expands in some models, which increase the treat on natural vegetation further. Across all models most of the cropland expansion takes place in South America and sub‐Saharan Africa. In general, the strongest differences in model results are related to differences in the costs of land expansion, the endogenous productivity responses, and the assumptions about potential cropland.     

The impact of urban expansion on agricultural land use intensity in China

China's urbanization has resulted in significant changes in both agricultural land and agricultural land use. However, there is limited understanding about the relationship between the two primary changes occurring to China's agricultural land – the urban expansion on agricultural land and agricultural land use intensity. The goal of this paper is to understand this relationship in China using panel econometric methods. Our results show that urban expansion is associated with a decline in agricultural land use intensity. The area of cultivated land per capita, a measurement about land scarcity, is negatively correlated with agricultural land use intensity. We also find that GDP in the industrial sector negatively affects agricultural land use intensity. GDP per capita and agricultural investments both positively contribute to the intensification of agricultural land use. Our results, together with the links between urbanization, agricultural land, and agricultural production imply that agricultural land expansion is highly likely with continued urban expansion and that pressures on the country's natural land resources will remain high in the future.     

Does demographic change affect land use patterns?: A case study from Germany

Recent demographic change, mainly characterised by a decreasing and ageing population, is seen as one of the main factors for future land use development in Europe. However, there is still insufficient evidence about the relationship between demographic changes and land use changes since quantitative studies dealing with these interactions are still rare. We aim to fill that gap by presenting the first comprehensive study that investigates statistical relationships and spatial differentiations between demographic and land use change for the whole of Germany. Our study is based on data for the period from 1995/1996 to 2003/2004. The results clearly show that in most growing regions in the West of Germany a correlation was found between land use, natural population growth and net-migration, whereas for land use change in the shrinking regions in the East of Germany economic variables are of noticeable importance. A cluster analysis reveals “gaining” and “shrinking” regions concerning both urbanisation and demographic change. Neither a decreasing nor an ageing population imply reduced land consumption for housing and transportation. Furthermore we found a decreasing settlement population density for almost all German districts regardless of population growth or shrinkage.     

近10年崇州市土地利用变化基本特征与空间格局

[目的]土地利用变化研究是揭示土地利用对人类活动响应程度的重要途径,通过对其变化特征及空间格局的研究讨论人地关系在不同地域空间上的强度与作用模式。[方法]基于2002年、2014年TM/ETM+影像,在RS和GIS技术的支持下,采用人机交互图像处理方法提取了崇州市土地利用信息,应用土地利用动态度、土地利用程度、空间转移图谱、城市扩展指数、缓冲分析模型和方法对崇州市近10年来土地利用变化时空特征进行了研究。[结果](1)土地利用类型以林地、耕地、建设用地为主,建设用地动态度最大达到5.72;整体土地利用程度由254.25增长到260.93,各乡镇变动值差异较大。(2)土地空间转换面积达1.850 85万hm~2,占研究区总面积的16.94%;增长面积最大的图谱单元依次是新增建设用地、新增耕地和新增林地;建设用地、耕地、水体与高程、坡度之间负相关性显著,坡度0°~6°是人类活动最频繁的区域。(3)中心城区建设用地面积大幅增长,缓冲范围内建设用地面积增加了2 120.76hm~2,城市中心自河流向东、东南、东北3个方向扩展。[结论]崇州市土地利用整体处于快速发展时期,地域差异明显,受人类活动影响显著。     

Prospective evaluation of the impact of land use change on ecosystem services in the Ourika watershed,Morocco

Land use change at the local stage affects the flow of ecosystem services at all levels. Analyzing the causes of land use change such as anthropogenic activities in the case of the Ourika watershed will facilitate sustainable policies. A decision-making tool, InVEST (Integrated Valuation of Ecosystem Services and Trade Offs) was used to quantify three ecosystem services and to generate three spatially explicit land use scenarios (trend, development and conservation) with expert stakeholders and the local population. The results indicate that forest expansion under the conservation scenario increased carbon sequestration and sediment retention by 34.29 % and 7.17 % but decreased water yield by 0.75 %. Comparably, a combination of forest and cropland expansion under the trend scenario generated a moderate increase by 8.4 % and 0.98 % but a negligible decrease of 0.09 %. A decline in the forests under the development scenario caused an improvement in the water yield by 0.12 % but a decrease in carbon sequestration and sediment retention by 6.06 % and 0.88 % respectively. A combination of forests and croplands through agroforestry systems enhances the provision of all the three ecosystem services. Community-based ecosystem and land management is the best way to improve ecosystem services at the local level.     

The Edmonton-Calgary corridor: Simulating future land cover change under potential government intervention

The region connecting Edmonton and Calgary, the two largest cities in Alberta, contains rich agricultural land and is one of the most rapidly changing areas in the province. There is little legislation to restrict urban sprawl or adequately protect agricultural land or native grasslands, and there has been little research to predict future alteration. The main study objectives are, therefore, to assess historical changes in the Edmonton-Calgary corridor from 1984 to 2013 and simulate the future landscape change to 2022 under potential government intervention scenarios. Satellite imagery from Landsat, used in conjunction with biogeophysical variables, was used to create a history of cover in the Edmonton-Calgary area. This history of the environment can be used as a baseline to project changes into the future. Testing different legislative scenarios under two major branches of modifying rates of change or locations of change can be used to identify effective policies for limiting damage to the environment while still allowing for urban growth. Five scenarios were created for this purpose: (1) business as usual, (2) increased rate of urban expansion, (3) no urban expansion, (4) implementation of greenbelts around urban areas, (5) protection of the best agricultural land. This study finds that over the past 30 years, urban area has nearly doubled in size, targeting predominately farmland, especially due to an increase in rural subdivisions. Each scenario impacts growth differently, however, greenbelts and the no expansion model decease growth the most, while the agricultural protection is comparable to the business as usual scenario.     

长江中游城市群土地利用生态风险分析——以长株潭城市群为例

为揭示城市群发展对区域生态风险的影响,以位于长江经济带的长株潭城市群为研究区,利用1993-2013年Landsat遥感数据,定量获取土地利用变化特征,并基于移动窗口的景观生态风险指数,获得区域空间连续的生态风险指数等级分布图,分析长株潭城市群土地利用动态变化及生态风险时空变化特征。结果表明,近20年来,研究区土地利用变化较为显著,建设用地呈持续增加的趋势,耕地、林地面积在波动中减少且变化明显;近20年,生态风险等级面积变化显著,低风险区波动减少,中等风险区先减少后增加,较高风险区、高风险区均波动性增加。本研究为长株潭城市群土地资源可持续利用、生态风险的有效防范,以及对城市建设用地开发边界和生态红线的确定提供了参考,也为区域生态风险定量评价提供了有效的技术方法。     

Scenario simulation of land system change in the Beijing-Tianjin-Hebei region

Urbanization-induced land use problems have been haunting China’s urban agglomerations ever since the beginning of this period of unparalleled economic progress. The Beijing-Tianjin-Hebei (BTH) region is no exception, where coordinated development planning has been implemented by the central government to further resolve attributed problems. Land use simulation models can be used to help governments and planners understand how planning and policies affect the future landscape, by developing sustainable land use strategies which may reasonably balance urbanization and eco-environmental protection. In this paper, we explored the characteristics of historical land use dynamics from 2000 to 2015 in the BTH region and simulated its future land use patterns for 2030 by combining the Dyna-CLUE model with a Markov model to deal with some short comings of existing land use models. The main conclusions are as follows: (1) The figure of merits (FoM) based on the method of three-map comparison reached 85.89 %, which indicated that the simulation model has satisfactory accuracy. (2) Land use structures and spatial patterns differed significantly under business as usual (BAU) scenario, cropland protection (CP) scenario and ecological security (ES) scenario, respectively, owing to the variation of the major objectives designed for different scenarios. (3) By scenario analysis and through tradeoffs, the land use mode under the ecological security scenario might be the optimal solution for future coordinated development in the BTH region. These results will provide theoretical basis and meaningful guidance for regional land optimal allocation.     

Why have land use change models for the Amazon failed to capture the amount of deforestation over the last decade?

Land cover change in the Neotropics represents one of the major drivers of global environmental change. Several models have been proposed to explore future trajectories of land use and cover change, particularly in the Amazon. Despite the remarkable development of these tools, model results are still surrounded by uncertainties. None of the model projections available in the literature plausibly captured the overall trajectory of land use and cover change that has been observed in the Amazon over the last decade. In this context, this study aims to review and analyze the general structure of the land use models that have most recently been used to explore land use change in the Amazon, seeking to investigate methodological factors that could explain the divergence between the observed and projected rates, paying special attention to the land demand calculations. Based on this review, the primary limitations inherent to this type of model and the extent to which these limitations can affect the consistency of the projections will also be analyzed. Finally, we discuss potential drivers that could have influenced the recent dynamic of the land use system in the Amazon and produced the unforeseen land cover change trajectory observed in this period. In a complementary way, the primary challenges of the new generation of land use models for the Amazon are synthesized.     

Modeling of ecosystem services informs spatial planning in lands adjacent to the Sarvelat and Javaherdasht protected area in northern Iran

Dynamic models of ecosystem services supply and scenario analysis of changes in multiple services are being increasingly used to support land use planning and decision making. This approach reduces potential and real conflicts among various stakeholders potentially creating win–win solutions for all. It is particularly applicable in areas where insufficient land for agriculture and settlements is resulting in high rates of conversion of natural forest and grasslands. We quantified and mapped multiple ecosystem services, including habitat provision as a proxy for biodiversity, carbon storage and sequestration, and water balance and supply in the Sarvelat and Javaherdasht region of the globally-significant Hyrcanian (Caspian) forests in northern Iran using the Integrated Valuation of Ecosystem Services and Tradeoffs tool. This region is experiencing a rapidly increasing rate of forest conversion and as a result, the protected area located within the study landscape is threatened by human encroachment. Plausible future landscapes were modeled under three scenarios: (i) business as usual; (ii) protection-based zoning which reflects an expansion of the protected area boundary to prevent land use changes; and (iii) collaborative zoning through redefining the protection boundary simultaneously with an adjustment to meet local stakeholders’ objective of expansion of anthropogenic cover. The results showed that the collaborative zoning scenario would best contribute to effective policy because it presents a more rational spatial configuration of the landscape maintaining the provision of ecosystem services. This scenario may lead to reduced environmental impacts while achieving less conflict between the government and local communities. These results will help to inform and shape natural resource management policies in Iran and is applicable elsewhere in the world.     

Spatially explicit micro-level modelling of land use change at the rural–urban interface

This paper describes micro‐economic models of land use change applicable to the rural‐urban interface in the US. Use of a spatially explicit micro‐level modelling approach permits the analysis of regional patterns of land use as the aggregate outcomes of many, disparate individual land use decisions distributed across space. In contrast to the models featured by Nelson and Geoghegan, we focus on models that require spatially articulated data on parcel‐level land use changes through time. In characterising the spatially disaggregated models, we highlight issues uniquely related to the management and generation of spatial data and the estimation of micro‐level spatial models.     

面向规划国土数据融合的深圳市土地利用分类体系研究

研究目的：整合规划和国土分类标准,促进规划和国土数据融合;根据管理需求细分用地类型,支撑精细化管理。研究方法：采用实地调研、需求分析、对照转换、征求意见、实践验证等研究方法,对整合原则、分类标准异同点、对应关系、地类细分及编码等关键环节进行研究。研究结果：制定了一套深圳市土地变更调查工作地类及其与规划和国土分类标准之间的对应关系。研究结论：深圳市2011年调查实践表明,采用工作地类进行调查,不但可以通过一次调查获取两套适用于城市规划、土地规划、用地审批、执法监察等精细化管理的数据,而且在数据获取源头为规划和国土数据的无缝融合打下基础。