湖北省道路网络中心性与土地利用景观格局关系分析

深入理解道路网络与土地利用之间的关系有助于开展可持续的土地利用与道路网络规划。引入多中心性评价模型,对临近中心性、中介中心性、直线中心性3个指标,运用UNA对湖北省道路网络中心性进行测度;选取景观百分比,香农多样性指数,平均斑块大小,平均形状指数4个景观格局指数计算土地利用景观格局特征,并通过斯皮尔曼相关方法对两者之间的关系进行探讨。结果表明:(1)湖北省道路网络中心性格局和空间特征各异,整体上东高西低,临近中心性呈现条带状分布,中介中心性呈孔隙状分布,直线中心性呈片状分布;(2)景观层面上,土地利用景观破碎化和多样化对直线中心性最为敏感,而临近中心性与中介中心性与景观格局指数关系相对复杂;(3)在类型层面上,道路网络中心性与各类土地利用景观格局相关性各异,其中高中心性区域对林地表现为鲜明的排斥和破碎化效应,而对建设用地表现为强烈的吸引和空间集聚现象。该研究以道路网络中心性视角探讨道路网络与土地利用景观格局之间的关系,为区域空间形态和构成及其相关影响因素提供了新的视角。     

秦淮河流域城镇用地增长格局及其演化机制——秦淮河流域江宁段实证

利用四期遥感TM数据和GIS技术,通过分析20年秦淮河流域城镇用地增长格局及其演化机制,为流域综合管理和模拟提供重要参数,研究结果表明:①城镇用地增长显示阶段性和空间的不均匀性,增长拐点发生在1994年和2000年,空间上表现出增长"热极"与"热带";②城镇用地增长阶段性是经济社会过程及驱动因子演化阶段的反映,回归分析显示城镇用地增长与城镇人口、经济总量及开发区发展相关系数高,这归于1992年开发区创建、投资增加与2000年撤县设区驱动的结果;③城镇用地增长格局变化是社会经济物质载体演化的体现,1992年后开发区成为城镇用地增长首要来源,2000年后东山新市区与大学城成为其增长核心和新形式,机场与高速公路网强化对城镇用地的空间导向.研究结果较客观地刻画了城市化格局与过程的演化规律,参数应用与数据精度的提高是今后研究的重点.     

基于空间自相关模型的农村居民点时空演变格局与特征研究

农村居民点作为农村人口重要空间聚集区,其空间布局、演变特征受历史、自然、社会、经济、传统文化等多重因素的影响。科学识别农村居民点的时空分布形态,并揭示其内在的变化规律和驱动因素,对促进农村居民点科学规划、提高农村土地资源空间布局优化均具有重要意义。利用都江堰市2005和2012年两期遥感影像提取农村居民点、城镇、道路、河流等矢量数据,借助RS、GIS空间分析技术,定量研究都江堰市农村居民点时空变化过程、格局和特征,并引入空间自回归模型深入分析不同环境因素对农村居民点空间布局的影响程度。研究结果表明:(1)都江堰市农村居民点的空间分布密度存在显著的空间正相关性,即密度值较高或较低的地区在空间上呈现显著的聚集状态,但局部的空间异质性在增强;(2)密度的高值集群主要集中分布在都江堰市东南部沙西线沿线以及南部成青快速通道一线,并且有进一步沿道路延线纵深扩张的趋势,而密度的低值集群由于受地形的影响,在空间分布上变化不大,主要位于龙门山沿线的乡镇;(3)2005~2012年,地形位指数每增加1%,农村居民点的空间密度减少0.505%,而距城镇、河流和道路的距离每增加1%,农村居民点的空间密度分别增加0.124%、0.144%、0.006%;(4)不同环境因素对农村居民点空间分布的影响程度大小为:地形影响城镇辐射影响河流影响道路影响,并且随着时间的推移,各环境因素的影响程度都在不断地增强。该研究以期为今后同类研究提供一定的方法借鉴,为农村居民点动态变化监测、农村土地节约集约利用、新农村规划等提供理论方法和技术应用支撑。     

Combining remote sensing and household level data for regional scale analysis of land cover change in the Brazilian Amazon

Land cover change in the Brazilian Amazon depends on the spatial variability of political, socioeconomic and biophysical factors, as well as on the land use history and its actors. A regional scale analysis was made in Rondônia State to identify possible differences in land cover change connected to spatial policies of land occupation, size and year of establishment of properties, accessibility measures and soil fertility. The analysis was made based on remote sensing data and household level data gathered with a questionnaire. Both types of analyses indicate that the highest level of total deforestation is found inside agrarian projects, especially in those established more than 20 years ago. Even though deforestation rates are similar inside and outside official settlements, inside agrarian projects forest depletion can exceed 50% at the property level within 10–14 years after establishment. The data indicate that both small-scale and medium to large-scale farmers contribute to deforestation processes in Rondônia State encouraged by spatial policies of land occupation, which provide better accessibility to forest fringes where soil fertility and forest resources are important determinants of location choice.     

Scenarios of land-use change in a deforestation corridor in the Brazilian Amazon: combining two scales of analysis

Local, regional, and global processes affect deforestation and land-use changes in the Brazilian Amazon. Characteristics are: direct conversions from forest to pasture; regional processes of indirect land-use change, described by the conversion of pastures to cropland, which increases the demand for pastures elsewhere; and teleconnections, fueled by the global demands for soybeans as animal fodder. We modeled land-use changes for two scenarios Trend and Sustainable Development for a hot spot of land-use change along the BR-163 highway in Mato Grosso and Pará, Brazil. We investigated the differences between a coupled modeling approach, which incorporates indirect land-use change processes, and a noncoupled land-use model. We coupled the regional-scale LandSHIFT model, defined for Mato Grosso and Pará, with a subregional model, alucR, covering a selected corridor along the BR-163. The results indicated distinct land-use scenario outcomes from the coupled modeling approach and the subregional model quantification. We found the highest deforestation estimates returned from the subregional quantification of the Trend scenario. This originated from the strong local dynamics of past deforestation and land-use changes. Land-use changes exceeded the demands estimated at regional scale. We observed the lowest deforestation estimates at the subregional quantification of the Sustainable Development story line. We highlight that model coupling increased the representation of scenario outcomes at fine resolution while providing consistency across scales. However, distinct local dynamics were explicitly captured at subregional scale. The scenario result pinpoints the importance of policies to aim at the cattle ranching sector, to increase land tenure registration and enforcement of environmental laws.

     

村镇路网通达性与空间出行研究——以武汉市李集镇为例

道路网络是乡村地区社会经济发展的基础。综合道路网络分析和通达性分析方法,构建路网密度、公路可达性、接近中心性、直达性等指标研究了武汉市李集镇村镇范围内各行政村路网通达性空间格局,并结合农户调查将路网通达性与村民空间出行进行关联分析。结果表明：（1）境内部分行政村道路密度低、断头路较多,导致局部地区通达性较差;（2）受地理区位和公路覆盖两方面因素影响,境内行政村接近中心性呈现出明显的核心-边缘分布模式;（3）高等级道路覆盖不足,未能形成完善的路网体系,极大限制村民的对外出行效率、出行范围,显著影响居民出行满意度,并阻碍地区农业机械化推广和农业产业规模化发展。最后,结合路网通达性特征和居民出行需求,提出李集镇道路网络整治建议,研究结果对完善农村地区道路体系研究、指导新农村建设有一定意义。     

道路交通网络与城市土地利用时空耦合关系——以南京市为例

城市的扩张与道路交通的发展是相辅相成的。道路建设造成了城市景观的破碎化,使城市景观呈现不同的空间格局和空间异质性特征,并且这种空间异质性随着时间的变化而发生改变。在RS和GIS技术的支持下,利用1989、1999和2008年的Landsat TM/ETM+数据,以南京市为例对道路交通网络与城市土地利用之间关系进行了不同层次和尺度的空间分析。结果表明：1989～2008年近20 a来,南京市城市空间形态扩展迅速,建设用地面积从1989年的1003 km2增加到2008年的6847 km2;在不同时期,南京市城市化过程表现出不同的道路交通网络结构和城市空间扩展模式;由道路交通建设造成的局部区域的景观破碎度在一定程度上能够反映周边区域的土地利用强度;土地利用强度和由道路交通建设造成的景观破碎度均表现出显著的空间自相关性,随时间推移,这种特征愈加明显,并且二者在表征城市空间拓展方面具有较高的耦合度;受其他辐射中心的作用,交通干线周边地区土地利用强度并未表现出距离指数衰减效应     

基于城市腹地的乡镇通达性的时空格局及其演化——以湖北荆州市112个乡镇为例

行政边界对路网的分割效应和以出行方向机会均等为前提是当前通达性研究中的两大问题。基于2000~2011年荆州市城乡道路网空间数据库,自下而上揭示了2000~2011年荆州市乡镇通达性的时空格局及其演化特征:(1)基于城市腹地范围的乡镇通达性评价较好的模拟了乡镇的出行意愿,且实现了区内通达性与区际通达性的综合。十多年间,交通网络建设带来的城市腹地时空压缩效应显著:荆州市乡镇地域所属地级市腹地格局由荆州"一城主宰"演变为荆州和岳阳"两城瓜分",所属县级市腹地格局也经历了由"荆州独享"到"周边共享"的发展历程;(2)十多年间,荆州市乡镇通达性空间分布基本遵循距离衰减律,呈现以荆州城区为中心的环状分布格局,且时序上表现出微观动态性和宏观稳定性特征:一是,通达性空间分布呈现由低水平集聚向优化均衡的动态性发展趋势。二是,乡镇通达性空间分布结构由核心-边缘向等级圈层结构的演进。三是,乡镇通达性发育具有时空惯性,呈现显著的快速干道指向性;(3)十多年间,荆州市乡镇通达性发育呈现出"单核单轴弱扩散"→"单核多轴强扩散"→"双核多轴全扩散"的空间演化模式。     

基于RS与GIS的无锡市城镇建设用地扩展时空特征分析

随着工业化的迅速发展,城市化过程加快,使得城镇建设用地需求增加,土地利用中的矛盾日趋紧张。从不同时相的城市及区域土地利用多源遥感信息提取入手,运用GIS空间分析方法,以“时间过程”与“空间格局”为主线,对无锡市城镇建设用地扩展的时间过程与空间格局特征进行分析,将区域城镇建设用地扩展与自然交通条件和社会经济条件进行综合研究,揭示了无锡市城镇建设用地扩展的时空分异规律。研究表明:改革开放以来,无锡市城镇建设用地扩展具有显著的阶段性,用地扩展模式反映了城市发育、成长乃至成熟的历程;自然交通、社会经济条件的差异以及政策的引导,无锡市城镇建设用地扩展的空间方位差异显著,具有较强的向心性,主城区不同时段扩展的主导方向明显,对其周围集镇具有强大的吸引力和辐射力,它主宰着周围一定范围内集镇用地发展方向。     

Evaluating the effect of flood damage-reducing measures: a case study of the unembanked area of Rotterdam,the Netherlands

Empirical evidence of increasing flood damages and the prospect of climatic change has initiated discussions in the flood management community on how to effectively manage flood risks. In the Netherlands, the framework of multi-layer safety (MLS) has been introduced to support this risk-based approach. The MLS framework consists of three layers: (i) prevention, (ii) spatial planning and (iii) evacuation. This paper presents a methodology to evaluate measures in the second layer, such as wet proofing, dry proofing or elevating buildings. The methodology uses detailed land-use data for the area around the city of Rotterdam (up to building level) that has recently become available. The vulnerability of these detailed land-use classes to flooding is assessed using the stage–damage curves from different international models. The methodology is demonstrated using a case study in the unembanked area of Rotterdam in the Netherlands, as measures from the second layer may be particularly effective there. The results show that the flood risk in the region is considerable: EUR 36 million p.a. A large part (almost 60 %) of this risk results from industrial land use, emphasising the need to give this category more attention in flood risk assessments. It was found that building level measures could substantially reduce flood risks in the region because of the relatively low inundation levels of buildings. Risk to residential buildings would be reduced by 40 % if all buildings would be wet-proofed, by 89 % if all buildings would be dry-proofed and elevating buildings over 100 cm would render the risk almost zero. While climate change could double the risk in 2100, such building level measures could easily nullify this effect. Despite the high potential of such measures, actual implementation is still limited. This is partly caused by the lack of knowledge regarding these measures by most Dutch companies and the legal impossibility for municipalities to enforce most of these measures as they would go beyond the building codes established at the national level.     

大城市边缘区土地利用时空格局模拟--以武汉市洪山区为例

大城市边缘区的土地利用变化复杂而迅速,采用定量模型对此地域的时空格局进行模拟,在土地规划领域有重大意义。以武汉市洪山区为例,首先采用DPSIR模型对大城市边缘区的工业用地、居住用地、服务设施用地、绿地等进行驱动力机制的定性分析,得出每种用地相应的驱动力、压力和状态;进而采用CLUE S模型,通过用地变化驱动力因子作用权重系数的求解,模拟时段内各类用地的需求分析与用地变化的动态分配过程,对边缘区的用地演变进行模拟;最后通过用地现状图对模拟用地进行验证,模拟结果基本拟合。在模拟的基础之上,设定了两种大城市边缘区空间发展的情景模式,即不作任何空间约束的用地演变和进行可持续发展约束的用地演变,有针对性地提出该区域的发展需要重点保护水体和自然风景区。其方法及成果可为大城市边缘区制定发展管理政策提供科学参考。     

Use of rainwater for non-potable purposes in the Amazon

The Brazilian Amazon has about 69 % of available freshwater in Brazil, an amount that ends up creating the illusion that no lack of water and not lacking in the region, the large supply of this resource becomes a problem when it comes to the Management and Planning Water Resources in the Amazon, according to the wasteful use and lack of maintenance of stocks, compounded by the release of untreated wastewater. Speaking of water conservation programs in the Amazon a few decades ago and still today, with less intensity, is somewhat strange, given the large amount of water available and the culture of abundance. Thus, this research discusses the importance of the use of rainwater for non-potable purposes, since the potential for exploitation, throughout the year, due to this high rainfall in the Amazon region, ranging from, on average, 119.6 mm in months from November to 441.6 mm in March. The methods used for sizing of the reservoir were the Rippl and interactive, and economic viability checking done by the methods of net present value and discounted payback. As a result, there was a volume exceeding 1,000 m³ obtained by the method of Rippl, while the interactive method was a maximum of 75 m³. The economic viability presented fragile as a function of time to return exceeds the useful life of the utilization system for rainwater.     

Indicators of deforestation in the Southern Brazilian Pre-Amazon

In recent years, Amazonian deforestation has become a question of global concern. Deforestation in Amazon is a complex phenomenon in nature and has been related to traditional agriculture expansion. In this work, land use, socioeconomic and conservation indicators, combined with statistical analysis, were used to understand forces associated with patterns of deforestation. This approach was applied in Southern Brazilian Pre-Amazon in Mato Grosso State, which represents an extensive rain forest-savanna ecotone, located in the south border of Amazon biome. Based on data from the last two agricultural censuses (1995/1996–2006), we compared agricultural expansion in this area and Mato Grosso state. Results have shown that 85 % of state deforestation was concentrated in Southern Pre-Amazon and was closely related to increase in number of cattle and pasture area. PCA results pointed that population (92 %), number of cattle (86.5 %), pastures (84.2 %) and tractors (78.4 %) were variables with highest positive correlation to deforestation. It showed that GDP contributes to an individual axis and has a low correlation to deforestation (37.8 %). Conservation units and indigenous reserves also contribute to a single axis and were negatively correlated to temporary crops area. Results revealed a significant reduction in production and commercialization of extractive products in the region, revealing that the main, almost only conservation policy in Mato Grosso remains the creation of Special Areas. We suggest that further studies are necessary to screen development alternatives to simple cutting trees down. It is important to diversify strategies for deforestation control, and development aspects must be more seriously considered to reach a sustainable deforestation control policy.     

Historical carbon fluxes in the expanding deforestation frontier of Southern Brazilian Amazonia (1985–2012)

In tropical areas, pioneer occupation fronts steer the rapid expansion of deforestation, contributing to carbon emissions. Up-to-date carbon emission estimates covering the long-term development of such frontiers depend on the availability of high spatial–temporal resolution data. In this paper, we provide a detailed assessment of carbon losses from deforestation and potential forest degradation from fragmentation for one expanding frontier in the Brazilian Amazon. We focused on one of the Amazonia’s hot-spots of forest loss, the BR-163 highway that connects the high productivity agricultural landscapes in Mato Grosso with the exporting harbors of the Amazon. We used multi-decadal (1984–2012) Landsat-based time series on forested and non-forested area in combination with a carbon book-keeping model. We show a 36% reduction in 1984s biomass carbon stocks, which led to the emission of 611.5 TgCO₂ between 1985 and 1998 (43.6 TgCO₂ year⁻¹) and 959.8 TgCO₂ over 1999–2012 (68.5 TgCO₂ year⁻¹). Overall, fragmentation-related carbon losses represented 1.88% of total emissions by 2012, with an increasing relevance since 2004. We compared the Brazilian Space Agency deforestation assessment (PRODES) with our data and found that small deforestation polygons not captured by PRODES had increasing importance on estimated deforestation carbon losses since 2000. The comparative analysis improved the understanding of data-source-related uncertainties on carbon estimates and indicated disagreement areas between datasets that could be subject of future research. Furthermore, spatially explicit, annual deforestation and emission estimates like the ones derived from this study are important for setting regional baselines for REDD+ or similar payment for ecosystem services frameworks.

     

Assessing the impacts of sustainable development projects in the Amazon: the DURAMAZ experiment

Since 1992, a boom of “sustainable development projects” has been registered in the Brazilian Amazon, turning it into a kind of open-air laboratory for sustainability. But their real impacts remain unclear, especially because of inadequate evaluation tools. A new device is therefore needed to unveil the inner mechanisms of development aid despite the difficulties linked with the diversity of contexts or the heterogeneity in the relevant parameters. Those are the challenges we met when we engaged in comparing the impacts of sustainable development programs in 13 sites throughout the Brazilian Amazon in order to identify determining factors of sustainability. To achieve our objective, we conceived an indicator system based on the results of intensive fieldwork, including social, economic, environmental, and biographical issues. Our results show that the most prominent problem of sustainability—evaluation of effectiveness—has not been tackled; life conditions and environmental preservation continue to appear antagonistic. At the same time, variability appears among outwardly coherent social groups, showing that a case-to-case approach is definitely indispensable and confirming the need to go “beyond panaceas” to find resolutions. This article successively addresses three points. First, we present the starting point of our research, or how the Amazon region was turned into a laboratory for sustainability and how our research project aimed at analyzing the consequences of this trend. Second, we discuss how available indicator systems fail to respond to the need for a multidimensional evaluation at the local level and, therefore, how we constituted our own analytical tool. Third, we focus on some results that can be derived from our system, especially in terms of identifying key factors needed to achieve sustainability in the Amazon.     

Toward a ‘Sustainable’ land degradation? Vulnerability degree and component balance in a rapidly changing environment

Land degradation is a process negatively affecting environmental sustainability and requires permanent monitoring for understanding its nonlinear trajectories of change over time and space. Environmental sustainability is linked to a theoretical definition of dynamic balance among various components contributing to the ecosystem quality and functioning. The aim of this study is to develop a diachronic analysis (1960–2010) of the equilibrium/disequilibrium condition of key environmental factors (climate, soil, vegetation, land-use) influencing the vulnerability of land to degradation in a Mediterranean country experiencing processes of desertification at the local scale. Three indicators of components’ balance have been proposed and tested for spatial and temporal coherence. Land classified at high vulnerability and low component’s balance has been identified as a possible target for mitigation strategies against desertification; the surface area of this class increased rapidly during 1960–2010 and concentrated in high-intensity agricultural lowlands of northern Italy.     

基于CLUE-S模型的重庆市渝北区土地利用变化动态模拟

以重庆市渝北区为研究区域,运用CLUE-S模型,结合Logistic回归分析,分别以2007年和2009年为基期,对渝北区2013年土地利用情况进行模拟研究,在此基础上构建了渝北区2013~2020年3种不同情景的土地利用变化模式,模拟了3种情景模式下渝北区在2020年的土地利用空间分布格局。结果表明:(1)两期模拟的正确率分别达到了92.26%和94%,Kappa系数值分别为90.32%和92.5%,均取得了较好的模拟效果,说明CLUE-S模型适用于渝北区的土地利用空间格局变化的模拟研究,具有较好的模拟区域土地利用时空变化的能力;(2)地形、国道、省道、高速公路等主要道路、河流、城镇和村庄是影响渝北区土地利用空间格局变化的重要驱动因素;(3)在3种情景模式中,主要的用地格局变化均发生在两江新区,区内建设用地总体呈现向东北部扩张的趋势,表明区域经济社会发展政策对用地类型的变化具有较大的影响;(4)从促进城乡统筹和谐发展、土地节约集约利用、生态环境显著改善和保护耕地的区域发展目标而言,情景模式2为较为合理的发展模式。研究结果可为决策部门在土地可持续利用和土地管理方面提供参考依据。     

基于3D理论与SEM的县域交通可达性与空间贫困的耦合机制

为获取连片特困地区县域交通可达性与空间贫困程度之间的耦合关系,运用路网-栅格集成法的加权时间成本距离模型对县域综合交通可达性进行测算,构建了基于“3D”理论的空间贫困评价指标体系,基于结构方程模型获取了二者的空间耦合机制,并以滇西边境山区为例进行分析验证。结果表明：滇西边境山区各贫困县（区）可达性水平的空间分异特征显著,且邻近效应突出,骨干路网的完善在一定程度上提高了贫困县域的县外可达性水平;滇西边境山区的贫困发生率呈现中心发散、集聚分布的空间特征,贫困程度的改善与地均GDP、市场距离、产业距离、交通分割、贫困分割呈正向相关,与地均人口密度呈负相关;区域空间贫困程度与交通可达性的耦合强度为023,呈显著负向影响。通过提升可达性水平和县域间通达程度,可为扶贫攻坚和经济社会发展提供有力支撑     

基于SD和CLUE-S模型的区域土地利用变化对土壤有机碳储量影响研究

土地利用/土地覆被变化改变土壤呼吸条件,进而对土壤有机碳储量变化产生影响,而土壤有机碳储量则是影响农业可持续发展和全球碳平衡领域的重要因素。以上海市崇明岛为例,运用系统动力学模型(System Dynamics Model)预测2020、2030年土地利用需求变化,结合CLUE-S模型(Conversion of Land Use and its Effects at Small region extent Model)得出各种用地类型的空间分布,并引用碳密度法估算三种发展幕景下土地利用变化对土壤有机碳储量的影响。结果表明:2030年三种发展幕景土壤有机碳储量分别为:低速发展幕景为3 093.03×106kg,惯性发展幕景为3 079.47×106kg,高速发展幕景为3 059.81×106kg;研究期内土壤有机碳储量呈现缓慢下降趋势,但人类活动对其扰动较小;SD和CLUE-S耦合模型可以从时间和空间两方面对土壤有机碳储量进行模拟,具有可行性;建议通过加强城镇用地集约利用、农田保护、林地建设来减少人为活动对土壤有机碳储量的影响。