干旱区典型山地绿洲荒漠系统中绿洲土地利用/覆盖变化对生态系统服务价值的影响

研究土地利用/覆盖变化对区域生态系统服务价值的影响具有重要意义。对处于干旱区典型MODS（Mountain-Oasis-Desert System）系统中的新疆南部且末绿洲1989年Landsat TM 影像及2004年的CBERS遥感影像进行处理,分析且末绿洲15 a来的土地利用/覆盖变化。在此基础上,采用中国陆地生态系统服务价值的测算方法,评估且末绿洲土地利用/覆盖变化引起的生态系统服务价值的变化。结果表明,1989-2004年,且末绿洲减少的土地面积有林地、戈壁沙地和盐碱地,增加的土地面积有水域、建筑用地和耕地。林地减少了41.73％,耕地增加了58.04％。1989年且末绿洲生态系统服务价值总额为184 349.88万元,2004年为176 970.72万元,15 a间,生态系统服务价值损失了7 379.16万元。林地面积的减少是生态系统服务价值减少的主要原因。保护区域生态环境,恢复和提高区域生态系统服务功能是该区域生态环境建设的重要任务。     

Forest dynamics and the importance of place in western Honduras

Analyses of landscape change using remotely sensed satellite imagery constitute a large component of forest transition research, allowing for assessments of large areas. In the western highlands of Honduras is an area of complex forest dynamics (～45,000 ha) that has seen significant forest regeneration in recent years. However, analysis of the larger region (～500,000 ha) shows net forest loss. The comparative aspects highlight the importance of site selection and scale in forest transition analysis, a process often ignored in the land-use and land-cover change (LULCC) and forest transition literature. Results also highlight the importance of analyzing human-induced fragmentation at a variety of selected sites and a range of spatial scales, and producing quality, accurate forest cover and change maps.     

流域土地利用／土地覆被变化的生态效应

土地利用／土地覆被变化改变了地表生态系统组成结构,影响着生态系统功能,威胁着区域生态安全。本文以辽河流域的浑河-太子河流域为研究区,探讨了流域空间尺度上的LUCC特征及其所带来的生态效应。研究表明,不同的生态指标对LUCC的响应程度略有不同：（1）从景观生态格局角度看,反映生态系统斑块形状特征的景观指数对LUCC的响应...     

2000-2025年环境保护政策情景下中国陆地碳储量估算

政策总是通过对土地利用/土地覆被的强烈影响而影响陆地碳平衡。本研究旨在探讨环境保护政策（主要是退耕还林）政策对我国陆地碳平衡的影响,从而为政府部门等相关政策制定者提供环境保护和应对气候变化的决策支持。利用DLS（Dynamics Land System）模型对2000-2025年环境保护政策情景下的土地利用变化模拟结果和前人对碳密度的研究成果,运用碳密度法估算了该政策情景对中国陆地碳储量的影响。研究结果表明,在整个阶段,林地将增加23%,耕地和草地将分别减少37%和11%,由此会引起我国森林碳储量每年增加66.0 Tg C,土壤碳储量每年增加13.3 Tg C,而草地碳储量则每年减少5.7 Tg C。总体而言,在环境保护政策情景下,2000-2025年中国整个陆地生态系统的碳储量将增加1.8 Pg C,年均增加量为0.074 Pg C,而这种变化89.6%的原因源于森林碳储量的增加。     

东北地区历史时期森林空间格局网格化重建方法研究(英文)

The spatially explicit reconstruction of historical land-cover datasets plays an important role in studying the climatic and ecological effects of land-use and land-cover change(LUCC). Using potential natural vegetation(PNV) and satellite-based land use data, we determined the possible maximum distribution extent of forest cover in the absence of human disturbance. Subsequently, topography and climate factors were selected to assess the suitability of land for cultivation. Finally, a historical forest area allocation model was devised on the basis of the suitability of land for cultivation. As a case study, we used the historical forest area allocation model to reconstruct forest cover for 1780 and 1940 in Northeast China with a 10-km resolution. To validate the model, we compared satellite-based forest cover data with our reconstruction for 2000. A one-sample t-test of absolute bias showed that the two-tailed significance was 0.12, larger than the significant level 0.05, suggesting that the model has strong ability to capture the spatial distribution of forests. In addition, we calculated the relative difference of our reconstruction at the county scale for 1780 in Northeast China. The number of counties whose relative difference ranged from-30% to 30% is 99, accounting for 74.44% of all counties. These findings demonstrated that the provincial forest area could be transformed into forest cover maps well using the model.     

Projecting land-use change processes in the Sierra Norte of Oaxaca, Mexico

The objective of study was to explore short-term trends of processes that determine land-use change in Sierra Norte of Oaxaca (SNO), Mexico. Land use and land cover changes (LULCC) were estimated in a complex mosaic of vegetation in the SNO from 1980 to 2000, and projected them to 2020 through a Markovian model. SNO is highly vulnerable to climatic change according to a 2050 GCM scenario. However, 3% annual rate of tropical and temperate forest deforestation from agriculture and livestock encroachment, suggest the threat from land-use change is higher than that from climatic change for this study site. Productive land-use strategies are needed to reduce such high deforestation rates for tropical regions. Controlling deforestation would also reduce short-term effects of CO₂ emissions to the atmosphere. Because of the necessity to evaluate anthropogenic ecosystem changes, it is imperative to separate short-term influences such as deforestation, from long-term influences such as climatic change.     

吴哥神庙平面规划特征

通过实地考察和资料分析,研究得出吴哥神庙平面规划特征为:以东、西向中轴线为主,左右对称,四周闭合;与华夏传统坛庙建筑平面布局特征取向一致,其主要原因为:在吴哥时期封建奴隶制社会突出帝王的权力;华夏传统建筑文化平面布局对吴哥神庙建筑文化的渗透影响。吴哥神庙建筑群由若干建筑语言组合而成,其模式承传了600多年,由简约演化为繁复。     

An approach to spatially explicit reconstruction of historical forest in Northeast China

The spatially explicit reconstruction of historical land-cover datasets plays an important role in studying the climatic and ecological effects of land-use and land-cover change（LUCC）. Using potential natural vegetation（PNV） and satellite-based land use data, we determined the possible maximum distribution extent of forest cover in the absence of human disturbance. Subsequently, topography and climate factors were selected to assess the suitability of land for cultivation. Finally, a historical forest area allocation model was devised on the basis of the suitability of land for cultivation. As a case study, we used the historical forest area allocation model to reconstruct forest cover for 1780 and 1940 in Northeast China with a 10-km resolution. To validate the model, we compared satellite-based forest cover data with our reconstruction for 2000. A one-sample t-test of absolute bias showed that the two-tailed significance was 0.12, larger than the significant level 0.05, suggesting that the model has strong ability to capture the spatial distribution of forests. In addition, we calculated the relative difference of our reconstruction at the county scale for 1780 in Northeast China. The number of counties whose relative difference ranged from-30% to 30% is 99, accounting for 74.44% of all counties. These findings demonstrated that the provincial forest area could be transformed into forest cover maps well using the model.     

基于地理模拟方法的昆明市空间拓展情景分析简

改革开放以来,西部高原湖滨城市经历的快速城镇化进程给湖泊流域带来了较为严重的生态环境问题,未来城市空间发展政策的调整需要关注城市空间拓展对区域生态环境的影响。以位于滇池湖滨地区的昆明市为例,设定6种不用的城市空间拓展政策情景,应用SLEUTH模型预测了6种情景下未来20年的城市空间格局,采用空间指数和空间分析方法对预测结果进行了分析评价。结果表明：昆明市城市建成区具有典型的摊大饼式空间拓展模式,城市道路网对城市形态具有重要的影响。6种情景模式下未来昆明市建成区空间格局既有相似性,也表现出显著的差异。城市建设用地空间格局总体上呈集约、紧凑型的发展趋势。生态保护与城市发展管制相结合的政策情景对滇池湖滨地区的景观影响最小。多中心城市发展格局和城市发展管制相结合的政策情景对城市总体空间规模的控制具有明显的效果,但不宜在湖滨地区实施。滇池湖滨地区需要划定景观或生态保护区,严格禁止城市建设用地对湖滨用地景观的占用与分割。滇池湖滨以外的区域,适宜执行生态保护与城市发展管制相结合的多中心发展模式。     

Carbon Sequestration Potential of the Forest Ecosystems in the Western Ghats,a Global Biodiversity Hotspot

Global warming with the burgeoning anthropogenic greenhouse gas (GHG) emissions (400 parts per million from 280 ppm CO₂ emissions of pre-industrial era) has altered climate, eroding the ecosystem productivity and sustenance of water, affecting the livelihood of people. The anthropogenic activities such as burning fossil fuel, power generation, agriculture, industry, polluting water bodies and urban activities are responsible for increasing GHG footprint of which 72% constitute CO₂. GHG footprint needs to be in balance with sequestration of carbon to sustain ecosystem functions. Forests are the major carbon sinks (about 45%) that aid in mitigating global warming. The current research focusses on the carbon budgeting through quantification of emissions and sinks in the forest ecosystems and changes in climatic conditions of Western Ghats. This would help in evolving appropriate mitigation strategies toward sustainable management of forests and mitigate impacts of global warming. The land-use land-cover (LULC) dynamics are the prime driver of climate change due to the loss of carbon sequestration potential as well as emissions. The Western Ghats are one among 36 global biodiversity hotspots and forests in this region sequester atmospheric carbon, which aid in moderating the global climate and sustaining water to ensure water and food security in the peninsular India. Assessment of LULC dynamics using temporal remote sensing data shows the decline of evergreen forest by 5% with an increase in agriculture, plantations and built-up area. The interior or intact forests have declined by 10%, and they are now confined to protected areas. The simulation of likely changes indicates that the region will have only 10% evergreen cover and 17% agriculture, 40% plantations and 5% built-up. Quantification of carbon reveals that the WG forest ecosystem holds 1.23 MGg (million gigagrams or Gt) in vegetation and soils. The annual incremental carbon is about 37,507.3 Gg, (or 37.5 million tons, Mt) and the highest in the forests of Karnataka part of WG. Simulation of the likely changes in carbon content indicates the loss of 0.23 MGg (2018–2031) carbon sequestration potential under business as usual scenario. The conservation scenario depicts an increase in carbon sequestration potential of WG forests with the protection. Sequestered carbon in WG is about INR 100 billion ($1.4 billion) at carbon trading of INR 2142 ($30) per tonne. Large-scale land-cover changes leading to deforestation has contributed to an increase in mean temperature by 0.5°C and decline in rainy days, which necessitates evolving prudent landscape management strategies involving all stakeholders for conservation of ecologically fragile WG. This will enhance the ability of forests to sequester atmospheric carbon and climate moderation, with the sustenance of ecosystem goods and services.

     

The land use and land cover change database and its relative studies in China

In the mid-1990s, we established the national operative dynamic information serving systems on natural resources and environment. During building the land-use/land-cover change (LUCC) database for the mid-1990s, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted into land-use/land-cover categories at scale of 1:100,000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use/land-cover in China at the scale of 1:100,000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as an operative dynamic information serving system, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999–2000 and 1989–1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper.     

基于地理模拟方法的昆明市空间拓展情景分析

改革开放以来,西部高原湖滨城市经历的快速城镇化进程给湖泊流域带来了较为严重的生态环境问题,未来城市空间发展政策的调整需要关注城市空间拓展对区域生态环境的影响。以位于滇池湖滨地区的昆明市为例,设定6种不用的城市空间拓展政策情景,应用SLEUTH模型预测了6种情景下未来20年的城市空间格局,采用空间指数和空间分析方法对预测结果进行了分析评价。结果表明：昆明市城市建成区具有典型的摊大饼式空间拓展模式,城市道路网对城市形态具有重要的影响。6种情景模式下未来昆明市建成区空间格局既有相似性,也表现出显著的差异。城市建设用地空间格局总体上呈集约、紧凑型的发展趋势。生态保护与城市发展管制相结合的政策情景对滇池湖滨地区的景观影响最小。多中心城市发展格局和城市发展管制相结合的政策情景对城市总体空间规模的控制具有明显的效果,但不宜在湖滨地区实施。滇池湖滨地区需要划定景观或生态保护区,严格禁止城市建设用地对湖滨用地景观的占用与分割。滇池湖滨以外的区域,适宜执行生态保护与城市发展管制相结合的多中心发展模式。     

The land use and land cover change database and its relative studies in China

In the mid-1990s, we established the national operative dynamic information serving systems on natural resources and environment. During building the land-use/land-cover change (LUCC) database for the mid-1990s, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted into land-use/land-cover categories at scale of 1:100,000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use/land-cover in China at the scale of 1:100,000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as an operative dynamic information serving system, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999-2000 and 1989-1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper.     

Accessibility and land-use patterns at the forest fringe in the northeastern part of the Philippines

Accessibility is considered to be one of the most important determinants of use and land-cover change. In rural land-use change studies, the accessibility situation is often described by simple measures of the distance to a location of interest. In this paper, different measures of access are tested for a rural area at the forest fringe in the northeastern Philippines. The accessibility measures addressed range from simple distance measures to land-use type specific transport costs and a population potential measure. The different measures are tested based on their capacity to explain the spatial pattern of different land-use types. A comparison of the findings based on a spatial analysis and an analysis of household level data is made. It is concluded that the relation between land use and accessibility is dependent on the specific characteristics of the different land-use types. The (dis-)advantages of the use of the different accessibility measures are discussed.     

Modelling spatiotemporal land dynamics for a trans-boundary river basin using integrated Cellular Automata and Markov Chain approach

Nowadays, trans-boundary natural systems are facing land management issues due to conflicts of two territories. Thus, land dynamics information has great importance to understand the consequences of natural resources at spatial and temporal scales. In this study, spatiotemporal LU/LC modelling approach has been emphasized to address land resource problems of a trans-boundary river basin of Central India using satellite imagery data. An integrated Cellular Automata (CA)-Markov Chain (MC) model was employed over the Betwa River basin (BRB), located in Madhya Pradesh and Uttar Pradesh States, facing agriculture and water resource management issues. The spatiotemporal LU/LC pattern during 1972–2013 has been elaborated to focus changes in agriculture and waterbody area. Historical LU/LC analysis shows that 4.16% area under agriculture was accrued due to increased 1.62% waterbody in the BRB. However, after the year 2007 agriculture area is accrued by 1.75% mainly due to irrigation water availability from newly accomplished Rajghat reservoir. Further, the CA-MC model has been firstly validated, and then successfully employed to predict future LU/LC maps for the years 2020, 2040, 2060, 2080 and 2100. Future analysis shows that vegetation pattern may alter in future due to decline in dense forest (1.39%) and agriculture area (6.41%), which cease to increase in degraded forest and barren land by 4% and 4.23%, respectively. The modelling results depicted that 0.71% decrement in waterbody and subsequent decrease in the agriculture area by 6.41% could occur in future. The present study reveals that, changes in future LU/LC may lead to severe reduction in food productivity land of Central India. Therefore, it is evoked that integrated CA-MC modelling approach can interactively predict future LU/LC scenarios by furnishing some solutions to the current land resources problems.     

Land Cover Changes on Ambergris Caye,Belize: A Case Study of Unregulated Tourism Development

Measuring land-use, land-cover change in biodiverse, tropical countries is critical for conservation management and sustainable planning because it provides quantifiable data regarding broad environmental changes. This project uses Landsat satellite imagery to document vegetation cover change on Ambergris Caye, Belize, from 2000 to 2017. The close proximity of the Belize Barrier Reef Reserve System has made Ambergris Caye the most popular tourist destination and economic hub in Belize. As a result, the region has undergone intense commercial and residential development coupled with rapid population growth over the past two decades. Understanding general trends in landscape dynamics is critical for the natural resource–based tourism industry of Belize to continue to thrive. Unsupervised classification methods and a per pixel postclassification comparison were used with Landsat imagery to estimate loss in vegetation cover and increases in urban and barren land. The results indicate a 10.85 percent decrease in vegetation and a 39 percent increase in urban and barren land during the seventeen-year study period with an annual forest loss rate of 0.67 percent per year using a compound interest rate formula. The results of this analysis represent a baseline study of vegetation change on Ambergris Caye to inform management and conservation efforts.     

大理市土地利用变化及其驱动力分析

利用大理市1995年和2000年两期TM影像解译土地利用数据,在GIS分析工具支持下,对土地利用变化和驱动因素进行分析,得出以下结论：（1）1995年到2000年这5年期间,土地利用变化总体呈现出林地和草地减少、耕地和建筑用地增加的趋势,水域面积变化不明显;（2）土地利用年变化率为0．5％,其中以建设用地面积的年变化率最大为5．84％,耕地和林地的年变化率分别为1．85％和-1．41％,而草地和水域年变化率较小,分别为-0．7％和0．01％;（3）土地利用类型转化主要呈现出林地和草地转化为耕地,耕地和草地转化为建筑用地,林地和草地相互转化的特点;（4）土地利用结构变化不明显,总体上表现出林地占优势,耕地、草地、水域相当的结构特征;（5）自然条件对土地利用结构具有重要的控制作用,而人口增长,政府行为决策和经济的发展直接影响土地利用的变化。     

土地利用/土地覆被变化研究:寻求新的综合途径

土地利用/土地覆被变化是很复杂的现象,参与该项目的研究人员要避免“瞎子摸大象”那样的片面性,必须寻求新的综合研究途径。为此,不能简单地沿袭传统土地利用研究的思路和方法,需要不断提出新的研究论题;对土地利用变化驱动力必须有一种普遍的、综合的认识;需要将多个案例研究联结为一个可代表区域空间异质性的网络,需要作多空间尺度的研究,从而将地方尺度和区域尺度的土地覆被动态联系起来;需要发展新的研究方法,并将从农户调查到遥感数据的各种信息综合起来;尤其需要形成关于土地利用/土地覆被变化的综合科学理论框架     

Historical Land-Use/Land-Cover Changes in a Bottomland Hardwood Forest,Bayou Fountain,Louisiana

Historical surveys have proven important for assessing changes in forest composition and for providing insights into the influences of human activities on forest ecosystems. We used GIS to compare past land-use/land-cover information from General Land Office (GLO) surveys taken in 1849/1851 with current forest composition to illustrate the extensive changes that have occurred in bottomland hardwood forest composition over the past 150 years in East Baton Rouge Parish (EBRP), Louisiana. Agricultural lands, hardwood wetlands, and urban lands increased in area at the expense of rangelands and swamplands. A comparison of forest composition between A.D. 1849/1851 and today illustrates that the bottomlands were once a cypress-tupelo gum association but are now an elm-ash-sugarberry association. These changes are related to expanding urban conditions and encroaching human activities (e.g., levee construction) that substantially changed surface hydrological properties, especially the potential for flooding. Bottomland hardwood forests provide important services to low-lying urban areas mainly through storage of flood waters. Without conservation efforts, bottomland hardwood forests will experience continued human-mediated changes.