局地土地利用变化现实情景研究

局地土地利用变化表现为时序短、空间倾向性强且多为人类强制干扰, 其变化过程与结果 是区域尺度响应与反馈国家尺度、全球尺度最有效的途径。城市化、农业结构调整和土地整理是 目前我国局地土地利用变化的几种主要利用方式。城市化是一个不可逆过程, 农村景观转为城市 景观, 改变了诸如地表反照率、粗糙度等下垫面特征, 局地生境与物种的数量与种类发生改变, 逐 步形成以人类为主的均质化景观格局; 农户微观土地利用选择行为是局地农业产业结构调整的 原动力, 不同类型农户在投资、生产与经营等经济活动的差异将导致局地土壤结构、水分、养分等 土壤条件及环境改变; 土地整理是一个复杂的系统工程, 在一定程度上改变了局地土壤性状与土 壤生物, 更甚的是改变了局地斑块- 廊道- 基质模式的景观格局。因此, 为进一步加深局地土地利 用变化情景的理解, 厘定“人- 地协调系统”的理论框架, 进行局地土地利用变化的情景模拟和生 态环境效应研究将是未来局地土地利用变化的研究方向。     

海平面上升对珠江三角洲咸潮入侵的影响

海平面上升,潮汐作用加强,在无其它因素影响下,通常认为必然导致包括盐水入侵灾害加剧。根据河口盐淡水混合扩散原理,结合珠江三角洲河口整治延伸规划及河口淤积发展趋势,动态分析了海平面上升对珠江三角洲咸潮入侵的影响,认为海平面上升后,盐水入侵对珠江三角洲的影响总的来说不会加剧,而且还会逐步减弱。     

三峡库区山地生态系统预警

论述了三峡库区山地生态系统的特征，建立山地生态系统预警评价的指标体系和预警，在假定不作重大投资进行调控修复的前提下对三峡库区山地生态系统进行预警分析，复合生态系统及各子系统都将处于逆向演替状态，绝大多数子系统及复合生态系统在2010年前将处于各种预警状态。在预警分析基础上，提出优化调控战略要点，其核心是经济、社会发展与生态环境建设的协调。     

1956年以来9个时期湖南省湿地动态研究

在遥感和地理信息系统技术支持下,利用湿地调查资料、地图和遥感影像数据,获得1956~2016年期间9个时期湖南省的湿地数据;采用景观分析方法,系统地分析了9个时期湖南省的湿地分布及其变化特征和湿地景观格局变化及其影响因素。研究结果表明,与1956年相比,2016年湖南省的湿地面积减少了955.4 km^2,其中,永久性淡水湖泊和河流面积明显减少,水产养殖场面积明显增加;湿地的景观结构也相应地发生了改变,1986年湖南省的湿地的破碎化程度最严重;1956~2016年期间,湿地景观类型分布不均衡程度在不断加剧;永久性河流和永久性淡水湖泊是湖南省的优势湿地景观类型,且永久性淡水湖泊的最大斑块指数都远大于其它类型湿地;围垦和退耕还湿活动是影响湿地变化的主要因素。     

Linking Spatial and Temporal Variation at Multiple Scales in a Heterogeneous Landscape*

Anthropogenic, ecological, and land‐surface processes interact in landscapes at multiple spatial and temporal scales to create characteristic patterns. The relationships between temporally and spatially varying processes and patterns are poorly understood because of the lack of spatiotemporal observations of real landscapes over significant stretches of time. We report a new method for observing joint spatiotemporal landscape variation over large areas by analyzing multitemporal Landsat data. We calculate the spatiotemporal variation of the Normalized Difference Vegetation Index (NDVI) in the area covered by one Landsat scene footprint in north central Florida, over spatial windows of 10⁴–10⁸ m² and time steps of two to sixteen years. The correlations, slopes, and intercepts of spatial versus temporal regressions in the real landscape all differ significantly from results obtained using a null model of a randomized landscape. Spatial variances calculated within windows of 10⁵–10⁷ m² had the strongest relationships with temporal variances (regressions with both larger and smaller windows had lower coefficients of determination), and the relationships were stronger with longer time steps. Slopes and y‐intercepts increased with window size and decreased with increased time step. The spatial and temporal scales at which NDVI signals are most strongly related may be the characteristic scales of the processes that most strongly determine landscape patterns. For example, the important time and space windows correspond with areas and timing of fires and tree plantation harvests. Observations of landscape dynamics will be most effective if conducted at the characteristic scales of the processes, and our approach may provide a tool for determining those scales.     

基于水环境保护的流域景观格局 优化理念初探

流域范围内因水体的联系使得不同类型景观斑块之间的相互作用变得更为紧密, 因而景 观格局的变化会显著影响流域内水体质量。着眼于流域尺度上水环境保护的需要, 必须合理考虑 景观斑块的类型、格局和空间分异等特征, 尽可能地减少非点源污染输出量, 从而降低水体遭受 污染的威胁程度。本研究从水环境保护的角度出发, 以“源”“汇”景观在镶嵌组合和空间分异方面 利用的适宜性作为优化依据, 以“源”“汇”景观空间分布的关键地段作为研究战略点, 同时考虑 “源”“汇”景观在数量、空间和转换成本等方面的客观约束条件, 将景观数量结构优化和空间结构 优化进行有机结合, 最终确定了流域尺度上以调控非点源污染、保护水体质量为目标的景观格局 优化研究的概念框架。本研究不仅为解决流域尺度上非点源污染问题提供了一个全新的研究视 角, 而且为降低景观类型及其格局对水体质量的威胁程度提供了一个行之有效的优化方案。     

Unsiting Nuclear Power Plants: Decommissioning Risks and Their Land Use Context*

Nuclear power plant siting provided the first significant public opportunity to examine nuclear safety and to affect nuclear policy. These discussions were prompted and fueled by perceptions of nuclear risk. Now, as we begin the process of nuclear decommissioning, we are finding that power plant removal—unsiting–is also likely to attract public interest. This paper presents a preliminary survey of how we are likely to react to this emerging theme, applying these findings within a land use context to see if it is likely to produce issues salient to the public. In so doing it also examines how these issues could affect decommissioning timing and type. It suggests that the most likely prospect is that power plants will remain on the landscape long after they are closed.     

干旱区土壤盐渍化灾害预警——以渭-库绿洲为例

针对中国西北干旱区普遍存在的土壤盐渍化,以渭干河-库车河绿洲TM影像数据,建立BP神经网络结合Adaboost算法的土壤盐渍化预警度评价模型。首先,根据研究区实际情况设置该模型的4个预警指标（地下水埋深、海拔、盐分指数、归一化干旱指数）,分别提取其连续表面信息,结合BP神经网络作为弱预测器进行预测,将通过不同训练集得到的弱预测器结果结合成强预测器。在利用该模型训练样本时,依据各评价因子对分类结果的贡献率调整其权重,预测的结果能客观反映每个评价因子对该地区土壤盐渍化的贡献程度。结果表明,研究区警情总体情况较严重,绿洲北部内部耕地周围的荒地以及含水量少的区域,盐渍化危险度较高。     

基于RBF的湖南省土地生态安全动态预警

基于1996-2010 年湖南省土地生态安全的相关数据, 从压力、状态、响应3 方面构建湖南省土地生态安全预警指标体系, 运用RBF模型对2011-2015 年湖南省土地生态安全演变趋势进行预测, 并结合预警指数和警度标准对1996-2015 年湖南省土地生态安全警情状况进行分析, 结果表明:① RBF模型有较高的模拟精度, 能够较好地拟合2011-2015 年湖南省土地生态安全各系统的发展趋势。② 就各子系统的安全警度而言, 1996-2010 年湖南省土地生态安全的压力和状态系统的警度呈波动上升趋势, 响应系统的警度呈下降趋势, 2011-2015 年, 压力系统将逐步由“中警”(黄灯) 转变为“重警”(橙灯), 状态系统将处于“中警”(黄灯) 状态, 响应系统将处于“无警”(绿灯) 状态。③ 总体而言, 1996-2010 年, 湖南省土地生态安全警度呈略有下降态势, 2011-2015 年, 预警指数将处于0.42 左右, 警度将处于“中警”(黄灯) 状态。④ 影响湖南省土地生态安全的主要因素包括农业经济比重、建设占用耕地面积量、自然灾害受灾面积比重、人均建设用地面积、第三产业比重、自然保护区面积比重等, 是今后调控的重点。     

2003-2017年北京市地表热力景观时空分异特征及演变规律

利用2003-2017年MODIS地表温度数据,分别从数量、形状和结构角度揭示北京市不同季相和昼夜间地表热力景观时空分异特征,并进一步通过热力等级变化图谱及质心迁移轨迹揭示城市热力景观空间演变规律,探究热力景观等级转换生态过程。结论如下：① 城市地表热力景观季节和昼夜空间特征差异显著;② 中温区在城市热环境中占主导地位。白天中温区是最不稳定的热力景观等级;夜间次低温区和次高温区不稳定性增加;③ 地表热力景观等级变化以稳定型占主,反复变化型和前期变化型次之。地表热力景观等级通常呈现逐级递增或递减规律,山区呈现逐级降温趋势,北部城郊—山地交错地带表现出次低温和中温的反复转向,南部地区有一定的升温趋势;④ 2003-2017年高温区面积增大且质心向城市中心集中,低温区质心向城市外围扩散。生态涵养发展区对北京市地表热力景观质心迁移贡献率最高。热力景观时空分异特征及演变规律可为有效缓解城市热岛效应提供管理决策支持。     

Degradation of unconsolidated Quaternary landforms in the western North America

One of the major goals of geomorphology is to understand the rate of landscape evolution and the constraints that erosion sets on the longevity of land surfaces. The latter has also turned out to be vital in modern applications of cosmogenic exposure dating and interpretation of lichenometric data from unconsolidated landforms. Because the effects of landform degradation have not been well documented, disagreements exist among researchers regarding the importance of degradation processes in the dating techniques applied to exposures. Here, we show that all existing qualitative data and quantitative markers of landform degradation collectively suggest considerable lowering of the surface of unconsolidated landforms over the typical life span of Quaternary moraines or fault scarps. Degradation is ubiquitous and considerable even on short time scales of hundreds of years on steeply sloping landforms. These conservative analyses are based entirely on field observations of decreasing slope angles of landforms over the typical range of ages in western North America and widely accepted modeling of landscape degradation. We found that the maximum depth of erosion on fault scarps and moraines is on average 34% of the initial height of the scarp and 25% of the final height of the moraine. Although our observations are limited to fault scarps and moraines, the results apply to any sloping unconsolidated landform in the western North America. These results invalidate the prevailing assumption of no or little surface lowering on sloping unconsolidated landforms over the Quaternary Period and affirm that accurate interpretations of lichen ages and cosmogenically dated boulder ages require keen understanding of the ever-present erosion. In our view, the most important results are twofold: 1) to show with a large data set that degradation affects universally all sloping unconsolidated landforms, and 2) to unambiguously show that even conservative estimates of the total lowering of the surface operate at time and depth scales that significantly interfere with cosmogenic exposure and lichen dating.     

东北天然林区森林景观格局与环境关系的研究

借助1997年二类调查数据，在AreInfo的支持下，运用典范对应分析（CCA）法，对吉林省汪清林业局金沟岭林场的森林景观要素空间分布与环境关系进行了研究。结果表明：在金沟岭林场范围内，坡度和土层厚度对景观格局分布的影响极为有限，景观要素空间格局更多地受海拔和坡向综合控制，海拔是控制景观要素空间分布格局的主要因素，其次是坡向；森林景观总体分布是从河谷地低海拔榆杂林和杨桦林到高海拔红松云冷杉林；CCA排序图可将整个林场森林划分6组景观类型：榆树林景观、阔叶混交林景观、杨桦林景观、针阔混交林景观、阔叶红松林景观、人工纯林景观。     

景观空间异质性对地表水质服务的影响研究——以河南省伊河流域为例

人类干扰使景观空间异质性发生了剧烈变化,进而对生态系统服务产生了严重影响。目前,针对景观空间异质性与生态系统服务的关联关系研究还较为薄弱。以河南省伊河流域为研究区域,以地表水质服务为研究对象,分析了地表水质服务的空间变化;通过以水质采样点为中心建立缓冲区,分析了不同尺度下的景观空间异质性特征,并与地表水质指标进行相关性研究,以探讨景观空间异质性与地表水质服务间的影响规律及响应机制。结果表明：① 研究区地表水质状况整体上为西南、东北部较差,中部较好;② 从景观组成来看,林地面积占比或斑块个数的增加有利于地表水质的提高;③ 类型水平上,林地的景观构型与化学需氧量的质量浓度在200 m半径缓冲区内显著相关（P<0.05）,城镇用地的景观构型对地表水质的影响则在2000 m半径缓冲区内更为明显;④ 景观水平上,总磷的质量浓度受到景观构型变化的强烈影响（P<0.05）,景观构型异质性越低,总磷的质量浓度就越高;⑤ 适当增加景观空间异质性可有效降低地表水质污染物的质量浓度,提高地表水质服务。研究结论可为伊河流域的空间开发及水环境保护政策的制定提供科学依据。     

The effects of land consolidation on the ecological connectivity based on ecosystem service value: A case study of Da’an land consolidation project in Jilin province

Land consolidation has a profound impact on landscape patterns and ecological functions at various scales through engineering and biological measures. In recent years, China invests more than 100 billion RMB yuan on land consolidation each year. To understand how land consolidation affects landscape patterns and ecosystems, we investigated the ecosystem service value and the ecological connectivity in a consolidated area of Da’an city from 2008 to 2014 using a revised ecological connectivity index. The results indicated that land consolidation has certain negative influences on the ecosystem services in this area. The total ecosystem service value will decrease by nearly 30% in the late stage of consolidation. This decrease is caused by the loss of ecosystem service of the wetland and grassland, despite a sensible increase of cultivated land. In addition, land consolidation could change the ecological connectivity as well as the land use structure. Up to 85% of the entire area will be in low connectivity in the late stage of consolidation, representing a 6.23% increase in the total coverage compared to pre-consolidation. Finally, the different connectivity landscape and their key areas can be identified by the revised ecological connectivity index effectively. This study is helpful to trace out the relationships between landscape pattern and ecological process, and provides insights for ecological planning and designing of land consolidation in this area. We suggest that more attentions should be paid to improve the quality and ecosystem service value per unit area of the landscape, to establish ecological compensation mechanism of wetland losses, and to create the ecological corridors along the least accumulated impendence surface in the key areas during land consolidation.     

城市水系功能治理方法及应用

城市水系治理经历了末端治理、综合治理、系统治理等发展阶段。从系统角度恢复城市水体生态环境是进行水污染治理与水环境修复的主要方法,末端治理与综合治理对生态的考虑比较少,而系统治理在强调工程设计生态化的同时又忽略了水系的景观要素。为实现水质、生态、景观的协同发展,本文在系统治理的基础上提出功能治理的方法框架,包括水系问题诊断、问题评价、功能治理、措施优化与管理等步骤,其优势在于借助一系列生态修复措施及景观设计原理,将生态工程景观化。汉阳水系治理的案例表明:对城市水系而言,水环境修复措施与工程景观的同步设计较生态修复与景观的分步设计有更明显的效果。     

Medium-term evolution of a gully developed in a loess-derived soil

Field surveys in the Belgian loess belt revealed the presence in many forested areas of large, permanent gully systems, most of which are currently inactive. In cultivated areas, such gullies can only be observed in cross-sectional soil profiles through hollows, as virtually all such large gullies are currently infilled with colluvium. Little is known about the spatial distribution, initiation and temporal evolution of these large, permanent gully systems on loess-derived soils. Therefore, the medium-term evolution of a gully initiated in a cultivated area on loess-derived soils southwest of Leuven (Belgium) in May–June 1986, was studied over 13 years. Two intense rainfall events created this (ephemeral) gully, which was not erased by subsequent tillage. Between June 1986 and the December 1999, eight field surveys were conducted to measure gully dimensions. During two surveys, topographic indices (e.g., slope and drainage area) were also measured. Daily rainfall for the measuring period were obtained from a rainfall station located some 10 km southwest of the gully. Analysis of rainfall data showed that no extreme rainfall event was required to initiate such large (permanent) gullies, as observed in forested areas and through cross-sectional profiles in cultivated fields in the Belgian loess belt. Return periods of the event that caused the gully varied between <1 year and 25 years, depending on the assumptions used for defining event rain intensity. Once established, length, surface area and volume of the studied gully evolved with time, cumulative rainfall or cumulative runoff, following a negative exponential relation. This accords with observations reported for gullies in Australia and the USA. This study shows that a degressive increase of gully extension, can be largely explained by the evolution of a “slope–drainage area” factor (S×A, which is proportional to stream power) with time. While gully length and gully surface area asymptotically evolve towards a final value, gully volume decreased at a given point in time. From this, it is inferred that sediment deposition will potentially infill the gully to such an extent that the farmer can drive across it. From this moment on, the combined effect of water and tillage erosion in the gully drainage area, will lead towards rapid infilling. This expected evolution of a gully in cultivated fields accords with observations of large infilled gully systems in cultivated areas in eastern Belgium. The permanent gullies observed under forest are attributed to the fact that after severe gully erosion, this area was reforested or abandoned. Therefore, the sediment source was cut off and the gully was not filled in by sediment deposition.     

农田景观空间异质性分析及遥感监测最优尺度选择——以三江平原为例

农情遥感监测需要高时间分辨率的遥感数据,目前这些数据大都为中低空间分辨率影像。在这些尺度下,像元内部往往是异质的,从而影响农情参数反演精度。因此分析和表达农田景观空间异质性和最优尺度选择对遥感农情监测质量的提高具有重要的应用价值。选取建三江农垦区四种典型农田景观为研究点,Landsat/TM NDVI为实验数据,利用实验变异函数对四种景观类型的各向空间异质性进行了分析, 而后通过变异函数模型拟合,定量分析了各个研究点的整体空间异质性,并在此基础上进行了研究区遥感监测最优尺度选择。研究表明:(1) 基于实验变异函数的结构分析方法,可定性地认识空间异质性的大小和方向,进而挖掘出其背后的自然和人为驱动因素。(2) 对实验变异函数进行拟合分析,可定量地刻画不同景观格局各自的空间异质性特性。此外,基于变异函数对空间异质性的定量表达,讨论了利用积分变程A结合Nyquist-Shannon采样定理进行最优尺度选择的方法。     

抚仙湖北岸景观生态建设

抚仙湖北岸是旅游业发展的黄金海岸，开发历史长，污染较为集中。通过对现存的主要环境问题的分析，根据流域生态学与管理学的原理，提出抚仙湖北岸景观生态建设的途径：（1）实施老环湖公路以下农田的退垦还湖，减少农田污染；（2）拆迁湖滨带居民点，消除农村污染。（3）拆除部分规模小、污染大的旅游度假设施，消除旅游污染和景观障碍。（4）建立主要人湖口经济性人工湿地，净化面源污水。（5）恢复万米沙滩，营造自然和谐的湖滨环境。（6）发展观光农业生态园，创建高原湖泊滨海旅游度假区新型模式。     

位涡和Q矢量诊断在毛乌素沙地沙尘天气预报中的应用

利用常规的天气图、卫星云图、湿位涡和Q矢量等,对2007年4月30日和2007年5月2日发生在毛乌素沙地的两次沙尘天气进行了综合分析\.结果表明:对流层低层MPV1＜0中尺度对流不稳定区的生成,为干对流的发生提供了不稳定能量条件;来自上游对流层中高层的干侵入和扰动干侵入在沙尘天气发生过程中起着重要作用;对流层低层由Q矢量辐散、辐合激发生成的次级环流为沙尘天气发生、发展和维持提供了动力机制。在对毛乌素沙地中β尺度沙尘暴的预报预警过程中,同时应考虑下沉对流有效位能的作用。     

基于MODIS数据的城市光化学污染预警系统及预警等级研究

通过分析MODIS遥感数据反演的大气气溶胶光学厚度(AOD)与大气环境污染的关系,结果表明当空气清洁没有污染时,AOD小于0.3,当空气轻度污染时,AOD在0.3~1.0之间,当空气污染严重时,AOD大于1.0。在分析AOD与地面大气污染的关系的基础上,结合地面空气污染监测数据的空气污染指数,将城市光化学污染的预警等级分为无、微弱、较弱、较强和强五级,并对城市光化学污染预警系统进行了框架分析,为进一步建设城市光化学污染预警系统提供基础。