热岛效应季节动态随城市化进程演变的遥感监测

作为城市特有的一种环境问题,热岛效应动态发展变化的规律是城市热岛研究的基础工作.遥感技术在城市热岛动态变化监测方面的有用性已经得到了证实.然而当前城市热岛遥感研究基本都取少数几景进行对比分析,这使得遥感在城市热岛时空动态监测方面不能充分发挥作用.采用50景长时间序列Landsat TM和ETM+SLC-on/off影像,采取定性和定量分析相结合的方法,使用热岛强度、热岛范围等指标和热岛显著区的概念对厦门市1987-2008年20年间热岛季节动态随城市化进程演变的趋势进行分析,结果表明:厦门城市热岛在2003、2004年之后已由春夏秋扩展到冬季,且冬季热岛的高等级斑块在数量、个体面积和总面积上均有明显增长趋势.引起这种变化的原因还需要进一步研究和分析.     

Developments in remote sensing, dynamic modelling and GIS applications for integrated coastal zone management

The International Institute for Aerospace Survey and Earth Sciences (ITC) has a research programme that should result in an integrated environmental coastal zone management system through three subprojects. The programme aims to develop methodologies and tools for assessing coastal zone changes, and for the evaluation of scenarios for coastal zone management, based on a spatio-temporal Geographical Information System (GIS) working platform which integrates remote sensing data, physical-morphodynamic and eco-hydrologic modelling, and a decision support system. The first subproject develops methodologies for the generation of optimum Remote Sensing (RS) data sets, leading to better interpretation and complementary use of conventional and new remote sensing imagery. It also integrates RS, GIS, and modelling through hypothesis generation, parameter estimation, evaluation and validation. The second subproject facilitates qualitative and quantitative analysis and prediction of the physical aspects of coastal landscape development under the influence of natural processes and human impacts. This subproject is based on the application of remote sensing and dynamic modelling. The third subproject leads to a spatio-temporal working platform which supports data integration of RS and in-situ measurements, and qualitative and quantitative analysis for the prediction of coastal landscape development. Both support decision making in Integrated Coastal Zone Management.     

遥感与GIS在蝗虫生境研究中的应用进展

蝗虫生境是蝗虫赖以生活、生存的环境。利用遥感技术获取与蝗虫密切相关的各种生境因子,并结合GIS技术研究和阐明蝗虫的生境因子对东亚飞蝗的产卵、孵化、成虫、迁飞等生育周期的影响机理,是实现对蝗虫监测、预测预警的基础。文章首先分析了各种蝗虫生境因子对蝗虫发生的影响机理,认为这些生境因子对蝗灾发生的影响不是孤立地起作用的,仅靠单个生境因子进行蝗灾的预测是不全面的,而遥感和GIS技术方便的获取、管理和分析多种生境因子数据,在大尺度蝗灾发生监测和预警中起到不可替代的作用。通过对遥感与GIS在蝗虫的不同发育阶段（蝗卵发育阶段、蝗蝻发育阶段和成虫阶段）的应用及其进展的分析,认为对蝗虫不同生育阶段的遥感监测需采用不同的参数和技术才能达到更好的效果,最后提出了遥感与GIS在蝗虫生境监测方面的未来发展方向。     

Crustacean habitat potential mapping in a tidal flat using remote sensing and GIS

To make a macrofaunal (crustacean) habitat potential map, the spatial distribution of ecological variables in the Hwangdo tidal flat, Korea, was explored. Spatial variables were mapped using remote sensing and a geographic information system (GIS) combined with field observations. A frequency ratio (FR) and logistic regression (LR) model were employed to map the macrofauna potential area for the Ilyoplax dentimerosa, a crustacean species. Spatial variables affecting the tidal macrofauna distribution were selected based on abundance and biomass and used within a spatial database derived from remotely sensed data of various types of sensors. The spatial variables included the intertidal digital elevation model (DEM), slope, distance from a tidal channel, tidal channel density, surface sediment facies, spectral reflectance of the near infrared (NIR) bands and the tidal exposure duration. The relation between the I. dentimerosa and each spatial variable was calculated using the FR and LR. The species was randomly divided into a training set (70%) to analyse habitat potential using FR and LR and a test set (30%) to validate the predicted habitat potential map. The relations were overlaid to produce a habitat potential map with the species potential index (SPI) value for each pixel. The potential habitat maps were compared with the surveyed habitat locations such as validation data set. The comparison results showed that the LR model (accuracy is 85.28%) is better in prediction than the FR (accuracy is 78.96%) model. The performance of models gave satisfactory accuracies. The LR provides the quantitative influence of variables on a potential habitat of species; otherwise, the FR shows the quantitative influence of a class in each variable. The combination of a GIS-based frequency ratio and logistic regression models and remote sensing with field observations is an effective method to determine locations favorable for macrofaunal species occurrences in a tidal flat.     

Interpreting spatial heterogeneity of crop yield with a process model and remote sensing

A process-based crop growth model (Vegetation Interface Processes (VIP) model) is used to estimate crop yield with remote sensing over the North China Plain. Spatial pattern of the key parameter—maximum catalytic capacity of Rubisco (V_cmax) for assimilation is retrieved from Normalized Difference of Vegetation Index (NDVI) from Terra-MODIS and statistical yield records. The regional simulation shows that the agreements between the simulated winter wheat yields and census data at county-level are quite well with R² being 0.41-0.50 during 2001-2005. Spatial variability of photosynthetic capacity and yield in irrigated regions depend greatly on nitrogen input. Due to the heavy soil salinity, the photosynthetic capacity and yield in coastal region is less than 50 μmol C m⁻² s⁻¹ and 3000 kg ha⁻¹, respectively, which are much lower than that in non-salinized region, 84.5 μmol C m⁻² s⁻¹ and 5700 kg ha⁻¹. The predicted yield for irrigated wheat ranges from 4000 to 7800 kg ha⁻¹, which is significantly larger than that of rainfed, 1500-3000 kg ha⁻¹. According to the path coefficient analysis, nitrogen significantly affects yield, by which water exerts noticeably indirect influences on yield. The effect of water on yield is regulated, to a certain extent, by crop photosynthetic capacity and nitrogen application. It is believed that photosynthetic parameters retrieved from remote sensing are reliable for regional production prediction with a process-based model.     

水土流失的定量遥感及其应用研究进展

简要介绍了水土流失定量遥感的概念，阐述了它的四项基本要求，报道了它的应用研究进展，并为尽快实现中国水土流失定量遥感提出了若干建议。     

Comparison between remote-sensed data and in situ measurements in coastal waters: The taranto sea case

Monitoring and managing small coastal ecosystems requires a considerable understanding of the temporal dynamics of biophysical factors describing the coastal water systems. For this reason, daily observation from space could be a very efficient tool. The objective of the work described in this paper is to evaluate the contribution of remote sensing to the continuous monitoring of coastal areas. It is well known that in coastal areas, the presence of inorganic suspended sediments and coloured dissolved organic matter can make chlorophyll-concentration measurements from remote sensing difficult. To overcome these difficulties, an alternative approach to the SeaWiFS standard chlorophyll algorithm is presented, based on a semi-analytic model for sea water and on the use of MODIS data as input in a model for atmospheric effects removal. Moreover, land contamination (mixed sea–land pixels) can introduce ambiguities in sea-surface temperature measurements from remote sensing. This paper proposes the use of a hydrodynamic model as a time–space interpolator of in situ campaign data, to extensively validate the temperature values extracted from AVHRR sensor. We validated the proposed approach, using experimental field data collected over a two-year campaign in the Taranto Gulf. The results seem to indicate a good agreement between remote-sensed and in situ data.     

Development of a framework for fire risk assessment using remote sensing and geographic information system technologies

Forest fires play a critical role in landscape transformation, vegetation succession, soil degradation and air quality. Improvements in fire risk estimation are vital to reduce the negative impacts of fire, either by lessen burn severity or intensity through fuel management, or by aiding the natural vegetation recovery using post-fire treatments. This paper presents the methods to generate the input variables and the risk integration developed within the Firemap project (funded under the Spanish Ministry of Science and Technology) to map wildland fire risk for several regions of Spain. After defining the conceptual scheme for fire risk assessment, the paper describes the methods used to generate the risk parameters, and presents proposals for their integration into synthetic risk indices. The generation of the input variables was based on an extensive use of geographic information system and remote sensing technologies, since the project was intended to provide a spatial and temporal assessment of risk conditions. All variables were mapped at 1 km² spatial resolution, and were integrated into a web-mapping service system. This service was active in the summer of 2007 for semi-operational testing of end-users. The paper also presents the first validation results of the danger index, by comparing temporal trends of different danger components and fire occurrence in the different study regions.     

Evaluating the environmental flows of China's Wolonghu wetland and land use changes using a hydrological model, a water balance model, and remote sensing

Environmental flows are critical to sustaining a variety of plant and animal communities in wetlands. However, evaluation of environmental flows is hampered by the problem of hydrological and ecological data shortage, especially in many developing countries such as China. Based on a hydrological model, a water balance model and remote sensing data, we assessed the environmental flows of China's Wolonghu wetland with limited data. The hydrological model provides input data for the water balance model of the wetland, and the remote sensing data can be used to assess land use changes. Integration of these two models with the remote sensing data revealed both the environmental flows of the Wolonghu wetland and the relationships between these environmental flows and land use changes. The results demonstrate that environmental flows have direct and indirect influences on the wetland ecosystem and should be linked to sustainable wetland management.     

遥感水文耦合模型的研究进展

遥感水文的耦合模型在目前生态环境领域,特别是在水资源的应用和管理中其作用日益重要,具有大流域尺度上快速应用、实时动态监测等优点。结合国内外近年来取得的研究成果,文章综述了遥感水文耦合模型的研究进展。首先介绍了遥感技术在水文学中的应用,讨论了它的分类发展概况,接着介绍了几种主要的遥感水文耦合模型及其应用实例,包括SCS(SoilConservationServices)模型、SiB2(SimpleBiosphereModelversion2)简化生物圈模型、SRM(SnowmeltRunoffModel)融雪径流模型以及SWAT(SoilandWaterAssessmentTool)模型,最后展望了遥感水文耦合模型未来的发展趋势,指出尺度问题上的时空变异性仍是其发展的关键,与GIS(Geographicinformationsystem)及其他空间技术的相结合是其未来发展的重要方向,从而为水文学、水资源的预测评价等研究提供参考。     

Quantification and reduction of erroneous differences between images in remote sensing

The reliability of image data, along with the difficulty of accurately comparing images acquired at different times or from different sensors, is a generic problem in remote sensing. Measurement repeatability errors occur frequently and can substantially reduce the system’s ability to reliably quantify real spectral and spatial change in a target. This paper outlines methodologies for quantifying and reducing erroneous differences between monochrome and multispectral or hyperspectral images. [Each of these image types is acquired by an instrument that collects light photons across a variable range of the electromagnetic spectrum (often referred to as an image band). The hyperspectral image is often referred to as a hyperspectral cube with XY spatial dimensions and many Z bands (spectral demotions)]. In this paper, we specifically discuss the Pixel Block Transform (PBT), the Spectral Averaging Transform (SAT), and the Wavelet Transform (WAVEL). We briefly address sensor fusion. Results indicate that the PBT is a powerful cross-noise and repeatability error reducing tool, applicable to monochrome, multispectral, and hyperspectral images. The SAT is as powerful as the PBT in reducing error but is suitable only for hyperspectral imagery. WAVEL can reduce some of the finer scale noise, but it is not as powerful in reducing cross-noise as PBT or SAT and it requires some trial and error for selecting the appropriate wavelet function. It is important that those involved in developing statistically sound relationships between remotely sensed imagery and other data sources understand the problems and their solutions to prevent wasting time or developing relationships that are statistically insignificant or unstable, or that lead to faulty conclusions.     

Assessing wetland changes in the venice lagoon by means of satellite remote sensing data

Not only does lagoon ecology represent a transitional zone between the sea and the continent but it also expresses the equilibrium belt between erosion and sedimentation processes. Within the framework of a coastal management scheme, a precise and timely mapping of morphological changes in this environment is important. This paper illustrates the possible contribution of multi-temporal satellite observations in the monitoring of the erosion/sedimentation processes of coastal zones, where landscape features are subjected to highly morphodynamical modifications. In particular, an improved mapping accuracy was obtained by the successive application of the Maximum Likelihood (MLH) classifier and the Linear Mixture Model (LMM) techniques to the satellite image classification procedure. In fact, by estimating the amount of shallow water and wetland within each satellite pixel, the LMM technique allows for an accurate mapping of the transitional zones in the lagoon environment, thus permitting an optimal separation between land and water. The study concerns the Venice lagoon (Italy) which has been sinking slowly since the beginning of this century. This has led to widespread loss of wetlands. In order to monitor the development of the land cover, four Landsat Thematic Mapper scenes were examined, during the period 1984 to 1993. The results obtained proved that the digital analysis method of multitemporal satellite imagery, applied over a selected test area, enables the evolution of an estuarine environment landscape, with its different sequences of erosion and periods of accretion, to be monitored. The significant influence of tidal stages is discussed in the data analysis.     

两栖动物监测方法和国外监测计划研究

两栖动物是生物多样性的重要组成部分,对环境变化非常敏感,可被用作环境监测的指示物种.介绍了两栖动物监测的指标、时间、频次以及监测的主要方法,包括目视遇测法、样线（带）法、繁殖区调查法、鸣叫调查法、围栏陷阱法、人工庇护所法、人工隐蔽物法和标志重捕法,分析了各种方法的适用性和局限性;还详细介绍了国外比较成熟的2个两栖动物监测计划——美国两栖动物监测计划和英国两栖爬行动物监测计划.     

Optical remote sensing of coastal plumes and run-off in the Mediterranean region

Sea surface colour data, derived from the Coastal Zone Colour Scanner (CZCS) archive, have been used to assess the space/time variability of coastal plumes and run-off in the Mediterranean Sea. A time series of 2645 scenes, collected by the CZCS from 1979 to 1985, was processed to apply sensor calibration algorithms, correct for atmospheric contamination, and derive chlorophyll-like pigment concentration. Individual images, remapped on a 1-km² pixel grid, were generated for each available day, and then mean values calculated pixel by pixel to form monthly, seasonal and annual composites. The results obtained must be taken with caution, due to the CZCS limitations in the quantitative assessment of bio-optical pigments when high concentrations of dissolved organics or suspended sediments are present, e.g. along littorals or within plumes. Marked differences appear in the distribution of water constituents between coastal zones and open sea, northern and southern near-coastal areas, western and eastern sub-basins. The oligotrophic character of the basin contrasts with areas of high concentration related to river plumes—Ebro (Ebre), Po, Rhone, Nile—, coastal run-off patterns, and persistent mesoscale features (e.g. coastal filaments and eddies). Seasonal variability appears to be high, with higher concentrations occurring over most of the basin in the cold season, when climatic conditions are favourable to coastal run-off and vertical mixing. Atmospheric forcing (wind and rainfall over continental margins) could play an important role in establishing the observed space/time distribution of water constituents. The impact of continental interactions (fluvial and coastal run-off), or that of exchanges between coastal zone and open sea, could have paramount influence on the biogeochemical fluxes in the entire basin.     

我国鸟类监测的现状、问题与对策

鸟类是开展生物多样性监测的重要指示类群.对鸟类的长期、系统监测工作在欧美已经有百余年历史,且野鸟多样性指数已经成为欧美一些国家开展生物多样性监测工作的官方指标.通过对国内鸟类监测现状的分析,结合监测对象、指标、抽样策略和监测方法等监测工作中应重点关注的几个方面,提出了我国鸟类监测存在的问题,并结合国情提出了下一步开展鸟类监测工作的对策与建议.建议我国有关部门尽快制定鸟类监测技术规程和标准,统一数据收集和分析平台,逐步构建政府引导,科研院所、高等院校、自然保护区、观鸟协会和志愿者等多方参与的鸟类监测网络.     

中国陆地植被生态系统生产有机物质价值遥感估算

可持续发展的战略要求推进生态资产研究,对生态系统生产有机物质功能价值的估算则是生态资产评估的重要组成部分。利用改进的CASA模型对中国陆地生态系统1995年NPP进行了估算,它与实测数据和国内其他研究成果的比较验证证明了该方法的可靠性;进而对1995年全国陆地生态系统生产有机物质的价值进行了估算,结果表明,1995年中国陆地生态系统净第一性生产力生产有机物质的总价值为1.902049×1012元.a-1,其空间分布是从东部向西北递减、由中部向东北和南部递增;从类型上看,常绿阔叶林的单位面积值最高,裸地和极稀疏植被的单位面积值最低。     

珠江口沿岸土地利用变化及其地表热环境遥感分析

以遥感和GIS为技术手段,选择四期TM/ETM＋影像为数据源,对珠江口沿岸区域的土地利用及其地表热环境的变化进行了定量分析。1990—2008年期间,建设用地扩展是珠江口区域土地利用变化最为显著的特征,建设用地从1990年的605.50km^2增加到2008年的2394.26km^2。土地利用变化导致区域热环境效应增强,并促使不同土地利用类型在7个热力区间中的组成发生变化。珠江口东岸建设用地在数量上的优势使得珠江口的热力重心始终分布在东岸。研究结果表明,以建设用地扩展为突出特征的土地利用变化,深刻影响着区域热环境。     

广东省水质自动监测的现状及发展规划

介绍了广东省在东江、小东江、珠江、北江、武江、九洲江和顺德水道7个江河流域设立了7个水质自动监测站，控制流域面积约57093km^2。“十五”期间每年建成1－2个省界断面和3－4个地级市界断面，形成全省的水质自动监测网络。     

中国各省区近10年遥感气溶胶光学厚度和变化

用2000—2009年MODIS大气气溶胶光学厚度（AOD））资料,分析中国29个省（区、市）AOD多年平均值和年际间变化趋势。中国10年平均AOD高值区主要集中在华北、华中、华南和新疆,低值区主要在青藏高原、西北（除新疆外）、东北和西南地区。中国有13个省（市、区）多年平均AOD超过0.4。最高为0.735（江苏）。只有西藏和黑龙江的AOD小于0.2,其余15个省区市的AOD在0.2至0.3之间。除新疆外,中国的AOD高值区全部集中在工业发达和人口密集的地区。中国年际间AOD的变化为上升趋势。近10 a来AOD增长的倾向率为0.019/10a,即增加了4.3%。其中在2000—2007年间的上升最为明显,在2007年达到近10 a来的最高峰（0.437 6）,2008年以后中国的AOD开始出现下降趋势,2009年达到近10 a来最低值（0.372 0）。有17个省区市AOD气候学变化倾向率为正值,变化的范围为0.006~0.099/10a。有12个为负值,变化的范围为-0.037~-0.003/10a。出现AOD增加和减少趋势的区域两极分化,即高排放地区继续增加,低排放地区持续减少。     

计算机网络系统结构设计在环境监测中的应用

天津市环境监测中心计算机网络系统的建立,解决了天津市监测中心与下属19个县站监测信息传递的问题,也改变了以往用报表和软盘上报国家环保总局,国家环境监测总站监测数据的方式,实现了环境监测信息的快速传递和办公自动化管理。