The low impact development (LID) approach has been recommended as an alternative to traditional stormwater design. Research on individual LID practices such as bioretention, pervious pavements, and grassed swales has increased in recent years. Bioretention cells have been effective in retaining large volumes of runoff and pollutants on site, and consistently reduced concentrations of certain pollutants such as metals. However, retention of certain pollutants such as nitrate itrogen and phosphorus has been problematic. Porous pavements have been extremely effective in infiltrating stormwater runoff. Concerns have been raised about groundwater contamination, but research has shown that this is not a problem in most settings. Green roofs have been found to retain a large percentage of rainfall (63% on average) in a variety of climates. A common thread across bioretention, green roofs and grassed swales was found: the export of phosphorus. The issue appears to be linked to high phosphorus levels in the soil media, or possibly to fertilization of turf or planted areas. Solutions to this problem have been recommended. Contrary to popular belief, research has shown that bioretention and pervious pavements continue to infiltrate even with frost in the ground. Although issues have been identified with retention of certain pollutants, the LID approach has been found to result in increased retention of stormwater and pollutants on site, mimicking pre-development hydrologic function. Future research needs have also been identified.

Sustainable stormwater management facilities such as bioswales and rain gardens are one way in which cities are simultaneously addressing the need to replace or repair stormwater infrastructure while also meeting regulatory obligations. Retrofitting patterns of neighborhood development through the implementation of infrastructure like bioswales is localized solution to stormwater management. Such infrastructure addresses sustainability and resilience goals while reflecting the city as part of rather than separate from the ecosystem. This article presents results of a subset of 42 semi-structured interviews collected through an exploratory qualitative case study of Portland Oregon's Tabor to the River program. These findings focus on Green Streets (bioswales), asking whether participants consider them small scale nature, and whether stormwater visibility fosters environmental learning. Results suggest that sustainable stormwater management facilities have potential toward aiding in stormwater awareness, particularly if combined with additional ways of learning (e.g., informational signs). Participant perceptions of Green Streets as small scale nature are less straight forward. This study gives some insight into the subtleties of human experiences with sustainable stormwater infrastructure, giving a glimpse into the potentials of Green Streets, and other educational inputs, in contributing to increased understanding of Portland's stormwater system. Building upon this first attempt at discovering the potential for environmental learning through sustainable stormwater infrastructure, or in their capacity in fostering connectedness with nature, could be instructive for future infrastructure planning and policy development that seeks to foster human ature connectedness and ecological understanding within our communities.

Land-use/land cover (LULC) data from the United States Geological Survey (USGS) was used to extrapolate these results from neighborhood scales to metropolitan Sacramento. Of an area of roughly 80002km 2 , defining most urban areas of the metropolitan Sacramento, about half is residential. The total roof area comprises about 15002km 2 and the total paved surfaces (roads, parking areas, sidewalks) are about 31002km 2 . The total vegetated area covers about 23002km 2 . The remaining 11002km 2 consist of barren land and miscellaneous surfaces.

文章概述了海绵城市建设的三大关键策略：消纳、减速与适应。并分别通过哈尔滨群力湿地公园、六盘水明湖湿地及金华燕尾洲的实验工程检验了它们的有效性。这三个关键技术可以被组合运用，形成“源头消纳滞蓄，过程减速消能，末端弹性适应”的基本模式。

2013年中国环境艺术设计金奖问题和挑战 贵州六盘水是一个在20世纪60年代中期建立起来的工业城市，以其凉爽的高原气候而著称，城市被石灰岩的山丘环抱，母亲河——水城河穿城而过。城市人口密集，在60平方千米的土地上，居住了约60万的人口。作为改善环境的重要举措之一，市政府委托景观设计师制定一个整体方案以应对城市所面临的多项挑战，

由于高空间分辨率遥感影像海量数据、复杂细节和尺度依赖的特点决定了高分辨率遥感影像处理的技术难点。在总结以往高分辨率影像(航空影像)信息提取技术的主要难点和不足,从理论上和实践上分析了基于特征基元的高分辨率遥感影像处理与分析的意义,提出了基于特征基元的高分辨率遥感影像多尺度信息提取技术框架。最后对此框架进行总结与分析,指出了目前研究中仍存在的难点和今后的研究重点。

Due to prolonged droughts in recent years, the use of rainwater tanks in urban areas has increased in Australia. In order to apportion sources of contribution to heavy metal and ionic contaminants in rainwater tanks in Brisbane, a subtropical urban area in Australia, monthly tank water samples (24 sites, 31 tanks) and concurrent bulk deposition samples (18 sites) were collected during mainly April 2007–March 2008. The samples were analysed for acid-soluble metals, soluble anions, total inorganic carbon and total organic carbon, and characteristics such as total solid and pH. The Positive Matrix Factorisation model, EPA PMF 3.0, was used to apportion sources of contribution to the contaminants. Four source factors were identified for the bulk deposition samples, including ‘crustal matter/sea salt’, ‘car exhausts/road side dust’, ‘industrial dust’ and ‘aged sea salt/secondary aerosols’. For the tank water samples, apart from these atmospheric deposition related factors which contributed in total to 65% of the total contaminant concentration on average, another six rainwater collection system related factors were identified, including ‘plumbing’, ‘building material’, ‘galvanizing’, ‘roofing’, ‘steel’ and ‘lead flashing/paint’ (contributing in total to 35% of the total concentration on average). The Australian Drinking Water Guideline for lead was exceeded in 15% of the tank water samples. The collection system related factors, in particular the ‘lead flashing/paint’ factor, contributed to 79% of the lead in the tank water samples on average. The concentration of lead in tank water was found to vary with various environmental and collection system factors, in particular the presence of lead flashing on the roof. The results also indicated the important role of sludge dynamics inside the tank on the quality of tank water.

在生态城建设取得日益广泛共识的大背景下,阐述生态城市规划建设的模式和既有传统城市生态化改造分级的一些关键技术。

Green roofs (roofs with a vegetated surface and substrate) provide ecosystem services in urban areas, including improved storm-water management, better regulation of building temperatures, reduced urban heat-island effects, and increased urban wildlife habitat. This article reviews the evidence for these benefits and examines the biotic and abiotic components that contribute to overall ecosystem services. We emphasize the potential for improving green-roof function by understanding the interactions between its ecosystem elements, especially the relationships among growing media, soil biota, and vegetation, and the interactions between community structure and ecosystem functioning. Further research into green-roof technology should assess the efficacy of green roofs compared to other technologies with similar ends, and ultimately focus on estimates of aggregate benefits at landscape scales and on more holistic cost-benefit analyses.

屋顶绿化是现代城市改善生态环境条件，缓解高密度建成区人为活动负面影响的重要策略选择。以深圳市福田中心区为工作区，利用高精度遥感数据结合设计资料查询和实地调查构建基础数据源；在总结国内外研究成果的基础上，筛选适宜的屋顶绿化约束影响因子，构建资源潜力评估方法；对工作区进行城市屋顶绿化资源潜力评估和绿化策略探讨。结果表明：（1）建筑年代、承重结构、屋顶属性、屋顶小气候是城市屋顶绿化4个方面的主要适建要素，其所涵盖的建筑年代、建筑结构、屋面构造、屋顶功能、屋顶坡度、设备面积、建筑高度和遮荫状况等8个影响因子是决定城市屋顶绿化资源潜力的关键性指标；（2）把城市屋顶绿化纳入城市生态结构和功能建设的整体考虑中，积极开展资源评估、规划研究和配套管理政策建设是推进我国城市屋顶绿化发展重要任务；（3）深圳市中心区现状屋顶绿化率仅9％，剩余构筑物中有51％适合进行全部或部分屋顶绿化覆盖，今后应考虑采取强制、引导和鼓励等不同政策手段，选择适宜的绿化技术方案，对于现有以及正在建设的并且条件适宜的构筑物进行屋顶绿化。

Abstract Green roof technology is recognized for mitigating stormwater runoff and energy consumption. Methods to overcome the cost gap between green roofs and conventional roofs were recently quantified by incorporating air quality benefits. This study investigates the impact of scaling on these benefits at the city-wide scale using Washington, DC as a test bed because of the proposed targets in the 20-20-20 vision (20 million ft(2) by 2020) articulated by Casey Trees, a nonprofit organization. Building-specific stormwater benefits were analyzed assuming two proposed policy scenarios for stormwater fees ranging from 35 to 50% reduction for green roof implementation. Heat flux calculations were used to estimate building-specific energy savings for commercial buildings. To assess benefits at the city scale, stormwater infrastructure savings were based on operational savings and size reduction due to reduced stormwater volume generation. Scaled energy infrastructure benefits were calculated using two size reductions methods for air conditioners. Avoided carbon dioxide, nitrogen oxide (NO(x)), and sulfur dioxide emissions were based on reductions in electricity and natural gas consumption. Lastly, experimental and fugacity-based estimates were used to quantify the NO(x) uptake by green roofs, which was translated to health benefits using U.S. Environmental Protection Agency models. The results of the net present value (NPV) analysis showed that stormwater infrastructure benefits totaled $1.04 million (M), while fee-based stormwater benefits were $0.22-0.32 M/y. Energy savings were $0.87 M/y, while air conditioner resizing benefits were estimated at $0.02 to $0.04 M/y and avoided emissions benefits (based on current emission trading values) were $0.09 M-0.41 M/y. Over the lifetime of the green roof (40 years), the NPV is about 30-40% less than that of conventional roofs (not including green roof maintenance costs). These considerable benefits, in concert with current and emerging policy frameworks, may facilitate future adoption of this technology.

61Plugrisost is a good tool for urban planning of RWH.61Environmental indicators are more conservative than the financial indicators.61Economic and environmental analysis can help avoid oversizing tanks.61The scale of analysis is a main factor.61Rainfall simulation using stochastic models is a factor that must be analysed.

This paper introduces an optimization formulation to design residential water systems that satisfy the water demands in a housing complex involving rainwater harvesting, storage and distribution as well as the simultaneous design of water networks for recycling, reusing, regenerating and storing reclaimed water. The design task is considered as a multi-objective optimization problem where one objective is the minimization of the fresh water consumption and the other objective is the minimization of the total annual cost. The proposed model accounts for the variability in the water demands through the different hours of the day and for the different seasons of the year. The seasonal dependence of the rainwater has also been considered in the optimization model. A case study for the city of Morelia in Mexico is presented. The results show that significant reductions can be obtained in the total fresh water consumption and in the total cost.

Rainwater harvesting is increasingly becoming an integral part of the sustainable water management toolkit. Despite a plethora of studies modelling the feasibility of the utilisation of rainwater harvesting (RWH) systems in particular contexts, there remains a significant gap in knowledge in relation to detailed empirical assessments of performance. Domestic systems have been investigated to a limited degree in the literature, including in the UK, but there are few recent longitudinal studies of larger non-domestic systems. Additionally, there are few studies comparing estimated and actual performance. This paper presents the results of a longitudinal empirical performance assessment of a non-domestic RWH system located in an office building in the UK. Furthermore, it compares actual performance with the estimated performance based on two methods recommended by the British Standards Institute - the Intermediate (simple calculations) and Detailed (simulation-based) Approaches. Results highlight that the average measured water saving efficiency (amount of mains water saved) of the office-based RWH system was 87% across an 8-month period, due to the system being over-sized for the actual occupancy level. Consequently, a similar level of performance could have been achieved using a smaller-sized tank. Estimated cost savings resulted in capital payback periods of 11 and 6 years for the actual over-sized tank and the smaller optimised tank, respectively. However, more detailed cost data on maintenance and operation is required to perform whole life cost analyses. These findings indicate that office-scale RWH systems potentially offer significant water and cost savings. They also emphasise the importance of monitoring data and that a transition to the use of Detailed Approaches (particularly in the UK) is required to (a) minimise over-sizing of storage tanks and (b) build confidence in RWH system performance.

Impervious surfaces, such as rooftops, parking lots, and roads, increase runoff and the potential for flooding. Green roof technologies, which entail growing plants on rooftops, are increasingly being used to alleviate stormwater runoff problems. To quantify the effect that roof slope has on green roof stormwater retention, runoff was analyzed from 12 extensive green roof platforms constructed at four slopes (2%, 7%, 15%, and 25%). Rain events were categorized as light (<2.0 mm) (0.08 in.), medium (2.0–10.0 mm) (0.08–0.39 in.), or heavy (>10.0 mm) (>0.39 in.). Data demonstrated an average retention value of 80.8%. Mean retention was least at the 25% slope (76.4%) and greatest at the 2% slope (85.6%). In addition, runoff that did occur was delayed and distributed over a long period of time for all slopes. Curve numbers, a common method used by engineers to estimate stormwater runoff for an area, ranged from 84 to 90, and are all lower than a conventional roof curve number of 98, indicating that these greened slopes reduced runoff compared to traditional roofs.

城市屋顶花园是城市绿化的重要组成部分,传统的测量方法无法满足现实需要.利用遥感技术进行城市屋顶花园调查是有效的方法,论文主要探讨了从遥感影像中提取屋顶绿化面积的方法和步骤,以及遥感在屋顶绿地方面的应用前景.

<p>本文提出一种有效提取高分辨率遥感影像建筑区的算法。作者通过模拟人类视觉系统感知环境的过程，引入视觉注意机制，提出了基于自信息最大化视觉注意机制的建筑区显著指数。其中根据建筑区在高分辨率遥感影像中的特点，基于时/频域的纹理分析，提出了一种针对建筑区的纹理特征描述方法，实现了建筑区的高效提取。通过对8组高分辨率遥感影像进行实验，验证了本文算法的有效性。</p>

为了快速定位中高分辨率可见光遥感图像中的人工建筑目标，一般需要先对目标进行粗定位，提取人工建筑区域。根据遥感图像中的不同地貌具有不同的频谱特性，人工建筑区相对其他区域具有较高的频率，提出了基于小波变换和数学形态学的遥感图像人工建筑区提取算法。该算法先对遥感图像进行小波变换，将不同地貌的信息转换到不同频带，再对高频信息进行融合，并将融合后的高频信息中幅度变化剧烈的区域看作“山峰”，变化平稳的区域看作“盆地”，最后采用形态学重建的方法提取人工建筑区，实验结果表明，该算法具有快速性和准确性的特点。

无参数高分辨率遥感影像快速提取建筑高度,在城市建设和土地管理中有重要的现实意义。当前的研究多以已知参数的遥感影像获取,但其提取方法受限制条件多。本文提出以无参数高分辨率遥感影像,综合利用单张影像上的特征点所构成的4类特征线换算建筑高度的方法。4类特征线包括屋顶位移点与其阴影点的连线、建筑高差引起的屋顶像点位移、阴影全长和建筑遮挡后的阴影长。通过已知的少量建筑的实际高度和推导出的4类特征线换算建筑高度的计算模型,可对大量建筑进行快速、精确地高度量算。结合南京市的Google Earth影像进行了验证,结果表明,该方法采用的影像易于获得,综合量算方法大大增加了单张影像上提取建筑高度的可操作性,并解决了量算建筑高度时无相关参数的问题。该方法精度较高,可大面积、快速提取建筑高度,在生产实践中有较大的实用价值。

利用1970年地形图、1984、1991、1998年的遥感影像,通过对无锡市地区遥感影像的光谱特征分析,采用仿归一化植被指数法提取无锡市城乡聚落空间信息.在此基础上,根据分形理论计算无锡地区城乡聚落空间形态的分数维,从分数维的变化,分析无锡城乡聚落空间形态的特征.结果表明,无锡地区城乡聚落空间形态具有分形现象,并且城区和集镇的分数维变化不一致,反映了城乡聚落空间形态在不同的阶段,其复杂程度、稳定性以及扩展变化趋势是不一样的.

如何快速、准确与客观地提取城镇用地信息，以获得城镇用地的分布范围和面积资料，是有关城镇问题研究中经常涉及到的一个基本问题，现代遥感技术为这个问题的有效解决提供了强有力的保证，运用提出的归一化建筑指数，从TM图像进行了无锡市城镇用地信息的自动提取，研究结果表明，与传统的计算机分类和手工屏幕数字化方法相比，归一化建筑指数法是一种非常行之有效的方法。

<p>城市建筑用地是一种复杂的土地利用类型,在电磁波反射光谱上表现出明显的异质性。因此,很难用简单的方法将其从遥感影像中准确地提取出来。在详细研究了城市建筑用地的光谱特征以后,创建了一种不直接采用影像的原始波段,而是采用由它们衍生的3个指数波段来构成新型建筑用地指数(IBI)。通过对ASTER和Landsat ETM+两种多光谱影像进行的实验表明,新指数除了能够有效地增强影像中的建筑用地信息外,还能和植被指数、水体指数一样,用于进行数值运算,从而实现了建筑用地对城市生态环境影响的定量研究。对厦门、福州两城市的实例分析表明,新的建筑指数与地表温度呈正相关关系,而与植被指数、水体指数呈负相关关系。研究进一步发现,建筑指数与地表温度的关系不是简单的线性关系,而是一种指数函数关系,说明高建筑用地比例地区的升温效应要明显高于低建筑用地比例地区,因此,对城市热岛的形成起着更大的作用。</p>

面向对象分类方法是实现精确详细提取遥感信息的新方法。以2010年TM影像作为基础数据,采用面向对象方法着重提取了西辽河流域平原的植被信息(耕地、林地、中生偏旱和中生偏湿草)。通过对不同地物的光谱和空间信息(位置、形状)进行比较分析,建立适当的隶属度函数和阈值范围,在草地的分类规则中,参考野外采集的草地植被光谱信息,辅助草地属性特征选择。最后构建分类决策树,完成自动分类,分类总体精度达到82.13%。在分类结果的基础上,讨论了植被分布特点,对不同类型的植被面积、不同区县植被面积以及植被与一级河流关系三方面进行分析。结果显示:研究区植被以林地和耕地为主,分别占总面积的38.9%和23.3%;耕地、林地、中生偏湿草地多分布于河流中下游区县,受人为因素影响较大的林地、耕地主要集中在科尔沁左翼中旗和科尔沁左翼后旗;林地、中生偏湿草较集中分布在一级河流的10km缓冲区内,耕地主要集中在5km缓冲区内,中生偏旱草与一级河流的关系不显著。

植被覆盖度作为反映湿地植物生长状况的重要生态学参数,在评估和检测湿地生态环境方面起着关键的作用。以华北内陆典型的淡水湿地——北京市野鸭湖湿地自然保护区为研究对象,中等分辨率的Landsat TM影像为数据源,基于线性光谱混合模型(LSMM)对研究区的植被覆盖度进行了估算。针对湿地植被类型丰富、土地利用类型多样化的特点,利用归一化植被指数(NDVI)在反映植物生长状况、覆盖程度以及区分地表覆盖类型方面的优势,通过对原始Landsat TM影像增加NDVI数据维对影像进行维度扩展,克服了传统研究中通常从Landsat TM影像上提取3-4种端元的局限,经最小噪声分离变换(MNF变换)、纯像元指数(PPI)计算以及人机交互端元选取等一系列运算,构建以陆生植物、水生植物、高反射率地物、低反射率地物、裸露土壤为组分的五端元模型来反映研究区的地物组成;同时,以原始Landsat TM影像为基础,构建植物、高反射率地物、低反射率地物、裸露土壤为组分的四端元模型。针对两种端元模型,采用全约束下的LSMM算法进行混合像元分解以获取研究区的植被覆盖度,其次辅以研究区的纯水体信息对其进行优化。精度检验采用相同时期的高分辨率WorldView-2多光谱影像来进行。研究表明:虽然四端元模型与五端元模型对植被覆盖度的估算结果在空间上具有基本一致的分布趋势,但是前者的估算结果在数值上要普遍低于后者,在研究区的水体及其附近,四端元模型难以体现水生植物的植被覆盖信息;另外,五端元模型的估算结果与检验数据的相关系数<em>R</em>达到0.9023,均方根误差(RMSE)为0.0939,明显优于四端元模型的<em>R</em>=0.8671和RMSE=0.1711。这反映了通过对影像进行维度扩展的方法来改进端元提取的数量是可行的,而由此构建的五端元模型可以更充分的反映研究区地物之间的光谱差异,从而获得更好的估算精度。

A new technique, called multiple endmember spectral mixture analysis (MESMA), was developed and tested in the Santa Monica Mountains, using Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data acquired in the fall of 1994 to map California chaparral. The technique models remotely measured spectra as linear combinations of pure spectra, called endmembers, while allowing the types and number of endmembers to vary on a per pixel basis. In this manner, vegetation is characterized by a unique set of endmembers as well as by the fractions. Reference endmembers were selected from a library of field and laboratory measured spectra of leaves, canopies, nonphotosynthetic materials (e.g., stems), and soils and used to develop a series of candidate models. Each candidate model was applied to the image, then, on a per pixel basis, assessed in terms of fractions, root mean squared (RMS) error, and residuals. If a model met all criteria, it was listed as a candidate for that pixel. For this study, selection criteria included fractions between 0.01 and 1.01, an RMS less than 0.025 and a residual less than 0.025 in seven or more contiguous bands. A total of 889 two-endmember models were evaluated and used to generate 276 three-endmember models. To facilitate model selection from a large pool of candidates, an optimal set was selected to provide maximal areal coverage. A total of 24 two-endmember and 12 three-endmember models were chosen. These models were used to generate fraction images and vegetation maps showing evergreen and drought deciduous or senesced vegetation. We found that a majority of the image could be modeled as two-endmember models. Three-endmember models provided greater areal coverage, yet provided poorer vegetation discrimination due to an increase in model overlap (two or more model candidates modeling the same pixel). The vegetation maps demonstrate that the technique is capable of discriminating a large number of spectrally distinct types of vegetation while capturing the mosaic-like spatial distribution typical of chaparral. However, additional research is required to fully evaluate the technique and validate the vegetation maps that were produced.

ABSTRACT Five different types of mixture models are reviewed. These are: linear, probabilistic, geometric‐optical, stochastic geometric, and fuzzy models. A summary of the conception and formulation of each of these types of models is presented. A comparative analysis of the different attributes of the models is made. In a general sense, the linear, probabilistic, and fuzzy models are relatively simple while the geometric (geometric‐optical and stochastic geometric) models are complicated, involving the incorporation of parameters of scene geometry. There is some difference in the number and nature of components that can be resolved with the different models. Available information is insufficient to categorize the models in terms of accuracy levels, but it is evident that mixture models produce more accurate land‐cover estimation than conventional classification.

<p>我国西南喀斯特地区长期存在以石漠化为特征的土地退化问题,是我国三大生态问题之一。喀斯特地区地表复杂度高,具有高度时空异质性,像元混合现象严重,植被、裸岩和裸土为喀斯特地区典型地物,使得评价喀斯特石漠化的关键指标(如裸岩率、植被覆盖度)获取比较困难,高光谱遥感在混合像元分解方面有独特优势,可以获取地物端元的丰度。通过地面试验表明光谱指数能够表征地物覆盖度,进而以Hyperion高光谱影像为数据源,利用连续最大角凸锥方法从影像中提取这3类地物的端元,运用半约束和全约束线性光谱分解方法估算其丰度。研究表明:半约束线性分解得到的丰度优于全约束分解结果,其反演的植被、裸土和裸岩的丰度与相应的光谱指数间具有显著线性相关性,确定系数R²分别为0.92、0.66与0.84,表明地物丰度能够表征其覆盖度。因此,通过混合像元分解算法反演地物丰度来提取喀斯特石漠化因子具有一定的可行性,这为高光谱遥感在喀斯特石漠化中的评价和监测奠定了理论和算法基础。</p>

针对使用TM图像 反射波段信息难以将红树林与陆地植被、尤其是与水体&mdash;植被混合像元有效区分的问题,结合不同潮位的TM图像,基于反射波段信息,引入TM6热红外波段信息,提出了温湿度指数(temperature-moisture index,TMI)。分析结果表明,综合潮位信息、热红外波段信息及温湿度指数能显著提高红树林与其他地物之间的可分性。采用光谱角度制图(spectral angle mapping,SAM)监督分类法对红树林进行分类识别,较之其他研究者所采用的分类特征,热红外波段信息及温湿度指数能使红树林分类精度明显提高(<em>Kappa</em>系数提高了0.14,错分率降低了19.9%),说明利用潮位信息、热红外波段信息及温湿度指数可以提高红树林的遥感识别精度。

基于遥感信息技术提出一个新型的遥感生态指数(RSEI),以快速监测与评价区域生态质量.该指数耦合了植被指数、湿度分量、地表温度和土壤指数等4个评价指标,分别代表了绿度、湿度、热度和干度等4大生态要素.与常用的多指标加权集成法不同的是,本研究提出用主成分变换来集成各个指标,各指标对RSEI的影响是根据其数据本身的性质来决定,而不是由人为的加权来决定.因此,指标的集成更为客观合理.将RSEI应用于福建长汀水土流失区,并与国家环境保护部《生态环境状况评价技术规范》中的生态指数EI的计算结果相比较,发现二者的结果具有可比性.不同的是,RSEI不仅可以作为一个量化指标,而且还可以对区域生态环境变化进行可视化、时空分析、建模和预测.因此,可弥补EI指数在这些方面的不足.

沿袭了遥感地物分类中K-L变换思想,以归一化处理后的遥感数据,结合地面土壤湿度观测数据,应用主成分分析方法,采用MODIS不同红外波段数据,通过相关关系计算,在监测结果中融合MODIS具有250 m分辨率的第2波段数据,建立了青海省多维特征空间土壤湿度监测模型。模型的建立克服了热惯量法监测干旱需多时相遥感数据的缺陷,经初步检验,此模型可以在一定精度范围之内监测表层土壤湿度,具有业务应用潜力。

模拟分析了地表层湿度反演过程中地表及大气各种因素(卫星扫描角、地表粗糙度、地表植被覆盖和大气)对反演结果的影响情况;应用正演模拟技术得到了利用TMI低频10GHz通道微波极化比反演地表层湿度信息时,斜率和截距随像元植被覆盖度可调的反演方程;确定了反演方程中斜率、截距系数随像元植被覆盖度变化的对数关系和线性关系;反演技术中综合应用了多种途径获取到的被动微波像元中动态的植被覆盖信息;尝试了将这些因子用于地表层湿度反演的可行性;对于反演结果,研究工作中利用地表HUBEX外场观测资料进行了对比分析,得到了空间分布特征和时间演变趋势比较一致的对比分析结果。