【作者】 陈少辉；

【导师】 王乘； 曾致远；

【作者基本信息】 华中科技大学 ， 系统分析与集成， 2007， 博士

【摘要】 水土流失是全球性的生态环境问题之一。遥感是进行环境和灾害动态监测的有效技术手段。本文对遥感技术在土壤侵蚀调查中的应用方法进行概括和汇总,分析不同方法之间的优缺点以及它们各自的适用范围,并结合当前研究的热点问题,指出未来研究的重点及趋势。本文系统综述了多分辨率图像融合算法的发展历程和理论研究。首先论述了多分辨率图像融合算法的基本原理及发展状况;然后给出了多分辨率图像融合中的多源遥感影像数据融合技术,包括融合原理、融合的主要方法、遥感影像融合应用、融合评价指标,最后指出了融合中存在的问题。以生成土壤侵蚀图和遥感图像融合所涉及的基本概念、土壤侵蚀模型、数据处理流程、图像融合模型、图像融合体系结构、评价方法等,本文主要围绕以下几个方面展开:(1)从土壤侵蚀发生的物理过程、动力学过程和因子分析模型等方面回顾了国内外的土壤退化研究的历史与现状、过程机理影响因素、综合了土壤侵蚀防治方法。(2)概括和汇总了遥感技术在土壤侵蚀调查中的应用方法,分析了各自的优缺点以及适用范围,并指出当前热点的发展趋势。(3)基于Moderate Resolution Imaging Spectroradiometer (MODIS)数据,提出了一种土壤侵蚀强度快速估测方法。首先,利用解译后的TM遥感数据提取土地利用类型信息;利用MODIS植被指数模型提取湖北省的植被覆盖度信息;其次,利用数字高程模型数据生成坡度图;然后,结合土壤侵蚀强度分级指标,将坡度图与土地类型图、植被覆盖度图叠加,判断和计算侵蚀强度等级,就获得了湖北省的土壤侵蚀强度等级图。(4)对不同空间分辨率、时间分辨率和波谱分辨率的遥感图像进行综合、高效的利用,是当前图像融合的焦点问题之一。回顾图像融合的源起与发展,对融合的概念与基础理论做了界定与阐述,将目前存在的各种融合技术归纳为3种类型,剖析了其优缺点和适用领域。(5)在小范围上,利用TM影像和MODIS影像融合得到的高空间分辨率MODIS影像,然后利用它根据MODIS植被指数模型提取该地区的植被覆盖度信息。最后,结合土壤侵蚀强度分级指标,将相同范围的坡度图与土地类型图、植被覆盖度图进行叠加,就获得了小范围的土壤侵蚀强度等级图。本文的新颖之处在于以下几点:(1)对TM/ETM影像进行解译获取土地利用现状,利用MODIS数据实现对植被因子的动态监测,在宏观上实现了MODIS和TM影像的结合。(2)对于小范围重要区域,采用融合技术利用TM影像提高MODIS影像的空间分辨率。然后,采用融合的MODIS影像生成该地区的土壤侵蚀状况图,在微观上实现了MODIS和TM影像的结合。(3)应用MODIS数据和已有的土地利用、高程数据,对水土保持进行动态监测,在时间维上实现了MODIS数据和其它数据的融合。更多还原

【Abstract】 Soil erosion is the main reason for environment degradation globally. Remote sensing is the only method that can monitor land exhaustively and directly by providing good coverage of the earth at a great range of scales. Meanwhile, in this paper, an overview of the history and theory for multiresolution image fusion approaches is presented. First, the principle and development of the multiresolution image fusion approaches is given. Then, remote sensing image fusion techniques, including the theory of fusion, main algorithms, applications of remote sensing image fusion, and criteria for evaluating fused images are included. Finally, problems of remote sensing image fusion are also discussed.In this paper, the main study focus on basic concepts, soil erosion models, procedure of data processing, image fusion models, image fusion architecture etc. involved in producing soil erosion image of Hubei province at large scale and soil erosion image of Wuhan region at small scale. The following aspects are mainly discussed:(1) Basis on reviewing the history and present situation of the study on soil degradation process in the world and China, this paper summarizes the recent development in the forming mechanism, the models of soil degradation, and the assessment indexes for soil degradation. Finally, the main problems and futures of the research work in the field are also put forward.(2) This paper tries to gather and review the currently remote sensing approaches in soil erosion monitoring, whose dominances and limitations are also discussed.(3) This paper proposes a quick method of producing soil erosion based on moderate resolution imaging spectroradiometer (MODIS) data. Firstly, the land use image, and vegetation coverage image are obtained using interpreted TM image and MODIS vegetation index model, respectively. Secondly, slope image is created from Digital Elevation Model (DEM) . Thirdly, based on the soil erosion intensity classification, soil erosion intensity image is obtained by overlaying the images of land use, vegetation coverage and slope.(4) The efficient integration of remote sensing images with multiple spatial, temporal and spectrum resolution is a focus of image processing study. A full review of the origination and development of image fusion is given here. The concepts, and basic theories in this field are expatiated. Current image fusion techniques are classified into three types. The strong points and shortcomings of each type are analyzed.(5) For local area, we obtain high spatial resolution MODIS image by fusing TM and MODIS images. Then, vegetation coverage image is obtained using the fused MODIS based on normalized difference vegetation index model. Finally, soil erosion intensity image is obtained by overlaying the images of land use, vegetation coverage and slope of the same region.In this paper, there are three innovative tasks:(1) The land use image is obtained by interpreting manually the TM/ETM images, and the MODIS images are used to monitor the vegetation change. Therefore, the TM/ETM images and the MODIS images are fused at macroscale.(2) The spatial resolution of the MODIS images is improved using image fusion methods by means of the TM image, and the soil erosion image at small scale is obtained based on the fused MODIS images. Therefore, the TM/ETM images and the MODIS images are fused at microscale.(3) The available MODIS data, land use data, and elevation data are used to monitor water and soil preservation dynamically. Therefore, the TM/ETM images and the MODIS images are fused at time scale.更多还原