【作者】 海米提·司马义；

【作者基本信息】 新疆大学 ， 地图学与地理信息系统， 2008， 硕士

【副题名】以渭干河—库车河三角洲绿洲为例

【摘要】 土壤盐渍化对社会经济、环境和农业生态系统带来破坏性效果而越来越受到引人关注。利用遥感这种具有宏观、综合、动态和快速等特点的高新技术研究盐渍化土地的性质、范围、面积、地理分布、动态变化和盐渍程度,对治理盐碱地、防止进一步扩散、退化和稳步持续发展农业、进行合理规划非常重要。本文通过大量的野外调查以及实地测点收集回来的气象,水文地质,光谱及人文资料,运用遥感图像处理分析技术、借助地理信息系统空间分析技术定量评价研究区盐渍化的土地资源。评价干旱、半干旱地区土地盐渍化,提出盐渍化土地在时间和空间尺度上的变化,综合评价了研究区土地盐渍化的驱动力,为盐渍地的治理与区域农业可持续发展决策提供了科学依据,同时也为其它干旱地区土地盐渍化的研究工作提供些经验。研究内容主要有:1.本文在土壤盐渍化动态监测方法上研究的基本思想是:首先通过可见光-近红外波段、影像图锐化和主成分分析法分别对不同时期的影像图进行合成,算出信息量最大的波段组合方式,结果表明,TM4、K-L2、K-T3是最好的波段组合方式,应用1972年MSS, 1989年TM,2001年ETM+ 30年的遥感数据,利用监督分类的贝叶斯网络分类法对三种合成技术处理后的影像图,,并分别进行分类,三期影像分类结果达到90%以上。2.充分利用遥感与GIS技术在地学分析中的优势,计算各类盐渍地面积、耕地,荒漠、水体面积变化,分析近30年来研究区土地盐渍化动态变化的规律,包括面积变化、盐渍化程度的变化,分析大范围时间尺度上土地盐渍化动态发展的整体趋势。3.土壤盐渍化的形成是多种环境因素影响和人类活动作用下的一种土地退化形式。土地盐渍化的过程和机理比较复杂,这里仅对研究区1972-2001至30年的土地盐渍化的主要驱动因子进行综合评价。(1)气候因素:渭干-库车河三角洲绿洲是我国最干旱的地区,干燥炎热,蒸发强烈,大量地下水和土壤中的盐分随着土壤毛细管不断上升至地表而积聚,造成积盐过程十分强烈并呈现了气候越干旱,积盐强度越大,积盐层越厚的规律。(2)地质条件:盆地周围分布有含盐石膏的第三纪地层,大部分含盐地层出露地表,雨后大量盐分随地表径流或地下径流向洪积扇和平原输送,更增加了局部地区的盐源.(3)水文因素:在干旱地带的低地和大陆洼地,广泛分布着不同特性的盐渍地,在这里,矿化的地下水并接近土壤表面,是盐渍地形成的最重要条件之一。在研究区地下水平衡的调节大部分不是通过出流,而是通过蒸发作用,从而使土体中溶解的盐分不断的向上运移,积聚在土壤表层。(4)人为因素:人为的土壤盐渍化是由于不正确地利用水和土地资源引起的,是由于忽视陆地盐的地球化学规律和忽视干旱区灌溉水和地下水的蒸发状况的作用而造成的,人类活动能从正反两个方面对土地盐渍化产生巨大的影响。干旱区盐渍化形成有其自身的自然因素诸如:气候、地质、地貌、水文和土壤条件而导致的盐渍化为原生盐渍化,但次生盐渍化主要是人为所致。本研究在自动提取了土壤盐渍化信息的基础上,定量研究了自然和人为因素共同作用下的干旱区土壤盐渍化动态变化并描述各个驱动因子的影响;对于自然和人为因素共同作用的变化过程的研究方法进行了探讨。土地盐渍化的研究目的是有效治理和可持续利用。导致干旱区土地盐渍化的主要原因是人类不合理利用水土资源,那么治理的根本是转变人的观念,确立“人地协调”发展的观念,以水利建设为龙头,重建良好的水循环系统,进行综合治理和分区域治理相结合,提出具有针对性和可操作性的治理对策。更多还原

【Abstract】 Soil salinization is getting the world’s attention for its bringing dangerous to the social economy, environment and agricultural eco-system. Applied remote sensing technology which is characterized by its macroscopically, integrations, dynamic and speediness to analysis characters, distributions, dynamic changes, and degree of salinization is very important to control over the further expanding, degradations of soils and sustainable development and rational planning of agricultures.It has been investigated and examined a large number of field dada on the spot like meteorological, hydrological, spectral and social materials, and evaluated quantitative assessment on the study area by using remote sensing image processing technology and geographic information system space analysis technology. It has been evaluated and presented the changes of arid zone salinization on time and space scale. Comprehensive assessment method has been held on driving forces of study area and scientific criterion about controlling over policies on agricultural sustainable development has been provided with some experiences. . The main aspects of the paper as follows:1. The fundamental idea of salinization dynamic change detection in this paper is that firstly using 30-year satellite images like MSS in 1972 ,TM in 1989 and ETM+ in 2001 of study area author has synthesized the different images through image sharpening and principle component analysis in near-red and visible light bands and then select supreme amount of information in assembled bands and found out that TM4、K-L2、K-T3 is the best band compounding mode after that classified the images respectively by using Bayesian algorithm in supervised classification. The classification results were over 90%.2. Taking full advantages of RS and GIS on geosciences to calculate area changes of different saline soils, arable lands, waste lands and water. Salinization change regulation in study area during30 years has been analyzed. It includes area change, salinization change degree and analysis of trends in range amount of time scale.3. The forming of salinization is a land degradation form which caused by the different environmental factors affection with human activity. The process and mechanism of salinization is complex so that hereby author tried to find way to the driving factors of salinization of study among30 years from 1972 to 2001.(1)Climate factors: Ugan-Kucha delta oasis is part of mainly arid area of our country there the dryness and evaporations are so strong which causes the ground water and the salt in the soil coming up and gathering on the surface. The drier the climate is the stronger the salt gathering and thicker the salt gathering bed.(2)Geological conditions: There are tertiary stratum salty calcium around basin and most of them are outcrops that means after rain there considerable amount of salt with water in the flow to the plain area which causes more salinization.(3)Hydrological factors: Saline lands have been distributed in the arid zones to some extend where mineralized under ground water are close to ground surface and this is the main factor of causing salinization. In the study area most of the underground water do not come out by flowing on ground but by evaporation and gathered on surface.(4) Social factors: Secondary salinization is caused by human irregular usage of land resources, ignorance of saline land chemical regulations and roughness on the water functions etc. Human activity effect the land in two ways like improving or degrading.The forming of salinization in the arid zone has its natural forces like climate, geomorphology, hydrology, soil condition and human social factors etc. The main reason for secondary salinization is of human activity. In this study, author tried to evaluate the salinization information based on change detection in 30year time period and discusses its causing factors. The purpose of research on salinization is that controlling effectively and using the land resources sustain ably. Irrationality on using water resources in arid and semi-arid zone is the main cause of sail salinization. So the concept of human is the fundamental of controlling the degradation. Establishing harmony between human and land, starting from the irrigation construction rebuilt water recycling system, implementing comprehensive controlling and regional controlling in the same time, presenting pertinence and maneuverable controlling suggestions.更多还原