景观方向性是景观空间格局的重要特征,能够反映和影响景观的生态流.实现快速、准确地从遥感影像上自动提取景观的方向性信息,对于景观的驱动力分析和景观异质性分析等都具有十分重要的意义.本文基于面向对象的方法对乾安县TM影像进行多尺度分割提取湖群,并利用正方像元指数SqP提高分类精度,应用矢量景观指数于分割处理后的湖群对象,提取景观的方向性信息.实验结果表明:该方法对象分割精度高(制图精度:97.8%,用户精度:97.5%),方向性信息提取准确、快速,为湖群的成因分析提供了数量化和可视化依据.本文同时结合了两方面的研究方法,提供了两方面的研究思路:一方面是景观格局指数在影像分类中的应用,另一方面是矢量景观格局理论进一步的应用扩展.

Pattern directionality is a key characteristic of landscape pattern, it both reflects and affects ecological flow within the landscape, and it is very mi portant to realize fastand accurate auto-extraction of the pattern directionality infor-\nmation, especially for landscape heterogeneity analysis and driving forces analysis.Qian-an county lies in the northwestofJilin Province inChina, where the clmi ate is characterized as temperate semi-arid continentalmonsoon, the evaporation greatly exceeds the precipitation. W ind, especially the strongly prevailingwind in winter from northwest to southeastplays an mi portant role in shaping some local landscapes. Formost tmi e of the year,theweather is extremely dry and the soil is sandy and uncovered. There aremany lakes, known asQian-anGroup Lakes inQian-an county. The lakes are typically smal,l and the water in the lakes is salty, seasonal and shallow, commonly about1—2m deep. The lakes aremostly in the shape ofa raindrop, with gently sloping lake beds in each lake snorthwest(thewindward side), and a steeply sloping lake beds in the southeast(the downwind side) with dune or loess piling up on this side. W ind is considered to be one of themost mi portant forces driving the pattern formation of the lakes, .ie.,the current shape of the lakes is the resultofwindy erosion upon the tectonic basins.In order to provide a quantitative and visual basis for the abovementioned conclusion conveniently and objectively,based on object-orientedmethodQian-anGroup Lakes are extracted bymulti-resolution mi age segmentation from Qian-an TM mi age. To achieve the high classification accuracy, a permi eter-area shape complexitymetric called the Square Pixel Metric(SqP) is used, then vector analysis theory on landscape pattern (VATLP) is applied to the homogeneous objects to extractvector information ofgroup lakes. Where, vectoranalysis theory on landscape pattern (VATLP) isdeveloped by Shuqing Zhang et a.l (2006) based on planar characteristics defined inmechanics such as centroid, moment of inertia,productof inertia and principal axes, and its application helps us betterunderstand the pattern formation of the lakes and the related ecologicalprocesses thatoccuron both ends of themajorprincipalaxis,e.g.,the transportation ofenergy and materials flow, and the ecological gradients.The expermi ental results show that our method achieves the high segmentation accuracy (producer s accuracy:97.8%, user s accuracy: 97.5%),and extraction ofdirectionality information is accurate and convenient. This can establish the groundwork for the furthergeographic analysis. This paperoffered two-aspect idea: one is the use of landscape patternmetrics in mi age classification, the other is the further application of vector analysis theory on landscape pattern(VATLP).