基于多尺度层的遥感影像分类问题研究

近年来,基于面向对象的遥感影像分类方法已经被广泛使用,这种方法与传统的基于像元的分类方法相比较,精度较高,是以对象作为分类的最小单元,所以,对于面向对象的分类方法其关键就是如何获取较高精度的对象,本文是在对遥感影像进行不同尺度分割的基础上,得到不同尺度的对象,然后依据对象的分割精度,选择相应尺度再进行分类。实验证明,这种方法可以有效提高遥感影像的分类精度。     

STREAMFLOW CHARACTERISTICS OF THE EASTERN QINGHAI-XIZANG PLATEAU

The eastern Qinghai-Xizang (Tibet) Plateau is the headwater area for many large Asian rivers. Permafrost occurs above 4,200 m a.s.l. and glaciers occupy the summits and high valleys of the east-west trending mountain chains. Annual runoff generally increases with precipitation which is augmented southward by the rise in topography. Rainfall, snow melt, glacier melt and groundwater are the primary sources of stream flow, and the presence of permafrost enhances the flashiness of runoff response to rainfall and snowmelt events. Peak flows are concentrated between June and September. And winter is low flow season. Three types of runoff patterns may be distinguished according to their primary sources of water supply: snowmelt and rainfall, glacier melt and snowmelt, and groundwater. Large rivers generally drain more than one environments and their runoff regime reflects an integration of the various flow patterns on the plateau.     

高山冻土区水量平衡及地表径流特征

以天山空冰斗高山冻土区为例,通过实验观测资料,探讨高山冻土区独特的径流过程、水量平衡特征及产流模拟计算。     

基于SRTM数据生成地面高程模型技术研究

目前,对于一般地形图的制作主要依托野外数据采集和内业计算机成图。这种方法,虽然制图精度较高,但是制图速度慢、制图成本高以及制作过程专业、复杂一直是其待解决的问题。对于一些高程精度要求不高,主要研究地形起伏趋势的区域而言,可采用SRTM数据在Global Mapper平台下,生成地面高程模型。这种方法不再需要野外数据采集,速度快,成本低,为地形图的制作又提供了一个新的思路和方法。