蒙古国30米分辨率土地覆盖产品研制与空间格局分析

作为蒙古高原的重要组成单元,蒙古国的土地覆盖格局与变化对于东北亚的资源、环境、生态及可持续发展具有重要意义。针对本区域缺乏高精度、现势性的土地覆盖数据产品的问题,本研究利用Landsat TM影像,采用面向对象的分类方法开展蒙古国土地覆盖遥感数据产品研制与分析。首先针对蒙古国景观格局特征,自主研究了适宜于蒙古国的土地覆盖分类体系,基于面向对象的遥感解译技术方法研究了蒙古国自然地物和人工地物要素的提取算法规则与阈值,建立了一套完整的面向蒙古国的土地覆盖遥感解译技术方案,在分景解译基础上获取了蒙古国2010年土地覆盖分类产品。经验证,数据集一级类分类精度为92.34%,二级类分类精度为80.24%。蒙古国土地覆盖类型以裸地、草地、森林为主,其中裸地的面积最大,占总面积的48.64%,其分布比较集中连片,主要分布在蒙古国南部和西部;草地面积次之,占总面积的42.85%,其分布具有明显的地域性,主要集中在蒙古国北部湿润地区和河流附近;林地最少,占总面积的6.63%,以蒙古国北部及西北部高山地区为主要生长区域。整体上蒙古国土地覆盖空间格局呈现明显的区域差异与地类过渡性,从南向北依次为裸地、荒漠草地、典型草地、森林类型,其中荒漠草地在中部形成一条明显的分界条带。

Development and Pattern Analysis of Mongolian Land Cover Data Products with 30 Meters Resolution

Mongolia is an important part of the Mongolian Plateau. Its land cover patterns and changes are of great significance for resources, environment, ecology, and sustainable development of Northeast Asia. In order to address issues such as lack of high accuracy and up-to-date land cover products in this region, we have used images obtained through Landsat thematic mapper and object-oriented classification method to produce data products and analyze the Mongolian land cover patterns. A classification system suitable for Mongolian land cover was first proposed taking characteristics of the Mongolian landscape into consideration. Interpretation algorithms and rules of 10 kinds of natural and artificial features were studied using the object-oriented interpolation method, and a complete remote sensing interpolation technological program suitable for Mongolian land cover mapping was developed. Land cover products for Mongolia for 2010 were obtained by interpretation of individual Landsat scenes. The accuracies of classification of the datasets in the first and second class levels were 92.34% and 80.24%, respectively. The main land cover types in Mongolia consist of barren lands, grasslands, and forests. Out of these, barren lands account for the maximum area (approximately 48.64% of the total area) with concentrated and continuous characteristics, and are mainly distributed in the south and west of Mongolia. The second largest areas are covered by grasslands (42.85% of the total area) with clear regional characteristics, and mainly distributed in the north of Mongolia and near the rivers. Forest areas constitute the smallest part, accounting for only 6.63% of the total area, and are mainly distributed in the mountains of north and northwest Mongolia. The spatial distribution of the land cover presents clear regional differences and land type transitivity. The land cover changes from barren to desert steppe, to real steppe, and finally, to forests as one moves from the south to north. The desert steppe forms a clear separate belt in the central part of Mongolia.