关键词: 一带一路, 尼泊尔, 土地覆被, 空间格局, 遥感

Abstract:

Nepal, located in the core region of the Hindu-Kush-Himalayan region, has complicated and diverse land cover classes. Meanwhile, its topography shows a typical transition pattern from plain to mountain, and then to plateau. Land cover mapping of Nepal not only has a great scientific and practical significance to its land resource management and eco-environmental protection, but also contributes greatly to the basic data collection in this area, which will support China’s international regional economic cooperation strategy of “the Belt and Road Initiative”. In this paper, the land cover product of Nepal in 2010 (hereinafter referred to as the NepalCover-2010) was produced from Landsat TM image data sources, based on the combined cartographic method of object-oriented methods and decision trees. The product contains 8 primary categories and 32 secondary categories. Besides, the accuracy validation of the NepalCover-2010 was performed using samples obtained from high-resolution Google Earth imagery. The quantitative structural characteristics of Nepal and the relationships between the spatial distribution of typical land cover classes and the topographical and meteorological elements were analyzed. The results demonstrated that: (1) the overall accuracies of the primary and secondary categories for the NepalCover-2010 are 94.83% and 87.17% respectively. The Kappa coefficients are 0.94 and 0.85 respectively. The NepalCover-2010 can reflect the spatial distribution characteristics of land covers in Nepal. The comparison between the NepalCover-2010 with similar land cover products indicated that the NepalCover-2010 has the best accuracy. (2) Forest is the major land cover class in Nepal, and it accounts for 41% of the total land area of Nepal. Cultivated land accounts for 25% and the area ratio of paddy field to dry land is about 2:3. (3) The topographical and meteorological elements impact greatly on the spatial distribution of land cover classes. The spatial distribution of each land cover class possesses the characteristics of vertical zonality, and the appearance pattern of the typical land cover classes from the south to the north is paddy fields, evergreen broadleaf forests, dry lands, evergreen broadleaf shrubs, evergreen needleleaf forests, steppes, sparse vegetation, snow and ice, along with the increase in altitude.

Key words: the Belt and Road Initiative, Nepal, land cover, spatial pattern, remote sensing