北京市域土地类型基本分级与指标体系实证研究

土地类型是综合自然地理学的基本研究对象，反映中小尺度地段分异规律及其综合体整体特征。按北京市地段复杂层次和满足不同管理级别的应用需求，将北京市域土地类型从高级至低级划分出4 个基本级次，即土地类—土地型—土地组—土地相。不同级次划分指标是：土地类以地貌成因形态、土壤亚类、地带性植被生活型的综合为指标；土地型划分指标为中地貌形态、植被生态型、土壤成土条件的综合，突出植被生态型与土壤物质来源的耦合；土地组划分指标为坡向相同小地貌、相同土体构成与植被群系（或群系组）的综合；土地相划分指标为坡向坡度相同地貌面、相同根系土壤活动层、相同土壤含水量、相同植被群丛（组）和相同土地利用方式的耦合。

Empirical study of basic classification and index system of land types in Beijing

Land type is a basic study object of physical geography, which can reflect the meso-scale and small-scale section differentiation regularity and overall characteristics of the complex. Based on the complex hierarchy of the section and the application requirements of different management levels of Beijing, this study divided the land types in Beijing into four basic levels from high to low: land class, land type, land group and land phase. Divisional indicators for land class included morphogenesis form, soil sub-types, and zonal vegetation life form; divisional indicators for land type included meso-scale topographic feature, vegetation ecotypes, and soil forming conditions in order to give prominence to vegetation ecotype source coupled with soil material sources; divisional indicators for land group included small landforms with same aspect, same soil composition, and same vegetation group of association or formation; and divisional indicators for land phase included same geomorphic surface of aspect and slope, same root activities thickness and soil moisture, and same vegetation association coupled with same land use patterns.