我国是一个多山的国家,开展山地土地类型的研究和制图,对于土地资源评价、制定农业区划以及提高土地类型学的理论和方法都有特殊重要的意义。 六十年代初期,我们结合教学实习和指导毕业论文在北京门头沟区清水河流域开展了大、中比例尺土地类型制图工作,初步摸索关于山地土地类型制图的问题,有一些粗浅的体会,现加以总结,供今后开展全国土地类型研究与制图参考。

The procedure of mapping the land types in mountainous region is quite differentfrom that in the plain. In the mountain ous region, it needs to begin with the studyingof the basic morphological features of the mountains. These include the vertical zona-tion, the atternation of positive and negative landforms, the aspects of slopes, and so on.Moreover, the formation of the morphological features of the land units should beanalysed also.In the practice of making the large and middle-scale maps of the land types in themountainous region, west of Beijing, two facts have been noticed. One fact is that the la-titudina position and the altitude of the mountain determine the spectrum of vertical zonesand its structure. The other is that the geological and geomorphological factors (geologi-cal structure, new tectonic movement, lithology, types of landforms, and so on) have im-portant relations to the differentiation of the land units and their structural characteris-tics. They also form the basis of different agricultural land. use. Therefore, these twofacts have to be studied carefully for giving a sound foundation for mapping.Several related problems should be studied further. They are:1. The hierarchy of the classification of the land units. We considered that thehierarchy should be "the vertical zones of mountain landscape, land system, facet andelements". Such a hierarchy not only agrees with the characteristics of the mountainousregion but is also useful to make comparison with the land types of the plain.2. Basic contents of maps of different scale, considering the characteristics of themountainous region and the present agricultural land use conditions, we suggest that:(1) for large-scale mapping, the land facet should be the main object; (2) for middle-scale mapping, the land system should be the main object; and (3) for small-scale map-ping, the vertical zone of natural landscape should be the main object. As for the landelement, it seems not feasible to be mapped.3. Legend design and nomenclature. Legend design and nomenclature should reflectthe comprehensive character of the land. Both the sequent legend and the two-row ormulti-row index legend can be used. Each has its advantages and shortcomings. Butin compiling the land type maps of the whole country, it is convenient to use the sequentlegend.4. The synthesis of the land type maps. We have attempted to synthesize the landtype maps according to the regional principle and the type principle. This involves theshape and boundary of the mapping units, the unification and adjustment of the legendsymbols, and so on. All these problems need to be studied further.