中国沙地分类进展及编目体系

Study on classification progress and cataloging system of sandy land in China

中国历来重视沙地研究但至今尚未形成较公认的分类体系,详细的沙地资源数据库建设亦未开展。全面总结了中国沙地已有的研究成果,对中国沙地分类进展和编目体系进行了研究。结果表明:1已有的沙地分类主要根据沙地流动性、荒漠化程度、荒漠化过程、空间位置等方法进行,表现出研究区域不全面、分类指标定量程度低、空间信息表达能力差、分类指标体系混乱以及沙地分类的系统性和分类结果的可比性相对较差等问题。2沙地分类编目体系全面涵盖了中国沙地分布范围,突出了沙地的温度、干湿度、流动性、荒漠化程度、面积和土地利用属性等信息,能综合全面地反映沙地的自然和社会属性,具有较好的科学性和可操作性。

As unique landforms, sandy lands are mostly found in northern China, the QinghaiTibet Plateau, and along the edges of seas, lakes, and rivers. Sandy lands are generally in ecologically fragile zones and are important in maintaining regional sustainable development.Researchers in China have focused on sandy lands since the 1950 s and have proposed many classification methods for these lands. However, there is no widely accepted classification system, owing to a lack of integration of sandy land resources. Therefore, confusion has resulted from too many classification methods. Furthermore, the absence of a sandy land resource database might have restricted appropriate management of sandy land resources by the government and affected proper implementation of ecological management policies. In this paper, progress on sandy land research in China is comprehensively summarized. Sandy land classification methods and a cataloging system are also discussed. Results show that:(1)Existing sandy land classification methods are mainly based on sandy land mobility,desertification degree and processes, and geographic location. This may have resulted in the omission of some sandy land areas, a smaller quantitative classification index, degraded ability to express spatial information, a chaotic classification index system, and others. Moreover,systematicness and comparability of sandy land classification results were inadequate.(2)Vegetation coverage has been widely used for sandy land classification and its index can quantitatively express the mobility, desertification degree and processes, and other features of such land. According to climatic differences, using vegetation coverage to classify sandy land by sand mobility(fixed, semi- fixed and mobile sand) and desertification degree(mild,moderate, severe or very severe) could highlight the most important information.(3) The cataloging system here includes different code levels for identification, geographic location,mobility, desertification degree, and other sandy land features. The sandy land identification code can effectively differentiate desert, Gobi, and other desertification types. Based on an ecogeographical regional system of China, geographic location codes include information on 11 temperature zones, 21 wet and dry areas, and 49 natural regions, covering the entire sandy land area in the country. Those codes also effectively identify differences of temperature, humidity,vegetation, landscape, and others. Codes of mobility, desertification degree, area, and sandy land use can highlight its natural and social characteristics. Thus, the cataloging system of sandy land in this study is comprehensive, well-integrated, and easy to use.