基于黑土地保护目标的省级尺度土地类型划分研究——以黑龙江省为例

为提升对土地资源的质的了解程度，优化资源利用方式和方向，实现黑土地保护目标和“藏粮于地、藏粮于技”战略要求，以黑龙江省作为典型研究区域，考虑黑土地保护与利用需求，并借鉴地球关键带理念，从气候影响、地貌条件、地质条件、土壤特性、水文分布5个维度构建三级分类，基于GIS平台采用空间叠置法对主导因素中级分类进行叠加和综合，进行省级尺度土地类型划分。结果表明，黑龙江省共划分为39个土地类，2 121个土地型和4 945个土地组。黑龙江省土地类型单元较丰富，类型单元面积分布不均衡，低级单元相比高级单元属性更丰富，黑土区的土地类型单元呈现出不同的数量特征和空间分布特征。类型单元可反映区域的自然地理规律。空间组合结构上主要有对称式空间组合结构、重复式空间组合结构、镶嵌式空间组合结构3种结构形式。土地类型数量和结构呈现的规律性分布可为黑土地的农业生产布局优化奠定基础。

Classification of Land Types at Provincial Level Based on the Goal of Black Land Protection: A Case Study of Heilongjiang Province

Soil in black land has good quality, high fertility and is suitable for cultivation. As a rare resource, black land is the ballast stone to ensure China’s food security. China attaches great importance to the protection and utilization of black land, which has risen to the national strategic requirements. The black land in Northeast China is one of the four major black land areas in the world, and Heilongjiang Province is one of the most important black land distribution area in China. To improve the understanding of the quality of land resources, optimize the ways and directions of resources utilization, and achieve the black land protection goals and the strategic requirements of ‘Reserving Grain in Land and Technology’, Heilongjiang Province was used as a typical study area for the provincial-level land types classification. Considering the needs of black land protection and utilization and referring to the concept of Earth Critical Zone, a three-level classification system was constructed from the five dimensions of climate, geomorphic, geological, soil, and hydrological conditions. Based on the GIS platform, the spatial overlay method was used to superimpose and synthesize the intermediate classification of dominant factors. As a result, it is divided into 39 first-level land types, 2 121 second-level land types, and 4 945 third-level land types of Heilongjiang Province. The land type units in Heilongjiang are abundant, the area distribution of the land type units is not balanced, and the properties of the low-level units are richer than those of the high-level units. The type units can reflect the natural geographical law of the region. There are three kinds of spatial composite structures: symmetric spatial composite structure, repeated spatial composite structure, and mosaic spatial composite structure. The regular distribution of quantity and structure can lay a foundation for the optimization of the agricultural production layout of black land. The spatial characteristics of the distribution of land types in Heilongjiang Province reveal the natural background of the black land, which can be used as the natural standard for the protection and restoration of the black land and improve the current status of the black land. According to the strategic demand of ‘Reserving Grain in Land and Technology’, the elastic space of cultivated land can be identified, the appropriate utilization priority can be defined, and the differential utilization and protection measures can be taken at the provincial level, and then scientific and reasonable macro adjustment and allocation of black land can be carried out. In terms of classification ideas and methods, this study draws on the previous experience of land types classification, and adopts the data matching the provincial level. The classification results are reasonable and universal to a certain extent.