基于"三层"融合的松嫩平原盐碱地资源特征

构建盐碱地资源系统分析框架,清晰界定盐碱地概念与分类,对于盐碱地资源调查、治理与利用具有重要的意义。本研究基于地球关键带理论与逻辑,构建涵盖利用层、土壤层和DEM三层融合的盐碱地资源系统分析框架,界定盐碱地与盐碱土概念及类型,结合土地利用现状图、土壤图和DEM图,采用GIS叠加分析方法,分析松嫩平原盐碱地资源特征。结果表明：1）基于地球关键带理论和逻辑,以立体空间作为组织和联系各层级的纽带,以数字高程为基底,按照垂直和水平纬度,构建起的土地利用层、土壤层、DEM层"三层融合"的盐碱地资源系统分析框架清晰地界定和表达了盐碱地概念和特征;2）盐碱地是一种土壤类型为盐碱土的土地利用类型,下属盐碱耕地、盐碱林地、盐碱草地、盐碱湿地、盐碱未利用地和其他盐碱地6个类别,盐碱土分为盐土、碱土和盐碱化土3种类型;3）松嫩平原盐碱地总面积254.77万hm2,主要分布于松嫩平原西南部地区,类型以盐碱耕地和盐碱未利用地居多,土壤类型以盐-碱化土为主;4）盐碱耕地和盐碱未利用地海拔集中在100～150 m,坡度平缓。该研究可为盐碱地资源调查提供理论和方法支撑,为松嫩平原盐碱地治理与开发提供科学依据。

Characteristics of saline-alkali land and resources based on three-layer fusion of saline-alkali soil in Songnen Plain of China

As an important reserve cultivated land resource, the rational development and efficient utilization of saline-alkali land is of great significance to food security in China and even the world. It is of great significance for the investigation, management and utilization of saline-alkali land resources to construct a systematic analysis framework and clearly define the concept and classification of saline-alkali land. Based on the theory and logic of the key belt of the earth, this study constructs a systematic analysis framework of saline-alkali land resources covering three layers of utilization layer, soil layer and DEM, defines the concepts and types of saline-alkali land and saline-alkali soil, in order to answer the key question of what is saline-alkali land and saline-alkali soil. Combined with the land use status map, soil map and DEM map, the characteristics of saline-alkali land resources in Songnen Plain were analyzed by GIS overlay analysis method, and the feasibility and scientificity of the system analysis method of saline-alkali land constructed in this paper were verified. The results showed that: 1) based on the theory and logic of the Earth ''s critical zone, with the three-dimensional space as the link of organizing and connecting all levels, with the digital elevation as the base, according to the vertical and horizontal latitudes, the ''three-layer fusion'' system analysis framework of saline-alkali land resources was constructed, which clearly defined the concept and classification of saline-alkali soil and saline-alkali land, and accurately expressed the characteristics of saline-alkali land resources; 2) Saline-alkali land is the land whose soil type is saline-alkali soil, which includes 6 categories: saline-alkali cultivated land, saline-alkali forest land, saline-alkali grassland, saline-alkali wetland, saline-alkali wasteland and other saline-alkali land; saline-alkali soil is a simple soil concept, which belongs to three types : saline soil, alkaline soil and saline-alkaline soil; 3) According to the data superposition, the total area of saline-alkali land in Songnen Plain is 2.55 million hm2, which is concentrated in the west of Songnen Plain. Wherein the largest area of saline-alkali farmland, 0.96 million hm2, mainly in the southern Tongyu County and other places. Saline-alkali wasteland, saline-alkali grassland, saline-alkali wetland and other saline-alkali land, with an area of 0.64 million hm2, 0.47 million hm2, 0.12 million hm2, 0.08 million hm2; the area of saline-alkali soil in Songnen Plain is the largest, which is 2.00 million hm2, the area of alkaline soil is 0.47 million hm2, and the area of saline soil is 0.11 million hm2; 4) The elevation of saline-alkali cultivated land in Songnen Plain is concentrated at 100-200 m, and the elevation gradually increases from the middle to the surrounding area. The slope is relatively gentle, concentrated below 6°, and the slope gradually increases from west to east. Saline-alkali unused land is mostly distributed in the southern region, and the altitude is concentrated at 100-150 m. Most of the slopes are below 2 °.Saline-alkali unused land has low terrain, slow slope and good development conditions. From this point of view, through the analysis method of saline-alkali land system constructed in this paper, the characteristics of saline-alkali land resources are analyzed accurately and scientifically, the concept of saline-alkali land is clearly defined, and the relationship between saline-alkali land and saline-alkali soil is clarified. This study can provide theoretical and methodological support for the investigation of saline-alkali land resources, provide scientific basis for the management and development of saline-alkali land in songnen plain, and also provide some theoretical and methodological references for the third soil census and saline-alkali land investigation in this area.