基于TOPSIS模型的典型黑土区耕地质量评价及土壤侵蚀耦合协调分析

黑土区是中国重要的粮食产区,掌握黑土区耕地质量状况,探索耕地质量与土壤侵蚀的耦合协调发展关系,可以进一步保持耕地的健康发展。为探讨黑土区耕地质量与土壤侵蚀的耦合协调发展关系,以嫩江市为研究区,利用层次分析法及CRITIC权重法确定22项选取指标的综合权重,通过综合质量指数法构建地学特征、土壤特性、土壤健康、基础设施建设及植被生长5个维度的质量指数,引入TOPSIS模型分析确定嫩江市耕地质量等级,开展黑土区障碍因子诊断、侵蚀状况模型评估及耦合协调研究。结果表明：1）嫩江市以中等级耕地为主,占总耕地面积的29.6%,高等级耕地较少,占比为10.1%。耕地质量等级存在较大差异,集聚类型以不显著为主,且在市域内呈现散碎分布的空间格局。2）根据障碍因子诊断发现,指标层中土壤pH值、排水能力、灌溉能力、地块连片度及比值植被指数指数的障碍度较高,是制约耕地质量的主要因素。准则层中耕地的基础设施建设指数障碍度最高,对于耕地质量具有显著影响。3）嫩江市西南部区域土壤侵蚀强度相对较弱,侵蚀较为严重区域主要分布在嫩江市的北部及东部区域,空间分布格局呈现东北高西南低。4）空间耦合协调分析发现,耕地质量与土壤侵蚀强度的空间耦合度介于0.22～1.00之间,具有明显的耦合响应特征,呈现出一定的空间差异性,总体上土壤侵蚀与耕地质量处于良好的协同发展状态。研究为松嫩平原农业健康生产及黑土区耕地质量监测评价提供参考依据。

Coupling coordination analysis of the quality evaluation of cultivated land and soil erosion in typical black soil areas using TOPSIS method

The black soil area in northeast China is an important food producing area. The evaluation of cultivated land quality in the black soil area is the basis for mastering the quality status of cultivated land and promoting the sustainable use of cultivated land. In addition, it is important to clarify the soil erosion in black soil areas and explore the degree of coupled and coordinated development of cultivated land quality and soil erosion to maintain healthy agricultural development and national food production security. Based on this, this study took Nenjiang city, a typical black soil area in China as the research area. A comprehensive evaluation of the cultivated land quality in Nenjiang City was made based on technique for order preference by similarity to an ideal solution (TOPSIS) model by constructing five dimensional indices: geoscience characteristic index, property index, soil health index, infrastructure construction index, vegetation growth index. The RUSLE model was used to assess the soil erosion in the study area, the coupled coordination degree model was used to explore the degree of coupled and coordinated development of cultivated land quality and soil erosion, and further to clarify the main influencing factors limiting the cultivated quality. The results showed that: 1) the quality index of cultivated land in Nenjiang City ranged from 0.26 to 0.67, and the quality level of cultivated land varied greatly in different regions. The quality of cultivated land was mainly "intermediate grade" cultivated land, which accounted for 29.6% of the area. High grade cultivated land accounts for less, and the cultivated land quality needs to be further improved to maintain the safety of agricultural production. 2) The results of diagnostic analysis of barrier factors showed that the barrier degree of soil pH, drainage capacity, irrigation capacity, plot contiguity and relative vegetation index in the index layer was high, all exceeding 60%, which were the main reasons limiting the cultivated land quality. The highest degree of infrastructure development index barriers for cultivated land in the criterion layer had a significant impact on the cultivated land quality. 3) The soil erosion modulus of Nenjiang City was distributed between 0 and 30.7 t/(hm²·a). The area of slight erosion was the largest, accounting for 75.45% of the total study area, and the area of heavy erosion was the smallest, accounting for less than 1% of the study area. From the perspective of spatial distribution, the degree of erosion in the southwestern region was relatively weak, and the more serious erosion areas were mainly distributed in the northern, central and eastern areas of Nenjiang City. 4) The coupling coordination degree of soil erosion system and cultivated land quality ranged from 0.25 to 0.99, and there was some variability in the spatial distribution of the coupling coordination degree values. However, most of the spatial evaluation units had the coupling coordination degree values greater than 0.7, and overall soil erosion and cultivated land quality were in a good state of synergistic development. This study can provide a new perspective for the comprehensive and integrated evaluation of cultivated land quality assessment, and provide a theoretical basis and scientific reference for the sustainable development management of cultivated land in black soil areas and the formulation of related land use policies.