典型黑土区旱田保护性耕作适宜性评价及驱动因素分析—以沈阳市为例

Suitability evaluation and driving factors analysis of conservation tillage in typical black soil areas: a case study of Shenyang City

  • 摘要: 保护性耕作对提升东北黑土地旱田质量与保护生态环境意义重大,然而从区域尺度构建旱田保护性耕作适宜性评价指标体系,开展科学评价并确立优先序的研究仍然较少。沈阳市位于东北黑土地南缘腹地,旱田占耕地面积77%,是辽宁省重要的商品粮基地,明确其旱田保护性耕作适宜区域和优先序对于该区域耕地保护尤为关键,也为保护性耕作技术落地提供重要依据。以沈阳市旱田为研究对象,运用层次分析法和特尔斐法,从气候条件、地形地貌和土壤性状三方面构建了包括有效积温、年均降水量、平均风速、地形部位、坡度、地块规整度、耕层质地、有效土层厚度和有机质等9个指标的适宜性评价指标体系,利用GIS技术进行旱田保护性耕作适宜性评价及空间分析,通过计算各指标障碍度,明确主要驱动因素。沈阳市旱田保护性耕作适宜性呈西高东低、南高北低趋势。高适宜、比较适宜、一般适宜、不适宜区域分别占旱田面积28.24%、27.36%、31.24%、13.16%。从各子系统障碍度来看,气候条件障碍度为45%、地形地貌障碍度为33%、土壤性状障碍度为22%。其中,年均降水量、有效积温、坡度及有效土层厚度等指标为核心驱动因子。总体看,气候因素是影响区域旱田保护性耕作布局的主要因素。沈阳市西部和南部旱田保护性耕作适宜性较高,可以优先将保护性耕作技术进行落地实践;而东部和北部开展旱田保护性耕作适宜性较低,可以探索更适宜的技术模式进行保护,从而实现全域区旱田质量的保育和提升。

     

    Abstract: Conservation tillage is of great significance in improving the quality of drylands in Northeast China's black soil and protecting the ecological environment. However, there is still limited research on constructing a suitability evaluation index system for drylands conservation tillage at the regional scale, conducting scientific evaluations, and establishing priorities. Shenyang City is located in the hinterland of the southern edge of the black soil in Northeast China, with dry land accounting for 77% of the cultivated land area. It is an important commodity grain base in Liaoning Province. Clarifying the suitable areas and priority of drylands conservation tillage is particularly crucial for the protection of cultivated land in this region, and also provides important basis for the implementation of conservation tillage technology. Taking the drylands in Shenyang City as the research object, the Analytic Hierarchy Process and Delphi method were used to construct a suitability evaluation index system for 9 indicators including effective accumulated temperature, annual precipitation, average wind speed, terrain location, slope, plot regularity, cultivated land, effective soil layer thickness, and organic matter from three aspects: climate conditions, topography, and soil properties. GIS technology was used to evaluate the suitability of protective tillage in drylands and conduct spatial analysis. By calculating the obstacle degree of each indicator, the main influencing factors were identified. The suitability of conservation tillage in drylands in Shenyang city shows a trend of high in the west and low in the east, and high in the south and low in the north. The areas of high suitability, relatively suitability, general suitability, and unsuitability account for 28.24%, 27.36%, 31.24%, and 13.16% of the drylands area, respectively. From the perspective of obstacle levels in each subsystem, the obstacle level of climate conditions is 45%, the obstacle level of terrain and landforms is 33%, and the obstacle level of soil properties is 22%. Among them, indicators such as annual average precipitation, effective accumulated temperature, slope, and effective soil layer thickness are the core driving factors. Overall, climate factors are the main factors affecting the layout of conservation tillage in arid fields in the region. The suitability of conservation tillage in arid fields in the western and southern parts of Shenyang is relatively high, and conservation tillage techniques can be prioritized for practical implementation; However, the suitability of carrying out drylands conservation tillage in the eastern and northern regions is relatively low, and more suitable technical models can be explored for protection, thereby achieving the conservation and improvement of drylands quality in the entire region.

     

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