干旱区耕地质量等级时空变化及其评价——以西宁市为例

Spatiotemporal variation and evaluation of cultivated land quality grade in arid areas:A case of Xining City

以青海省西宁市为研究对象,依据《耕地质量等级》(GB/T33469-2016),采用特尔斐法、层次分析法、模糊数学法等方法,构建西宁市耕地质量评价指标体系;结合地理信息系统(GIS)软件技术,对西宁市2015年和2018年耕地质量进行评价,并分析西宁市耕地质量时空分布和土壤养分特征,探究西宁市耕地质量现状。结果表明:(1)2015年和2018年耕地质量平均等级分别为6.74和6.33,4 a间提升0.41,耕地质量等级总体提升主要来自三、四、五、七等地,其中高、中等地总面积占总耕地面积的比例2018年较2015年增加1.49%。(2)4 a间的耕地质量等级在空间分布上差异较大,高、中等地主要集中在中部的湟中区及北部大通回族土族自治县(简称大通县),低等地主要分布在边缘靠山区及海拔较高地区,耕地质量提升的耕地主要来自大通县、湟源县、湟中区。(3)相较2015年,2018年土壤有机质、有效磷、速效钾含量均增加,其中有效磷含量评价等级上升。研究结果对西宁市全域范围内耕地质量展开综合评价,其结果能够很好地反映该地区当前耕地质量状况,对农业生产具有指导意义。

Taking Xining City of Qinghai Province,China,as the research object,based on the quality grade of arable land(GB/T33469-2016),the Delphi method,hierarchical analysis,and fuzzy mathematics were used to construct the evaluation index system of arable land quality in Xining City.Combined with geographic information system software technology,the quality of arable land in Xining City in 2015 and 2018 was evaluated,the spatial and temporal distribution of arable land quality and soil nutrient characteristics in Xining City were analyzed,and the current situation of arable land quality in Xining was explored.The results showed the following:(1)The average arable land quality grades in 2015 and 2018 were 6.74 and 6.33,respectively,with an improvement of 0.41 between 4 a.The overall improvement of arable land quality grades mainly came from the grades third,fourth,fifth,and seventh,whose total area of high and medium grades increased by 1.49%in 2018 compared with 2015.(2)Regarding 4 a between the quality level of arable land in the spatial distribution of large differences,high and medium lands are mainly concentrated in the central Huanzhong District and the northern Datong County,low land is mainly distributed in the edge by the mountains and higher altitude areas,and the quality of arable land improved mainly from Datong County,Huangyuan County,and Huanzhong District.(3)Compared with 2015,the content of soil organic matter,available phosphorus,and rapidly available potassium increased in 2018,among which the evaluation grade of available phosphorus content increased.This study performed a comprehensive evaluation of the quality of arable land in the whole area of Xining City,and the results can well reflect the current quality of arable land in the area and have guiding significance for agricultural production.