基于3S技术的甘肃省耕地质量等别监测评价研究

Study on monitoring and evaluating the cultivated land quality grade in Gansu Province based on 3S technology

为全面掌握甘肃省耕地质量变化情况及其驱动因素,从宏观层面上建立"省-区-县-渐变类型区-地块"监测体系,以甘肃省标准耕作制度三级区为单位选取监测县,运用"重点分等因素划定"方法划分监测县耕地等别渐变类型分区、确定驱动因素,通过在县域范围内布设监测单元,对监测单元耕地质量渐变的驱动因素进行监测,并对其引起的耕地质量等别渐变做出趋势性评价。最后,以监测县耕地质量变化情况为基础,运用克里金空间插值方法对甘肃省耕地质量进行空间局部估计,对耕地质量变化空间分布进行特征分析。结果表明:(1)相比2015年耕地质量评价成果,全省监测县耕地等别平均提高了0.14等。河西走廊区中部、陇南山区南部等别有较大幅度提高;晋陵丘陵沟谷区、陇东黄土旱塬区东部、甘南高原区中部等别有较大幅度降低;南部地区变化的幅度整体高于北部地区。(2)甘肃省耕地土壤有机质含量差异较大,且整体偏低;全省耕地类型以旱地为主,耕地灌溉保证率多为一般满足和不满足,但得益于近年来全省修建大型引、供水工程,全省耕地灌溉保证率有了提高;耕地质量分布区域性特征明显。

In order to fully grasp the change of cultivated land quality and its driving factors in Gansu Province,in this article,a＂province-prefecture-county-gradient type district-plot＂monitoring system was established from the macroscopic view. Then the grade of cultivated land is divided and the driving factors are determined. Based on the monitoring in various monitoring counties,the driving factors of the cultivated land quality variation in the monitoring units were revealed and the trend evaluation of cultivated land quality was obtained. Finally,based on the change of cultivated land quality in the monitoring counties,the Kriging space interpolation method was used to estimate the quality of cultivated land in the province,and the spatial distribution of cultivated land quality was analyzed. The results show that：（ 1） Compared with the results of the evaluation of cultivated land quality in 2015,the average utilization rate in the monitoring counties has increased by 0. 14 grade. The central region of the Hexi corridor and the southern part of the Longnan mountainous region has increased more. In the Jinling hilly and valleys,east of the Longdong loess highland and in the central Gannan plateau,the cultivated land quality has been greatly reducing,and the changes in the south has been higher than that in the north.（ 2） In Gansu Province,the content of organic matter in cultivated land is quite different,and low as a whole; the province＇s land is of dryland type,farmland irrigation guarantee rate is generally satisfied or no-satisfied; in recent years,the province has built large-scale water supply projects to make the province＇ s cultivated land irrigation guarantee rate improved; cultivated land quality distribution regional characteristics are obvious.