川西平原油菜种植区域时空变化分析

Remote sensing spatial-temporal changes of rape planting region in Chuanxi Plain

【目的】提取四川省粮食生产核心区川西平原油菜种植区域空间分布信息,分析种植区域的空间特征和面积变化,以期为四川省农业政策制定、产业结构进一步调整和优化提供参考。【方法】文章将GF-1、Sentinel-2和Landsat-8全色波段影像和多光谱影像进行融合,分别得到空间分辨率为15 m、10 m和15 m的融合图像;利用最大似然分类法对融合图像的RGB假彩色图像进行地物分类,提取油菜种植区域信息。以Google Earth发布的历史影像建立验证样区,通过目视解译提取油菜种植区域,验证遥感影像的提取精度。【结果】获得了该地区2016年和2018年共2期油菜种植区域空间信息。川西平原油菜主要分布在北部、东北部、西部和南部浅丘地带,零散分布于中部平原地区。2018年油菜种植面积较2016年有所增长,主要增加区域在川西平原崇州市、大邑县、邛崃市等市县。【结论】川西平原近年来油菜种植面积总体保持增长势态。四川省油菜产业的发展使得油菜种植区域差异化逐渐明显,需要进行针对性分析,因地制宜地研究和确定产业的战略目标与规划、区域农业产业化经营应遵循的法律或规则。

[Purpose]Rape,which is one of the most oil-crops.The most important growing region of rape in China is in Chuanxi Plain.This research is intended to extract the rape planting region of Chuanxi Plain based on the GF-1、 Landsat-8 OLI、 Sentinel-2 images and provides agricultural information for formulating agricultural policies and adjustment of industry structure through an analysis of the spatial characteristics and area changes of planting regions.[Method]Obtaining 15 m、10 m、15 m resolution fusion images from the panchromatic image and multispectral images of GF-1、Sentinel-2、Landsat-8.The maximum likelihood classification was used to classify the RGB images and extract the information of the rape planting region.The verification sample area was established based on the historical image published in Google Earth.Planting region information was extracted by visual interpretation,which was used to verify the monitoring accuracy of the remote sensing images.[Result]Obtaining spatial information of the rape planting region in 2016 and 2018.The rape planting region was mainly distributed in the north, northeast, west, and south plateau shallow hill of Chuanxi Plain and scattered distribution in the central plain.The area of the rape planting in 2018 increased by annual 6.5%compared with that in 2016.The increased area is in Chongzhou city,Dayi county,Qionglai city of Chuanxi Plain.[Conclusion]The results of this study show that the rape planting area in Chuanxi Plain has maintained an overall growth trend in recent years.With the development of the rapeseed industry in Sichuan Province,the regional differentiation of the rape planting is gradually obvious.Therefore,it is necessary to analyze the target and planning of rape industry in order to provide a decision-making basis for agricultural policymaking and industrial structure further adjustment in Sichuan Province.