应用MODIS数据监测神农架林区大小蠹虫害时空分布

Spatial and temporal distribution of Dendroctonus armandi infestation in Shennongjia forested region using MODIS data

【目的】分析影响神农架林区大小蠹虫害区域变化的因素,探索大小蠹虫害发生区域的时空分布格局。【方法】结合华山松大小蠧的生活习性以及遭受大小蠧侵害后华山松的冠层表现,选择湖北神农架林区作为研究区,以2008—2015年MODIS数据中提取出的归一化植被指数(NDVI)作为数据源,利用趋势线分析模型研究神农架华山松大小蠹虫害2008—2015年年际和2014年年内虫害发生区域分布的空间特征,并利用趋势线分析模型的显著性检验方法对虫害发生区域内的不同受灾程度区域进行划分,利用分区统计方法统计不同海拔范围内遭受华山松大小蠹虫害侵害区域的面积及虫害爆发的时间,利用相关系数模型求解遭受华山松大小蠹虫害侵害区域的NDVI值与海拔之间存在的相关性。【结果】1)利用MODIS-NDVI数据监测虫害受灾区域和受灾程度与实际调查数据基本保持一致;2)华山松大小蠹虫害发生区域的NDVI值与海拔之间存在较为显著的负相关关系(相关系数r=-0.491,显著性水平P=0.001);3)华山松大小蠹虫害在不同海拔范围内爆发的时间与其在该海拔范围内的生活习性密切相关。【结论】利用MODIS数据能够识别神农架林区大小蠹虫害区域和爆发时间,为分析神农架林区植被生长状况提供基础,为神农架林区内大小蠧虫害防治工作的进行提供了有力依据。

【Objective】To analyze the influence factors on the change of Dendroctonus armandi infestation area and explore the spatial and temporal distribution of the area.【Method】This study combines the living habits of Dendroctonus armandi and the canopy performance of Pinus armandii.Shennongjia forest area in Hubei province was selected as the study area in this study.The normalized vegetation index(NDVI)extracted from the MODIS data ranging from 2008 to 2015 was used as the data source.A trend line analysis model was used to study the spatial distribution characteristics of the Dendroctonus armandi infestation area in 2008-2015 and 2014.The significance test method of the trend line analysis model was used to divide the different severity areas in the pest infestation areas.A zoning statistical method was used to calculate the area and time of Dendroctonus armandi infestation at different altitudes.A correlation coefficient model was then employed to solve the correlation between NDVI and altitude in the pest infestation areas【.Result】1)Using MODIS data to monitor the distribution of Dendroctonus armandi severity was basically consistent with the actual survey data;2)A significant negative correlation between NDVI value in the pest infestation areas and altitude,where the correlation coefficient was-0.491 and significance level was 0.001;3)The time when pests and diseases occured at different altitudes had a close relationship with their living habits.【Conclusion】The MODIS data can be used to identify the infestation area of Dendroctonus armandi and outbreak time,indicting that it may provide a basis for analyzing the situation of vegetation growth and for prevention and control of Dendroctonus armandi infestation in Shennongjia forest area.