遥感估算及分析油杉河牧场近30年植被覆盖度变化

Remote sensing estimation and analysis on plant cover change of Youshanhe Farm in recent 30 years

为了解油杉河牧场建立对植被动态的影响,给研究区畜牧业的可持续发展和草地资源的开发利用提供科学依据,以贵州省油杉河牧场为研究区域,将野外实地测量21个样方的覆盖度与每个采样点的7种植被指数(NDVI,DVI,RVI,EVI,SAVI,GVI,OSAVI)建立相对应回归模型,比较每种植被指数与覆盖度之间的相关性,然后选择最佳覆盖度估算模型估算研究区近30年覆盖度,定量分析年际覆盖度变化的特征,探讨了研究区覆盖度与气象因子的相关性。结果表明,所建估算模型中线性模型和二次多项式模型相关性高于其他模型,其中植被指数SAVI的二次多项式模型精度高达90.27%,说明该模型具有可行性;1993年~2019年油杉河牧场覆盖度整体呈上升趋势,2006年和2015年上升幅度最大;近30年研究区覆盖度在月际水平上与温度、降水的相关性随着人类活动的增加呈逐渐减小趋势,牧场建立以后相关性不显著。人类活动对油杉河牧场植被覆盖度具有深远影响,推荐植被指数SAVI估算温暖湿润地区的人工草地覆盖度。

To understand the impact of the establishment of Youshanhe Farm on vegetation dynamics,and to provide a scientific basis for the sustainable development of animal husbandry and the development and utilization of grassland resources in the study area.Taking Youshanhe Farm in Guizhou Province as the research area,explored the changes in the grassland plant cover of the research area in the past 30 years.Grassland plant covers of 21 sites within the Youshanhe Farm were measured in the field.7 vegetation indexes including NDVI,DVI,RVI,EVI,SAVI,GVI and OSAVI of each sampling site were obtained based on Landsat remote sensing images using remote sensing and geographic information system technology and then we compared the correlations between each vegetation index and the grassland plant cover,finally,we selected the best grassland plant cover estimation model to estimate the Youshanhe Farm in the past 30 years.The characteristics of the interannual grassland plant cover change were quantitatively analyzed and the correlation between grassland plant cover and meteorological factors in the research are explored.We also explained the trend of grassland plant cover change in the research are in the past 30 years.The correlation between the linear model and the quadratic polynomial model in the estimation model were higher than that of other models.The accuracy of the quadratic polynomial model of the vegetation index SAVI was 90.27%,it shows that the model is feasible.From 1993 to 2019,the grassland plant cover of Youshanhe Farm showed an upward trend with the largest increasing in 2006 and 2015.The grassland plant cover at monthly average temperature and water in the study are decreased gradually with the increase of human activities,and the correlation was not significant after the establishment of Youshanhe Farm.This study showed that human activities had a profound effect on the grassland plant cover of the Youshanhe Farm.The vegetation index SAVI was recommended to estimate the plant cover of artificial grazing grassland.