Evaluating MODIS-vegetation continuous field products to assess tree cover change and forest fragmentation in India – A multi-scale satellite remote sensing approach
用MODIS-VCF数据评估印度地区森林覆盖率的改变和森林破碎化-根据多卫星系统的遥感方法
Abstract
Monitoring the changes in forest-cover and understanding the dynamics of the forest is becoming increasingly important for the sustainable management of forest ecosystems. This paper uses temporal MODIS Vegetation Continuous Field (MODIS-VCF) to monitor the tree cover change in the Indian region over a period of 6 years (2000–2005). Pixel-based linear regression model is developed to identify rate of deforestation and fragmentation at landscape level. The regression parameters viz., slope, offset and variance are used to identify threshold between forest and non-forest classes. The classification algorithm resulted into change area, no change area, positive change and negative changes. MODIS-VCF raw product of 2005 was validated using the field data and showed a coefficient of determination (R 2 = 0.85) between percent tree cover and individual plot wise canopy cover information. The results were overlaid with UNEP protected area boundary. On a long-term basis, the forest cover change was monitored using medium spatial resolution (Landsat and IRS) satellite data to identify the rate of deforestation and fragmentation at landscape level. The developed approach is efficient and effective for regional monitoring of forest cover change. It could be automated for regular usage and monitoring.
监测森林覆盖率的改变并理解森林的动态变化对于对森林生态系统的可持续管理已经变的越来越重要。本文使用时态的MODIS-VCF数据监测印度地区6年间的树木覆盖率的改变。发展基于像元的线性回归模型去识别森林采伐的强度和景观水平的破碎化。回归方程的参数包括斜率、截距和方差系数被用来识别森林和非森林。分类的算法产生了，改变的区域，未改变的区域，好的改变和不好的改变。使用使用场数据验证2005年的MODIS-VCF数据并且显示森林覆盖百分比和个别的覆盖区域之间的相关系数R2=0.85。这个结果被UNEP保护区的边界覆盖。在一个长期的监测中，使用中等分辨率卫星数据监测森林覆盖率的改变，识别森林采伐率和景观水平上的破碎化，这个方法的发展对于森林覆盖率改变的区域监测是有效的。可以自动的进行规律的使用和监测。
Introduction
Mapping and monitoring of forest cover provides important inputs to the modelling of biogeochemical cycles, quantifying woody biomass and gives feedback on climate change. Additionally forest cover mapping has gained importance in the policy criteria (Rosenqvist et al., 2003) as these are directly linked to carbon storage and stocks. The information is also useful for a wide range of global environmental monitoring applications, including bioresource utilisation, allocation, distribution and assessment (Townshend et al., 1994; Sellers et al., 1997; Hansen et al., 2002).
介绍
监测并绘制森林覆盖率是重要的参考对于生物化学循环模型的建立，木质生物质的量化和气候改变的反馈。 此外，绘制森林覆盖对于政策条件的制定是重要的，因为它直接关系到碳的存储。森林覆盖也被用来监测大范围的全球环境，包括生物资源的利用、分配、分布和评价。
