کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10114117 1621384 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Global mapping of foliage clumping index using multi-angular satellite data
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات کامپیوتر در علوم زمین
پیش نمایش صفحه اول مقاله
Global mapping of foliage clumping index using multi-angular satellite data
چکیده انگلیسی
Global mapping of the vegetation clumping index is attempted for the first time using multi-angular POLDER 1 data based on a methodology that has been demonstrated to be applicable to Canada's landmass. The clumping index quantified the level of foliage grouping within distinct canopy structures, such as tree crowns, shrubs, and row crops, relative to a random distribution. Vegetation foliage clumping significantly alters its radiation environment and therefore affects vegetation growth as well as water and carbon cycles. The clumping index is useful in ecological and meteorological models because it provides new structural information in addition to the effective LAI retrieved from mono-angle remote sensing and allows accurate separation of sunlit and shaded leaves in the canopy. The relationship between an angular index (normalized difference between hotspot and darkspot) and the clumping index is explored using a geometrical optical model named “4-Scale”. A simplified version of the mechanistic hotspot model used in 4-Scale is developed to derive the hotspot reflectance from multi-angle measurements for mapping purposes. An accurate clumping map for areas with significant tree (shrub) covers has been achieved, although further research is required to reduce topographic effects.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Remote Sensing of Environment - Volume 97, Issue 4, 15 September 2005, Pages 447-457
نویسندگان
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