A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...
22.08.2015 • Views
Share Embed Flag

A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

SHOW MORE
SHOW LESS
ePAPER READ
DOWNLOAD ePAPER
  • No tags were found...
iag.usp.br

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

START NOW

Detecting deforested areas from NDVI series in <strong>Amazon</strong>ia 1982-1999N. Dessay, H. Laurent, L. Machado, J. Ronchail, Y. ShimabukuroCTA /IAE/ ACACentro Técnico Aeroespacial /Instituto de Aeronáutica e Espaço/ Divisão de CiênciasAtmosféricas CEP 12228-904, São José dos Campos, SP, Brasil.andInstitut de Recherche pour le développement/Labor<strong>at</strong>oire d'Etude des Transferts enHydrologie et Environnement, Grenoble, Francendessay@iae.cta.br, hlaurent@iae.cta.br, machado@iae.cta.br,josyane@aneel.gov.br, yosio@ltid.inpe.brThe aim of this work is to localize forest areas th<strong>at</strong> evolved toward a deforest<strong>at</strong>ion or areforest<strong>at</strong>ion using <strong>the</strong> Normalized Difference Veget<strong>at</strong>ion Index (NDVI). We shall pay special<strong>at</strong>tention to 9 areas chosen among <strong>the</strong> LBA study areas. When <strong>the</strong> forest undergoes <strong>at</strong>ransform<strong>at</strong>ion such as deforest<strong>at</strong>ion, <strong>the</strong> NDVI presents a very sharp minimum during <strong>the</strong> dryseason, th<strong>at</strong> we shall use in this work. Firstly, we use <strong>the</strong> areas th<strong>at</strong> have remained steadyduring 18 years as a reference to calibr<strong>at</strong>e <strong>the</strong> NDVI d<strong>at</strong>aset over this period. Secondly, <strong>the</strong>regions of rain forest are geographically distinct because <strong>the</strong> dry season is not <strong>the</strong> same fromone region to <strong>the</strong> o<strong>the</strong>r. To take this into account, we define homogeneous areas using <strong>the</strong>IBGE (Instituto Brasileiro de Geografia e Est<strong>at</strong>ística) veget<strong>at</strong>ion classific<strong>at</strong>ion, <strong>the</strong>precipit<strong>at</strong>ion series th<strong>at</strong> are provided by <strong>the</strong> Agência Nacional de Energia Eléctrica (ANEEL)and <strong>the</strong> Instituto Nacional de Meteorologia (INMET) and <strong>the</strong> high level cloud cover availablefrom <strong>the</strong> Intern<strong>at</strong>ional S<strong>at</strong>ellite Cloud Clim<strong>at</strong>ology Project (ISCCP). Then we define referencedry season NDVI by averaging <strong>the</strong> NDVI minimum in different areas th<strong>at</strong> are known as nothaving suffered deforest<strong>at</strong>ion. Afterwards, we compare <strong>the</strong> d<strong>at</strong>e and amplitude of <strong>the</strong> NDVIminimum for 9 LBA target areas <strong>with</strong> th<strong>at</strong> of <strong>the</strong> nearest reference area. We observe in somecases large differences th<strong>at</strong> permit to analyze <strong>the</strong> deforest<strong>at</strong>ion or <strong>the</strong> reforest<strong>at</strong>ion. Thisapproach gives both a sp<strong>at</strong>ial and a temporal vision of <strong>the</strong> evolution of <strong>the</strong> forest.

logo

products

Resources

Company

Terms of service
Privacy policy
Cookie policy
Cookie settings
Imprint
Change language
Made with love in Switzerland
© 2024 Yumpu.com all rights reserved

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!