REMOTE SENSING DEFORESTATION

THE APPLICATIONS OF REMOTE SENSING

All geographical features - such as forests, oceans, crops, rivers, lakes, and buildings has its own spectral signature through electromagnetic radiation from the sun. The variation of reflectance is a function of the wavelength interaction with the environment. This reflected reading of the environment gets captured by satellites and the information is stored. The data that gets stored is later processed through software/applications which further turns into a map, graph, or chart.
Vegetation - such as the characteristics of forests - is a resource with many varieties, and different characteristics depending on the species (conifers vs deciduous, leaf type, stem, trunk, humidity, etc.) Healthy vegetation has a low reflectance value in the visible spectrum other than green due to the chlorophyll in the leaves. The reflectance value of forests are also very high in the near infrared due to low energy absorption by the leaves in this band. Dying vegetation has a decrease of reflectance value in the infrared, but has an increase in the red and blue light (visible). This is usually caused by the the amount of water it contains, due to the behavior of water with respect to radiation. Remote sensing deforestation can also be done with normal color as it is usually easy to distinguish the patterns of commonly used deforestation techniques.
Some of the most common satelites used to capture deforestation are Landsat 4 and 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Earth Observing-1 Advanced Land Imager (ALI), Satellite pour l'Observation de la Terre 4 and 5 (SPOT), and the Moderate Resolution Imaging Spectrometer (MODIS). Example of these satellite images are shown below.

Satellite images provided by NASA show the high landscape change between 1975 and 2007 on the Guatemala-Belize border. Source: UNEP, CATHALAC

The Amazon rainforest is shrinking at a rapid rate to provide land for farming and raising cattle. Each frame of the timelapse map is constructed from a year of Landsat satellite data, constituting an annual 1.7-terapixel snapshot of the Earth at 30-meter resolution. The Landsat program, managed by the USGS, has been acquiring images of the Earth's surface since 1972. Landsat provides critical scientific information about our changing planet.

The Amazon Rainforest

After decades of unsustainable logging, which depleted timber stocks and undermined the viability of traditional forestry management, Malaysia’s forests are increasingly being converted for industrial oil palm plantations. The palm oil industry is a powerful political force in the country.

Democratic Republic of Congo

Rondonia, Brazil

Bornea, Indonesia
MODIS

Rondonia, Brazil

Peru
Gold Mining

Google interactive deforestation map