Deforestation Method

DEFORESTATION AND REGENERATION METHOD


(UNDER CONSTRUCTION)

BRIEF DESCRIPTION OF DEFORESTATION AND REGENERATION MODULE STEPS:

Forest and Non-Forest Natural Vegetation Suppression and Regeneration


1.  Fitting the land cover and land use maps to filter transitions with an area smaller than one hectare. Since maps in the initial series have more classification noise due to the reduced amount of the mosaic images, considering these years in these adjustments could generate accumulation of errors throughout the adjusted series.


Therefore, the adjustment begins in 2000 as the base year, in three steps:


  1. Adjustment considering transitions in consecutive years prior to 2000 (adjusts 1985 - 1999).
  2. Adjustment considering transitions in consecutive years after 2000 (until 2001 - 2017).
  3. Adjustment or map of the year 2000 based on the adjusted maps of 1999 and 2001.


2. Considering the 1988 map as the basis for the beginning of the algorithm execution, deforestation and regeneration events are established by analyzing the trajectory of each pixel according to the following criteria:


Suppression t =

VN t-2

VN t-1

A t

A t+1

 

 

Regeneration t =

A t-2

A t-1

VN t

VN t+1

VN t+2

VN t+3


Where:

  • VN corresponds to any vegetation class (grasslands, wetland, other non-forest natural formation, forest formation, savannah formation, mangrove);
  • A corresponds to any anthropogenic use class (Annual Agriculture, Semi-perennial Agriculture, Forest Plantation, Pasture, Mining, Aquaculture, Urban Infrastructure, Other Non-vegetated Areas);
  • et = 1988, ..., 2017.

3. Based on the trajectory analysis over the time series, the algorithm allocates each pixel in one of the classes established for the product (see color palette at end of document):


Class

Description 

Value

Primary vegetation

Indicates absence of Deforestation event: permanence since base year in one or more Natural Vegetation classes or transition to Anthropic Use class with permanence in this class for a shorter period than established (item 2.)

2

Primary Vegetation Suppression

Indicates Deforestation event, in a given year, in a previously allocated pixel in the Primary Vegetation class, after the pixel or pixel is allocated in the Anthropic Use class (at t + 1).

4

Regeneration  for Secondary Vegetation

Indicates Regeneration event at a given year t, after which the pixel is allocated to the Secondary Vegetation class (at t + 1).

5

Secondary Vegetation

Indicates trajectory with event of Regeneration for Secondary Vegetation in previous years.

3


Secondary Vegetation Suppression

Indicates Deforestation event, at a given year t, in a pixel previously allocated to the Secondary Vegetation class, after which the pixel is allocated to the Anthropic Use class (at t + 1).

6


Anthropic

Indicates permanence in any Anthropic Use class since base year or trajectory with Primary Vegetation Suppression event or Second Vegetation event in previous years.

1