Spatial Model of Deforestation in Sumatra Islands Using Typological Approach
Abstrac: tHigh rate of
deforestation occurred in Sumatra Islands had been allegedly triggered by
various factors. This study examined how the deforestation pattern was related
to the typology of the area, as well as how the deforestation is being affected
by many factors such as physical, biological, and socio-economic of the local
community. The objective of this study was to formulate a spatial model of
deforestation based on triggering factors within each typology in Sumatra
Islands. The typology classes were
developed on the basis of socio-economic factors using the
standardized-euclidean distance measure and the memberships of each cluster was
determined using the furthest neighbor method. The logistic regression method was
used for modeling and estimating the spatial distribution of deforestation. Two
deforestation typologies were distinguished in this study, namely typology 1
(regencies/cities with low deforestation rate) and typology 2 (regencies/cities
with high deforestation rate). The study found that growth rate of farm
households could be used to assign each regencies or cities in Sumatra Islands
into their corresponding typology. The resulted spatial model of deforestation
from logistic regression analysis were logit (deforestation) = 1.355 +
(0.012*total of farm households) – (0.08*elevation) – (0.019*distance from
road) for typology 1 and logit (deforestation) = 1.714 + (0.007*total of farm
households) – (0.021*slope) – (0.051*elevation) – (0.038* distance from road) +
(0.039* distance from river) for typology 2, respectively. The accuracy test of
deforestation model in 2000–2006 showed overall accuracy of 68.52% (typology 1) and 74.49% (typology 2),
while model of deforestation in 2006–2012 showed overall accuracy of 65.37%
(typology 1) and 72.24% (typology 2), respectively.
Keywords: deforestation model,
logistic regression, typology, Sumatra Islands
Author: Nurdin Sulistiyono, I
Nengah Surati Jaya, Lilik Budi Prasetyo, Tatang Tiryana
Journal Code: jpkehutanangg150014