Simulation of Forest Cover Map for 2025 and Beyond
using Remote Sensing and GIS
Krishna Pahari, Shunji Murai
Space Technology Applications and Research program
Asian Institute of Technology
Abstract
Forest is one of the most important natural resources of the world, vital for sustaining the global environment including the human life. However, deforestation due to increased needs of the human population has been an issue of major concern for global environment. This study is an attempt to make predictions for the future state of global forest cover by first developing a correction model linking population with the forest loss and then making the spatial forest loss projections for the future based on the UN medium variant long term population projections.
Introduction
Human impact on global land cover change, especially in terms of change from forest cover to other land cover, has been one of the important issue on global change research. In the primitive times when there was little human population and low level of economic activity, deforestation was not a problem because the natural regeneration of forest was adequate to cover for any loss of forest by the human beings. However, with the advent of modern civilization and industrialization and the increase in population, the forest loss to meet the ever growing needs of the human population became so huge that it posed a problem for the global environment. Considering that loss of global forest has already become a matter of serious concern, it is important to make predictions on the state of forests in the future when the population is expected to reach almost 8 billion in 2025 and 9.40 billion in 2025.
Correlation Model Between Population Density and Forest Loss
Various researchers have conducted studies trying to relate the deforestation with factors such as population, GNP, external trade, land ownership, etc. However, it has been found that population has been the single most driving force to global deforestation. Out of various analyses carried out to establish the relationship between population and deforestation, the authors found that the correlation between the logarithm of the population density and the total accumulated forest loss is the most significant, with the correlation factor ranging from 0.71 to 0.91 for various regions of the world.
The total accumulated forest loss has been defined as the percentage area of forest loss to the current level of human impact compared to the potential natural land cover without the human impact. The potential natural land cover is defined as the land cover that potentially exists under given climatic conditions without the human impacts. Figure 1 shows the potential land cover based on climatic data, and Figure 2 shows the current land cover map for 1990, based on dynamic of NOAA GVI data (based on Murai and Honda, 1991). Figure 3
shows the correlation plots of logarithm of population density and total forest loss for different regions and Table 1 gives the summary of such correlation.
Figure 1: Potential natural land cover map developed from climatic data
Figure 2: Current land cover map for 1990 from NOAA GVI data (based on Murai and Honda, 1991)
Figure 3: Correlation diagram between population density (logarithmic) and cumulative forest loss
Table 1: correlation on population density and total cumulative forest loss for different regions
| Region |
Correlation function |
R |
| Tropical Asia |
16.042In(x)-19.56 |
0.799 |
| Tropical Africa |
15.206 In(x)+7.8446 |
0.847 |
| Tropical South America |
17.607 In(x)-7.1178 |
0.813 |
| Sahelian Africa |
16.872 In(x)+12.305 |
0.799 |
| Central Africa |
21.063 In(x)-29.643 |
0.908 |
| Europe |
14.712 In(x)+0.9315 |
0.718 |
