Things I’ve Worked On: An Assessment of Deforestation Based on Travel Times

This project uses GIS to assess deforestation based on travel times in the Peru Amazonian forest area (see Map 1). More than 90% of deforestation occurs in the 0 to 50 hour travel time area. Furthermore, the deforested areas exhibit a clustering pattern in low travel time areas. The results of this project provide a clearer understanding of the relationship between geography and opportunity in Peru, which is critical given the country’s current efforts to create sustainable regulation and plan for forestry development.

Introduction

In this study, we used GIS to evaluate deforestation patterns in Peru. Deforestation is of great interest and concern in the Amazonian region due to the slow forest succession rates of tropical forests as well as the importance of maintaining one of the most biologically diverse and rich areas in the world. Tropical forests play a significant role in ecological services. However, due to increasing demand for timber, space, and other resources in the Amazon, more and more trees have been cut down. In Peru, deforestation has increased from approximately 45,000 hectares cleared in 2004 to approximately 165,000 hectares cleared in 2012.  Illegal timber trafficking, which has also forced indigenous populations to migrate from their homelands, is one culprit, but slash-and-burn and other space-clearing activities, particularly for coca growing, have also driven Peru’s current deforestation. Forest concessions for Brazil nuts, which are inscribed in law, have also exacerbated the problem (Myers, N, 1994).

We believed that travel time estimations from city centers and settlements would be helpful in identifying which areas of forests are most likely to experience deforestation, given that cities serve both as sources for capital, including human capital, and as final markets. In particular, we surmised that areas temporally close and accessible to cities will experience significant attention, resulting in clustered deforestation. This is a problem because clustered deforestation, as opposed to well-distributed deforestation, presents increased risk of total loss for forests, which is particularly precarious in areas such as the Amazon, where biodiversity is invaluable and irreplaceable.

We first created a cost-distance grid based on roads, railways, rivers, land cover, and slopes. We then analyzed deforested areas in the year 2012, comparing these to the travel times that we calculated. From this study, we hoped to attain a better understanding of how policies need to be implemented spatially to encourage sustainable harvesting practices.

Map1: Research Area (Country boundary and amazon forest of Peru). Source: MODIS

Map 1

Map2: Input for travel time to markets in Peru. Source: GEM, MODIS, VMAP0

Map2

Map3: Travel time in Peru’s amazon forest with all settlements as markets. Source: GEM, MODIS, VMAP0

Map3

Map4: Travel time in Peru’s amazon forest with over 30,000 population cities as markets. Source: GEM, MODIS, VMAP0

Map4

Map5: Travel time in Peru’s amazon forest with over 75,000 population cities as markets. Source: GEM, MODIS, VMAP0

Map5

Map6: Travel time in Peru’s amazon forest with over 150,000 population cities as markets. Source: GEM, MODIS, VMAP0

Map6

Map7: Kernel density of deforestation areas in Peru Amazon Forest, 2012. Source: MODIS

Map7

Table1: Time Equivalent for Land Cover Types

Land Cover Type Speed Time per 1,000m Cell
Primary Roads 60km/hr 1
Railroads 30km/hr 2
Secondary Roads 30km/hr 2
Urban 30km/hr 2
Perennial/Permanent Rivers 20km/hr 3
Water Bodies 20km/hr 3
Grass/Shrubland 2.5km/hr 24
Open Forest 1.67km/hr 36
Permanent Snow/Ice 1.25km/hr 48
Closed Forest 1km/hr 60
Slope (factor applied to landcover) (EXP (-3 * Tan(0.0174532925* “slope”))

Table2: Relationship between deforested areas and travel time (all settlements)

All
Settlements
Total
Deforested Areas
Number of
Cells
Deforested Areas
per Square Km

Percentage of All Deforested Areas
0-25 Hours 26848 598239 0.0449 82.0764
25-50 Hours 5199 281308 0.0185 15.8937
50-75 Hours 606 60506 0.0100 1.8526
75-100 Hours 44 11582 0.0038 0.1345
100-125 Hours 10 4589 0.0022 0.0306
125-150 Hours 2 2287 0.0009 0.0061
150-177 Hours 2 736 0.0027 0.0061

Table3: Relationship between deforested areas and travel time (75,000 population city)

Cities Over
75,000
Total
Deforested Areas
Number of
Cells
Deforested Area
per Square Km

Percentage of All Deforested Areas
0-25 Hours 19065 397357 0.0480 58.2831
25-50 Hours 10471 303471 0.0345 32.0106
50-75 Hours 2822 177643 0.0159 8.6271
75-100 Hours 212 40957 0.0052 0.6481
100-125 Hours 82 19979 0.0041 0.2507
125-150 Hours 42 12668 0.0033 0.1284
150-175 Hours 16 6152 0.0026 0.0489
175-200 Hours 1 1020 0.0010 0.0031

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