Road Construction, Deforestation, and Land Use in Belize

Chomitz, K. M., & Gray, D. A. (1996). Roads, land use, and deforestation: a spatial model applied to Belize. The World Bank Economic Review, 10(3), 487-512. https://lms.southwestern.edu/file.php/5760/Literature/Chomitz-1996-Belize_deforestation.pdf

This article examines the relationship between distance from markets in Belize, road construction, and the likelihood of road construction and land use. The authors contend that while road construction has many economic and social benefits of connecting the rural poor to more urban centers, there are also great environmental drawbacks. This is largely seen through deforestation, loss of biodiversity, and climate change. According to Chomitz and Gray, Belize is facing rapid population growth. With this, there is an increase in slash and burn agriculture. As a result, the authors assert that the impact of building roads in these rural areas must be quantified in order to see the full tradeoff between economic development and environmental preservation (Chomitz and Gray 487)

In order to conduct this study, the authors used “spatially explicit framework” in order to show variation that is not present in aggregate data and location, such as the physical extent of deforestation and the effect on habitats and watersheds (Chomitz and Gray 488).  The authors developed a spatial model of land use following the ideas of von Thünen that assumed land use would occur where the output was greater then input  (490). A sample of land points south of the Western Highway in Belize was used, which yielded 11, 712 data points for the study. These points were collected via geographic information systems methods. SPOT satellite imagery from 1989 to 1992 was used to collect the data along with field data. Nine variables where used to analysis the data (nitrogen percentage, slope, available phosphorus, pH, wetness, flood hazard, rainfall, national land, and forest reserves). Additionally, the distance to the markets was computed by the cost of transport and the slope of the region. The land use was classified into three categories- semi-subsistence agriculture, commercial agriculture, and natural vegetation- to help analyze the results and create a dependent variable of type of land use (Chomitz and Gray 495).  

The study suggests that land quality, market distance, and tenure, strongly suggest type of cultivation, likelihood, as well as probability of road construction (Chomitz and Gray 501). For example, the study found that for every 0.1 percent increase in nitrogen, there was 24-33 percent decrease in distance to a market, suggesting that higher soil quality increases the likelihood of cultivation and thus road construction (Chomitz and Gray 500). This model also allowed the authors to study the type of agriculture that occurs in variation to distance from markets and road availability. For example, the study found that semi-subsistence and commercial agriculture decrease as one progresses away from markets (Chomitz and Gray 500). Due to these findings, the authors’ advocate for greater consideration to be taken by planners in terms of agriculture and road construction due the variety of variables involved as well as environmental and economic trade off. 

  

Caitlin Schneider