Impacts of Rapid Urban Growth on Farmland Conversion: Application of New Regional Land Use Policy Models and Geographical Information Systems1

Geographical Information Systems (GIS) computer mapping programs and new land use policy models are shown to be useful in understanding the dynamics of rural land conversion to urban uses. The California Central Valley Alternative Futures Model was constructed to evaluate patterns of growth that are forecasted to triple the population of the California Central Valley by 2040. The GIS sub-divided the Valley into over 750,000 land units, and a logit analysis evaluated factors leading to actual patterns of recent growth. Undeveloped land units were assigned a probability of future development, and expected population increases were allocated to those land units with the highest probability of future growth under two growth scenarios: low density and compact growth. The model shows that low density growth would convert over 1,035,000 acres of farmland to urban uses, including over 600,000 acres of prime or statewide important quality land. Compact growth would convert only 474,000 acres total, of which only 266,000 would be on prime soils. This paper shows how new land use models and GIS programs enable rural sociologists to better understand how rural communities and their spatial environment interact—in particular, how these tools enable researchers to explore the forces and consequences of rural and exurban growth.