How Effective Is Spatial Planning for Cropland Protection? An Assessment Based on Land-Use Scenarios

Spatial planning plays an important role in cropland protection, but its effectiveness is often questioned in the face of ongoing urban and infrastructure growth. Moreover, methods to assess the effectiveness of spatial planning are lacking. In Switzerland, the revision of the national spatial planning act in 2014 was a new starting point for stricter prescriptions on urban development. We assessed whether the new regulations would better protect dedicated prime cropland from conversion to urban areas using land-use suitability models and land-use scenarios. The findings show that with the planning according to the revised planning act, the potential consumption of prime cropland for new urban areas is six times smaller than that occurring through extrapolation of the observed trend in urban development over the past 25 years. However, scenario modeling suggests that, still, more prime cropland will be converted into urban areas than necessary, and that it may be difficult to protect prime cropland to the extent mandated by the Swiss prime cropland protection policy. We have developed an approach to a priori evaluate spatial planning measures. However, the strict implementation of these planning measures will be needed in order to maintain prime cropland to a level required for agricultural self-sufficiency and food security.