Soil erosion from hill tribe opium swiddens in the golden triangle, and the use of karren as an erosion yardstick.

Shifting cultivation by hilltribes and regular burning of the forests in opium-producing areas of the Golden Triangle is responsible for serious damage to the soil resources. The study of exposed karren forms that are assumed to have developed under subsurface rather than subaerial conditions has some promise as a means of documenting soil erosion, although serious problems remain to be resolved before reliable results can be achieved.