THEME 3. LOSS OF WATERSHED FUNCTIONS

Papers on Watershed Functions

Historical Evidence for Watershed Degradation in Thailand: How Important is Agriculture and How Reliable is the Science?

by Timothy Forsyth¹

Keywords: watershed degradation, water shortages, Cesium-137 measurements of soil erosion, tree species, local knowledge, sociology of scientific knowledge, northern Thailand

Most land-use policies assume upland agriculture is degrading to watersheds without questioning the scientific basis for this assumption. In this paper I summarize the results of three research projects in northern Thailand that have conducted detailed empirical research of historic impacts of upland agriculture on water shortages, soil erosion and forests, and also questioned the sociological basis upon which scientific knowledge is constructed. The results suggest that much so-called watershed degradation is actually the result of long-term naturally occurring biophysical processes, and that upland communities may lessen degradation through conservation practices. The implications of these results are that upland agriculture is less degrading than commonly thought, and that researchers need to question more the social and political basis for scientific statements about degradation.

Footnote_______________

¹ Fellow in Environment and Development, Institute of Development Studies, Sussex, BN1 9RE, UK. Email: t.forsyth@ids.ac.uk