Research Guidelines to Sound Watershed Development

Watershed research studies may be (1) experimental, chosen and instrumented for study of hydrologic phenomena, or (2) representative, selected to represent a larger area. Research emphasis has been on the latter. Since 1935, hundreds of watersheds have been studied; many proved unproductive or obsolete, and were discontinued. The major reason for project failures is relatively crude experiments in which general understanding essential to detect effects of induced changes in land-use practices is lacking. Most successful studies are related to land-use or structure-effects on sedimentation. Less success has accompanied measuring effect of land-use or management practices on water yield. Determination of downstream effects from upstream land-use or structural measures have been generally unsuccessful. Costliness and lengthy duration account for some discouraging results. Many factors accounting for difficulties in applying results to other areas lie below ground surface. Sound guidelines for the future include: Geology and soils should be as uniform as possible; a single land-use or management practice should prevail; and complete physical makeup and entire water movement should be thoroughly understood and instrumented.