Runoff from a semiarid Ponderosa pine hillslope in New Mexico

摘要: The mechanisms by which runoff is generated in semiarid forests have been little studied. Over the past 4 years we investigating processes regions continuously monitoring runoff, both surface and lateral subsurface, from an 870-m2 ponderosa pine hillslope northern New Mexico. We found that accounts for between 3 11% of annual water budget. also subsurface flow a major mechanism generation, especially following periods above-average fall winter precipitation. In one winter, was equivalent to about 20% snowpack (about 50 mm). When antecedent soil moisture high, extremely responsive snowmelt rainfall events much more dynamic than would be suggested low (laboratory determined) hydraulic conductivity soil. rapidity with follows these suggests macropore occurring. case generation are intense summer thunderstorms, prolonged frontal storms, over frozen soils. Surface at our site took form infiltration-excess overland flow; this type has not dominate other sites These detailed continuous investigations increasing understanding thereby laying groundwork improved predictions, only but concomitant transport sediment contaminants within zones.