Topography effects on small-scale precipitation variability in the Swiss pre-Alps

Long-term precipitation and snow-cover measurements were carried out to est imate the areal pattern of precipitation in a small, rugged Swiss pre-Alpin e basin. The dense networks used consisted of 34 storage gauges and 32 pit gauges with orifice parallel with slope, the latter being corrected for wet ting losses. Consequently, the corrected data was very near to the "true" p recipitation at a particular point. In the winter season also snow-cover ch aracteristics were measured at 11 locations. Altitude turned out to be the best overall predictor for corrected data (R-2 = 0.67) and longitude for un corrected data (R-2 = 0.67 vs only 0.58 for altitude!). The combination of altitude, longitude and latitude explains almost 75% of the spatial varianc e of summer season precipitation and snow-cover characteristics. However, t he three variables used in the analysis were found to be interrelated, part icularly in networks of storage gauges and snow-cover measurements (R-2 = 0 .40-0.70).