Comparison of Geostatistical Procedures for Spatial Analysis of Precipitation in Mountainous Terrain

摘要

Application of simulation models to assessment of global climate change effects often requires spatially distributed estimates of precipitation, both under current and future climate scenarios. Simple interpolation methods fail to consider the effects of topography on precipitation and may be in considerable error in mountainous regions. The performance of three geostatistical methods for making mean annual precipitation estimates on a regular grid of points in mountainous terrain was evaluated. The methods were (1) kriging, (2) kriging elevation-detrended data, and (3) cokriging with elevation as an auxiliary variable. The study area was the Willamette River Basin, a 2.9 million hectare region spanning the area between the Coast Range and the Cascade Range in western Oregon.