Submitted to: Applied Climatology
Publication Type: Abstract Only
Publication Acceptance Date: May 8, 2000
Publication Date: May 8, 2000
Technical Abstract: Precipitation varies from one point to another within a region. Assessing and quantifying the properties of spatial variability is necessary to interpret the reliability of regional climate forecasts for applications at the farm-level. In this study the spatial variability at the "climate division" and "super climate division" scales are analyzed. The analysis is sconducted for four climate divisions and one super climate division in Oklahoma. The time steps for the precipitation values are monthly, seasonal (3-months) and annual. For a single climate division the spatial variability at the monthly time scale was found to range from 20 to 29% of the mean monthly precipitation, depending on the month of the year; at the seasonal scale it ranges from 13 to 17% of the mean seasonal precipitation, depending on the season; and at the annual scale it was 8% of the mean annual precipitation. This demonstrates the decrease in the spatial variability of precipitation with increasing time scale. On the other hand if the spatial variability is related to the mean temporal variation of precipitation, the spatial variability is of the same order of magnitude (about 35%) for the monthly, seasonal and annual time scales. At the climate division scale the spatial variability is around 35% of the mean temporal variation of precipitation, whereas at the super climate division scale the spatial variability is 47% of the mean temporal variation. This significant spatial variability within a region leads to large localized departures from the average regional values.