ISSN:
1752-1688
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
Notes:
The probabilities of wet- and dry-day sequences (wet and dry periods) of various lengths were determined for several intensities. Intensity (or threshold) refers to the daily amount of rainfall in the sequence, i.e., for the dry sequences each day has no rain or less than a given amount, whereas for the wet sequences, each day has an amount equal to or greater than a given amount.Dry- and wet-day sequences were studied from actual records of daily precipitation from 35 stations, most of which are east of Denver, for the purpose of describing their statistical distribution. The geometric distribution is shown to represent the variation in the length of wet-day sequences. It had previously been demonstrated that the cumulative distribution function provides a reasonable description of the frequencies of dry-day sequences up to at least 20 days. The results are identical to those derived from a simple Markov chain model. A relationship is presented which can be used with published data to obtain the one parameter required for the geometric distribution. The average relationship between this one parameter for both the wet and dry sequences is presented. Another illustration displays the relationship between the variability of annual rainfall and the total number of dry (or wet) sequences as a function of the annual number of precipitation days. In general, the larger the number of rain days, the less variability in the annual rainfall totals from year to year and the larger the number of dry (or wet) sequences. Examples are presented which show the probabilities of occurrence associated with recent dry periods in Minnesota and the Washington, D.C., area.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1752-1688.1970.tb00440.x
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