Modeling of runoff-producing rainfall hyetographs in Texas using L-moment statistics.

摘要

Temporal distributions of storm rainfall are known as hyetographs. Design hyetographs are important for cost-effective risk-mitigated rainfall-runoff modeling. The hyetographs considered are known to produce or generate runoff on small watersheds (typically about 50 square kilometers) in Texas. L-moment statistics and the nonparametric median are used to summarize the dimensionless representations of over 1,600 observed hyetograph distributions. A focus is made on storm depths in excess of about 25 mm and durations of 0–12, 12–24, and 24 hours and greater. Statistical distributions are fit to the L-moments of the dimensionless hyetographs including the newly described L-gamma. L-gamma hyetograph models are anticipated to be reliable predictors of expected hyetographs. Finally, a separate permeability-related L-moment application to the popular Carman-Kozeny equation is described.