Determination of probability distributions for Strahler stream lengths based on Poisson process and DEM |
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Authors: | MING-SANG YANG KWAN TUN LEE |
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Institution: | Department of River and Harbor Engineering , National Taiwan Ocean University , Keelung, 202, Taiwan, ROC E-mail: ktlee@mail.ntou.edu.tw |
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Abstract: | Abstract One of the basic tasks in geomorphologic analysis is to know the probability distributions of the stream lengths of different orders. In practical applications, this information is useful for basin rainfall-runoff modelling. The objective of this study is to determine the length distributions of the Strahler streams. A Poisson process was used to derive the theoretical distributions. The result showed that the length distribution of the first-order stream is an exponential distribution and the second-order or higher order stream length is a gamma distribution. In order to verify the theoretical distributions, a digital elevation model (DEM) was adopted to calculate the stream lengths of four basins in Taiwan. Kolmogorov-Smirnov and chi-square tests were used to test the goodness-of-fit of the data. Results showed that the length distributions of the first- and second-order streams analysed by using DEM correspond with those from the derived distribution method. |
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Keywords: | geomorphologic analysis Strahler stream ordering stream length distribution Poisson process digital elevation model |
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