This work presents the formulation of the pickup probability for sediment entrainment under the log-normally distributed instantaneous velocity. Herein two mathematical approaches, namely the analytical method and the first-order approximation method, are employed in the theoretical derivation. The results are compared with the published experimental data and the previous pickup probability der...

Based on the subdistrict (jie-dao) data from 1982 and 1990 national population censuses, this research employs two approaches to investigate the urban population change patterns in Shenyang, China. The density function approach examines what function best characterizes its density distribution, how the density pattern has changed over time, how many centers can be identified in the city, and ho...

Four phases of interest in the distribution of city sizes are identified and current conflict in the literature is shown to be a consequence of poorly-selected units of observation. When urban regions are properly defined, US urban growth obeys Gibrat’s Law and the city size distribution is strictly Zipfian rank-size with coefficient q = 1.0. Care has to be taken with definition of the largest ...