Evaluating longshore sediment transport rates by integration of beach evolution model and GIS approach

Abstract

A new integration approach of beach evolution model and Geographical Information System (GIS) is developed to evaluate the longshore sediment transport rates. Nanhui Beach of Shanghai is selected as study area to demonstrate an integration scheme. Study area is partitioned into some calculation units. It is further and modified one-line model to meet complex physical settings of the study area. Firstly, we got the 0-m isobaths, as the beach evolution indicator. It is developed by digitizing the nautical charts of 1990 and 2004. Shoreline change rates were derived from End Point Rate (EPR) method based on GIS. Bathymetry was digitized from the nautical charts to calculate the beach evolution complexity factor in the modified one-line model. The closure depth can be obtained from the published literatures about the study area. Longshore sediment transport rate of every calculation unit was calculated by inversion of the modified one-line model. Results show that integration scheme is effective and the precision is high. Total relative error is 8.77%.