Integrating Satellite Imagery and Meteorological Data for Typhoon Rainfall Estimation Using ANNs

• Main Authors: Huei-Yin Hsu, 許惠茵
• Other Authors: Li-Chiu Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/81495429796740059902

碩士 === 淡江大學 === 水資源及環境工程學系碩士班 === 98 === The main purpose of this study is to explore the influence of satellite imagery and meteorological data on typhoon rainfall forecast using artificial neural networks. The self-organizing map (SOM) is adept at recognizing infrared and visible images and can extract some useful information. In this study, six watershed rainfall estimation models are constructed to forecast the amount of rainfall for one, three and six-hour totals during typhoon events. The models are based on SOM, back-propagation neural network (BPNN) or linear regression to investigate the characteristics of satellite imagery information and its influence on rainfall forecast. Twenty-seven typhoon events are collected from 2000 to 2007. The available data are GMS-5/MTSAT remotely sensed data, hourly rainfall data of sixteen rainfall gauge stations of the Shihmen watershed, wind velocity and atmospheric pressure data of three meteorological observation stations. In order to investigate the characteristics and compare the performance among the different models, we design different cases for forecasting the rainfall totals in the daytime and the whole day. Six different models, multivariate linear regression model (MLR), back-propagation neural network (BP), self-organizing map linking with BP (SOMBP), self-organizing map linking with linear regression (SOMMLR), SOMBP linking with BP (SOMBPI+BP) and SOMMLR linking with BP linear regression (SOMMLRI+BP), are constructed to forecast rainfall totals. Seven different combinations of the inputs are used to investigate the effect of rainfall forecast. The results show that (1) the MLR and BP models have nice performances when the input variable only include the past rainfall totals of gauge stations, (2) SOM indeed has the ability to extract patterns from satellite data, (3) SOM can improve results when the rainfall totals are joined, (4) the wind velocity and atmospheric pressure data are helpless for rainfall forecast. The satellite imagery information is indeed helpful to improve the accurate of rainfall forecast.