Dissertation
by Ruminta
Promotor : Bayong Tj H K
Co-Promotor : The Houw Liong
Co-Promotor : Indratmo Soekarno
Abstract
A study on characteristics, mechanisms, and temporal models of the hydrometeorology was carried out in the Upper and Middle Citarum River Basin, West Java. The investigations based on monthly observations data of the rainfall, evapotranspiration, humidity, and river discharge from January 1968 to December 2000 and monthly data of global phenomena from reanalysis National Centers for Environmental Prediction (NCEP) and National Geophysical Data Center (NGDC). Identification of hydrometeorolgical components characteristics was based on statistics analysis i.e., cumulative sum (CUSUM), variability, correlation dimension, empirical probability, return periods, power spectrum, long-term trends, and sensitivity. While identification of the temporal dynamical model of the hydrometeorology based on Adaptive Neuro-Fuzzy Inference System (ANFIS) analyses. The results indicated that rainfall had two firm persistence i.e. wet and dry periods. The rainfall and river discharge have very high variability i.e., 73% and 62%, respectively. These data indicated that the processes of the rainfall and river discharge were very chaotic. Variability patterns of the rainfall and river discharge had increasing trends, the facts indicated that drought and flood events can to be extreme. The hydrometeorological processes in the Citarum river basin was low-dimension chaotic (correlation dimension, .<4). The .-values of the rainfall, evapotranspiration, humidity, and river discharge are 1.83, 1.68, 1.23, and 2.05 respectively that showed a minimum numbers of the main variables in the dynamic model of the hidrometeorological processes are 2, 2, 2, and 3 respectively. The rainfall and river discharge are chaotic mono-fractal (qD<2) that showed deterministic processes but the evapotranspiration and humidity are chaotic multi-fractal (qD>2) that showed stochastic processes. The extreme values of the rainfall and river discharge had return periods i.e., 5 and 25 months respectively. The rainfall and river discharge had the same three main cyclic there are 5-7, 9-25, and 100-125 monthly. The facts indicated that rainfall and river discharge had controlled by monsoon, quasi biennial, and sunspot oscillations. The hydrometeorological processes in the Citarum river basin was the results of the unbounded cascade processes because that had the value of exponent spectrum (B) less than one. The rainfall and river discharge had been decreased by about 3.64% and 1.11% respectively for every a hundred months. The decreasing trend in the rainfall and river discharge had controlled mainly by the decreasing of the clouds and convection rains formation as a consequence of the deforestation and global climate variability. The evapotranspiration and air humidity had been increased by about 3.88% and 4.21% respectively for every a hundred months. The increasing trend in the evapotranspiration and air humidity had been influenced by the increasing of the water vapour removal from vegetation lands surface to the atmosphere by both evaporation and transpiration. The river discharge is very sensitively against the rainfall's fluctuation, especially in June-July-August periods. Water storages had been decreased and coefficient of runoff had been increased, that facts indicated that reservoirs while land cover by vegetation had been decreased so that drought and flood events can to be extreme. The rainfall and river discharge in the Upper and Middle Citarum River Basin were influenced by global phenomena, especially Global Temperature, Indian Oceans Dipole Mode, Southern Oscillation, Indian Monsoon, and Precipitable Water. The temporal dynamical model of the hydrometeorology based on ANFIS can simulate the observations data accurately. The model is capable to minimize the bias and root mean squared error (RMSE) values and maximize the precision (E) value. Annually temporal models can predict more accurately rainfall and river discharge than theses of the monthly temporal models. The hydro-meteorological temporal model results of the ANFIS indentification very potential used to predict the rainfall and run off. The results of study on characteristics, mechanisms, and temporal models of the hydrometeorology can give an information for improvement of an integrated water management in the Citarum River Basin.
Copyrights : Copyright Â(c) 2001 by ITB Central Library. Verbatim copying and distribution of this entire article is permitted by author in any medium, provided this notice is preserved.
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