Abstract

Water temperature is one of the important parameters in the aquatic systems, and it remains an interesting subject of world-wide environmental research. The objective of this study is to identify the parameters of hydrological, meteorological and topological that influence water temperature and its change at pond Cibuntu based on data from April 2008 to April 2009. In addition, the analysis of changes in water temperature during rainfall events could lead to the identification of the mechanisms that generates the initial response as direct inputs of rainwater. In order to gain an insight on water temperature fluctuations, the results of water temperature measurement for one year were statistically analyzed using root mean square (Rms) and harmonic methods. From our analysis, the highest temperatures of air (Ta) and water (Tw) were of 30.6 and 30.9°C, respectively. On the contrary, the lowest of those were 21.1 and 23.0°C, respectively. In addition, the highest values of Rms 7-days for Ta and Tw in September were 1.51 and 1.57, respectively. Based on hourly Tw changes during rainfall events, it seemed that subsurface flow influenced water temperature changes. In addition, the management of pond influenced the flow paths differently through the changes of infiltration rate, surface runoff, interflow/subsurface flow and groundwater percentage.

Key words: Water temperature, air temperature, root mean square, harmonic method, rainfall event