Limnological studies on river forested watersheds (Int. Proceeding)

The changes in water temperature is one of the important parameters in the aquatic systems. Meanwhile, the changes in land uses on upstream could help to identify the mechanism that generates the erosion and sedimentation rate at River Cisadane. The objective of this study is to identify the parameter characteristics of hydrological condition and clarify the landuse changes on upstream watershed that influenced the hydrological dynamics. River Cisadane is an important water resource for development activities of Jabodetabek area. An upstream region that had annual rainfall 3500-4000 mm as catchment areas, which play an important role as a source of clean water and irrigation water to downstream areas. Most of 4.1 – 6.4 persen population growth that followed by the necessity of clean water and settlement. Research was conducted at Cisadane upstream watershed, with cover 26.71 km2 area, included Karacak power plant that produced 3 x 5500 Kw for electricity. Based on two landuse maps from 1996 and 2006, produced a pattern of landuse change and land conversion from other landuses. From analysis, it could be explained that the land had the greatest conversion of forests, which experienced a reduction of almost 50 persen to gardens, fields, shrubs, and other settlements. The maximum and minimum discharge ratio’s tendencies indicate the improvement of watershed conditions even with the land conversion. In order to gain insight on water temperature fluctuations, water temperature data for two years were statistically analyzed using root mean square (Rms) and harmonic methods. Tthe average values of Ta and Tw at River Cisadane upstream were 25.0 ± 1.0 and 25.0 ± 0.7, respectively. In addition, monthly Rms 7-days of daily Ta and Tw changed nearly simultaneously. Next, the changes of water quality concentration and the proportions of flow paths could be analyzed with water temperature changes during rainfall events.Keywords: Cisadane upstream watershed, landuse, forest, water temperature, water quality Proceeding of the 2nd International Symposium on “Advanced Technology for River Management”, November 7 – 9, 2013, Seoul – South Korea.