Bionatura,Vol. 9, No. 1, March 2007
TREND OF HYDROMETEOROLOGY IN THE CITARUM RIVER BASIN
Ruminta, Bayong Tjasyono, The Houw Liong, dan Indratmo Soekarno
A study on trends of the hydrometeorology had been carried out in the Upper Citarum River Basin, West Java. The investigations based on monthly observations data of the rainfall, evapotranspiration, humidity, and runoff from January 1968 to December 2000. The results indicated that odds ratio of the rainfall, evapotranspiration, humidity, and runoff are -3.64, 3.88, 4.21, and -1.11 respectively. The rainfall and runoff had been decreased by about -3.64% and -1.11% respectively. The decreasing trend in the rainfall and runoff had controlled mainly by the decreasing of the clouds and rains formation as a consequence of the global climate change. On the other hand, the evapotranspiration and air humidity had been increased by about 3.88% and 4.21% respectively. The increasing trend in the evapotranspiration and air humidity had influenced by the increasing of the water vapour removal from vegetation lands surface to the atmosphere by both evaporation and transpiration.