Remote Sensing Application Land Cover Change Detection

13 13 Hydrologic system is said to be a linear system if the relationship between storage, inflow, and outflow is such that it leads to a linear differential equation. The hydrologic response of such systems can be expressed in terms of an impulse response function through a so-called Convolution Equation. Linear systems possess the properties of additively and proportionality, which are implicit in the convolution equation Ramírez, 2000. The impulse response function of a linear system represents the response of the system to an instantaneous impulse of unit volume applied at the origin in time t=0. The response of continuous linear systems can be expressed, in the time domain, in terms of the impulse response function via the convolution integral as follows, = − , ℎ = 0 0 … … … … … … … … … … . 5 Where ut represents the instantaneous unit hydrograph, and Qt and Iet represent direct runoff and excess or effective precipitation, respectively. 14 14 This page intentionally left blank 15 15 III. METHODOLOGY

3.1 Study Area

The study area is situated in Palu catchment, Central Sulawesi Province. Geographically, it is located between 0 o 52’50” to 1 o 35’12” S and 119’45’24” to 120’10’50” E. Palu River is the main river that crosses the Palu City and ended in Palu Bay, study site is show in Figure 3.1. Palu catchment has unique topographic condition; where in the west and east sides are the mountainous area, while the north side is hilly and some parts in the southern side is coverage of National Reserve of Lore Lindu. Figure 3.1 Palu Catchment; located in Central Sulawesi.

3.1.1 Topography Condition

Palu catchment has unique of topographic characteristic. The elevation of Palu River Catchment is varying from 0 to 2500 meters above sea level. On the eastern and western side of Palu River Catchment are hilly areas. As well as the upstream area of Palu River is a mountainous region that is located in Lore Lindu National Park.