Spatial application of wetness index? 一→ Soil attribute data generally unavailable Therefore, assume t is uniform and equal to 1 Topographic wetness defined as an index TWI= As/ tan B ) Interpretation? Therefore factor out soil and therefore need only calculate two topographic characteristics: (1)Asf(USCA, plot width) (2) Slope angle(tanβ)• Spatial application of wetness index? Soil attribute data generally unavailable Therefore, assume T is uniform and equal to 1 Topographic wetness defined as an index: TWI = As / tan  } Interpretation? Therefore factor out soil and therefore need only calculate two topographic characteristics:- (1) As  f (USCA, plot width) (2) Slope angle (tan )