Hydrology of tropical podzols in Kalimantan

Three Soil Profile of Tropical podzols in Kalimantan heve beenstudied in order to understand its role to hydrology the lowland of Ka­limantan. Tropical podzols widespread in Kalimantan on flat to gently sloping iowland. Morphology of the three observed profles show the different stages of soil development. However, permeability of B­ horizons of the three soils has reduced significantly. The reduction of soil permeability takes place as the consequences of the accumulation of aluminum/iron-organic complexes and clay minerals in B-horizon during Podzolisation. In developed podzols, both Bh and Bt horizons mag behave as impermeable layers. Whereas in juvenile podzols, as shoun by the profile of Kasongan, the role accumulated clay at Bt­ horizon is more important than that of organic complexes in Bt-horizon. Therefore water infiltration into this soils and beneath groundwater is very limited. The physical properties of the soils indicates that almost all af rainfall in the lowlands af Kalimantan is immediately trans­ forms into surface run-off, peat water or soil water. The physical prop­ erties of soils recommends that water resources management concept of podzols area and it surrounding require particular approachadapted to hydrological characteristics.