GIS and Remote Sensing in Hydrology, Water Resources and Environment (Proceedings of ICGRHWE held at the Three Gorges Dam, China, September 2003). IAHS Publ. 289, 2004, 308-315

Abstract High erosivity induced by high rainfall volume and high intensity in the tropical climate of Malaysia has rendered soil being easily eroded during rainfall. With an annual rainfall depth of more than 2000 mm, rainfall intensities exceeding 100 mm in 24 h regularly occur. Stream suspended solid concentrations immediately after a high intensity storm often exceed 5000 mg l^-1, with high variations over space and time. Soil loss and sediment yield in virgin forest is usually low. However, logging activities with high intensity of roads and skid trails drastically changes the fundamental characteristics of the forest floor with regard to sediment generation, storage and transport causing soil loss and sediment yield to increase by an order of magnitude or more. This paper presents a review of data on sediment yield and stream suspended solid concentration due to logging in Malaysia to assess the potential impact of logging on water quality in the Ulu Muda forest. Some soil loss simulation results are presented to highlight the potential risk posed by logging within water catchment areas.

Key words logging; Malaysia; sediment yield; soil loss simulation