Trends of Sediment Loading in Catchment Areas of Pinang River in Malaysia

Abstract

This study aimed to investigate the trends of sediment loading in the Pinang River, a small microtidal tropical river system of 6.5 km length in Penang Island in Malaysia. It is classified as a primary coastal plain system and can be considered as a partial-mixed system whereby tidal influence extends up to the middle part of the river. This river has economic and strategic importance and serves as entrance for tourists to visit Penang National Park. Nevertheless, many anthropogenic activities occur along the river corridor, most of which have resulted in the deterioration of water quality. The purpose of this study was to provide a review on sedimentation loading in the river system. This study was carried out for 13 months during spring tide at both low and high tides, and wet and dry seasons to evaluate the pollution of sediment loadings by discharges from anthropogenic activities into the river. A total of 408 water samples were collected. High accumulation of sediments occurred, especially during low tide in the dry season with 428,816.2 kg/day (middle part) and 189,453.3 kg/day (lower part); these parts indicate the zone of sedimentation. The sediments were derived from soil erosion, effluent from aquaculture ponds during dry season as well as tidal mixing. These factors play an important role in deteriorating the river water transparency and cleanliness.