The Role of Rainfall and Erosion in Shaping Water Quality: A Case Study of TSS and TDS in Besut Campus Lake, Terengganu, Malaysia

Abstract

Erosion significantly influences water quality in lakes and rivers, primarily through the transportation of soil particles, organic matter, and pollutants, leading to changes in water quality indicators such as Total Suspended Solids (TSS) and Total Dissolved Solids (TDS). This study aimed to investigate the relationship between erosion, rainfall, and water quality in Besut Campus Lake, located in Terengganu, Malaysia, by monitoring two plots over three months. Data was collected on erosion rates, water quality (TSS, TDS), and meteorological conditions, including rainfall, and their correlation was analyzed using statistical methods. The results indicate that erosion varied between the plots, with observed trend fluctuated, especially in March and April. The Pearson correlation coefficient, r, between erosion and TSS in Plot A was very low at r = -0.1089, with a further low correlation in Plot B. Therefore, even though erosion is a factor contributing to TSS, plots being near the lake and direct runoff can be seen as the key determinants of TSS in this context suggesting that erosion is not the primary factor impacting water quality. During the inter-monsoon period, erosion rates peaked in March and early April, corresponding to increased rainfall, which totalled 20 mm. Notably, rainfall significantly influenced TDS levels, as evidenced by the strong correlation observed in Plot A. This highlights the critical role of precipitation in dissolving solids and facilitating their transport into water bodies. These findings provide valuable insights into the dynamics of erosion and water quality in tropical climates and suggest that rainfall, rather than erosion or wind, plays a more critical role in determining the TDS levels in the lake. Policy recommendations for mitigating the effects of erosion and improving water quality include installing vegetation cover and more frequent monitoring of meteorological factors.