Response of Partially Covered Road Embankments and its Environmental Impact

Abstract

Tropical regions have always suffered soil loss by water which deteriorates the surrounding environment in several ways. This paper focuses on one of an issue that under the tropical rainfall event how the newly constructed bare highway affects the water turbidity and total suspended solids in a water channel. The study was based on a pilot scale field test which was constructed in compliance with the real field conditions. The study was limited to the tropical rainfall event of 40 mm/hr, native grass cover, sandy loam, and for the road side slope of 1V:1.5H (~ 30°). To determine the turbidity and total suspended solids (TSS), three plots were observed with the different percentage of covers namely, no cover (plot A-control plot), 50% of the grass covered surface (plot B), and 30% of the grass covered surface (plot C). The purpose of the study was to observe the influence of these three plots on the dependent variables that is turbidity and TSS. The study summarizes that the presence of cover is adequate enough to cope with this issue to an extent. The results obtained showed that the bare soil surface performed worst under the rainfall intensity of 40 mm/hr for both the dependent variables. The maximum turbidity values observed from plot B and plot C were 30% and 90.25% respectively of the maximum turbidity value obtained from plot A. Similarly, the maximum TSS values observed from plot B and plot C were 35.21% and 63.76% respectively of the maximum TSS value observed from plot A.