Backwater Zone Research Articles

Trace metals in a tropical river environment-distribution

Distribution of trace metals in the Periyar river has been investigated in detail. The fluvial concentrations of trace metals increase in river water and decrease in sediments during the summer months due to solubilization and concentration by evaporation. The levels, especially of Zn and Cd which are industrial pollutants increase by a factor of 10 both in water and sediments at the industrial zone. The concentration of Cd in the river water approaches the WHO standards for safe limits in drinking water. Solubilization at the backwater zone under high salinity is identified as one of the major mechanisms of trace metal transport to the marine environment. River meandering is responsible for large scale deposition of suspended solids at the industrial zone during the monsoon period. The trace metals exhibit build-up in specific concentration in the suspended solids in proportion to their residence time.

Simulation of Vegetation Response to Modified Hydrologic Regimes: A Probabilistic Model Based on Niche Differentiation in a Floodplain Forest

This study was initiated to develop a model for predicting the relative impacts of alternative reservoir designs on vegetation in the backwater zone. The result is a probabilistic model based on niche differentiation in the floodplain forest. Existing methodologies provided estimates of the flooding regime modifications produced by variable backwater conditions during reservoir operation. The model is exercised, with hydrolic modifications as input, to simulate shifts in species distribution. The model has been applied to evaluate the impact of a proposed reservoir on the vegetation of Robert Allerton Part, a 607 km2 natural area in east—central Illinois. Comparison of simulations for three alternative plans for the reservoir provides a basis for distinguishing among them, and suggests that the impact of one would be substantially less than the other two.