Testing of evaporation reduction methods in humid climates

Many researchers have studied evaporation reduction of open water bodies using inexpensive locally available materials. However, such studies lacked information on the effects of the covers on water quality. This study focused on the assessment of the capability of floating and structural covers to reduce evaporation from open water bodies in a humid climate. Mengkuang mat and pieces of plywood were evaluated for the floating materials and the structural cover was galvanised iron corrugated sheets. The average evaporation reductions for a 1-year test period were 40%, 33% and 26% for the mengkuang mat, pieces of plywood and galvanised iron corrugated sheets respectively. Water quality analyses performed on the treatments showed that the covers have no serious effect on water quality. The results confirm the effectiveness of these covers for evaporation reduction with no harmful effects on water quality.