Transboundary Environmental Effects of Hydropower: Water Temperature

Abstract

Downstream effects of the Lancang cascade of hydropower projects on water temperature were investigated through temperature data comparisons and modeling. Similar to the approach for hydrology (Chap. 4), comparisons of water temperature were conducted in part by comparing water temperature between baseline (historical) and post-project periods. Other comparisons were also made, such as comparing post-project water temperature upstream and downstream of a hydropower project and comparing temperature gradients within different river segments and during different time periods. Modeling of actual and virtual development scenarios, in which the effect of a hydropower project could be included or removed, was also used to investigate the consequences of the presence of a particular hydropower project on water temperature. Water temperature data were compiled from existing hydrological stations along the Lancang-Mekong River Basin (MRC data) and additional data collected from gauges installed specifically for the study.