Hazard assessment and outburst flood estimation of naturally dammed lakes in Central Asia

Více o knize

The studies on naturally dammed lakes in Central Asia focused on key locations in the Russian Altai Mountains and mountain ranges in Kazakhstan and Uzbekistan, alongside inventories of potentially hazardous lakes. Hazard assessments of potential outburst flood magnitudes were conducted and shared with local authorities. Year-round water level observations, dam conditions, and percolating water analyses, including electric conductivity and temperature measurements, were performed. Indicators of instability, such as incised channels downstream of springs and over-steepened dam slopes, were identified. Geo-electric surveys confirmed previous estimates of permafrost distribution within several dams. The inventories utilized new data from remote sensing and literature compilations, as well as personal observations. Initial assessments of dam stability led to the identification of hazardous lakes for further study. Modeling approaches for estimating flood magnitudes were constrained by natural dam and lake parameters, prompting the development of a new method based on normalized hydrograph patterns. While outburst floods pose minimal risk to settlements, local infrastructure like bridges and roads is at risk. Mudflows resulting from these floods should also be considered in risk assessments. Engineering solutions like artificial spillway cutting were found counterproductive, as they expose permafrost, risking dam collapse. Additiona