[News] 26 days to over-topping the debries of Landslid
Monday, April 5, 2010
Update 10: 5th May 2010 at 18:30 UT
This is a summary of the current situation with the landslide. Data correct to 5th May 2010. Red indicates a rising trend from the previous reading and purple a falling trend. Orange numbers indicate no change. All data courtesy of Focus Humanitarian Assistance unless otherwise indicated. Please see notes of caution at the end of this post.
Current estimated date of overtopping: 1st June 2010. Overtopping is likely to occur sooner than this date.
Depth of lake (NDMA data) : 89.18 m (most recent update = 3rd May)
Depth of lake (Focus data): 90.24 m
Freeboard (Focus data): 20.10 m
Length of lake: 14.33 km (Note recent rapid increase)
Rate of inflow: 53.06 cubic metres per second
Total seepage (NDMA data): 0.99 cubic metres per second (3rd May)
Total seepage (Focus data): 1.42 cubic metres per second
Average rate of decrease of freeboard over the last ten days: 66.95 cm per day
Number of days to over-topping at current rate of freeboard loss: 26 days
Estimated date of over-topping based on rate of loss of freeboard for last ten days (see note below): 1st June 2010. Actual over-topping is likely to occur earlier than this date.
Important: The calculation of days to over-topping is subject to substantial uncertainty and must not be used for planning purposes. The rate at which the lake fills changes considerably with time according to variations in the rate of inflow, the rate of seepage, the rate of excavation of the channel, the shape of the valley etc. Under some circumstances, such as an earthquake, a landslide into the lake or rapid piping failure the dam could fail prior to overtopping. source