Statistical, remote sensing-based approach for estimating the probability of catastrophic drainage from moraine-dammed lakes in southwestern British Columbia

An approach for estimating the breach probabilities of moraine-dammed lakes in the Chinese Himalayas using remote-sensing data

“…Numerous researchers arbitrarily categorized probabilities, particularly for display purposes (e.g. Dai and Lee, 2003;McKillop and Clague, 2007b). A curve showing the cumulative percentage of drained lakes versus probability provides a more objective basis for defining probability thresholds (Fig.…”

“…A curve showing the cumulative percentage of drained lakes versus probability provides a more objective basis for defining probability thresholds (Fig. 3), and the probability thresholds of 0.24, 0.18, 0.12 and 0.06 were set to prioritize the morainedammed breaching probabilities as very high, high, medium, low and very low, respectively, in British Columbia (McKillop and Clague, 2007b). Model results indicate that the breach probabilities of the 142 PDGLs in the Chinese Himalayas ranged 0.037-0.345, and it seems that the thresholds of 0.24, 0.18, 0.12 and 0.06 can reasonably categorize the hazards from very high to very low.…”

“…MDLOFs endanger lives and property as well as the natural and social environment and have thus drawn much attention. Studies on MDLOFs have evaluated and simulated past MDLOF events (Lliboutry et al, 1977;Xu, 1988;Cenderelli and Wohl, 2003;Kershaw et al, 2005), modeled the magnitude and spatial extent of possible MDLOFs (Costa and Schuster, 1988;Clague and Evans, 2000;Huggel et al, 2002Huggel et al, , 2004Carrivick, 2006;Bajracharya et al, 2007;McKillop and Clague, 2007a;Wang et al, 2008), assessed the vulnerability of high mountain areas to the hazards of moraine-dammed lake outbursts (Carey, 2005;Vilímek et al, 2005;Hegglin and Huggel, 2008), estimated the breach probability of a moraine-dammed lake (McKillop and Clague, 2007b), and analyzed the mechanisms of a dam breach (Clague and Evans, 2000;Jiang et al, 2004;Rushmer, 2007;Balmforth et al, 2008Balmforth et al, , 2009Awal et al, 2010). With widespread glacier retreat on the one hand and the growing population living close to high mountains on the other, there are more potentially dangerous morainedammed lakes (PDMDLs) appearing in glaciated regions (Clague and Evans, 2000;Richardson and Reynolds, 2000;Bajracharya and Mool, 2009).…”

“…Aerial 106 photographs were the original source data of topographic maps and were mainly used to 107 Table 2 and the identification numbers are those used in the table). (B) Expansion of two field-surveyed PDMDLs, Longbasaba and Pida Lakes, based on aerial photographs (1978), Landsat TM data (1989, 2000 Evans, 2000; Richardson and Reynolds, 2000;Huggel et al, 2004;McKillop and Clague, 2007b) and the mechanisms of MDLOFs have been discussed on the basis of experimental methods and numerical simulation (Yue et al, 2008;Balmforth et al, 2008Balmforth et al, , 2009Awal et al, 2010), there is no practicable method to calculate the outburst probability using a physical process model. Scholars have proposed appropriate indicators to qualitatively evaluate the breach probabilities of MDLOFs according to the characteristics of the morainedammed lakes.…”

“…For example, the ratio between the volume of dangerous ice of the parent glacier and lake volume was labeled the moraine lake outburst dangerous index by Lv et al (1999); similarly, the danger levels of a moraine-dammed lake are calculated from the ratio between the volume of possibly falling matter and lake volume (Huggel et al, 2004). McKillop and Clague (2007b) proposed an approach to estimate the probabilities using logistic regression methods and remote-sensing data. Statistical approaches should be prudentially applied to calculate the breaching probabilities of MDLOFs in different areas (such as the Himalaya) because failed lakes and calculation parameters have regional features.…”