210 likes | 357 Views
Lomonosov Moscow State University Faculty of Geography. Calculation of mountain lakes outburst hydrographs. Kidyaeva Vera. FIRST VINOGRADOV'S READINGS. FUTURE OF HYDROLOGY Saint-Petersburg, 2013. The importance of the mountain lakes studies. Parts of the mountain lakes research.
E N D
Lomonosov Moscow State University Faculty of Geography Calculation of mountain lakes outburst hydrographs Kidyaeva Vera FIRST VINOGRADOV'S READINGS. FUTURE OF HYDROLOGY Saint-Petersburg, 2013
Parts of the mountain lakes research 1. Potentially hazardous lakes search 2. Surveying and monitoring 3. Morphometrical and hydrological characteristics determination 4. Regional relationsdetermination 5. Potential outburst possibility evaluation 6. Scenarios of the outbursts 7. Lake outburst hydrographscalculation/evaluation 8. Mathematical simulation of floods or debris flows 9. Spatial distribution of the flood or debris flow parameters 10. Intensity and hazard zoning in river valley 11. Social and infrastructure vulnerability assessment 12. Risk evaluation
Objects Mountain lakes Barrier Glacial • ice-dammed • moraine dammed • proglacial • rock, and etc. • Caused by: • lanslides, mudslides • debris flows, and etc. Study areas: Central Caucasus, Russia (Elbrus region) & Sichuan Province, China (region of the 12.05 Wenchuan earthquake) Glacial lakes location (near Mt. Elbrus) Caucasus Black sea Caspian sea
Outburst or overflow hydrographs andmaximum discharge evaluation • field surveys • empirical formulas and methods • water-balance methods • mathematical and hydraulic outburst models • hydrodynamic modeling
Measured hydrographs Tangjiashan barrier lake dam Q, m3/s
Modeling the outburst flood that occurred in 10-12 of June 2008 after the artificial cut at the dam the dam
Empirical formulas Probable maximum discharge of sudden breaks of ice dams: Qmax = W/t (1) or for moraine-dammed lakes: Qmax = 2W/t (2) Subglacial drainage of ice dammed lakes: (3) Qmax – maximum discharge, m3/s, W - volume in m3, t - drainage duration in seconds, t =1000 s for maximum estimates • Haeberli, W. 1983. Frequency and characteristics of glacier floods in the Swiss Alps. Annals of Glaciology, 4: 85–90. • Huggel, C. et. al. 2002. Remote sensing based assessment of hazards from glacier lake outbursts: a case study in the Swiss Alps. Canadian Geotechnical Journal, 39: 316–330. • Clague, J.J., and Mathews, W.H. 1973. The magnitude of Jökulhlaups. Journal of Glaciology, 12: 501–504.
Water-balance method based on field surveys Ice-dammed glacial lake outburst 11 august 2006 Q, m3/s • Parameters: • Estimated volume of the flood 420 000 m3 • Maximum discharge of the flood 20 m3/s • Volumetric concentration of the • debris flow 0.42 Chernomorets S., Petrakov D., Tutubalina O. 2007 Glacial lake outburst in the north-eastern slope of Mount Elbrus August 11, 2006: the forecast, the event and the consequences// Materials of glaciological studies.№ 102. P. 211–215.
Mathematical and hydraulic models Computational model by Yu. B. Vinogradov for outburst through ice tunnel: ρ0- water density, 1000 kg/m3 ρ - water and ice density, 850-910 kg/m3 g- gravitational acceleration, 9.81 m/s2 r - latent heat of fusion of ice, 334000 J/kg l - length of the tunnel, 550 m h- excess between entrance and the exit of the tunnel, 61 m W0 - volume of the lake before the outburst, 821 000 m3 a, m - morphometrical parameters of the lake C0- specific mass heat capacity of water, 4190 J/kg·оС t - lake water temperature, 2,5 оС for Bashkara lake
Mathematical and hydraulic models lake GnezdilovJu., Ivashchenko E., Krasnikh N. 2007 Evaluation of a hypothetical ouburst of the Lake Bashkara // Proceedings of "Sevkavgiprovodhoz", Issue 17, p.127-149.
Mathematical and hydraulic models Computational model for a step-shaped schematized lake hollow by V.Mochalov and I.Zuckerman Tangjiashan barrier lake W – volume of the lake, m3 S- surface area, m2 Z – depth, m Zп – depth of the spillway, m k – spillway koef. β – erosion intensity koef., m-2
Mathematical and hydraulic models Tangjiashan barrier lake outburst, 10-12 of June 2008 vs. ? t, h 17 36 0
Hydrodynamic simulation The Tangjiashan Barrier Lake – overflow in case of huge rockfall (volume > 106 m3). The dam is stable
Methodology: two-dimensional hydrodynamic simulation, using «River» modelby V. Belikov, A. Militeev Saint-Venant equations
Irregular rectangular-triangular grid Digital terrain modelof the valley lake dam riverbed m
Simulated overflow discharge at the dam of the Tangjiashan Lake, the highest peak 5000 m3/s
Some results Depth, m Max velocity, m/s
Thank you for your attention Спасибо за внимание I thank Krylenko I.N., Norin S.N., Chernomorets S.S., Petrakov D.A. and Su P. for help and useful discussion
Parts of the research Выявление опасных объектов в горах Мониторинг Определение морфометрических и гидрологических характеристик Построение региональных зависимостей Оценка потенциальной опасности прорывов Сценарии прорывов Расчет/оценка гидрографов прорыва Математическое моделирование паводков и селей Пространственная оценка распределения параметров по дну долины Зонирование долины по интенсивности потока и по опасности Оценка уязвимости населения/инфраструктуры Расчет риска