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Emergency response service of scientific data for Myanmar M 7.9 earthquake (20250328)
An earthquake of magnitude 7.9 occurred in Myanmar at 14:20 local time on March 28, 2025,with a focal depth of 30 kilometers. The epicenter was located at 21.85 degrees north latitude and 95.95 degrees east longitude. The epicenter of the earthquake is very close to Mandalay, the second largest city in Myanmar, and all the energy of the strong earthquake will be released along the densely populated Irrawaddy River, which was strongly felt in Yangon, the largest city in Myanmar. The epicenter is 294 kilometers away from the nearest borderline of China, causing strong tremors in Xishuangbanna, Dehong, Kunming, Lijiang, Baoshan, Dali and other places in Yunnan, and there is also tremor feedback in Guizhou and Guangxi. Up to now, reports of casualties and property damage are being tallied. The National Cryosphere Desert Data Center (NCDC) for Glaciology and Permafrost Desert collects and prepares basic geographic data, satellite remote sensing data, population data, topographic data and other emergency response scientific data based on disaster situations. The "Emergency response service of scientific data for Myanmar M 7.9 earthquake (20250328)" system has been released, which provides data visualization, interoperation and data download capabilities. For use by relevant emergency, rescue and research departments. The subsequent NCDC will continue to further collect and sort out various data resources in the earthquake area and gradually release them through the data center platform for the use of relevant emergency, rescue and research departments. Service Website:http://www.ncdc.ac.cn/portal/emergency?eid=d1324137-c7cc-4d29-95ea-37d70517b5d6&lang=en
New Models
A large number of reservoir inflow with preserved data, spillway discharge and discharge of breach ditch (unstable flow with sediment transport capacity) formed along erosion are comprehensively applied in the model. It is assumed that the slope ratio at the bottom of the breach is basically the same as that at the downstream of the dam. The development of breach ditch depends on the material properties of dam body (D50 size, unit weight, friction angle, bond strength). The model takes into account the following possible complexities: 1) the material properties of the dam core and the outside of the dam are different; 2) before the real breach caused by overtopping flow is formed, the erosion ditch along the downstream slope surface of the dam is determined; 3) the downstream slope of the dam may be covered with grass or contain materials larger than the external components of the dam; 4) the shear strength and cohesive force are exceeded The results show that more than one sudden structural collapse mechanism is enlarged due to the hydrostatic pressure; 5) the width of the breach obtained from the slope stability theory is enlarged; 6) the free surface breach flow is developed by piping, which causes the collapse; and 7) the non cohesive material (gravel) or cohesive material (clay) may be carried away by erosion. The discharge water level hydrograph is obtained by time step iterative method, which can be completed in only a few seconds on a main computer. The model is not constrained by numerical stability and convergence stability.