What Is Sciatica? Sciatica refers to back pain caused by a problem with the sciatic nerve. This is a large nerve that runs from the lower back down the back of each leg. When something injures or puts pressure on the sciatic nerve, it can cause pain in the lower back that spreads to the hip, buttocks, and leg. Up to 90% of people recover from sciatica without surgery.
River flooding occurs when river levels rise and overflow their banks or the edges of their main channel and inundate areas that are normally dry. River flooding can be caused by heavy rainfall, dam failures, rapid snowmelt and ice jams.
A flash flood after a thunderstorm in the Gobi, Mongolia. A flash flood is a rapid flooding of geomorphic low-lying areas: washes, rivers, dry lakes and basins.It may be caused by heavy rain associated with a severe thunderstorm, hurricane, tropical storm, or meltwater from ice or snow flowing over ice sheets or snowfields.lash floods most often occur in normally dry areas that have recently received precipitation, but may be seen anywhere downstream from the source of the precipitation, even many miles from the source.