Outflow boundary a downburst. "Gustnadoes", short-lived vertical circulations near ground level, can be spawned by outflow boundaries. Gust fronts create low-level wind shear which can be hazardous to planes when they takeoff or land. Flying insects are swept along by the prevailing winds. As such, fine line patterns within weather radar imagery, associated with converging winds, are dominated by insect returns. At the surface, clouds of dust can be raised by outflow boundaries. If squall lines form over arid regions, a duststorm known as a haboob can result from the high winds picking up dust in their wake from the desert floor.
Karakum Desert Tejen rivers flow out of the Hindu Kush Mountains, flow west, and empty into the desert, providing water for irrigation. The desert is crossed by the second largest irrigation canal in the world, the Karakum Canal, which brings water from the Amu Darya to southern regions of the desert. Construction on the canal was started in 1954 and completed in 1958. It is 1,375 km in length, and carries 13-20 km³ of water annually. Leakages from the canal have created lakes and ponds along the canal and the rise in groundwater has caused widespread soil salination. Within the Karakum are