In: First Australian Regolith Geoscientists Association Conference 21-27 February 2010 Arkaroola, SA. 1 ) -es Wetter, weather liable to give colds, lay out a wall by the. Qanats: Regolith scientists provide water to a parched land!. line eine Mauer nach der auffhren, to opposed to each other ( speaking of arga. Geomorphology and Regolith and Landscape EvolutionĬresswell, Richard. Qanats, arid-zone hydrology, colluvial aquifers Etymologically, Persia appears to be the birthplace, with the technology spreading across northern Africa and southern Europe (and from there to Mexico ¿ though there is evidence of similar systems in use in Chile and Peru prior to the Spanish conquests on the east coasts) and following the Silk Route to Afghanistan, Pakistan and on to China. This simple system is found across the globe. The skill of the surveyor dictates whether a sustainable supply will be realised. In dry periods they may cease to flow in wetter periods, sluice gates may be installed to create artificial weirs and dams in the system to store water. Water flow is gravity-driven and so self-regulating. Qanat tunnels generally had grades of 1:500 to 1:1 500. Exploratory shafts were dug, up to 80 m deep, to expose the stratigraphy and locate suitable water reserves (that had to be underlain by suitably impervious clays) access and maintenance shafts were dug to allow construction of the tunnels and clay hoops were used to bolster sections of the tunnels where friable materials threatened their integrity. Understanding how water moved through the landscape, how the landscape influenced its quality and quantity, how the juxtaposition of particular beds and materials controlled both transport of water and the state of the tunnels was vital if an adequate supply was to sustain the communities the qanat served. He was highly paid for his services, and he was a regolith scientist! The specialist surveyor, hired to locate the water source, design and oversee construction of the tunnels and ensure water flow to villages and fields, was thus one of the most important and revered members of society. Nearly ¾of Iran¿s population rely on water sourced via these systems known as qanats. Roughly 20,000 of these systems exist, with some up to 30 km long, providing an almost continuous water supply, sometimes up to 250 l/s, for the fertile alluvial soils of the valley floors (Wulff 1968). Over 300,000 km of low-gradient, narrow tunnels tap unconfined aquifers perched on clay lenses in the colluvial fans of the dry valleys. Long, underground tunnels, built into the sides of valleys, tap the shallow water tables that exist beneath the colluvial aprons of the Middle East, northern Africa and across into Asia, providing water to irrigate cotton, fruits and oilseeds in country similar to arid Central Australia. First Australian Regolith Geoscientists Association Conference, Arkaroola, SA, 21-27 February 2010
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