Farouk El-Baz

Document Type

Article

Publication Date

11-28-1980

Abstract

In the desert, running water plays no significant role in the transportation and deposition of sediment; the desert environment is colians being doninated the wind- Thus, it Ls vecy important co understand the wind patterns of any idesert region under investigation. Hovever, in most deserts neteorolosical stations are placed in oages, which are located in depressions. Cliffs and scarps that surround these depressions exert a marked influence ion wind direction and velocity. Additionally many of the desert oases, therefore the neteorological stations, are separated by great distances, sometines exceeding 600 ka. The result of these two factors is that the surfacc vind data are usually scant and often reflect local influences rather than the wind regime in the open desert. Studied examples of the effects of local copography on the orientation of wind deposits in the Westera Desert of Egypt include: the Kharra depression, where the major scarp is aligned close to the direction of sand transport; and the Facafra depression ahere a searp is oriented nearly normal to the direction of the wind. In both cases, sand is deposited in dunes whose axes are parallel to the scarps rather than to the duncs in the surrounding open desert. Thus, it is important to consider 1ocal topographic effects then comparing wind airections and dune orientations, particularly in the absence of wind stations in the open desert above the depressions. Space-age technology has paved the way for the utilization of automated stations that can gather meteorological data in remote desert regions. Data collected such means cant be raasaitted to arbiting satellites, which then retransmit the data to ground recelving stations for processing, distribution and analysis. There are three basic elenents to such a scheme: a data collection platform connect el Co che sensor recorders; (2) a radio cransponder with receiving and transmitting capabil- ities on board a satellite; and (3) a data recetving stacion for retrieval, processing, and dissemination of the collected data. At the present time, the U.S. Ceological Survey is operating a prograd of remote monitoring of hydrologic data for assessment of water tesources. Results of this program indicate both the cost-effeetiveness of the method, and the advantages gained from realtimc colleet ion of the data. In one case, improved estimates of runoff were instrumencal in avoiding flood danage and generating extra electrical energy during the runoff period. The sane technology is being tested for meteorological data collection. Twa experi- mental programs are being condusted in remote places that represent extremes of Earth weather; one in Antaretica and the ocher in che sputhestern U.S. deserts. The "'Desert Winds Project" of the U,s. Geological Survey in Flaßstaff, Arizona alms at establishing automated weather stations capable of monitoring critical envíronmental factors that determine the capability of wind to erode and transport varioua types of matcrials in deserts. Stations now under study include sensors for measuring wind speed, wind direction, precipitation, air temperature, humidity, soil temperature, and barometric pregsure. The stations are powered by solar panels and their data are stored in the collection platform prior to tranemission CO the COES-1 satellíte via Results from these stations indicate that this method is exceedingly antenna, practical and should be utilized for the cost-effective and tinely collection of meteorological data in remote desert regions.

Download

Share

COinS