<P> Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks which consequently break in pieces . Although rain seldom occurs in deserts , there are occasional downpours that can result in flash floods . Rain falling on hot rocks can cause them to shatter and the resulting fragments and rubble strewn over the desert floor is further eroded by the wind . This picks up particles of sand and dust and wafts them aloft in sand or dust storms . Wind - blown sand grains striking any solid object in their path can abrade the surface . Rocks are smoothed down , and the wind sorts sand into uniform deposits . The grains end up as level sheets of sand or are piled high in billowing sand dunes . Other deserts are flat , stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones . These areas are known as desert pavements and little further erosion takes place . Other desert features include rock outcrops , exposed bedrock and clays once deposited by flowing water . Temporary lakes may form and salt pans may be left when waters evaporate . There may be underground sources of water in the form of springs and seepages from aquifers . Where these are found , oases can occur . </P>
where can water be found in the desert
underground sources of water in the form of springs and seepages from aquifers