<Dt> or seasonal stream </Dt> <P> In the United States, an intermittent or seasonal stream is one that only flows for part of the year and is marked on topographic maps with a line of blue dashes and dots . A wash or desert wash is normally a dry streambed in the deserts of the American Southwest which flows only after significant rainfall . Washes can fill up quickly during rains, and there may be a sudden torrent of water after a thunderstorm begins upstream, such as during monsoonal conditions . These flash floods often catch travelers by surprise . An intermittent stream can also be called an arroyo in Latin America, a winterbourne in Britain, or a wadi in the Arabic - speaking world . </P> <P> In Italy, an intermittent stream is termed a torrent (Italian torrente). In full flood the stream may or may not be "torrential" in the dramatic sense of the word, but there will be one or more seasons in which the flow is reduced to a trickle or less . Typically torrents have Apennine rather than Alpine sources, and in the summer they are fed by little precipitation and no melting snow . In this case the maximum discharge will be during the spring and autumn . However, there are also glacial torrents with a different seasonal regime . </P> <P> In Australia, an intermittent stream is usually called a creek and marked on topographic maps with a solid blue line . </P>

In the us and canada a narrow ravine cut out by a fast stream