روشي جديد براي ترسيم خودكار شبكه آبراهه ها در حوزه هاي آبخيز (حوزه آبخيز امامه ) با استفاده از سيستم اطلاعات جغرافيايي

The method to draw stream networks automatically in watersheds (Amameh watershed) by using GIS (GIS programming)

Proper stream network mapping is highly needed for any hydrological studies particularly for automatic flow routing in GIS based raster models. Generally, one of the disadvantages of making use of digitized stream network, based on topographic maps is incompatibility of stream features with flow direction vectors. In an uncertainty condition, making use of this stream network will terminate routing program before normal ending. An algorithm was designed, making use of Avenue program in Arcview GIS.Designing this algorithm was based on D8 method, which is one of the pixelto-pixel flow conduction methods. Points lying on digitized stream network can get elevation in a vector domain. Then, these points can be used in determining stream flows, which produces new stream network of catchments.The new generated stream network, in spite of having vector property, exactly coincide with flow direction patterns. One of the most important specifications of this algorithm is reallocation of stream network without generating extra features.