砂防在治水上所起到的作用是对下游防止土砂为害这是众所周知的事情.砂防坝可以良好地保护因洪水而荒芜的土地,使土地利用价值提高,农田在不知不觉中园田化了.除这种主要目的之外,砂防坝也可以在其它方面进行有效利用,兹就水源丰富的富山县加以介绍.1、河川生产物作为骨材采取利用富山县的主要荒废河流,均由3,000米高的群山向下流泻.在上流有很多搁荒地,这些河川曾经形成广阔的富山平原. It is a well-known fact that sand and flood control can play a role in flood control. It is well-known that sand and flood dam can well protect the land which is desolate due to flood so as to increase the value of land use and unknowingly garden land. In addition to these main purposes, sand and dam can also be effectively used in other areas, it is introduced to the rich water of Toyama Prefecture introduced .1, River produced as aggregate to take advantage of the main abandoned river in Toyama Prefecture, by 3,000 meters High mountains flowed downwards, and there was a lot of waste in the upper stream, which formed the vast Toyama Plain.