valley form meaning in English

河谷地形
河谷形状

Central california is a long valley formed by two rivers .
加利福尼亚中部是由两条河形成的一个很长的谷地。
In the research area , the incised valley was formed during the sea level downwards and was provided source by the arenaceous river from qiaotou . it is stacked by 3 incised valleys formed in 3 different sequences
研究区内子洲镇川堡地区发育的下切河谷形成于海平面下降时期，来源于桥头的砂质河流沉积，为叠置的、形成于三个不同三级层序底部的下切河谷充填沉积。