纵向岭谷三江并流区河谷地貌特征分析

西南纵向岭谷地貌区北部的三江并流区是我国高山深谷发育的典型区域。金沙江、怒江、澜沧江、独龙江自北向南奔流，形成了较为典型的以峡谷为主的河谷地貌。其河谷地貌的主要特征有：突出的纵向岭谷地貌，构成了少有的三江并流奇观；地貌相对高差大，河谷深切；河谷地貌形成演化发育明显受地质构造控制；流域范围内地貌类型和地貌组合多样化特征突出；地质地貌环境具有较强烈的生态脆弱性；河谷支流水源多发源于高山湖泊，两岸支流河谷分布不均衡。形成了独具特色的“三江并流”河谷地貌。

The Analysis to the Landforms Character of the River Valley in the Three Parallel Rivers Region

The three parallel rivers region in the north part of the longitudinal range-gorge region of south-west China is the typical area to form high mountains and deep valleys.Jinsha river,Nu river,Lancang river and Dulong river flush from the north to the south and form the relatively typical river-valley landforms which gives priority to the valleys.The main characters of the river-valley landforms are followed: The outstandingly longitudinal rangegorge landforms constitute the unique view of three parallel rivers;the relative highness difference of the landform is great and the river valley cut deeply;the formation and evolution of the river-valley landforms are obviously controlled by the geological structure;the landforms types and the various characters of the landforms combination in the drainage area are prominent;the geological environment has relatively strong frangibility;the branches riverhead of the river-valley mostly come from high mountains and lakes,and the river-valleys of the branches along the banks have disproportional distribution.All these characters form unique river-valley landforms of the three parallel rivers.