The survey area , of a terrain of middle and low mountains and narrow valleys , is characterized by distinct topographical relief , high mountains , steep slopes , deep valleys , developed gulches , crisscross network of ravines , and plenty of hills and mountains .

勘察区属于中低山窄谷地貌，地形起伏较大，山高、坡陡、谷深，冲沟发育、深切，沟壑纵横，山峦重叠。