英文關鍵字
angle
bed
black
blur
bottleneck
boulders
canyon
channel
clear
close
closeup
countryside
creek
daylight
flow
flowing
fluid
fresh
glacier
gravel
hilly
horizontal
hydrology
infrared
low
middle
river
rocky
running
rural
speed
states
stone
stones
stream
trees
trough
united
wash
water
wet
white
wilderness