Imagery of filth and dirt
Imagery of filth and dirt is present in the second article most prominently when the writer describes the state the migrant families live in the squatters' camp. They live in makeshift paper or branch houses and sleep on the ground; hygiene is impossible to maintain; women try to wash muddy clothes in muddy water; it is a ground for infections and diseases.
Imagery of harvest/crops
The migrant workers come to California to harvest various crops. There are various types of orchards such as peach orchards, plantations of cotton and lettuce. There is a rush to get to these plantations first to get the highest wage which often leads to too much labour force where it's not needed.
Imagery of drought
Imagery of drought is present when describing the places the American migrant families have fled from. The drought was so bad that it destroyed their entire farms and every sources of income. The writer calls these places all together "a dust bowl".