The Indians of the southwest culture group developed Irrigation techniques but the Indians of the Columbia plateau did not because the southwest is an arid region whereas the Columbian plateau is a region having abundant rainfall.
Irrigation is an activity to provide water to the soil for the growth of plants in a large area by various artificial methods like pumping, spraying, etc.
The irrigation techniques are required to be developed in the southwest region as it is an arid region, that is, the area where not enough water is available for plantation and cultivation of crops. In contrast, the Columbian plateau has got abundant rainfall which is enough for the plants and crops to grow.
Therefore, the irrigation methods have been adopted by Indians of the southwest region and not by the Columbian plateau area.
Learn more about the irrigation in the related link:
https://brainly.com/question/22708021
#SPJ1
