Dear student,
a. Wells and tube wells are the most popular means of irrigation in northern plains.
b. They are popular means of harnessing groundwater resource.
c. This is primarily because of the topography of the region.
d. Plains and flat terrain of northern plains allow best to use wells and tube wells.
e. Besides that canal irrigation is also used in this region, as certain areas in northern plain region have a good flow of perennial rivers, making it rich in groundwater resources.