What is the content of the policy of "border consolidation" in the Western Han Dynasty?

Immigration border refers to the migration of a large number of people in the mainland to enrich the border, strengthen border defense forces and develop border counties. During the reign of Emperor Wu of the Han Dynasty, in order to strengthen the border defense in the north, in 1 19 BC, more than 700,000 people immigrated at one time, enriching the northern counties and counties, and the combination of soldiers and farmers was implemented, which not only reduced the burden of national soldiers' salaries, but also ensured the security of the border. In Han Dynasty, the economy and culture of the northwest frontier developed rapidly because of the measures of emigrating to the real frontier and stationing fields to defend the frontier.