The Law of April 6, 1830, was designed to stop the flood of immigration from the United States to Texas. The law was a result of the Mier y Teran Report's fourteen recommendations about stopping the colonization of Texas by Mexicans and Europeans, encouraging military occupation, and stimulating coastal trade.
As with most locations for settlements in any civilization the key factor is settlements were located in the lowlands where the land was fertile and could be farmed. Geography is very important when a site is picked for settlement. The site must be able to support human activity.