Which provinces was Dong Thap merged from?

Dong Thap province was established in February 1976 on the basis of merging these two provinces.

2012

According to the National Tourism Administration, on May 22, 2012, Tram Chim National Park was recognized as the world's 2,000th Ramsar site.
This National Park covers an area of over 7,580 hectares. This is one of the eight most important bird conservation areas in Vietnam with over 100 vertebrate species, 40 fish species and 147 waterfowl species. In particular, many rare bird species in the world such as red-crowned cranes, golden geese, pelicans, Javan chickens... continuously appear in Tram Chim National Park.
According to the Ramsar Convention adopted in 1971 in Ramsar City (Iran), wetlands to be recognized as Ramsar sites must meet many standards. These include standards for rare, unique, typical species of flora and fauna that play a supporting role for threatened ecosystems or species that are at risk of being endangered or extremely endangered.

Source: https://vtcnews.vn/dong-thap-duoc-hop-nhat-tu-nhung-tinh-nao-ar930137.html