Building Sustainable Indicators for Mangrove Forests Based on a Survey to Determine Forest Erosion in the Southwestern Sea of Vietnam

The increased erosion of mangrove forests has alarmed the government about the damage to both the economy and livelihoods. To evaluated forest and land erosion the coast. Based on survey data is divided into five levels (F1: no erosion; F2: little erosion; F3: moderate erosion; F4: high erosion; F5: strong erosion), and ecological conditions, the coast is divided into sub-regions for investigation. From the surveyed indicators at each erosion level, forest structure is analyzed for comparison. The erosion level is defined as an erosion function (Er) from 1 to 5 (+), where (1) parameters include the number of trees per hectare (Ntr/ha), height to top (Ht), trunk diameter at 1.3 m (D1.3), tree canopy diameter (Dc), and width of the forest range (Wf); (2) land erosion is a function (Erl = Erlte + Erlsa + Erlsi + Erlcl), with parameters including erosion by terrain (Erlte), sand (Erlsa), silt (Erlsi), and clay (Erlcl); and (3) climate change leading to erosion is an inverse function (Cl) from 1 to 5 (–), with parameters including erosion by rainfall (Clra), wind (Clwi), waves (Clwa), and tide (Clti). The resulting function output is Er = (Erf + Erl)–Cl. On eroded forest land, species were tested under climate change conditions and their growth in the next rainy season to assess survival rates affected by rainfall, waves, wind, and tides. These results help to plan planting mangrove forest anti-erosion models and construct a theoretical function of mangrove erosion and proposes restore forests using pioneer species.