Determination of aquaculture distribution by using remote sensing technology in Thanh Phu district, Ben Tre province, Vietnam

Aquaculture is an important economic activity in the coastal zone of Vietnam. Thanh Phu is one the coastal districts in Ben Tre province that rears brackish aquaculture. In recent years, farmers could not grow shrimp because of salinity intrusion and market price fluctuation. This study aims to determine aquaculture and fallow aquaculture pond distribution by using the three indices of NDVI (Normalized Difference Vegetation Index), MNDWI (Modified Normalized Difference Water Index) and NDBaI (Modified Difference Bareness Index) on Landsat 8 imagery. The results reveal that remote sensing can support the detection of aquaculture and fallow ponds with a high accuracy of 77%. The total aquaculture area is approximately 13,093.65 ha, of which the total fallow area is 581.49 ha (roughly 4.44% of the total aquaculture area). Moreover, the fallow ponds are randomly distributed in all four ecological zones and mostly in the fourth ecological region (about 73.92%). In the fourth region, saline concentration in water is from 20 to 30‰, which directly influences cultured shrimp farms. The results also indicate the spatial distribution of aquaculture ponds and ineffective aquaculture locations using Landsat 8 imagery via index image analysis. The findings support the local management’s decision making on further aquaculture planning.