Detecting geographic hotspots of human-induced land degradation in Vietnam and characterization of their social-ecological types

This study aims to identify and classify the geographic hotspots of human-induced land degradation in Vietnam. We used the long-term (1982-2006) trend of inter-annual NDVI, derived from AVHRR/NOAA imageries, as a proxy for the decline or improvement in biomass productivity on a national scale. By analyzing the temporal correlation between rainfall and NDVI time-series over the last 25 years, we identified areas showing human-induced productivity decline from those in which the degradation was driven by climate dynamics. Finally, we identified areal clusters of human-induced productivity degradation associated with different profiles of social-ecological factors, which can be considered in follow-up causal analyses. We found that about 63,900 km² of land (19% of the national land) showed a persistent decline in biomass productivity. The maximum degraded areas were found in the southeast, Mekong River Delta, north western mountains, and Central Highland. We identified concrete social-ecological types of degradation hotspots, which can guide follow-up land degradation studies at different levels.