Rapid Land-Cover and Land-Use Change in the Indo-Malaysian Region over the Last Thirty-Four Years Based on AVHRR NDVI Data

The Indo-Malaysian region is a hot spot of rapid land-cover and land-use change (LCLUC) with little consensus about the rates and magnitudes of such change. Here we use temporal convolutional neural networks (TempCNNs) to generate a spatiotemporally consistent LCLUC data set for nearly thirty-five years (1982-2015), validated against two reference data sets with over 80 percent accuracy, better than other LCLUC products for the region. Our results both confirm and complicate estimates from earlier work that relied on decadal, rather than interannual, changes in regional land cover. We find forests decrease in mainland and maritime Southeast Asia and increase in South China and South Asia. Consistent with geographic theory about the drivers of land-use change, we find cropland expansion is a driving force for deforestation in mainland Southeast Asia with savannas playing a superior role, suggesting widespread forest degradation in this region. In contrast to earlier work and theory, we find that South China's increasing forest cover comes principally from savanna (rather than cropland) conversion. The explicit interannual LCLUC patterns, rates, and transitions identified in this study provide a valuable data source for studies of land-use theory, environmental and climate changes, and regional land-use policy evaluations.

Automated summary

This study utilizes temporal convolutional neural networks to generate a consistent land-cover and land-use change dataset for the Indo-Malaysian region over a period of nearly 35 years. The results reveal a decrease in forests in Southeast Asia and an increase in South China and South Asia. Cropland expansion is identified as a major driving force behind deforestation in mainland Southeast Asia, while the increasing forest cover in South China is primarily attributed to savanna conversion. These findings provide valuable insights for studies on land-use theory, environmental and climate changes, and regional land-use policy evaluations.