Quantifying impact of deforestation using multi-satellite and multi-spatial model in the North Korea

Deforestation in North Korea has been covered in many studies, but the exact amount of its impact and geographical area is still very different depending on the research and literature. In this study, we used Sentinel-2, the latest multi-spectral satellite image in Europe, and Landsat satellite image, which can detect forest cover before deforestation, to find out where to restore not only the degraded area. Forest area was identified in 1970-1980s using Landsat satellite images and focused on changes in the area. Monthly Sentinel-2 images are calculated as NDVI to identify forest-related covers through phenological change of vegetation. Random forest machine learning classification is used to classify each cover. And for the impact of deforestation also quantified in terms of agriculture and water by multi-spatial model. Agro-environmental variables, agricultural water demand and forest water supply were estimated using the EPIC and InVEST-WY models, respectively. Analysis of deforestation showed that area under forests decreased by 25%, whereas that under cropland increased by 63%, and that the conversion from forest to cropland was the largest for the study period. As a result, agricultural water demand increased and forest water supply decreased, significantly. Analysis of the net impact of deforestation on water budgets using recent climate and two land covers showed that forest water supply decreased by 43% and agricultural water demand increased by 62%. In terms of agro-environment, the negative changes in organic carbon loss, water erosion, and runoff were observed, regardless of the crop type. On newly-converted agricultural lands, runoff is 1.5 times higher and water-driven erosion and soil organic loss are more than twice as high compared to older croplands. The North Korea has declined many benefits from ecosystem attributable to deforestation in recent three decades. In contrast, South Korea has experienced success in national-scale afforestation in recent decades, and North Korea can emulate this. The restoration of forests in North Korea promises more than environmental benefits; it will provide a new growth engine for the prosperity of the Korean Peninsula as a whole.