Publications

Tang, XJ; Woodcock, CE; Olofsson, P; Hutyra, LR (2021). Spatiotemporal assessment of land use/land cover change and associated carbon emissions and uptake in the Mekong River Basin. REMOTE SENSING OF ENVIRONMENT, 256, 112336.

Abstract
Land use and land cover (LULC) change caused by human activities is a major source of anthropogenic carbon emissions and a driver of climate change. The Mekong Region is highly dynamic, experiencing extensive LULC change in recent decades. This study provides a spatially and temporally continuous estimate of LULC change for the Mekong River Basin for 2001-2019 using time series analysis of MODIS data coupled with a spatiotemporal carbon bookkeeping model to track carbon losses and recovery. The LULC change product has an overall accuracy of 74.4 +/- 1.9% (82.1 +/- 1.7% after consolidating tree-dominated classes), including an increase of 5.6% after combining with existing MODIS products (referred to as the M-CCDC process). Two of the largest components of LULC change in the region are the establishment of plantations and agricultural expansion, which were estimated to be 33,617 +/- 7342 km(2) and 14,915 +/- 4682 km(2) between 2003 and 2014. We found that 82% of the deforested area was converted to tree plantations. Among all the newly added plantations, 86% replaced natural forests and 12% replaced agricultural land. In addition, existing maps of annual tree canopy cover (TCC) were used to assess forest disturbances that do not result in LULC conversions. The M-CCDC results combined with the forest disturbances derived from TCC maps were coupled to a spatiotemporal carbon bookkeeping model to estimate carbon emissions and uptake. Carbon emissions were 72.9 +/- 6.2 Tg C yr(-1) during 2001-2017; emissions increase to 102.8 +/- 8.6 Tg C yr(-1) if including carbon not yet released to the atmosphere in the form of decomposing slash and wood products. Carbon uptake for the same period was-35.5 +/- 4.9 Tg C yr(-1), with carbon uptake from new plantations offsetting almost half of the emissions from deforestation in this area. Assessment of post-deforestation land use is crucial for quantifying the short-and longer-term carbon consequences of LULC change.

DOI:
10.1016/j.rse.2021.112336

ISSN:
0034-4257