Nationwide mapping of shifting cultivation in Laos over the past three decades

Keywords: Disturbance, Forest degradation, Deforestation, Shifting cultivation, Shifting agriculture, Slash and burn, Swidden agriculture, Landsat, Google Earth Engine, Time series analysis, CCDC-SMA, Object-based image analysis.
Session Type: Virtual Paper Abstract
Day: Tuesday
Session Start / End Time: 3/1/2022 09:40 AM (Eastern Time (US & Canada)) - 3/1/2022 11:00 AM (Eastern Time (US & Canada))
Room: Virtual 36

Abstract

Shifting cultivation, also known as slash-and-burn or Swidden agriculture, is an agriculture practice in which land is cleared and burnt for cultivation, and then abandoned while vegetation is allowed to recover. Although shifting cultivation is one of the major drivers of forest disturbance in the tropics, the current research of shifting cultivation is very limited. The spatial and temporal patterns, and the associated carbon dynamics of shifting cultivation is still unknown in most of shifting cultivation regions. Monitoring shifting cultivation is challenging since the landscape resulted from shifting cultivation is highly dynamic and the individual slash-and-burn events occurred in a fine scale. In this research, we used Landsat dense time series to monitoring shifting cultivation in Laos from 1990-2020 on Google Earth Engine. We developed a workflow that combined time series analysis and object-based analysis to map shifting cultivation. CCDC-SMA (Continuous Change Detection and Classification - Spectral Mixture Analysis) was used to monitoring forest disturbance. The forest disturbances were classified into different drivers using land cover, change magnitude and size of object. We created annual maps of disturbance drivers including shifting cultivation, drought, plantation, deforestation and subtle disturbance. The preliminary results show that shifting cultivation is the major driver of forest disturbances in Laos. We will assess the accuracy of shifting cultivation maps, calculate the unbiased area estimates of shifting cultivation, and analyze the spatial temporal patterns of shifting cultivation.