Monitoring and changing pattern of shifting cultivation and reclamation in hilly regions using Geospatial Technology

In the history and civilization of mankind, shifting cultivation is being regarded as the oldest method of agriculture. Also this agricultural method is termed as “slash and burn agriculture,” “swidden agriculture,” “land-rotation cultivation,” “field-forest rotation agriculture,” “digging stick cultivation,” etc., and in North East India as “Jhum.” The practice is most prevalent in the hilly areas of tropical and subtropical regions of the globe. Notably, this oldest agriculture practice has practitioners in large scale till today in the hilly areas of North East India. This study is an attempt to understand the spatial and temporal dynamics of shifting cultivation in Anjaw district of Arunachal Pradesh using LISS IV and Landsat time-series from 2003 to 2017. Complete shifting cycles were extracted from the sequence of use and fallow periods and vulnerability codes were assigned accordingly. Geodatabase was generated by considering image of 2003 as the base year and the same geodatabase was used to digitize the shifting cultivation areas from the rest of the images. Analysis of shifting cultivation patches showed an increasing and decreasing trend in the occurrence of shifting cultivation practices across 2003–17. The increasing trend during the study period has been observed with the slight dip in 2004, 2005, 2008, and 2015 and some major dips in 2010 and 2014 in shifting cultivation practices. Vulnerability class was assigned to each of these shifting cultivation patches based on threshold level given for the rotation cycles (fallow periods). Vulnerability class analysis revealed that most of the completed shifting cultivation cycles are extremely vulnerable in nature which accounts for almost 40.07% of the completed shifting cultivation patches, whereas only about 13.16% of completed shifting cultivation patches falls under the nonvulnerable status.