Geospatial Assessment of Agriculture Land Use Change in Relation to Paddy Production along the Punakha-Wangdue Valley over the Last Decade

Paddy is a valued commodity considered paramount to Bhutanese food self-sufficiency goals. However, land-cover land-use change driven by various underlying factors have impacted agriculture systems affecting paddy production. As Punakha and Wangdue Phodrang are major paddy growing districts in the country, this study attempts to assess the spatial trends and patterns of land-use land-cover change and its relation to paddy production within the region. Supervised classification method and post classification technique were employed to generate and interpret the land-use land-cover change from the satellite images. The study showed that built-up areas have the highest net gain of 4.86% followed by vegetation and barren soil with 0.97% and 0.36% respectively from 2005 to 2020. On the contrary, agricultural land saw a loss in area by 5.3% while snow cover was reduced by 10.3% in the same period. Relative conversion index analysis of agricultural land indicated higher conversion intensity in central areas of the region with lower intensity at the external fringes. Paddy mapping displayed a net shrinkage in total paddy cultivation area by 13% in Punakha and 11% in Wangdue Phodrang from 2016 to 2021. Additionally, the rice self-sufficiency analysis also pointed to an increasing deficit with rice surplus of 127% in 2016 falling to a deficit of 6% in 2021 for Punakha while previously rice deficit of 17% in 2016 declined further to 57% in 2021 for Wangdue Phodrang indicating potential impacts of land-use change in the region calling for necessary intervention.