Accelerated degradation of Lake Inle (Myanmar): A baseline study for environmentalists and developers

Abstract, Land Degradation & Development, 2019

This study takes stock of the confusion that exists around the environmental state of Lake Inle, a flagship destination for tourism in Myanmar. Reports on the dynamics of its iconic floating gardens and on the evolution of the Lake's dimensions in response to land-use change in the watershed are inconsistent and provide a poor basis for policymaking. Here, we (a) present a critical overview of the literature concerning land degradation around Lake Inle; (b) provide an independent and quantitative reexamination of the Lake's size; (c) carry out a methodic assessment of the history of floating gardens based on written sources, interviews, and high-resolution imagery from 1967, 1983, 2002, and 2014; and (d) produce the first comprehensive and biseasonal bathymetric survey of the Lake, thereby providing a baseline water volume estimate fit for future monitoring purposes. Results challenge previous reports and show that floating agriculture boomed in the 1970s (11 km² in 1967 and 29 km² in 1983), peaked in 2002 (35 km²), then declined slightly (33 km² in 2014). Our bathymetric survey reveals that the Lake volume at the peak of the 2015 rainy season was 122.6 × 10⁶ m³, with maximum water depths having diminished substantially from 6 m (as reported in 1918) to just 3 m today as a combined result of sediment aggradation and waterlevel decline (−1 m in 25 years). Those dynamics have critical implications for the sustainability of floating agriculture, fishing, and the local tourist economy.