Contemporary changes in open water surface area of Lake Inle, Myanmar

Abstract

From 1935 to 2000, the net open water area of Inle Lake in Central Shan State, Myanmar decreased from 69.10 to 46.69 km², a loss of 32.4% during this 65-year period. Local beliefs are that losses in lake area have been even greater within the last 100–200 years. Various activities, including timber removal, shifting agriculture in the uplands by various ethnic groups, and unsustainable cultivation practices on the low- and mid-level hillslopes around the lake, have been blamed for both historical and ongoing sedimentation. We take issue with attributing loss of lake area to these activities, and propose instead that ongoing “in-lake” and “near-lake” agricultural practices are the main sources of contemporary sediment and loss of open water area. About 93% (i.e., 20.84 km²) of the recent loss in open water area of the lake is due to the development of floating garden agriculture, largely along the west side of the lake. Direct environmental impacts associated with this practice and with other agriculture activities within the wetlands and margins of the lake include sedimentation, eutrophication, and pollution. Whilst the sustainability of hillslope agriculture and past forestry practices can indeed be questioned, a more urgent need is to address these "in-lake" and "near-lake" practices.