Rice and bricks: environmental issues and mapping of the unusual crop rotation pattern in the Kathmandu Valley, Nepal.

The Kathmandu Valley in Nepal has experienced a very rapid increase in population resulting in considerable land use/land cover change and also a series of environmental problems. One of the results of the population increase is an expansion of brick manufacturing within the Valley because most structures are brick. The brick kilns are intense in several locations of the Valley and have an interesting pattern of using the same lands for bricks during the dry season and then conversion to rice during the wet, summer monsoon months. The increase in brick production has contributed to environmental problems including decreased soil productivity, lowered ground water levels, and particularly air pollution. Brick manufacturing has little, if any, effective regulation. There is a lack of current, accurate data on brick production that could be resolved by remote sensing methods. Controls should be established and more information acquired on the location and impacts of brick production.