Potential effects of climate change and variability on watershed biogeochemical processes and water quality in Northeast Asia.

摘要: An overview is provided of the potential effects climate change on watershed biogeochemical processes and surface water quality in mountainous watersheds Northeast (NE) Asia that provide drinking supplies for large populations. We address major 'local' issues with case studies conducted at three along a latitudinal gradient going from northern Japan through central Korean Peninsula ending southern China. Winter snow regimes ground snowpack dynamics play crucial role many ecological across Japan. A warmer winter less snowfall, as has been projected Japan, will alter accumulation melting snowpacks affect hydro-biogeochemical linking soil to quality. Soils steep hillslopes rich base cations have shown distinct patterns buffering acidic inputs during snowmelt. Alteration microbial response more frequent freeze-thaw cycles under thinner may increase nutrient leaching stream waters. The amount intensity summer monsoon rainfalls increasing Korea over recent decades. More extreme rainfall events resulted export sediments nutrients agricultural lands converted forests. Surface siltation caused by terrestrial these emerging new challenge management due detrimental Climatic predictions upcoming decades China include lower precipitation year-to-year variations. results four-year intensive study forested Chongquing province showed acidity concentrations sulfate nitrate waters were generally years precipitation, suggesting variations key factor modulating acid deposition this region. Results suggest spatially variable or associated regional NE significant impacts quality, interactions local topography, land use change, deposition.