Future trends in urbanization and coastal water pollution in the Bay of Bengal: the lived experience
Zinia, N.J. ; Kroeze, C. - \ 2015
Environment, Development and Sustainability 17 (2015)3. - ISSN 1387-585X - p. 531 - 546.
nutrient export - rivers - perspectives - management - phosphorus - nitrogen
The Bay of Bengal includes coastal seas of several countries, including Bangladesh, India, and Myanmar. We present scenarios for future river export of eutrophying nutrients into the Bay of Bengal, and the role of urbanization therein. We used NEWS (Nutrient Export from WaterSheds) model to analyze trends over the period 1970–2050. The scenarios are based on the Millennium Ecosystem Assessment and indicate the number of people living in urban areas may increase from 22 % in 1970 to about 50 % in 2050. We show that this may considerably increase nutrient levels in rivers from sewage and other sources. For 2050, we calculate that harmful algal blooms may be a potential problem in coastal waters of about 95 % of the total drainage basin of the Bay of Bengal. In addition, we analyze Bangladeshi citizens’ expectations of future trends and how citizens with different worldviews would experience environmental changes (i.e., their lived experience). The citizens indicate that trends as envisaged in our scenarios may be a negative experience. However, some people may experience the trends as positive, because they expected worse.
Increasing eutrophication in the coastal seas of China from 1970 to 2050
Strokal, M. ; Yang, H. ; Zhang, Y. ; Kroeze, C. ; Li, L. ; Luan, S. ; Wang, H. ; Yang, S. - \ 2014
Marine Pollution Bulletin 85 (2014)1. - ISSN 0025-326X - p. 123 - 140.
pearl river - future-trends - nutrient export - yangtze estuary - algal blooms - food-chain - management - nitrogen - waters - phosphorus
We analyzed the potential for eutrophication in major seas around China: the Bohai Gulf, Yellow Sea and South China Sea. We model the riverine inputs of nitrogen (N), phosphorus (P) and silica (Si) to coastal seas from 1970 to 2050. Between 1970 and 2000 dissolved N and P inputs to the three seas increased by a factor of 2–5. In contrast, inputs of particulate N and P and dissolved Si, decreased due to damming of rivers. Between 2000 and 2050, the total N and P inputs increase further by 30–200%. Sewage is the dominant source of dissolved N and P in the Bohai Gulf, while agriculture is the primary source in the other seas. In the future, the ratios of Si to N and P decrease, which increases the risk of harmful algal blooms. Sewage treatment may reduce this risk in the Bohai Gulf, and agricultural management in the other seas.
Nitrous Oxide (N2O) emissions from human waste in 1970-2050
Strokal, M. ; Kroeze, C. - \ 2014
Current Opinion in Environmental Sustainability 9-10 (2014). - ISSN 1877-3435 - p. 108 - 121.
water treatment-plant - coastal waters - climate-change - future-trends - sewage-sludge - anthropogenic nitrogen - reactive nitrogen - nutrient export - surface-water - united-states
Nitrous oxide (N2O) is an important contributor to climate change. Human waste is an important source of N2O emissions in several world regions, and its share in global emissions may increase in the future. In this paper we, therefore, address N2O emission from human waste: collected (from treatment and from sewage discharges) and uncollected waste. We review existing literature on emissions and emission factors, and present region-specific estimates of N2O emissions and their past and future trends. We show that human waste may became an important source of N2O emissions in the coming years as a result of increasing urbanization. About two-thirds of the global emissions are from uncollected waste, and about half from South Asia. We argue that more research is needed to improve emission factors.