Impact of biomass burning on surface water quality in Southeast Asia through atmospheric deposition: eutrophication modeling

Abstract

Abstract. A numerical modeling approach is proposed for the assessment of the nutrient loading of coastal waters from atmospheric sources. The 3-D eutrophication model NEUTRO was enhanced to simulate the spatial distribution and temporal variations of nutrients, planktons and dissolved oxygen due to atmospheric nutrient loadings. It was found that nutrient loading from the atmospheric wet and dry deposition was remarkable during hazy days, the contribution being between 2 and 8 times that of non-hazy days; the smoke haze was due to biomass burning in the Southeast Asian region as discussed in a companion paper on field observations. Atmospheric nutrient loads during hazy days can lead to anthropogenic eutrophication and chemical contamination. The importance of regional smoke haze events in relation to non-hazy days to atmospheric nutrient deposition in terms of their biological responses in the coastal water of the Singapore region was investigated. The percentage increases of surface water nutrients due to atmospheric deposition during non-hazy and hazy days from seawater baseline were estimated. Model computations showed that atmospheric fluxes might account for up to 17–88% of total mass of nitrate nitrogen in the water column during hazy days and 4 to 24% during non-hazy days, which might be a relatively significant contribution into regional eutrophication. The results obtained from the modeling study could be used for a better understanding of the energy flow through the marine food web, exploring various possible scenarios concerning the atmospheric deposition of nutrients onto the coastal zone and studying their impacts on water quality.

A model for describing the eutrophication in a heavily regulated coastal lagoon. Application to the Albufera of Valencia (Spain)

“…Additionally, some models with complex formulations and high resolution grids (Lonin and Tuchkovenko, 2001) do not have an expression to describe the variable connection of the lagoon with the sea. There are also threedimensional models such as NEUTRO (Sundarambal et al, 2010) and CE-QUAL-ICM (Cerco and Cole, 1993), which can be applied to these systems. However, the shallowness of these lagoons justifies the deep-averaged well-mixed assumption in order to simplify the model.…”

“…Due to the importance, complexity, and variability of eutrophicated systems, mathematical models are essential tools to represent the degree of eutrophication of natural water bodies (Chao et al, 2010;Fan et al, 2009). The complexity of the models that describe eutrophication in aquatic systems ranges from simple NPZ (Denman and Gargett, 1995;McClain et al, 1996), or NPDZ (Hood et al, 2003;Oschlies and Garcon, 1999), to multi-nutrient, multispecies and size-structured ecosystem models (Lima and Doney, 2004;Lopes et al, 2009;Sundarambal et al, 2010). In fact, most of the available models assessing water quality in variable and high productive environments like coastal lagoons (Everett et al, 2007;Ferrarin and Umgiesser, 2005;Ohno and Nakata, 2008); are complex.…”