The susceptibility of estuaries to nutrient loading is an important issue that cuts across a range of management needs. We used a theory-driven but data-tested simple model to assist classifying estuaries according to their susceptibility to nutrients. This simple nutrient-driven phytoplankton model is based on fundamental principles of mass balance and empirical response functions for a wide variety of estuaries in the United States. Phytoplankton production was assumed to be stoichiometrically proportional to nitrogen load and an introduced ``efficiency factor'' intended to capture the myriad processes involved in converting nitrogen load to algal production. A Markov Chain Monte Carlo algorithm of Bayesian inference was then employed for parameter estimation. The model performed remarkably well for chlorophyll estimates, and the predicted estimates of primary production, grazing, and sinking losses are consistent with measurements reported in the literature from a wide array of systems. Analysis of the efficiency factor suggests that estuaries with the ratio of river inflow to estuarine volume (Q/V) greater than 2.0 per year are less susceptible to nutrient loads, and those with Q/V between 0.3 and 2.0 per year are moderately susceptible. This simple model analysis provides a first-order screening tool for estuarine susceptibility classification.
Zhang J, Ma S, Zhang Y, Zhao D. Fast and Effective Interpolation Using Median Filter, in Advances in Multimedia Information Processing - PCM 2009, 10th Pacific Rim Conference on Multimedia, Bangkok, Thailand, December 15-18, 2009 Proceedings.; 2009:1174–1184. 访问链接
Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Sigma 17PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BIDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange. dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Sigma 10PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Sigma 10PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the Besides sedimentation and degradation, the majority of Sigma 10PBDE and BDE-209 PRE to coastal ocean. discharged into the PRE via riverine runoff was transported to the coastal ocean. (C) 2009 Elsevier Ltd. All rights reserved.