Controlling wasteloads from point and nonpoint sources to river system by GIS-aided Epsilon Robust Optimization model

Abstract

A stochastic multiobjective programming model, an 3-RO (Epsilon Robust Optimization) model as a simulationeoptimization model with an embedding approach, is developed for river water quality management under hydro-environmental uncertainty. The model is a hybrid of the 3-constraint method and the robust optimization framework, which depresses the high sensitivity of the model to the input data uncertainties by introducing a plausible set of scenarios. Possible pollutant sources (all kinds of point and nonpoint pollutant sources excepting forests) are treated as controllable. The finite element method is employed for approximations to COD (Chemical Oxygen Demand) and DO (Dissolved Oxygen) transport equations with convection and dispersion terms. Realizations for the in-stream CODeDO interactive events, thus described in discrete forms, are embedded as equality constraints in the model. Controlling wasteloads from a variety of sources is implemented by seeking noninferior solutions (management alternatives) that maximize total COD load to the stream while minimizing COD load deviations and in-stream water quality violations. Demonstrative operation of the model is made with its application to the Yasu River, Japan. It is shown that there is indeed an alternative management strategy to improve in-stream water quality as a whole while increasing the total allowable load to the stream. The 3-RO model developed could thus be a viable alternative to the conventional river water quality management models. Ó

Review of Mathematical Programming Applications in Water Resource Management Under Uncertainty

“…urban land use, agriculture, forestry, eutrophication) [52]. Point and non-point sources of pollution are often regarded as controllable [139]); however, other factors, such as the weather and climate, can also impact water quality [50]. On a global scale, water quality can be assessed using measures, such as the proportion of the population with sustainable access to an improved water source [190].…”

“…On a global scale, water quality can be assessed using measures, such as the proportion of the population with sustainable access to an improved water source [190]. However, for a particular water source, water quality typically involves the measurement of components, such as total phosphorus and total nitrogen [129], biological oxygen demand [33,42,129], chemical oxygen demand [132,139,141], dissolved oxygen [139] and Escherichia coli [33]. The impacts of pollution on water sources have been modelled by tools, such as the Streeter-Phelps equation [121] and the Soil and Water Assessment Tool (SWAT) [63].…”

“…A variety of mathematical programming techniques have been applied to address the issue of water quality, directly (e.g. where the objective is to improve quality [139] or to minimise the risk of poor quality [65]) or indirectly (e.g. where the solution is constrained by and must adhere to quality targets [17,42,91]).…”

Impact of spatial rainfall variability on hydrology and nonpoint source pollution modeling

“…Moreover, there has been increasing concern regarding to the NPS modeling in the past decade (Maeda et al, 2010;Zhu et al, 2011). The effect of spatial rainfall variability on NPS prediction still poses a valid question.…”

A Generalized Interval Fuzzy Chance-Constrained Programming Method for Domestic Wastewater Management Under Uncertainty – A Case Study of Kunming, China

“…Concerns with domestic wastewater management have become significant and the issues of surface water quality conservation and sustainable economic and social development are critical in many basins (Maeda et al 2010). However, a variety of complexities exist in such domestic wastewater management systems, including the wastewater generation rate to be treated, the wastewater treatment technologies to be used, the eco-environmental water requirements to be met, and the nutrients emission permits to be offered.…”