Allan Sarmento Vieira, et. al. International Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 12, Issue 1, (Series-II) January 2022, pp. 06-16 www.ijera.com DOI: 10.9790/9622-1201020616 6 | Page An Optimal Linearized Quali-Quantitative Multi- Objective Simulation Model to Planning and Managing Integrated Surface Resources Systems Allan Sarmento Vieira 1 , Wilson Fadlo Curi 2 1 Professor of University Federal of Campina Grande, Brazil (corresponding author). 2 Professor of University Federal of Campina Grande, Brazil. ABSTRACT This paper presents a multiobjective mathematical model that simulates integrated quali-quantitative aspects of water, using linear programming techniques, which may be used to evaluate the sustainability of existing or planned water resources scenarios in a watershed. One of its main features, which differentiates it from other simulation models available in the literature, is the objective function that incorporates weighted meeting requirements of multiuse water quantity demands, operational targets and the meeting of water quality parameters goals, the last one in accordance with the standards of the Brazilian CONAMA's law. The non-linear mathematical description of hydraulic, water quality and operational processes for water demands, rivers and reservoirs, which are constraints of the optimization model, were appropriately linearized. Biochemical oxygen demand, dissolved oxygen, total phosphorous, total nitrogen, chlorophyll-a and fecal coliforms water quality parameters were included in the model. Some indicators of performance analysis, such as reliability, vulnerability, resilience and sustainability were also included. Keywords - Water resources, Simulation, Linear programming, Quali-quantitative approach --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 10-01-2022 Date of Acceptance: 25-01-2022 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION Water shortage is a chronic problem that affects the entire planet. Its aggravation is related to the economic and population growth that requires a significant increase of water demands or cause pollution of the water bodies. Water quantity and quality crisis is already a today's reality in most regions around the world and requires an increasing phenomena and variables representation complexity to planning and managing water bodies towards reaching the water system sustainability. Under these conditions the evaluation of the water related problems can no longer be restricted to a simple water balance between supply and demand or a simple estimation of its pollution, but should also consider their interrelationships and meet the uses, the geo-environmental and socio-cultural peculiarities or requirements to achieve and ensure a certain level of a region quality of life. Therefore, the better the systemic and holistic mathematical model conception to be used, which takes into account the multi-objectives of the closest representation of water quantity and quality multiple uses requirements, operation and hydrology dynamics, the better the analysis and managing solutions to be provided. In the search for a solution to the complex problems of water resources planning, water resources managers have used techniques and tools, based on mathematical and computational approaches, including techniques of simulation and optimization, to assist in the operation, processes’ analysis, planning and decision-making in water resources system. However, is no longer acceptable the use, only, classic simulation models or optimization with only one goal, as, for example, the maximization of economic efficiency. Following the new trends in the treatment of water resources problems, the inclusion of quantifiable more generic objectives, allowing the consideration of economic, social, political, environmental and other aspects has become necessary (Labadie, 2004 & Wurbs, 2005). The current trend on water resources mathematical modeling is to match the use of simulation and optimization techniques. For Simonovic (1992), this approach helps to reduce or eliminate the gap between practice and theory in water resources system analysis. For Wurbs (2005), various solutions and strategies can be obtained with the use of combined techniques of simulation and RESEARCH ARTICLE OPEN ACCESS