An Interval Two-Stage Fuzzy Fractional Programming Model for Planning Water Resources Management in the Coastal Region – a Case Study of Shenzhen, China

In this study, an interval two-stage fuzzy fractional programming (TFFP) method is developed to support collaborative governance of economy and water resources. Methods of interval programming, fuzzy programming, two-stage programming, and fractional programming are integrated within a general system optimization framework. TFFP could help not only determine the optimized schemes for water resources allocation under various uncertainties, but also handle trade-offs between environmental and economic objectives. A case study of a highly urbanized coastal city (i.e., Shenzhen) in China is provided as an example for demonstrating the proposed approach. The results indicate industrial sectors should be allocated 34.8% of the total water supply, while agricultural sectors accounts for 1.5%. For the spatial allocation of water resources, Bao An, Long Gang, and Fu Tian districts should be allocated more water to promote the economic development. The discharge analysis indicates that chemical oxygen demand (COD cr ) and total phosphorus (TP) would be key pollutants. Moreover, the optimized seawater desalination volume would be negligibly influenced by price, while the upper bounds of desalination would be increased with the raising acceptable credibility levels in the period of 2031 to 2035. Analysis of desalination prices also reveals that the decision-makers should increase the scale of desalination in the period of 2021 to 2025. In addition, the effectiveness and applicability of TFFP would be evaluated under economic maximization scenarios. The result showed that the economic maximization scenario could obtain higher economic benefits, but it would be accompanied by a larger number of pollutant discharges.