Evaluation of Integrating SWAT Model into a Multi-Criteria Decision Analysis towards Reliable Rainwater Harvesting Systems

Shahab Doulabian,Babak Alizadeh,Ali Abbasi,Alireza Ghaderi Bafti,Erfan Ghasemi Tousi,Reza Aghlmand

doi:10.3390/w13141935

Abstract

Rainwater harvesting (RWH) has been recognized as one of the most reliable and efficient methods for water supply, especially in arid and semi-arid regions (ASARs) facing freshwater scarcity. Nevertheless, due to the inherent uncertainty of input data and subjectivity involved in the selection of influential parameters, the identification of RWH potential areas is a challenging procedure. In this study, two approaches for locating potential RWH sites were implemented. In the first approach, a frequently-used method of the multi-criteria decision analysis and geographic information system (MCDA-GIS) was utilized, while, in the second approach, a novel strategy of integrating the soil and water assessment tool (SWAT) model as a hydrology model into an MCDA-GIS method was proposed to evaluate its performance in locating potential RWH sites. The Mashhad Plain Basin (MPB) was selected as a case study area. The developed potential RWH maps of the two approaches indicated similar patterns for potential RWH areas; in addition, the correlation coefficient (CC) between the two obtained maps were relatively high (i.e., CC = 0.914) revealing that integration of SWAT as a comprehensive hydrologic model does not necessarily result in very different outputs from the conventional method of MCDA-GIS for RWH evaluation. The overlap of developed maps of the two approaches indicated that 3394 km2 of the study area, mainly located in the northern parts, was identified as high-potential RWH areas. The performed sensitivity analysis indicated that rainfall and slope criteria, with weights of 0.329 and 0.243, respectively, had the greatest sensitivity on the model in the first approach while in the second approach, the criterion of runoff coefficient (with weights of 0.358) had the highest impact. Based on results from the identification of the potential locations for conventional RWH techniques, pond and pan techniques are the most proper options, covering high-potential areas of RWH more effectively than other techniques over MPB.

Highlights

Freshwater scarcity has become a pivotal issue in sustainable development [1,2,3], especially in arid and semi-arid regions (ASARs) where communities are encountering water scarcity problems, in agricultural and industrial sectors, and for satisfying domestic water demands [4,5,6,7]
To guarantee the consistency of the analyses, the procedure of weighting thematic layers in analytical hierarchy process (AHP) was set such that the consistency ratio for all of the obtained thematic layers would be less than the limit of 0.10 [67]
Identification of potential Rainwater harvesting (RWH) areas is challenging due to the inherent uncertainty of input data and the subjectivity involved in selection of influential parameters

Summary

Introduction

Freshwater scarcity has become a pivotal issue in sustainable development [1,2,3], especially in arid and semi-arid regions (ASARs) where communities are encountering water scarcity problems, in agricultural and industrial sectors, and for satisfying domestic water demands [4,5,6,7]. East are facing water scarcity and its related consequences [8]. Various factors, such as accelerated climate change, population growth, intensive agricultural activities, and industrialization, as well as continuous pollution of water resources, will exacerbate freshwater scarcity and shortages in the future [9,10]. All schemes for collecting and storing rainwater to supply safe and inexpensive water for different purposes, such as domestic, industrial, and agricultural purposes are identified as RWHs [17,18,19]

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Results

Conclusion