Identification of suitable zones and sites for rainwater harvesting using GIS and multicriteria decision analysis

Rainwater collection systems play a crucial role in enhancing water availability in regions with low precipitation. This study focused on identifying potential rainwater harvesting (RWH) locations in drought-prone areas, specifically the Borena zone of Oromia and the regional states of Somali. This research leveraged geospatial techniques and a multi-criteria decision analysis (MCDA) to assess feasible RWH sites. The dataset comprises essential factors such as rainfall, drainage density, slope, soil texture type, and land use/land cover. These thematic layers serve as inputs for analysis, with each factor being weighted using the Analytical Hierarchy Process (AHP) method based on its significance. Reclassifying factors into subclasses facilitates suitability analysis. The weighted linear combination (WLC) technique is applied to identify and prioritize potential rainwater harvesting (PRWH) locations based on four suitability classes: highly suitable, moderately suitable, low suitability, and unsuitable. Our findings reveal that 1% of the study area, covering approximately 3288 km2, is highly suitable for RWH. Areas with moderate suitability constitute approximately 12% (37,498 km2), while regions with low suitability, representing the majority, encompass about 75% (242,170 km2). Additionally, 13% (41,000 km2) of the study area is deemed unsuitable for RWH. The proposed technique for identifying suitable RWH sites is adaptable to other low-precipitation regions. However, before implementing RWH structures, further research is imperative. This study proposed the exploration of socioeconomic variables in future research and urged for an in-depth examination of various aspects of environmental sustainability. Our research paves the way for adapting rainwater harvesting systems to align with community needs and life cycles while also exploring the socio-economic and environmental dimensions of sustainability for future study. The insights offer promising solutions to address the urgent issues associated with water scarcity. This should include comprehensive site depictions, an exploration of social and economic activities, and the meticulous preparation of a cost-benefit analysis.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Rainwater Harvesting Site Selection for Drought-Prone Areas in Somali and Borena Zones, Oromia Regional State, Ethiopia: A Geospatial and Multi-Criteria Decision Analysis

Bojer,

Bekalo,

Debelee

et al. 2024

“…Various methodologies have been developed for selecting potential RWH sites, which include remote sensing (RS) and geographical information systems (GIS) in combination with various multicriteria decision analysis and hydrological modeling approaches [9,16,17]. However, the application of RS and GIS along with multicriteria decision analysis (MCDA) has gained importance as it provides a systematic methodology for the complex problems to locate potential regions for soil and water conservation structures and artificial/traditional GW recharge techniques [18][19][20][21][22]. Further, reviewers have identified various types of discrete MCDA techniques, such as multi-attribute utility theory (MAUT), simple additive weighting (SAW), analytic network process (ANP), technique for order of preference by similarity to ideal solution (TOPIIS), preference ranking organization method for enrichment of evaluations (PROMETHEE) and Analytical Hierarchy Process (AHP).…”

Section: Introductionmentioning

confidence: 99%

Scaling Up Indigenous Rainwater Harvesting: A Preliminary Assessment in Rajasthan, India

Rawat

Panigrahi

Yadav

et al. 2023

Rainwater harvesting (RWH) has the potential to enhance the sustainability of ground and surface water to meet increasing water demands and constrained supplies, even under a changing climate. Since arid and semi-arid regions frequently experience highly variable spatiotemporal rainfall patterns, rural communities have developed indigenous RWH techniques to capture and store rainwater for multiple uses. However, selecting appropriate sites for RWH, especially across large regions, remains challenging since the data required to evaluate suitability using critical criteria are often lacking. This study aimed to identify the essential criteria and develop a methodology to select potential RWH sites in Rajasthan (India). We combined GIS modeling (multicriteria decision analysis) with applied remote sensing techniques as it has the potential to assess land suitability for RWH. As assessment criteria, spatial datasets relating to land use/cover, rainfall, slope, soil texture, NDVI, and drainage density were considered. Later, weights were assigned to each criterion based on their relative importance to the RWH system, evidence from published literature, local expert advice, and field visits. GIS analyses were used to create RWH suitability maps (high, moderate, and unsuited maps). The sensitivity analysis was also carried out for identified weights to check the inadequacy and inconsistency among preferences. It was estimated that 3.6%, 8.2%, and 27.3% of the study area were highly, moderately, and unsuitable, respectively, for Chauka implementation. Further, sensitivity analysis results show that LULC is highly sensitive and NDVI is the least sensitive parameter in the selected study region, which suggests that changing the weight of these parameters is more likely to decide the outcome. Overall, this study shows the applicability of the GIS-based MCDA approach for up-scaling the traditional RWH systems and its suitability in other regions with similar field conditions, where RWH offers the potential to increase water resource availability and reliability to support rural communities and livelihoods.

“…RWH represents a comprehensive approach to supporting agriculture in regions with limited precipitation during the period of crop growth and scarce water resources [13]. For easier and more cost-effective access to water for irrigation purposes, it is important to scientifically identify appropriate locations for RWH [14].…”

Section: Introductionmentioning

confidence: 99%

Using Geographic Information Systems and Multi-Criteria Decision Analysis to Determine Appropriate Locations for Rainwater Harvesting in Erbil Province, Iraq

Ahmed,

Bilgili,

Cullu

et al. 2023

Water scarcity is a prominent consequence of global climate change, presenting a significant challenge to the livelihoods of wide parts of the world, particularly in arid and semi-arid regions. This study focuses on Erbil Province in Iraq, where the dual effects of climate change and human activity have significantly depleted water resources in the past two decades. To address this challenge, rainwater harvesting (RWH) is explored as a viable solution. The purpose of this study is to make a suitability zone map that divides the study area into several classes based on the features of each area and its ability to collect rainwater. The map will then be used to find the best place to build different RWH structures. Seven different layers are used to make the RWH suitability zone map: rainfall, runoff, land use/cover (LU/LC), soil texture, slope, drainage density, and the Topographic Wetness Index (TWI). Each layer was assigned specific weights through the Analytical Hierarchy Process (AHP), considering its relevance to RWH. Results revealed four suitability classes: very highly suitable 1583.25 km2 (10.67%), highly suitable 4968.55 km2 (33.49%), moderately suitable 5295.65 km2 (35.69%), and lowly suitable 2989.66 km2 (20.15%). Notably, the suitability map highlights the northern and central regions as particularly suitable for RWH. Furthermore, the study suggested three suitable locations for constructing medium dams, six for check dams, and twenty-seven for farm ponds, according to the requirements of each type. These findings provide valuable insights for the strategic planning and effective management of water resources in the study area, offering potential solutions to the pressing challenges of water scarcity.