半乾旱與乾旱地區永續雨水收集適址之最佳化方法

Abstract

Rainwater harvesting (RWH) is a sustainable solution for mitigating water scarcity, particularly in regions experiencing irregular and declining precipitation. This research focuses on the Southern Province of Zambia, a region that is becoming increasingly susceptible to climate fluctuations and the resulting challenges to sustained water security. Despite previous studies have explored RWH, there remains a significant shortfall in developing integrated frameworks that are spatially optimized to address the unique requirements of semi-arid regions. Here, the study developed a hybrid model integrating Geographic Information Systems (GIS) with Multi-Criteria Decision Analysis (MCDA) to delineate suitable zones for RWH implementation. In the evaluation, twelve criteria were taken into account, addressing physical, environmental, and socio-economic factors, with the Standardized Precipitation Index (SPI) serving as a climatic indicator. The Fuzzy Analytic Hierarchy Process (Fuzzy-AHP) was applied to assess the relative weights of the criteria, identifying rainfall, curve number, and slope as the most influential factors. Suitability maps were generated and classified into five categories including not and low suitable regions, most, highly, and moderately suitable. Results from Fuzzy-AHP and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) indicated that 62% and 37.5% of the study area, respectively, are favorable for RWH. The northern and southwestern regions exhibited the highest suitability due to their advantageous physical and socio-economic conditions. Sensitivity analysis, conducted by varying the fuzziness degree (FD), confirmed the robustness of the model. Validation through TOPSIS revealed a 63% spatial agreement and 67% accuracy, supporting reliability of the model. This research presents a reproducible, affordable, and climate-adaptive approach for sustainable RWH site selection and informed water resource planning in drought-prone regions.

Rainwater harvesting (RWH) is a sustainable solution for mitigating water scarcity, particularly in regions experiencing irregular and declining precipitation. This research focuses on the Southern Province of Zambia, a region that is becoming increasingly susceptible to climate fluctuations and the resulting challenges to sustained water security. Despite previous studies have explored RWH, there remains a significant shortfall in developing integrated frameworks that are spatially optimized to address the unique requirements of semi-arid regions. Here, the study developed a hybrid model integrating Geographic Information Systems (GIS) with Multi-Criteria Decision Analysis (MCDA) to delineate suitable zones for RWH implementation. In the evaluation, twelve criteria were taken into account, addressing physical, environmental, and socio-economic factors, with the Standardized Precipitation Index (SPI) serving as a climatic indicator. The Fuzzy Analytic Hierarchy Process (Fuzzy-AHP) was applied to assess the relative weights of the criteria, identifying rainfall, curve number, and slope as the most influential factors. Suitability maps were generated and classified into five categories including not and low suitable regions, most, highly, and moderately suitable. Results from Fuzzy-AHP and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) indicated that 62% and 37.5% of the study area, respectively, are favorable for RWH. The northern and southwestern regions exhibited the highest suitability due to their advantageous physical and socio-economic conditions. Sensitivity analysis, conducted by varying the fuzziness degree (FD), confirmed the robustness of the model. Validation through TOPSIS revealed a 63% spatial agreement and 67% accuracy, supporting reliability of the model. This research presents a reproducible, affordable, and climate-adaptive approach for sustainable RWH site selection and informed water resource planning in drought-prone regions.