Rainwater harvesting is an effective alternative practice, particularly within urban regions, during periods of water scarcity and dry weather. The collected water is mostly utilized for non-potable household purposes and irrigation. However, due to the increase in atmospheric pollutants, the quality of rainwater has gradually decreased. This atmospheric pollution can damage the climate, natural resources, biodiversity, and human health. In this study, the characteristics and physicochemical properties of rainfall were assessed using a qualitative approach. The three-year (2017–2019) data on rainfall in Peninsular Malaysia were analysed via multivariate techniques. The physicochemical properties of the rainfall yielded six significant factors, which encompassed 61.39% of the total variance as a result of industrialization, agriculture, transportation, and marine factors. The purity of rainfall index (PRI) was developed based on subjective factor scores of the six factors within three categories: good, moderate, and bad. Of the 23 variables measured, 17 were found to be the most significant, based on the classification matrix of 98.04%. Overall, three different groups of similarities that reflected the physicochemical characteristics were discovered among the rain gauge stations: cluster 1 (good PRI), cluster 2 (moderate PRI), and cluster 3 (bad PRI). These findings indicate that rainwater in Peninsular Malaysia was suitable for non-potable purposes.

在缺水和干旱天气期间，雨水收集是一种有效的替代做法，尤其是在城市地区。收集的水主要用于非饮用水家庭用途和灌溉。但是，由于大气污染物的增加，雨水的质量逐渐下降。这种大气污染会损害气候，自然资源，生物多样性和人类健康。在这项研究中，使用定性方法评估了降雨的特征和理化性质。通过多变量技术分析了马来西亚半岛的三年（2017-2019年）降雨数据。由于工业化，农业，交通和海洋因素。降雨指数（PRI）的纯度是根据三个类别（好，中和坏）中六个因素的主观因素得分得出的。根据98.04％的分类矩阵，在测量的23个变量中，有17个是最显着的。总体而言，在雨量计站之间发现了反映理化特性的三个不同组的相似性：聚类1（良好PRI），聚类2（中度PRI）和聚类3（不良PRI）。这些发现表明，马来西亚半岛的雨水适合非饮用水用途。根据98.04％的分类矩阵，发现17个是最重要的。总体而言，在雨量计站之间发现了反映理化特性的三个不同组的相似性：聚类1（良好PRI），聚类2（中度PRI）和聚类3（不良PRI）。这些发现表明，马来西亚半岛的雨水适合非饮用水用途。根据98.04％的分类矩阵，发现17个是最重要的。总体而言，在雨量计站之间发现了反映理化特性的三个不同组的相似性：聚类1（良好PRI），聚类2（中度PRI）和聚类3（不良PRI）。这些发现表明，马来西亚半岛的雨水适合非饮用水用途。