Next Article in Journal
Evaluation of Fresh Groundwater Lens Volume and Its Possible Use in Nauru Island
Next Article in Special Issue
Comparing Performance of ANN and SVM Methods for Regional Flood Frequency Analysis in South-East Australia
Previous Article in Journal
Removal of Amoxicillin from Processing Wastewater by Ozonation and UV-Aided Ozonation: Kinetic and Economic Comparative Study
Previous Article in Special Issue
Assessing the Impacts of Climate Change on Rainwater Harvesting: A Case Study for Eight Australian Capital Cities
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Review of Rainwater Harvesting Research by a Bibliometric Analysis

School of Engineering, Design and Built Environment, Western Sydney University, Building XB 3.43, Penrith, NSW 2751, Australia
Author to whom correspondence should be addressed.
Water 2022, 14(20), 3200;
Submission received: 15 July 2022 / Revised: 4 October 2022 / Accepted: 7 October 2022 / Published: 11 October 2022
(This article belongs to the Special Issue Sustainable Water Futures: Climate, Community and Circular Economy)


This study presents a review of recent rainwater harvesting (RWH) research by a bibliometric analysis (based on performance analysis and science mapping method). Following the inclusion/exclusion criteria, a total of 3226 publications were selected for this bibliometric analysis. From the selected publications, the top journals were identified according to number of publications and number of citations, as well as the authors with the highest number of publications. It has been found that publication rate on RWH has been increasing steadily since 2005. Water (MDPI) journal has published the highest number of publications (128). Based on the literature considered in this review, the top five authors are found as Ghisi, E., Han, M., Rahman, A., Butler, D. and Imteaz, M.A. in that order. With respect to research collaborations, the top performing countries are USA–China, USA–Australia, USA–UK, Australia–UK and Australia–China. Although, the most dominant keywords are found to be ‘rain’, ‘rainwater’, ‘water supply’ and ‘rainwater harvesting’, since 2016, a higher emphasis has been attributed to ‘floods’, ‘efficiency’, ‘climate change’, ‘performance assessment’ and ‘housing’. It is expected that RWH research will continue to rise in future following the current trends as it is regarded as a sustainable means of water cycle management.

1. Introduction

Continuous urban development, changing climate and shirking cities have placed a lot of strain on the centralised water infrastructures leading to water scarcity in many cities as well as urban flooding [1]. It is reported that by 2050, urban water demand could increase by a further 80% as a result of growth in population and their wealth [2]. Several technologies have been implemented in easing these problems, and rainwater harvesting (RWH) is one of the decentralised technologies that has attracted several researchers’ attention in tackling water scarcity in many cities and urban flooding [3].
A decentralised RWH system involves purchasing rainwater tanks by households to collect and store rainwater which can be used for many nonpotable purposes and, in some cases, potable purposes if the water is treated properly [4]. The most important decision that has to be made by the household is to the selection of optimum tank size that would improve not only the reliability of the system but also the saving. The recognised definition of reliability is how much the water demand can be supplemented by stored rainwater [5,6]. The saving can be defined as the difference between the reduction in water bill because of the use of rainwater and the costs of purchasing and maintaining the rainwater tank.
The RWH system is considered a viable method of addressing water-related challenges by many researchers; however, the feasibility of this method has also been contested by others [1,7]. The primary benefit of decentralised RWH systems over centralised systems is they are multi-purpose. For example, they can increase water supplies, subsidise the use of high-quality drinking water for nonpotable purposes and contribute to the reduction of stormwater runoff [5,8]. Though the advantages of RWH systems in mitigating water supply and runoff reduction have been well supported in the existing literature [9,10,11], many argued that the system has low water supply potential and the cost is substantially higher than that of the centralised systems [12,13].
The inconsistent findings discussed above on the feasibility of a decentralised RWH system opens doors for further investigation. A literature review is one of the standard methods of accumulating recent results and systematically analysing them to make a decisive decision on an argument [14]. Several review articles can be found in the existing literature on the RWH system. Table 1 includes literature review articles published recently on RWH systems.
As we can see that the focuses of current review studies are on the benefits of RWH systems [15,28,29,30], optimisation of tank size [3,20,31], potential application in rural irrigation [19,21,26], quality of harvested rainwater and its treatment processes [8,17,27] and application of new technologies in maximising the benefits of RWH systems [16,24,28]. To provide a few more details, Semaan, et al. [3] performed a literature review on the optimal sizing of rainwater harvesting systems. Sizing of storage was identified as the most important objective of optimization, yet sizing for cost was the most frequently implemented outcome of optimization [3]. Musayev, et al. [14] investigated the performance of rainwater harvesting (globally) under climate conditions and argued that climate change would have little impact on the performance even in arid regions. Conversely, Haque, et al. [32] ‘s model showed that climate change would have a negative impact on the RWH system’s performance. Liu, et al. [33] studied the use of membrane technology in treating harvested rainwater. It was concluded that the proposed technology could significantly improve the water quality; however, the main challenge with this technology is membrane fouling. Deng [34] investigated contaminants in the harvested rainwater and their impact on urban agriculture. It was argued that a tailored water treatment system needed to be added to the RWH system to supply quality water to the crops. Hindiyeh, et al. [35] studied policies in different countries on implementing RWH system and revealed that many countries still do not have a comprehensive policy.
Based on the above discussion, it can be argued that most of the previous reviews articles focused on the optimal sizing of the RWH system which would be cost effective, quality of the harvested rainwater, treatment of the harvested rainwater, effect of climate change on the RWH system performance and policies/guidelines for adopting RWH systems. While all these studies have their own merit, a bibliometric analysis of the RWH system does not exist in the available literature. Therefore, this study aims to present a bibliometric analysis on RWH systems, which will complete the process of detecting the state of the art of this technology.

2. Materials and Methods

Methodological workflow [36] of the bibliometric analysis carried out in this study is given in Figure 1.

2.1. Step I: Designing of Research

This bibliometric analysis aimed to depict the conceptual evolution and trends of RWH studies between 1982 and 2021. Bibliometric methods (performance analysis and science mapping) were used to address scientific evolution (e.g., in terms of authorship, country of origin and citations) and their network (e.g., co-occurrence, co-citation and co-authorship) of a given topic. This study used the following keywords and their combinations to map the research on RWH: “roof harvest”, “rainwater harvest”, “rainwater tank”, “roof-harvested rainwater”, “rainwater usage”, “sustainable urban developments”, “potable water saving”, “urban flood mitigation”, “urban water cycle”, “rain barrel”, “water sensitive urban design”, “low impact development”, and “urban irrigation”.

2.2. Step II: Compilation of Bibliometric Data

Selection of a database depends on quality and quantity of information, ease to use, institutional access, maximum downloadable data at once, coverage of journals and volume of data. Elsevier’s Scopus and Thomson Reuters’ Web of Science (WoS) are the most widely used databases in bibliometric analysis in different fields [37,38,39,40]. It was argued that the results (documents) and impacts (citations) of countries obtained from the Scopus and WoS databases were highly correlated [41], even though both databases differ in terms of scope, the volume of data and coverage policies [42]. We selected the Scopus database due to its significant coverage of peer-reviewed publications [43] and allowance to download a high number of data at once (e.g., Scopus allows to download 2000 documents, whereas WoS allows downloading 500 documents at once) and institutional access. Published studies on RWH were obtained through the Scopus database covering the period from 1982 to 24 October 2021. Although our search was in October 2021, we noted eight documents’ publication dates as 2022 on Scopus. The query for data collection was searched in title (TITLE), abstract (ABS) and keywords (KEY) with Boolean logical functions-AND/OR- as follow: TITLE-ABS-KEY ((“roof* harvest*”) OR (“harvest* roof*”) OR (“roof* rainwater”) OR (“rainwater harvest*”) OR (“harvest* rainwater”) OR (“rainwater tank”) OR (“roof-harvested rainwater”) OR (“rainwater usage”) OR (“sustainable urban developments” AND rainwater) OR (“potable water saving” AND rainwater) OR (“urban flood mitigation” AND rainwater) OR (“urban water cycle” AND rainwater) OR (“rain barrel” AND rainwater) OR (“water sensitive urban design” AND rainwater) OR (“low impact development” AND rainwater) OR (“urban irrigation” AND rainwater)).
Downloaded data formats were RIS (Endnote and Zotero), csv (VOSviewer and Microsoft Excel) and BibTeX (Rstudio and LaTeX) for the analysis. The exported data from Scopus consists following information: citation information (author(s), document and source title/type, year, citation count), bibliographical information, keywords (keyword plus and author keywords), and other information (includes references). The search criteria were limited to language (English), source type (e.g., journal, conference proceeding and book), document type (article, conference paper, book chapter, review, conference review and book) and time span (1982 to 24 October 2021) in the search query.

2.3. Step III: Data Cleaning and Software

Data cleaning is one of the most crucial and critical steps of bibliometric analysis. It was reported that downloaded data might contain numerous inconsistencies in the data format [44]. For instance, inconsistent cells (e.g., misspellings, variant names and overflowing into the next cell in csv format), no author information, duplicates or irrelevant documents. Although detecting irrelevant documents is not exactly a part of the data cleaning phase, it is the most difficult and tricky one to detect for a reliable bibliographic analysis. The reason is that authors may suggest using “rainwater harvesting” in the abstract although they did not address it in the main text. Therefore, detecting irrelevant documents requires more effort and time in bibliometric analysis. Figure 1 illustrates number of initial search (n = 3394) and number of total removed documents (n = 168). We obtained 3226 documents after data cleaning (removing duplicates, no author information and irrelevant papers) for the analysis to be addressed.
Different tools can be used for science mapping [45,46,47,48,49,50,51,52,53]. The bibliometrix R-package and VOSviewer have been used widely in scientometrics studies in different field all around the world [54,55,56,57,58,59]. Bibliometric analysis in this study was carried out by using the bibliometrix R-package 3.1.4 [44] in Rstudio environment (, accessed on 24 October 2021) and VOSviewer 1.6.17 [53].

2.4. Step IV: Analysis and Visualization

There are two main pillars in bibliometric methods, which are performance analysis and science mapping. Performance analysis aims to evaluate scientific actors (authors, countries, institutions) and the impact of their activities. Science mapping seeks to reveal the cognitive (structure) and evolution of scientific fields.
We used auxiliary tools, Microsoft Excel 2016 and ArcGIS 10.6.1 (, accessed on 21 November 2021), in addition to the bibliometrix R-package and VOSviewer for bibliometric analysis.

2.5. Comprehensive Strength Analysis

The number of publications (academic scale) and citations (influence) can reflect the academic impact of the country [60].
Standard scores of indicators, which are total publications and citations, are calculated using the standard score method for each country as follows:
Z i j = x i j μ j σ i j
σ i j = i x i j μ j 2 N
where Z i j is the standard score of j indicator in i country; x i j is the original score of j indicator in i country; μ j is the average score of j indicator; N is the number of countries; σ i j is standard deviation of j indicator in i country. Table 2 represents the summary of downloaded data used in this study.

3. Results and Discussion

This section is organized into six sub-categories including general statistics, featured sources and publications, authors statistics, keywords statistics, countries and their collaborations.

3.1. General Statistics

Based on our search, a total of 3226 documents were published on RWHs between the years 1982 and 2021. Published documents were from 1002 different sources and 91 countries. Publishing trends and average citations of RWH studies are given in Figure 2. As can be seen, break year (abrupt change) was detected in the early 2000s and noticeable growth was continued up to date. In the last five years, the highest number of publications were occurred in 2020 (n = 331), 2021 (n = 283), 2018 (n = 282), 2019 (n = 263), 2017 (n = 254) in that order. Furthermore, the highest average citation per year has been increasing since the early 2000s, parallel to the number of publications.

3.2. Featured Sources and Highly Cited Publications

The data were collected from 1002 academic sources in RWH field from Scopus between 1982 and 2021 (October). According to the statistics of these sources, the top 15 journals that published most of the articles related to RWH and their publication trends over time are presented in Table 3 and Figure 3. The Water (MDPI) was the first ranked journal with the highest number of publication (n = 128), the highest publication ratio (3.97%) followed by Journal of Cleaner Production with 81 publications and 2.51% publication ratio. Although, these two journals started to publish first time in 2011, the Journal of Cleaner Production had a much higher total citation (TC = 1897) than Water (MDPI) (TC = 1386). However, Agricultural Water Management (TC = 2704) and Resources Conservation and Recycling (TC = 2670) had far higher total citations than other journals. Besides, Resources Conservation and Recycling had the highest H-index among other journals. The H-index was developed by Hirsch [61] to evaluate and quantify academic impacts. The H-index is an author’s (or journal’s) number of publications (h), each of which has been cited in other documents at least H times. Simply, a higher H-index shows a greater academic impact. Therefore, the H-index is an important parameter to evaluate the quantity and quality of academic studies in any bibliometric analysis [62,63]. Agricultural Water Management has the oldest publication history (first published in 1982), whereas Resources Conservation and Recycling started to publish first in 2007. Furthermore, Resources Conservation and Recycling holds the highest H-index (32) and the second-best citation per publication (CPP) (40.45). Figure 3 illustrates that Water (MDPI) was the only one showing the steepest growth trend among other journals. It should be noted that there were 16 articles published on rainwater harvesting in 2010 in Water Science and Technology (as evidenced by the peak in Figure 3). There was no special issue on rainwater harvesting in this year, and it was found that 4, 2, 4, 4 and 2 articles were published respectively in January, March, April, July and August regular issues. The very high growth rate of Water (MDPI) (in Figure 3) during 2018 to 2021 could be attributed to strong promotion/marketing by this journal.
The number of citations of an article is one of the prominent ways to reflect its academic impact and influence. Table 4 presents top 15 highly cited articles. The most frequently cited article on RWH related studies was published in 2009 in Field Crops Research by Li-Min Zhou from China [64]. It has been cited for 396 times with 30.46 citation per year. Among the top 15 most frequently cited articles, there are three from China and these highly cited articles are mainly related to agricultural studies. It is possible that an article can be cited by others in a different discipline. Therefore, citation analysis is an essential tool to see the degree of connectivity between pairs of articles in the created 3226-papers network. Table 5 illustrates results of citation analysis. As we can see, local citations show the number of citations within the 3226 publications whereas global citations present the actual Scopus citations (Table 4 also presents global citations). The citation analysis revealed that 1487 papers out 3226 have cited each other (at least once). In other words, 1739 papers out of 3226 have not cited each other. About 28% of 1487 papers have been cited only once. Furthermore, 821 papers out of 3226 have not been cited either locally or globally. The reason is the fact that considerable proportion of these 821 papers were published in the last few years. For example, the percentage of papers published between 2020 and 2022 was 41% (336 documents) whereas 5% (46 documents) of non-cited papers were published before 2005. Another reason is that a significant number of sources have been introduced recently. For instance, the number of sources that had their first issue between 2018 and 2022 is 113 whereas 222 sources had their first issue between 2014 and 2018. More details about non-cited documents can be found in Figure A1 and Figure A2. It can be seen from Table 5 that there are noticeable differences between local and global citations; the reason is that RWH field has also received interest from researchers in other fields. Besides, it can also be seen that the order of papers based on local and global citations does not need to match. For instance, Abdulla and Al-Shareef (2009) has ranked as first in Table 5 in terms of local citation yet has been placed at the sixth rank based on global citation (Table 4). Interestingly, highly cited articles (Table 4) from China were not appeared in local citation analysis (Table 5). In contrast to global citation in Table 4, Australia is the leading country in terms of local citation (Table 5) whereas China is not in the top 15 local citations list.

3.3. Author Statistics

Table 6 represents the top 15 authors in RWH related studies. The number of an academic publication can reflect an author’s research strength and academic impact of his/her work. Hence, the quantity of a researcher’s papers in a field is regarded as an important index in order to evaluate the author’s influence in the field [62]. According to the results, 7522 authors produced 3226 publications. Among them, 256 authors have more than five articles, representing 3.40% of the total authors and their publications account for 19.34% of the total number of publications. The most productive author in RWH field was Ghisi, E. from Brazil, who has 45 articles, 1454 citations, 19 H-index, 38 g-index and 91 citation per year. Egghe [88] introduced the g-index, which is the unique largest number such that the top g articles received together at least g2 citations. H-index and g-index complement each other [89]. Ghisi, E. (Brazil) and Rahman, A. (Australia) were the only authors who were cited more than 1000 times in RWH field. Rieradevall, J. from Spain has the highest citation per article with 38.5 times. Moreover, his first publication year was 2011, which was later than most of the top authors.
Co-citation analysis, which studies the cited documents [90], is the most common analysis in bibliometric area [44,91,92]. Co-citation analysis is a tool for monitoring the development of scientific fields, and for assessing the degree of interrelationship among specialities [90]. Co-citation of two documents occurred when two documents were cited together in a third document. It should be noted that self-citation issue was not considered in this study. It can be a legitimate way to reference authors’ earlier findings; however it affects all the citation metrices. Figure 4 presents the findings of frequently cited authors in terms of co-citation. Network visualization maps illustrate the extent and strength link among authors. The size of circles depicts the total strength of the cited authors (nodes) and thickness of lines represents the strength of collaboration between any two nodes. The distance between two authors roughly indicates the relatedness of the authors in terms of co-citation links. The closer the two authors (nodes) are, the stronger their relatedness. The cluster to which the item belongs determines the colour of an item. Co-citation analysis between cited authors with full counting method [53] shows that there were 4904 links between 100 out of 103,021 authors in five clusters in the RWH field (Figure 4). Authors with a minimum number of 100 citations were selected and 200 of 103,021 authors met the selected threshold. For each of the 200 authors, the total strength of the co-citation links with other authors were calculated. The top 100 authors with the greatest total link strength were selected and given in Figure 4.
Table 7 presents the top 15 co-cited authors which visualized in Figure 4. It can be seen that the top four authors who are Ghisi, E., Butler, D., Rahman, A. and Imteaz, M.A. had far higher total link strength than others. Those four authors were also placed in the same cluster (Cluster 1-Red). The biggest link strength (=2004) was between Rahman, A. and Imteaz, M.A. Link strength between Rahman, A. and Ghisi, E. was 1528 whereas between Butler, D. and Ward, S. was 1679.

3.4. Keyword Statistics

Table 8 presents the most frequently used keyword in RWH related studies. Although author’s keywords and keyword plus are very similar, there are noticeable differences in terms of their frequencies. For instance, frequency of rainwater is 131 and 1139 based on author’s keywords and keyword plus, respectively. The reason is because keywords plus are index terms obtained by a computer algorithm based on frequent words (more than once) in the titles and in the reference list of papers. Therefore, keywords plus comprise the majority of author keywords [93]. The use of keywords plus helps capturing a document content with greater variety and depth in bibliometric analysis [94]. Keywords plus have been widely used to identify gaps or research trends in different scientific studies [95,96,97,98].
Although number of keywords is important for a research area, changing of keywords over time helps to understand research trends. Figure 5 illustrates the thematic evaluation of author’s keywords between 1982 and 2021. Abrupt changes on number of publications were found based on the Pettitt test [99] and the SNHT [100] as 1999 and 2009, respectively (see Figure A3). Each node in Figure 5 represents a cluster of author’s keywords for a given sub-period. Furthermore, the size of the nodes is proportional to the number of author’s keywords for the corresponding cluster. The flow between nodes illustrates the evolutionary direction of the clusters.
Analysing the most frequent words with their occurrence by time allows us to interpret evaluation of research trends. For this purpose, trend topics (TTs) were analysed and given in Figure 6. The size of dots represented the frequency of words, whereas the horizontal line depicted the time frame of frequency of occurrence. We used the parameters to create the TTs (Figure 6) as follows: field (keyword plus), time span (1982–2021), minimum word frequency (15), and number of words per year (2).
For instance, the term ‘agricultural robots’ occurred 46 times between 2020 and 2021. Although ‘Iran’ placed in top of the TTs, it occurred only 22 times between 2013 and 2020. TTs also depicts the top Australian authors published mostly after 2010 (see also Table 4 and Table 5). It can be seen from the Figure 6, the term ‘Australia’ occurred 294 times between 2010 and 2015. This result also shows that several researchers focused on rainwater harvesting in Australia after one of the worst droughts, ‘Millennium Drought’ [101,102,103].
Figure 7 illustrates the co-occurrence map of all keywords (author keywords and keyword plus) over time with full counting method in RWH field. High frequency keywords which is occurred minimum 50 times were selected to make co-occurrence analysis of keywords. Based on selected criteria, 185 keywords met the threshold out of 16,466 keywords. The most frequent used keywords detected between 2013 and 2016. The closeness of a node (circle/keyword) to another reflects the degree of relatedness of the two nodes (keywords) [104]. Colour of circles represent the average publication year whereas size of the circle represents number of links between keywords. For example, number of occurrences and average publication year of ‘tanks (containers)’ were 271 and 2015.25, respectively. The purple colour shows the publishing time before 2013, most keywords like ‘water recycling’, ‘computer simulation’, ‘sanitation’, ‘water tanks’, ‘rural area’ etc. The most dominant keywords which had the highest total strength are as follows: rain (link strength = 12,962), rainwater (link strength = 10,645), water supply (link strength = 10,286), rain water harvesting (link strength = 8459), and water management (link strength = 8226). Occurrences of given keywords were 1357, 1159, 1062, 947, and 907 times, respectively. Figure 7 depicts that more and more researchers have focused on ‘floods’, ‘efficiency’, ‘climate change’, ‘performance assessment’, ‘housing’, and ‘decision making’ keywords after 2016.

3.5. Featured Countries and Collaboration Network Analysis

Table 9 and Figure A4 present the most active countries in RWH field. The number of publications is one of the important indicators to assess the development trends in a specific research area. It can be seen that Australia is the leading country in terms of number of articles on RWH (n = 318) and total citations (n = 6687) (Table 9). Table 9 shows that the USA was the first ranked country based on single country publication (SCP) whereas Australia had the highest number of multiple country publication (MCP). SCP and MCP refer to international collaboration of authors in the RWH related studies. SCP represents publications done by authors who belonged to the same country, whereas MCP represents that the publications were written by the authors who belonged to different countries.
We calculated the ranking of comprehensive strength of each country based on quantity of publications and citations. A country’s research strength in a particular field to a certain extent can be reflected by its number publications whereas the citation frequency of one publication reflects its academic influence [60]. Figure 8 depicts that Australia, China, USA and India were leading countries and their standard scores are far higher than other countries.
The result of co-authorship analysis between countries with full counting method [53] is shown in Figure 9. There were 413 links between 50 out of 69 countries, 1208 total link strength in six clusters. The following pairs of countries were found to be having strong collaborations: USA–China (link strength = 30), USA–Australia (link strength = 28), USA–UK (link strength = 17), Australia–UK (link strength = 14), Australia–China (link strength = 14), Australia–Bangladesh (link strength = 14) and Germany–Tanzania (link strength = 14). The number of co-authorship was the highest for the USA (40 links), UK (40 links), Australia (37 links), The Netherlands (35 links), and Germany (32 links). Average publication year of these countries are as follow: USA (2014.35), UK (2012.98), Australia (2013.73), The Netherlands (2014.62) and Germany (2014.38).
Table 10 shows the most productive institutions in RWH field. Seoul National University (n = 64) was the leading institution followed by CSIRO Land and Water (n = 63). These are the most dominant institutions based on number of publications. Australia is the most dominant country in terms of number of institutions in the top 15 productive institutions.

3.6. Comparison of the Most Cited Documents on Scopus, Web of Science and Google Scholar

Scopus, Web of Science (WoS) and Google Scholar (GS) are the most widely used databases for scientific search and analysis. However, they have pros and cons depending on purpose. This study did not aim to compare these databases. However, we would like to show comparison of the most cited articles from these databases. Other comparisons such as trends or network analysis are not possible with GS since GS does not allow to download data in any specific data format. Therefore, Table 11 present the most frequently cited document with their citations in Scopus, WoS, and GS. It clearly shows that all highly cited papers had higher number of citations in GS than Scopus and WoS. The reason is that GS includes several non-indexed repositories compared to Scopus and WoS. WoS had the lowest number of citations without exception compared to GS and Scopus. Furthermore, one paper was not found in WoS database.

4. Conclusions

This study presents a review of RWH studies using a bibliometric analysis considering publications between 1982 and 2021 sourced from Scopus database. A total of 3226 documents were found on RWH research. It has been found that since early 2000s, there is a continued growth in publication count in RWH research. Moreover, Water (MDPI) has published the highest number of publications (128), followed by Journal of Cleaner Production with 81 publications. In terms of total citations, Agricultural Water Management has the highest citations (2704), followed by Resources Conservation and Recycling (2670).
Based on the current analysis, it can be argued that Ghisi, E. is the most active author in RWH, followed by Han, M., Rahman, A., Butler, D. and Imteaz, M.A., Ghisi, E. and Rahman, A. are the only authors who were cited more than 1000 times in RWH research. However, Rieradevall, J. from Spain has the highest citation per article. In terms of link strength, the top four authors are identified as Ghisi, E, Butler, D., Rahman, A. and Imteaz, M.A. In relation to research collaboration, the top performing countries are USA–China, USA–Australia, USA–UK, Australia–UK, Australia–China, Australia–Bangladesh and Germany–Tanzania. The most productive institutions in RWH field (based on number of publications) are Seoul National University, CSIRO Land and Water, Universidade Federal de Santa Catarina, University of Exeter and Western Sydney University.
The most dominant keywords having the highest total strength are rain, rainwater, water supply, rainwater harvesting and water management; however, more and more researchers have focused on ‘floods’, ‘efficiency’, ‘climate change’, ‘performance assessment’, ‘housing’, and ‘decision making’ keywords after 2016.
It is expected that research on RWH will continue to rise in coming years as it is considered as a sustainable means of water cycle management. Many of the previous research studies were focused in urban areas to save mains water. Future research should focus on (i) RWH for drinking water production in rural areas fitted with disinfection systems; (ii) RWH for household irrigation; (iii) application of GIS to identify suitable areas to harvest rainwater at a larger scale; (iv) RWH for stormwater and flood management as a component of water sensitive urban design; (v) community scale RWH; (vi) RWH for urban livelihood improvement in developing countries; (vii) utilization of harvested rainwater for mitigating heat island effects; (viii) rural drinking water production mini industry based on harvested rainwater; (ix) use of harvested rainwater for artificial groundwater recharge; (x) storing harvested rainwater within seawater and in large flexible rubber balloons/bladder tanks; (xi) impact of climate change on RWH; (xii) innovative rainwater tanks to suit site and water quality requirements; (xiii) RWH in water-food-energy-ecosystems nexus; and (xiv) fully automatic/digital RWH systems with water quantity and quality monitoring.
The main contribution of this research is mapping the previous research on RWH, which will assist to direct future research in this important area. When the capability of the bibliometric analysis tools increases in future, a new bibliometric analysis should be carried out.

Author Contributions

G.Y. designed the research, analysed the data, and drafted the manuscript; M.A.A. and A.R. assisted to evaluate the results and edited the manuscript. All authors have read and agreed to the published version of the manuscript.


This research received no funding.

Data Availability Statement

The data presented in this study are openly available in the Scopus database (, accessed on 24 October 2021).


The authors acknowledge the developers of all the software/tools used in the bibliometric analysis.

Conflicts of Interest

The authors declare that there is no conflict of interest.

Appendix A

Figure A1. Distribution of non-cited documents.
Figure A1. Distribution of non-cited documents.
Water 14 03200 g0a1
Figure A2. Distribution of sources over time with their first issue year.
Figure A2. Distribution of sources over time with their first issue year.
Water 14 03200 g0a2
Figure A3. Significant change in number of publications with upward shift between 1982 and 2021 (mu1 and mu2 are the mean number of publications before and after the break years, respectively) based on the Pettitt and SNHT tests.
Figure A3. Significant change in number of publications with upward shift between 1982 and 2021 (mu1 and mu2 are the mean number of publications before and after the break years, respectively) based on the Pettitt and SNHT tests.
Water 14 03200 g0a3
Figure A4. Geographical distribution of single and multiple country publications. SCP presents single country publications whereas MCP presents multiple country publications.
Figure A4. Geographical distribution of single and multiple country publications. SCP presents single country publications whereas MCP presents multiple country publications.
Water 14 03200 g0a4


  1. Van Dijk, S.; Lounsbury, A.W.; Hoekstra, A.Y.; Wang, R. Strategic design and finance of rainwater harvesting to cost-effectively meet large-scale urban water infrastructure needs. Water Res. 2020, 184, 116063. [Google Scholar] [CrossRef] [PubMed]
  2. Flörke, M.; Schneider, C.; McDonald, R.I. Water competition between cities and agriculture driven by climate change and urban growth. Nat. Sustain. 2018, 1, 51–58. [Google Scholar] [CrossRef]
  3. Semaan, M.; Day, S.D.; Garvin, M.; Ramakrishnan, N.; Pearce, A. Optimal sizing of rainwater harvesting systems for domestic water usages: A systematic literature review. Resour. Conserv. Recycl. X 2020, 6, 100033. [Google Scholar] [CrossRef]
  4. Alim, M.A.; Ashraf, A.F.M.A.; Rahman, A.; Tao, Z.; Roy, R.; Khan, M.M.; Shirin, S. Experimental investigation of an integrated rainwater harvesting unit for drinking water production at the household level. J. Water Process Eng. 2021, 44, 102318. [Google Scholar] [CrossRef]
  5. Campisano, A.; Butler, D.; Ward, S.; Burns, M.J.; Friedler, E.; DeBusk, K.; Fisher-Jeffes, L.N.; Ghisi, E.; Rahman, A.; Furumai, H.; et al. Urban rainwater harvesting systems: Research, implementation and future perspectives. Water Res. 2017, 115, 195–209. [Google Scholar] [CrossRef]
  6. Rahman, A. Recent advances in modelling and implementation of rainwater harvesting systems towards sustainable development. Water 2017, 8, 959. [Google Scholar] [CrossRef] [Green Version]
  7. Alim, M.A.; Rahman, A.; Tao, Z.; Samali, B.; Khan, M.M.; Shirin, S. Feasibility analysis of a small-scale rainwater harvesting system for drinking water production at Werrington, New South Wales, Australia. J. Clean. Prod. 2020, 270, 122437. [Google Scholar] [CrossRef]
  8. Alim, M.A.; Rahman, A.; Tao, Z.; Samali, B.; Khan, M.M.; Shirin, S. Suitability of roof harvested rainwater for potential potable water production: A scoping review. J. Clean. Prod. 2020, 248, 119226. [Google Scholar] [CrossRef]
  9. Ennenbach, M.W.; Concha Larrauri, P.; Lall, U. County-scale rainwater harvesting feasibility in the United States: Climate, collection area, density, and reuse considerations. JAWRA J. Am. Water Resour. Assoc. 2018, 54, 255–274. [Google Scholar] [CrossRef]
  10. Rostad, N.; Foti, R.; Montalto, F.A. Harvesting rooftop runoff to flush toilets: Drawing conclusions from four major US cities. Resour. Conserv. Recycl. 2016, 108, 97–106. [Google Scholar] [CrossRef]
  11. Gonela, V.; Altman, B.; Zhang, J.; Ochoa, E.; Murphy, W.; Salazar, D. Decentralized rainwater harvesting program for rural cities considering tax incentive schemes under stakeholder interests and purchasing power restrictions. J. Clean. Prod. 2020, 252, 119843. [Google Scholar] [CrossRef]
  12. Farreny, R.; Gabarrell, X.; Rieradevall, J. Cost-efficiency of rainwater harvesting strategies in dense Mediterranean neighbourhoods. Resour. Conserv. Recycl. 2011, 55, 686–694. [Google Scholar] [CrossRef]
  13. Roebuck, R.; Oltean-Dumbrava, C.; Tait, S. Whole life cost performance of domestic rainwater harvesting systems in the United Kingdom. Water Environ. J. 2011, 25, 355–365. [Google Scholar] [CrossRef]
  14. Musayev, S.; Burgess, E.; Mellor, J. A global performance assessment of rainwater harvesting under climate change. Resour. Conserv. Recycl. 2018, 132, 62–70. [Google Scholar] [CrossRef]
  15. De Sá Silva, A.C.R.; Bimbato, A.M.; Balestieri, J.A.P.; Vilanova, M.R.N. Exploring environmental, economic and social aspects of rainwater harvesting systems: A review. Sustain. Cities Soc. 2022, 76, 103475. [Google Scholar] [CrossRef]
  16. Gee, K.D.; Sojka, S. Maximizing the Benefits of Rainwater Harvesting Systems: Review and Analysis of Selected Case Study Examples. In Resilient Water Management Strategies in Urban Settings: Innovations in Decentralized Water Infrastructure Systems; Younos, T., Lee, J., Parece, T.E., Eds.; Springer International Publishing: Cham, Switzerland, 2022; pp. 77–117. [Google Scholar]
  17. Latif, S.; Alim, M.A.; Rahman, A. Disinfection methods for domestic rainwater harvesting systems: A scoping review. J. Water Process Eng. 2022, 46, 102542. [Google Scholar] [CrossRef]
  18. Singh, S.; Yadav, R.; Kathi, S.; Singh, A.N. Chapter 14—Treatment of harvested rainwater and reuse: Practices, prospects, and challenges. In Cost Effective Technologies for Solid Waste and Wastewater Treatment; Kathi, S., Devipriya, S., Thamaraiselvi, K., Eds.; Elsevier: Amsterdam, The Netherlands, 2022; pp. 161–178. [Google Scholar]
  19. Kugedera, A.T.; Nyamadzawo, G.; Mandumbu, R.; Nyamangara, J. Potential of field edge rainwater harvesting, biomass transfer and integrated nutrient management in improving sorghum productivity in semi-arid regions: A review. Agrofor. Syst. 2022, 96, 909–924. [Google Scholar] [CrossRef]
  20. Odhiambo, K.O.; Iro Ong’or, B.T.; Kanda, E.K. Optimization of rainwater harvesting system design for smallholder irrigation farmers in Kenya: A review. J. Water Supply Res. Technol. Aqua 2021, 70, 483–492. [Google Scholar] [CrossRef]
  21. Mak-Mensah, E.; Yeboah, F.K.; Obour, P.B.; Usman, S.; Essel, E.; Bakpa, E.P.; Zhang, D.; Zhou, X.; Wang, X.; Zhao, X.; et al. Integration of ridge and furrow rainwater harvesting systems and soil amendments improve crop yield under semi-arid conditions. Paddy Water Environ. 2022, 20, 287–302. [Google Scholar] [CrossRef]
  22. Tolossa, T.T.; Abebe, F.B.; Girma, A.A. Review: Rainwater harvesting technology practices and implication of climate change characteristics in Eastern Ethiopia. Cogent Food Agric. 2020, 6, 1724354. [Google Scholar] [CrossRef]
  23. Pala, G.K.; Pathivada, A.P.; Velugoti, S.J.H.; Yerramsetti, C.; Veeranki, S. Rainwater harvesting—A review on conservation, creation & cost-effectiveness. Mater. Today Proc. 2021, 45, 6567–6571. [Google Scholar] [CrossRef]
  24. Preeti, P.; Rahman, A. Application of GIS in Rainwater Harvesting Research: A Scoping Review. Asian J. Water Environ. Pollut. 2021, 18, 29–35. [Google Scholar] [CrossRef]
  25. Słyś, D.; Stec, A. Centralized or Decentralized Rainwater Harvesting Systems: A Case Study. Resources 2020, 9, 5. [Google Scholar] [CrossRef] [Green Version]
  26. Velasco-Muñoz, J.F.; Aznar-Sánchez, J.A.; Batlles-delaFuente, A.; Fidelibus, M.D. Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research. Water 2019, 11, 1320. [Google Scholar] [CrossRef] [Green Version]
  27. Norman, M.; Shafri, H.Z.M.; Mansor, S.B.; Yusuf, B. Review of remote sensing and geospatial technologies in estimating rooftop rainwater harvesting (RRWH) quality. Int. Soil Water Conserv. Res. 2019, 7, 266–274. [Google Scholar] [CrossRef]
  28. Ndeketeya, A.; Dundu, M. Maximising the benefits of rainwater harvesting technology towards sustainability in urban areas of South Africa: A case study. Urban Water J. 2019, 16, 163–169. [Google Scholar] [CrossRef]
  29. Yannopoulos, S.; Giannopoulou, I.; Kaiafa-Saropoulou, M. Investigation of the Current Situation and Prospects for the Development of Rainwater Harvesting as a Tool to Confront Water Scarcity Worldwide. Water 2019, 11, 2168. [Google Scholar] [CrossRef] [Green Version]
  30. Hafizi Md Lani, N.; Yusop, Z.; Syafiuddin, A. A Review of Rainwater Harvesting in Malaysia: Prospects and Challenges. Water 2018, 10, 506. [Google Scholar] [CrossRef] [Green Version]
  31. Teston, A.; Geraldi, M.S.; Colasio, B.M.; Ghisi, E. Rainwater Harvesting in Buildings in Brazil: A Literature Review. Water 2018, 10, 471. [Google Scholar] [CrossRef] [Green Version]
  32. Haque, M.M.; Rahman, A.; Samali, B. Evaluation of climate change impacts on rainwater harvesting. J. Clean. Prod. 2016, 137, 60–69. [Google Scholar] [CrossRef]
  33. Liu, X.; Ren, Z.; Ngo, H.H.; He, X.; Desmond, P.; Ding, A. Membrane technology for rainwater treatment and reuse: A mini review. Water Cycle 2021, 2, 51–63. [Google Scholar] [CrossRef]
  34. Deng, Y. Pollution in rainwater harvesting: A challenge for sustainability and resilience of urban agriculture. J. Hazard. Mater. Lett. 2021, 2, 100037. [Google Scholar] [CrossRef]
  35. Hindiyeh, M.Y.; Matouq, M.; Eslamian, S. Rainwater harvesting policy issues in the mena region: Lessons learned, challenges, and sustainable recommendations. In Handbook of Water Harvesting and Conservation: Basic Concepts and Fundamentals; Eslamian, S., Ed.; Wiley: Hoboken, NJ, USA, 2021; pp. 457–473. [Google Scholar]
  36. Zupic, I.; Čater, T. Bibliometric Methods in Management and Organization. Organ. Res. Methods 2015, 18, 429–472. [Google Scholar] [CrossRef]
  37. Cabeza, L.F.; Chàfer, M.; Mata, É. Comparative Analysis of Web of Science and Scopus on the Energy Efficiency and Climate Impact of Buildings. Energies 2020, 13, 409. [Google Scholar] [CrossRef] [Green Version]
  38. Aghaei Chadegani, A.; Salehi, H.; Yunus, M.; Farhadi, H.; Fooladi, M.; Farhadi, M.; Ale Ebrahim, N. A comparison between two main academic literature collections: Web of Science and Scopus databases. Asian Soc. Sci. 2013, 9, 18–26. [Google Scholar] [CrossRef] [Green Version]
  39. Meho, L.I.; Yang, K. Impact of data sources on citation counts and rankings of LIS faculty: Web of Science versus Scopus and Google Scholar. J. Am. Soc. Inf. Sci. Technol. 2007, 58, 2105–2125. [Google Scholar] [CrossRef]
  40. Mongeon, P.; Paul-Hus, A. The journal coverage of Web of Science and Scopus: A comparative analysis. Scientometrics 2016, 106, 213–228. [Google Scholar] [CrossRef]
  41. Archambault, É.; Campbell, D.; Gingras, Y.; Larivière, V. Comparing bibliometric statistics obtained from the Web of Science and Scopus. J. Am. Soc. Inf. Sci. Technol. 2009, 60, 1320–1326. [Google Scholar] [CrossRef] [Green Version]
  42. López-Illescas, C.; De Moya-Anegón, F.; Moed, H.F. Coverage and citation impact of oncological journals in the Web of Science and Scopus. J. Informetr. 2008, 2, 304–316. [Google Scholar] [CrossRef]
  43. Falagas, M.E.; Pitsouni, E.I.; Malietzis, G.A.; Pappas, G. Comparison of PubMed, Scopus, web of science, and Google scholar: Strengths and weaknesses. FASEB J. 2008, 22, 338–342. [Google Scholar] [CrossRef]
  44. Aria, M.; Cuccurullo, C. bibliometrix: An R-tool for comprehensive science mapping analysis. J. Informetr. 2017, 11, 959–975. [Google Scholar] [CrossRef]
  45. Moral-Muñoz, J.A.; Herrera-Viedma, E.; Santisteban-Espejo, A.; Cobo, M.J. Software tools for conducting bibliometric analysis in science: An up-to-date review. Prof. Inf. 2020, 29, e290103. [Google Scholar] [CrossRef] [Green Version]
  46. Cobo, M.J.; López-Herrera, A.G.; Herrera-Viedma, E.; Herrera, F. Science mapping software tools: Review, analysis, and cooperative study among tools. J. Am. Soc. Inf. Sci. Technol. 2011, 62, 1382–1402. [Google Scholar] [CrossRef]
  47. Persson, O.; Danell, R.; Schneider, J.W. How to use Bibexcel for various types of bibliometric analysis. In Celebrating Scholarly Communication Studies: A Festschrift for Olle Persson at his 60th Birthday; International Society for Scientometrics and Informetrics: Leuven, Belgium, 2009; Volume 5, pp. 9–24. [Google Scholar]
  48. Chen, C. Searching for intellectual turning points: Progressive knowledge domain visualization. Proc. Natl. Acad. Sci. USA 2004, 101, 5303–5310. [Google Scholar] [CrossRef] [Green Version]
  49. Chen, C. CiteSpace II: Detecting and visualizing emerging trends and transient patterns in scientific literature. J. Am. Soc. Inf. Sci. Technol. 2006, 57, 359–377. [Google Scholar] [CrossRef] [Green Version]
  50. Sci2 T. Science of Science (sci2) Tool. Indiana University and SciTech Strategies. 2009. Available online: (accessed on 24 October 2021).
  51. Cobo, M.J.; López-Herrera, A.G.; Herrera-Viedma, E.; Herrera, F. SciMAT: A new science mapping analysis software tool. J. Am. Soc. Inf. Sci. Technol. 2012, 63, 1609–1630. [Google Scholar] [CrossRef]
  52. Van Eck, N.J.; Waltman, L. CitNetExplorer: A new software tool for analyzing and visualizing citation networks. J. Informetr. 2014, 8, 802–823. [Google Scholar] [CrossRef] [Green Version]
  53. Van Eck, N.J.; Waltman, L. Software survey: VOSviewer, a computer program for bibliometric mapping. Scientometrics 2010, 84, 523–538. [Google Scholar] [CrossRef] [Green Version]
  54. Rodríguez-Soler, R.; Uribe-Toril, J.; De Pablo Valenciano, J. Worldwide trends in the scientific production on rural depopulation, a bibliometric analysis using bibliometrix R-tool. Land Use Policy 2020, 97, 104787. [Google Scholar] [CrossRef]
  55. Orimoloye, I.R.; Belle, J.A.; Olusola, A.O.; Busayo, E.T.; Ololade, O.O. Spatial assessment of drought disasters, vulnerability, severity and water shortages: A potential drought disaster mitigation strategy. Nat. Hazards 2021, 105, 2735–2754. [Google Scholar] [CrossRef]
  56. Herrera-Franco, G.; Montalván-Burbano, N.; Carrión-Mero, P.; Bravo-Montero, L. Worldwide Research on Socio-Hydrology: A Bibliometric Analysis. Water 2021, 13, 1283. [Google Scholar] [CrossRef]
  57. Payán-Sánchez, B.; Belmonte-Ureña, L.J.; Plaza-Úbeda, J.A.; Vazquez-Brust, D.; Yakovleva, N.; Pérez-Valls, M. Open Innovation for Sustainability or Not: Literature Reviews of Global Research Trends. Sustainability 2021, 13, 1136. [Google Scholar] [CrossRef]
  58. Nobanee, H.; Al Hamadi, F.Y.; Abdulaziz, F.A.; Abukarsh, L.S.; Alqahtani, A.F.; Alsubaey, S.K.; Alqahtani, S.M.; Almansoori, H.A. A Bibliometric Analysis of Sustainability and Risk Management. Sustainability 2021, 13, 3277. [Google Scholar] [CrossRef]
  59. Liu, H.; Kong, F.; Yin, H.; Middel, A.; Zheng, X.; Huang, J.; Xu, H.; Wang, D.; Wen, Z. Impacts of green roofs on water, temperature, and air quality: A bibliometric review. Build. Environ. 2021, 196, 107794. [Google Scholar] [CrossRef]
  60. Yu, H.; Wei, Y.-M.; Tang, B.-J.; Mi, Z.; Pan, S.-Y. Assessment on the research trend of low-carbon energy technology investment: A bibliometric analysis. Appl. Energy 2016, 184, 960–970. [Google Scholar] [CrossRef]
  61. Hirsch, J.E. An index to quantify an individual’s scientific research output. Proc. Natl. Acad. Sci. USA 2005, 102, 16569–16572. [Google Scholar] [CrossRef] [Green Version]
  62. Wang, Z.; Zhao, Y.; Wang, B. A bibliometric analysis of climate change adaptation based on massive research literature data. J. Clean. Prod. 2018, 199, 1072–1082. [Google Scholar] [CrossRef]
  63. Molinari, J.-F.; Molinari, A. A new methodology for ranking scientific institutions. Scientometrics 2008, 75, 163–174. [Google Scholar] [CrossRef] [Green Version]
  64. Zhou, L.-M.; Li, F.-M.; Jin, S.-L.; Song, Y. How two ridges and the furrow mulched with plastic film affect soil water, soil temperature and yield of maize on the semiarid Loess Plateau of China. Field Crops Res. 2009, 113, 41–47. [Google Scholar] [CrossRef]
  65. Gan, Y.; Siddique, K.H.M.; Turner, N.C.; Li, X.G.; Niu, J.Y.; Yang, C.; Liu, L.; Chai, Q. Ridge-Furrow Mulching Systems—An Innovative Technique for Boosting Crop Productivity in Semiarid Rain-Fed Environments. Adv. Agron. 2013, 118, 429–476. [Google Scholar] [CrossRef]
  66. Kumar, R.; Singh, R.D.; Sharma, K.D. Water resources of India. Curr. Sci. 2005, 89, 794–811. [Google Scholar]
  67. Qadir, M.; Sharma, B.R.; Bruggeman, A.; Choukr-Allah, R.; Karajeh, F. Non-conventional water resources and opportunities for water augmentation to achieve food security in water scarce countries. Agric. Water Manag. 2007, 87, 2–22. [Google Scholar] [CrossRef]
  68. Wang, Y.; Xie, Z.; Malhi, S.S.; Vera, C.L.; Zhang, Y.; Wang, J. Effects of rainfall harvesting and mulching technologies on water use efficiency and crop yield in the semi-arid Loess Plateau, China. Agric. Water Manag. 2009, 96, 374–382. [Google Scholar] [CrossRef]
  69. Abdulla, F.A.; Al-Shareef, A.W. Roof rainwater harvesting systems for household water supply in Jordan. Desalination 2009, 243, 195–207. [Google Scholar] [CrossRef]
  70. Li, X.Y.; Gong, J.D.; Gao, Q.Z.; Li, F.R. Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions. Agric. Water Manag. 2001, 50, 173–183. [Google Scholar] [CrossRef]
  71. Villarreal, E.L.; Dixon, A. Analysis of a rainwater collection system for domestic water supply in Ringdansen, Norrköping, Sweden. Build. Environ. 2005, 40, 1174–1184. [Google Scholar] [CrossRef]
  72. Sazakli, E.; Alexopoulos, A.; Leotsinidis, M. Rainwater harvesting, quality assessment and utilization in Kefalonia Island, Greece. Water Res. 2007, 41, 2039–2047. [Google Scholar] [CrossRef]
  73. Boers, T.M.; Ben-Asher, J. A review of rainwater harvesting. Agric. Water Manag. 1982, 5, 145–158. [Google Scholar] [CrossRef]
  74. Pandey, D.N.; Gupta, A.K.; Anderson, D.M. Rainwater harvesting as an adaptation to climate change. Curr. Sci. 2003, 85, 46–59. [Google Scholar]
  75. Herrmann, T.; Schmida, U. Rainwater utilisation in Germany: Efficiency, dimensioning, hydraulic and environmental aspects. Urban Water 2000, 1, 307–316. [Google Scholar] [CrossRef]
  76. Yaziz, M.I.; Gunting, H.; Sapari, N.; Ghazali, A.W. Variations in rainwater quality from roof catchments. Water Res. 1989, 23, 761–765. [Google Scholar] [CrossRef]
  77. Farreny, R.; Morales-Pinzón, T.; Guisasola, A.; Tayà, C.; Rieradevall, J.; Gabarrell, X. Roof selection for rainwater harvesting: Quantity and quality assessments in Spain. Water Res. 2011, 45, 3245–3254. [Google Scholar] [CrossRef]
  78. Ghisi, E.; Bressan, D.L.; Martini, M. Rainwater tank capacity and potential for potable water savings by using rainwater in the residential sector of southeastern Brazil. Build. Environ. 2007, 42, 1654–1666. [Google Scholar] [CrossRef]
  79. Rahman, A.; Keane, J.; Imteaz, M.A. Rainwater harvesting in Greater Sydney: Water savings, reliability and economic benefits. Resour. Conserv. Recycl. 2012, 61, 16–21. [Google Scholar] [CrossRef]
  80. Jones, M.P.; Hunt, W.F. Performance of rainwater harvesting systems in the southeastern United States. Resour. Conserv. Recycl. 2010, 54, 623–629. [Google Scholar] [CrossRef]
  81. Domènech, L.; Saurí, D. A comparative appraisal of the use of rainwater harvesting in single and multi-family buildings of the Metropolitan Area of Barcelona (Spain): Social experience, drinking water savings and economic costs. J. Clean. Prod. 2011, 19, 598–608. [Google Scholar] [CrossRef]
  82. Khastagir, A.; Jayasuriya, N. Optimal sizing of rain water tanks for domestic water conservation. J. Hydrol. 2010, 381, 181–188. [Google Scholar] [CrossRef]
  83. Basinger, M.; Montalto, F.; Lall, U. A rainwater harvesting system reliability model based on nonparametric stochastic rainfall generator. J. Hydrol. 2010, 392, 105–118. [Google Scholar] [CrossRef]
  84. Mwenge Kahinda, J.; Rockström, J.; Taigbenu, A.E.; Dimes, J. Rainwater harvesting to enhance water productivity of rainfed agriculture in the semi-arid Zimbabwe. Phys. Chem. Earth 2007, 32, 1068–1073. [Google Scholar] [CrossRef]
  85. Evans, C.A.; Coombes, P.J.; Dunstan, R.H. Wind, rain and bacteria: The effect of weather on the microbial composition of roof-harvested rainwater. Water Res. 2006, 40, 37–44. [Google Scholar] [CrossRef]
  86. Aladenola, O.O.; Adeboye, O.B. Assessing the potential for rainwater harvesting. Water Resour. Manag. 2010, 24, 2129–2137. [Google Scholar] [CrossRef]
  87. Imteaz, M.A.; Shanableh, A.; Rahman, A.; Ahsan, A. Optimisation of rainwater tank design from large roofs: A case study in Melbourne, Australia. Resour. Conserv. Recycl. 2011, 55, 1022–1029. [Google Scholar] [CrossRef]
  88. Egghe, L. Theory and practise of the g-index. Scientometrics 2006, 69, 131–152. [Google Scholar] [CrossRef]
  89. Costas, R.; Bordons, M. Is g-index better than h-index? An exploratory study at the individual level. Scientometrics 2008, 77, 267–288. [Google Scholar] [CrossRef] [Green Version]
  90. Small, H. Co-citation in the scientific literature: A new measure of the relationship between two documents. J. Am. Soc. Inf. Sci. 1973, 24, 265–269. [Google Scholar] [CrossRef]
  91. White, H.D.; Griffith, B.C. Author cocitation: A literature measure of intellectual structure. J. Am. Soc. Inf. Sci. 1981, 32, 163–171. [Google Scholar] [CrossRef]
  92. White, H.D.; McCain, K.W. Visualizing a discipline: An author co-citation analysis of information science, 1972–1995. J. Am. Soc. Inf. Sci. 1998, 49, 327–355. [Google Scholar] [CrossRef]
  93. Zhang, J.; Yu, Q.; Zheng, F.; Long, C.; Lu, Z.; Duan, Z. Comparing keywords plus of WOS and author keywords: A case study of patient adherence research. J. Assoc. Inf. Sci. Technol. 2016, 67, 967–972. [Google Scholar] [CrossRef] [Green Version]
  94. Garfield, E. KeyWords Plus-ISI’s breakthrough retrieval method. 1. Expanding your searching power on current-contents on diskette. Curr. Contents 1990, 32, 5–9. [Google Scholar]
  95. Mao, N.; Wang, M.-H.; Ho, Y.-S. A Bibliometric Study of the Trend in Articles Related to Risk Assessment Published inScience Citation Index. Hum. Ecol. Risk Assess. Int. J. 2010, 16, 801–824. [Google Scholar] [CrossRef]
  96. Li, J.; Wang, M.-H.; Ho, Y.-S. Trends in research on global climate change: A Science Citation Index Expanded-based analysis. Glob. Planet. Change 2011, 77, 13–20. [Google Scholar] [CrossRef]
  97. Orimoloye, I.R.; Ekundayo, T.C.; Ololade, O.O.; Belle, J.A. Systematic mapping of disaster risk management research and the role of innovative technology. Environ. Sci. Pollut. Res. 2021, 28, 4289–4306. [Google Scholar] [CrossRef] [PubMed]
  98. Adisa, O.M.; Masinde, M.; Botai, J.O.; Botai, C.M. Bibliometric Analysis of Methods and Tools for Drought Monitoring and Prediction in Africa. Sustainability 2020, 12, 6516. [Google Scholar] [CrossRef]
  99. Pettitt, A.N. A Non-Parametric Approach to the Change-Point Problem. J. R. Stat. Soc. Ser. C Appl. Stat. 1979, 28, 126–135. [Google Scholar] [CrossRef]
  100. Alexandersson, H. A homogeneity test applied to precipitation data. J. Climatol. 1986, 6, 661–675. [Google Scholar] [CrossRef]
  101. Bond, N.R.; Lake, P.S.; Arthington, A.H. The impacts of drought on freshwater ecosystems: An Australian perspective. Hydrobiologia 2008, 600, 3–16. [Google Scholar] [CrossRef] [Green Version]
  102. Van Dijk, A.I.J.M.; Beck, H.E.; Crosbie, R.S.; De Jeu, R.A.M.; Liu, Y.Y.; Podger, G.M.; Timbal, B.; Viney, N.R. The Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society. Water Resour. Res. 2013, 49, 1040–1057. [Google Scholar] [CrossRef]
  103. Verdon-Kidd, D.C.; Kiem, A.S. Nature and causes of protracted droughts in southeast Australia: Comparison between the Federation, WWII, and Big Dry droughts. Geophys. Res. Lett. 2009, 36. [Google Scholar] [CrossRef]
  104. Haunschild, R.; Bornmann, L.; Marx, W. Climate Change Research in View of Bibliometrics. PLoS ONE 2016, 11, e0160393. [Google Scholar] [CrossRef]
Figure 1. Adopted workflow for conducting bibliometric analysis carried out in this study.
Figure 1. Adopted workflow for conducting bibliometric analysis carried out in this study.
Water 14 03200 g001
Figure 2. Publishing trend and average citation on RWH.
Figure 2. Publishing trend and average citation on RWH.
Water 14 03200 g002
Figure 3. Timeline of publications in the top 15 journals, 1982–2022.
Figure 3. Timeline of publications in the top 15 journals, 1982–2022.
Water 14 03200 g003
Figure 4. Network visualization of author co-citation network in RWH related studies. Minimum number of citations of an author was selected as 100 times. The map includes 100 authors (nodes) in five clusters.
Figure 4. Network visualization of author co-citation network in RWH related studies. Minimum number of citations of an author was selected as 100 times. The map includes 100 authors (nodes) in five clusters.
Water 14 03200 g004
Figure 5. Thematic evaluation of the author’s keywords (1982–2021).
Figure 5. Thematic evaluation of the author’s keywords (1982–2021).
Water 14 03200 g005
Figure 6. Trend topics on RWH field, 2005–2021.
Figure 6. Trend topics on RWH field, 2005–2021.
Water 14 03200 g006
Figure 7. The occurrence network map of all keywords (keywords plus and author’s keywords) of RWH area.
Figure 7. The occurrence network map of all keywords (keywords plus and author’s keywords) of RWH area.
Water 14 03200 g007
Figure 8. The national academic impact, 1982–2021. SSC is the standard score of citation, SSP is the standard score of publications and TSS is the total standard score.
Figure 8. The national academic impact, 1982–2021. SSC is the standard score of citation, SSP is the standard score of publications and TSS is the total standard score.
Water 14 03200 g008
Figure 9. Network visualization map of country co-authorship in the RWH field. Countries with a minimum of five published and cited articles were included. Number of countries met the thresholds was 69 out of 159 countries and the map includes 50 out 69 countries. Total link strength of top 5 countries are as follows: USA = 258, Australia = 182, United Kingdom = 164, China = 127 and The Netherlands = 108.
Figure 9. Network visualization map of country co-authorship in the RWH field. Countries with a minimum of five published and cited articles were included. Number of countries met the thresholds was 69 out of 159 countries and the map includes 50 out 69 countries. Total link strength of top 5 countries are as follows: USA = 258, Australia = 182, United Kingdom = 164, China = 127 and The Netherlands = 108.
Water 14 03200 g009
Table 1. Literature review articles published recently on RWH.
Table 1. Literature review articles published recently on RWH.
ReferencesCountryTheme Discussed
de Sá Silva, et al. [15]BrazilEnvironmental, economic and social aspects of RWH systems.
Gee, et al. [16]USAMaximising the benefits of RWH system.
Latif, et al.; Singh et al. [17,18]Australia, IndiaDisinfection methods to treat harvested rainwater.
Kugedera, et al. [19]ZimbabweUse of RWH system in improving sorghum productivity.
Odhiambo, et al. [20]KenyaDesign and optimisation of RWH system for irrigation.
Mak-Mensah, et al. [21]China and GhanaRidge and furrow RWH system for irrigation.
Semaan, et al. [3]Canada and USAOptimal sizing of rainwater harvesting at the domestic level.
Alim, et al. [8]AustraliaPotable water production and supply from harvested rainwater.
Tolossa, et al. [22]EthiopiaRWH system practices under climate change.
Pala, et al. [23]IndiaConservation, creation and cost-effectiveness of RWH system.
Preeti, et al. [24]AustraliaApplication of GIS in RWH system.
Słyś, et al. [25]PolandCentralised or decentralised RWH systems
Velasco-Muñoz, et al. [26]Spain and ItalyHow beneficial the RWH system is for Agricultural Irrigation.
Norman, et al. [27]MalaysiaQuality evaluation of harvested rainwater using remote sensing and geospatial technologies.
Ndeketeya, et al. [28]South AfricaRWH system towards sustainability
Yannopoulos, et al. [29]GreeceHow RWH system can mitigate water scarcity worldwide.
Hafizi Md Lani, et al. [30]MalaysiaThe potential and challenges for RWH system to be widely adopted in Malaysia.
Teston, et al. [31]BrazilEconomic, environmental and social benefits of RWH system when attached to a building
Table 2. Summary of data used in this study.
Table 2. Summary of data used in this study.
Main Information Document Contents
Timespan1982:2022Keywords plus12,198
Sources (Journals, Books, etc)1002Author’s keywords6509
Average citations per document13.13Authors7522
Average citations per year per doc1.744Authors of single-authored documents332
References103021Authors of multi-authored documents7190
Document Types Authors Collaboration
Article2302Single-authored documents383
Book15Documents per author0.429
Book chapter170Authors per document2.33
Conference paper620Co-authors per documents3.51
Review119Collaboration index2.53
Table 3. The top 15 productive sources in RWH field.
Table 3. The top 15 productive sources in RWH field.
RankSourcesTPTP R (%)H-IndexTCCPPPYS
1Water (MDPI)1283.9721138610.832011
2Journal of Cleaner Production812.5127189723.422011
3Agricultural Water Management732.2727270437.041982
4Water Science and Technology: Water Supply722.23135537.682003
5Resources Conservation and Recycling662.0532267040.452007
6Water Science and Technology631.96135538.782003
7Water Resources Management621.9225161726.082004
8IOP Conference Series: Earth and Environmental Science611.893300.492017
9Science of The Total Environment441.371992421.002009
10Sustainability (MDPI)401.2481624.052014
11Physics and Chemistry of The Earth371.1522149440.382003
12Urban Water Journal341.061349914.682008
13Journal of Hydrology331.0219130039.392002
14Water Research310.9621205966.421985
15Journal of Environmental Management290.901887030.002009
Note: TP is number of total publications; TP R (%) is the ratio of the number of one journal’s publications to total number of publications; TC is total citation; CPP is citation per publication, PYS is the first publication year of the journal.
Table 4. The most frequently cited articles on RWH related studies.
Table 4. The most frequently cited articles on RWH related studies.
RankAuthor (Year)CountryTCCPYJournal
1Zhou, et al. [64]China39630.46Field Crops Research
2Gan, et al. [65]Canada34137.89Advances in Agronomy
3Kumar, et al. [66]India28416.71Current Science
4Qadir, et al. [67]Canada27318.20Agricultural Water Management
5Wang, et al. [68]China24318.69Agricultural Water Management
6Abdulla, et al. [69]Jordan22317.15Desalination
7Campisano, et al. [5]Italy21142.20Water Research
8Li, et al. [70]China2089.91Agricultural Water Management
9Villarreal, et al. [71]Sweden19911.71Building and Environment
10Sazakli, et al. [72]Greece19713.13Water Research
11Boers, et al. [73]The Netherlands1914.78Agricultural Water Management
12Pandey, et al. [74]India19010.00Current Science
13Herrmann, et al. [75]Germany1838.32Urban Water
14Yaziz, et al. [76]Malaysia1815.49Water Research
15Farreny, et al. [77]Spain17916.27Water Research
Note: TC is total citation; CPY is citation per year. Country refers to the country where the first institution of the author’s latest paper.
Table 5. The top 15 articles’ citation measure in RWH field.
Table 5. The top 15 articles’ citation measure in RWH field.
RankAuthorYearCountryLocal Citations 1Global Citations 2
1Abdulla, et al. [69]2009Jordan159223
2Campisano, et al. [5]2017Italy144211
3Farreny, et al. [77]2011Spain130179
4Sazakli, et al. [72]2007Greece128197
5Ghisi, et al. [78]2007Brazil113136
6Rahman, et al. [79]2012Australia106137
7Yaziz, et al. [76]1989Malaysia106181
8Jones, et al. [80]2010USA100162
9Domènech, et al. [81]2011Spain98168
10Khastagir, et al. [82]2010Australia95125
11Basinger, et al. [83]2010USA94134
12Mwenge Kahinda, et al. [84]2007South Africa92152
13Evans, et al. [85]2006Australia89150
14Aladenola, et al. [86]2010Canada87133
15Imteaz, et al. [87]2011Australia82121
1 Local citations present citation within the 3226 publications. 2 Global citations present actual Scopus citation.
Table 6. The top 15 productive authors in RWH field.
Table 6. The top 15 productive authors in RWH field.
RankAuthorsCountryArticlesAFH-indexg-indexTCCPY (CPA)PYS
1Ghisi, E.Brazil4519.231938145491 (32.31)2006
2Han, M.South Korea3912.89122567245 (17.23)2007
3Rahman, A.Australia3611.601729112375 (31.19)2007
4Butler, D.United Kingdom3610.48152884450 (23.44)2005
5Imteaz, M.A.Australia3211.00132474468 (23.25)2011
6Ahmed, W.Australia255.29172485161 (34.04)2008
7Khan, W.South Africa244.88132043448 (18.08)2013
8Gabarrell, X.Spain234.45142180173 (34.83)2011
9Ward, S.United Kingdom235.95122170955 (30.83)2009
10Coombes, P.J.Australia208.08121757826 (28.90)2000
11Han, M.Y.South Korea207.48111939126 (19.55)2007
12Rieradevall, J.Spain203.41141877070 (38.50)2011
13Van Rensburg, L.D.South Africa206.056101268 (6.30)2006
14Sharma, A.Australia184.06101734929 (19.39)2010
15Wang, Y.China183.1581651232 (28.44)2006
Note: AF is articles fractionalized; TC is total citation; CPY is citation per year; CPA is citation per article; PYS is first publication’s year.
Table 7. The top 15 most co-cited authors.
Table 7. The top 15 most co-cited authors.
RankAuthorClusterCitationsTotal Link Strength
1Ghisi, E.1 (Red)101826,356
2Butler, D.1 (Red)100027,556
3Rahman, A.1 (Red)90727,353
4Imteaz, M.A.1 (Red)64721,395
5Coombes, P.J.2 (Green)62612,673
6Ward, S.1 (Red)57217,743
7Rieradevall, J.4 (Yellow)54316,950
8Ahmed, W.2 (Green)52015,286
9Gabarrell, X.4 (Yellow)51517,176
10Gardner, T.2 (Green)50015,510
11Rockstrom, J.5 (Purple)4923279
12Fletcher, T.D.3 (Blue)48514,648
13Fewkes, A.1 (Red)42210,406
14Campisano, A.1 (Red)42014,366
15Han, M.2 (Green)41810,140
Table 8. The most frequently used keywords.
Table 8. The most frequently used keywords.
RankAuthor’s KeywordsKeyword Plus
1Rainwater harvesting913Rain1811
2Rainwater131Water supply1609
3Water quality114Rainwater1139
4Climate change113Water management1096
6Water supply90Rain water harvesting918
7Runoff77Water quality759
9Rainwater tanks57Water conservation589
10Stormwater management55Drinking water480
11Rainwater harvesting system54Potable water443
12Rainwater tank54Rainwater harvesting system389
13Water conservation54Climate change371
14Water scarcity54Sustainable development350
15Drinking water53Water resources342
Table 9. The most productive countries.
Table 9. The most productive countries.
5United Kingdom128161412.618642
6South Africa108152714.148721
7South Korea93113712.237815
14The Netherlands4286720.641626
Note: TC is total citation; CPA is citation per article; SCP is single country publication; MCP is multiple country publication.
Table 10. The top 15 productive institutions, 1982-2021.
Table 10. The top 15 productive institutions, 1982-2021.
1Seoul National UniversitySouth Korea64
2CSIRO Land and WaterAustralia63
3Universidade Federal de Santa CatarinaBrazil47
4University of ExeterUnited Kingdom47
5Western Sydney UniversityAustralia43
6Chinese Academy of SciencesChina43
7Swinburne University of TechnologyAustralia41
8Universitat Autònoma de BarcelonaSpain37
9Northwest A&F UniversityChina37
10Ministry of Education ChinaChina35
11University of the Free StateSouth Africa34
12King Saud UniversitySaudi Arabia32
13Texas A&M UniversityUSA31
14Monash UniversityAustralia31
15UAB Instituto de Ciencia y Tecnología AmbientalesSpain30
Note: TP is total publications.
Table 11. The most frequently cited articles on RWH related studies from different databases (accessed on 31 January 2022).
Table 11. The most frequently cited articles on RWH related studies from different databases (accessed on 31 January 2022).
RankAuthor (Year)ScopusWoSGS
1Zhou, et al. [64]409338512
2Gan, et al. [65]366315416
3Kumar, et al. [66]291235634
4Qadir, et al. [67]284244513
5Wang, et al. [68]248201322
6Abdulla, et al. [69]235195478
7Campisano, et al. [5]229217338
8Li, et al. [70]212184330
9Villarreal, et al. [71]201177413
10Sazakli, et al. [72]204178403
11Boers, et al. [73]193166507
12Pandey, et al. [74]194154447
13Herrmann, et al. [75]188N/A387
14Yaziz, et al. [76]185159403
15Farreny, et al. [77]185163341
Note: WoS is Web of Science. GS is Google Scholar.
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Yildirim, G.; Alim, M.A.; Rahman, A. Review of Rainwater Harvesting Research by a Bibliometric Analysis. Water 2022, 14, 3200.

AMA Style

Yildirim G, Alim MA, Rahman A. Review of Rainwater Harvesting Research by a Bibliometric Analysis. Water. 2022; 14(20):3200.

Chicago/Turabian Style

Yildirim, Gokhan, Mohammad A Alim, and Ataur Rahman. 2022. "Review of Rainwater Harvesting Research by a Bibliometric Analysis" Water 14, no. 20: 3200.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop