## 3 Materials and Methods
### Methods  
The methodology of our study is presented in two steps: the quantitative analysis and the qualitative review. This subsection presents the PRISMA method used for quantitative analysis.  
The procedure developed to gather data on the topic consists of extracting information from the Web of Science (WoS) Core Collection database. The research was based on the keywords of publications, titles and abstracts. To gather an efficient collected database, synonyms of keywords selected on our topic were identified and inserted in the search string. The search string obtained is presented as follows: _(Agriculture OR Farming OR Environment OR Livestock OR Crop OR \"air pollution\" OR \"Forest Fire\" OR Atmosphere OR fish) AND (IoT OR WSN OR \"Internet of Things\" OR \"Wireless Sensor Network\" OR sensor OR LoRA) AND (\"West Africa\" OR \"Burkina Faso\" OR \"Cape Verde\" OR \"Ivory Coast\" OR \"Cote d'Ivoire\" OR Gambia OR Ghana OR Guinea OR Guinea-Bissau OR Liberia OR Mali OR Mauritania OR Niger OR Nigeria OR Senegal OR \"Sierra Leone\" OR Togo OR Bentin)._ The country name \"Ivory Coast\" was also translated in French \"Cote d'Ivoire\" as this country is known to publish papers with its name appearing in French. It is relevant to note that there was no restriction of time period for the study. A total of 226 documents were recorded between 1996 and 2023 and extracted from the WoS database on 14 August 2023. This data has been filtered using the PRISMA method as presented in Figure 1. The recorded database is accessible using the link after logging in with a WoS account: [[https://www.webofscience.com/wos/woscc/summary/faled2](https://www.webofscience.com/wos/woscc/summary/faled2) dd-437a-4981-b034-3 ddb92e6696f-ed267 ada/relevance/1]([https://www.webofscience.com/wos/woscc/summary/faled2](https://www.webofscience.com/wos/woscc/summary/faled2) dd-437a-4981-b034-3 ddb92e6696f-ed267 ada/relevance/1) (accessed on 14 August 2023). As a disclaimer, we should mention that we only extracted information from the WoS database. Including other databases such as Scopus, IEEE Xplore or Google Scholar could have enlarged the number of documents considered for the study.  
The PRISMA method includes 3 processing steps: the identification process, the screening process and the inclusion process. It consists of filtering the database to identify  
Figure 1: Bibliometric study process using PRISMA method.  
the relevant papers. First, 1 duplicate paper was excluded in the identification process. After that, in the screening stage, 94 papers were excluded based on their titles, and 59 papers were excluded based on their abstracts. The papers whose titles and abstracts are only related to agriculture, environment or IoT are not relevant for our study. In other words, the papers maintained in the database are related to an IoT application in agriculture or in environment. The screening was pursued by selecting 72 relevant papers by reading their abstracts. Among them, paper abstracts that present applications of IoT in biology or human health were excluded. One paper was not retrieved. The papers' full access screening led to 18 excluded papers. Then, in the inclusion stage a total of 53 papers were selected for further analysis. In the following section, the 53 papers selected following the PRISMA method are exploited for the bibliometric study, which constitutes the quantitative analysis. It is followed by the qualitative analysis, after performing a further selection on papers that present low-cost solutions for West Africa.