2.5 Qualitative data collection and analysis
To understand the context-specific socio-economic criteria for the best-siting of sand dams, we have conducted qualitative research with the 10 communities in Namibe, collecting information on water availability, water use and needs based on participants perception. We performed three focus group discussions in each community, including a representation of participants of both sexes and all ages (Figure 3). The groups were previously engaged and initiated in participatory work by the NGO leading the cooperation project TransAgua, to build a certain degree of trust and collaboration throughout the participatory activities. Focus group discussions were held in August 2021 and facilitated by the first author and local facilitators of the NGO, who also helped with the logistics and translation from Portuguese to the local language. The topics of the focus groups concerned water availability (i.e. length and intensity of the rainy season and stream water availability and timing), water use and needs of transhumant pastoralism (i.e. animal water consumption and dynamics related to water needs and availability during transhumance) and domestic water (i.e. quantity, quality and location of local water sources and water and domestic water use).
During the group discussions, we also asked about the familiarity of the communities with water harvesting structures and the possible presence of small dams in the area. The presence of sand dams in the area has not been reported in scientific or grey literature, but we were expecting the presence of colonial water structures to provide water to the “modern” large-scale livestock ranching in Namibe during the late colonial time (Carvalho, 1974).
The focus group discussions were facilitated using the semi-structured interview guide available in supplementary material. Interviews were reported using edited transcription to avoid repetitions and to increase readability and clarity, particularly useful when translating answers between English, Portuguese and the different local languages. The lead author then coded the transcripts using a mix of deductive and inductive coding. The scope of the qualitative analysis was to identify the socio-economic criteria to be considered for the siting of sand dams. To come up with a list of criteria that would account for the communities water needs and priorities, we first identified the main water security themes of the communities. The water security themes were first deductively coded guided by the water security framework proposed by Loring et al. (2013), which is broad enough to include other potential emerging themes specific to the local context (Penn et al., 2017). The framework categorises water security based on availability, accessibility, utility, and stability of water resources. Water availability is the water considered to be extractable in and around the community; accessibility concerns the degree of access the water points (e.g. having a well in the village makes water more accessible than having to dig a hole in a sandy river far away from the village);  utility refers to the level of safety in water accessibility and use (e.g. polluted or salty water); finally, stability indicates reliability of water resources over time, including the presence of water shortage periods or natural disasters (e.g. droughts and floods).
Starting with coding for these themes we then inductively added other potential water security categories emerging from the interviews. The lead author coded the focus group discussions and reviewed sections of the coded interviews with the local facilitator to make sure to properly interpret the transcripts and to discuss preliminary themes.
After the identification of the themes related to water security problems, we gave a 5-grade score to each problems based on their severity from none, to low, medium, high and very high according to participants’ perception. Finally, based on the set of problems identified with the communities and their severity score, we associate a socio-economic criteria for the best-siting of sand dams addressing the identified problems.
During the whole participatory process, we triangulated the results from the focus groups with notes from participant observations (Hertel, 1974), field visits with key informants from the communities as well as conversations with other experts involved in development projects with pastoral communities based in Namibe.