How do people gain access to water resources in the Brazilian semiarid (Caatinga) in times of climate change?

Climate change is becoming an imminent reality, especially in arid and semiarid regions. Therefore, it is essential to understand the relationships between humans and aquatic ecosystems in order to devise efficient management and conservation strategies. We conducted 126 interviews using a semi-structured form to record water sources, transport strategies, and the use and treatment of water by communities surrounding four reservoirs within two drainage basins in the semiarid region of Brazil. These factors were then compared to the mean water volumes of the respective reservoirs from 2013 to 2015, a period of severe drought in that area. Seven types of water sources were considered, according to the perspectives of the interviewees: large reservoirs (dams) (43% of the citations), other smaller reservoirs (25%), rainwater (17.5%), wells (7%), waterholes (3%), bottled water (4%), and water tanks (0.5%). The water resources obtained are transported to human residences in seven different manners: actively pumped (34% of the citations), by water tanker truck (33%), distributed in pipes by local resident associations (11%), transport by animal (14%), human transport (4%), by car (2%), and by motorcycle (2%). The water is then used for domestic purposes (21%), for personal hygiene (20%), by animals (19%), in agriculture (18%), for cooking (10%), for fishing (7%), and for drinking (6%). A worrisome trend was that many local residents did not treat the water they were consuming. Climate change affects seasonal patterns of rainfall that will, in turn, determine the availability and quantities of water resources, provoking changes in the sources of water used by human populations, their strategies of access to that resource, and water-use patterns. It is necessary sustainable use of water resources based on the realities of local populations.

Application of a statistical model for the assessment of environmental quality in neotropical semi-arid reservoirs.

The aim of this study was to develop a statistical model to assess the environmental quality of reservoirs located in semi-arid region using metrics of anthropogenic disturbance, water quality variables, and benthic macroinvertebrate communities as indicators. The proposed model was applied to 60 sites located in three reservoirs in the Paraíba river basin, Brazilian semi-arid region. Collections were made in December 2011. In each site, we collected one sample of benthic macroinvertebrates and one water sample for the determination of physical and chemical parameters. Characterization of the landscape was made through application of 10 physical habitat protocols on each site for the collected information on disturbance and subsequent calculation of disturbance metrics. The results showed the formation of two groups: group 1, consisting of 16 minimally altered sites, and group 2, with 44 severely altered sites. The proposed statistical model was sensitive enough to detect changes. In the minimally altered group, the Chironomids Aedokritus and Fissimentum were dominant, indicating a higher environmental quality, while Coelotanypus and Chironomus were abundant in severely altered sites with lower environmental quality. The conservation and management of reservoirs in semi-arid regions should be intensified in view of the need to maintain the environmental quality of these ecosystems.