Investigating the environmental response to water harvesting structures: a field study in Tanzania

摘要: Abstract. Sand dams, a popular water harvesting structure employed by rural communities, capture and store for use during the dry season in arid semi-arid regions. Most sand dam research has been performed on the “ideal” dam, despite approximately 50 % of dams not functioning as intended. This involves 1-year long, in-depth field study three in Tanzania, one which is essentially non-functioning. The study investigated dam's impact on macroinvertebrate habitat, vegetation, streambank erosion explored a sand loss mechanisms. Surveys macroinvertebrate assemblage were each season. Vegetation surveys were every other month, was recorded semi-monthly. Water table monitoring wells were installed at measurements taken twice day. The found that are too homogeneous to provide sustenance and refugia macroinvertebrates need different life stages. The non-functioning thick layer silt preventing infiltration of rainwater. functioning significant amount water, but most lost evapotranspiration within few months last rainfall. Unlike non-functioning dams have positive on local vegetation minimal erosion. Sand can increase security community, but site characteristics construction methods must be strongly considered to maximize impact.