Integrated groundwater characterization for biodiversity protection in limpopo national park (Mozambico)

This paper deals with the first results coming from the research activity of the SECOSUD Phase II, called “Conservation and equitable use of biological diversity in the SADC region (Southern African Development Community) a project supported by the Italian Ministry of Foreign Affairs in the SADC [1]. The goal of this tiered study is to give an integrated view of three focus themes inside the area of Limpopo National Park, in Limpopo River Basin: groundwater, climate change, biodiversity. Limpopo National Park is one of the jewels in the crown of Mozambique’s protected areas: it is exceptionally rich in biodiversity and, as such, has a wide variety of genes, species and ecosystems. Groundwater, climate change, biodiversity make a linked system. The way to protect and keep biodiversity is to evaluate the implications between these themes, because climate change has a large impact on groundwater, which plays a crucial role in supplying water and biodiversity depends on groundwater quality and quantity. The management of biodiversity and ecosystems, highly dependent on water and how rainfall may evolve over the basin plays a crucial role on aquifer recharge. For a comprehensive groundwater recharge assessment, the first phase of the present study focused the impact of the climate change on groundwater recharge ranging from the regional scale of Mozambique to local scale of Limpopo Park area. Mozambique is situated on the East coast of Southern Africa between 10”27’S and 26”52’S latitude. The morphology of the country can be characterized by distinct units such as coastal lowlands, middle plateaus, uplands plateaus, mountainous area. The climate of Mozambique varies spatially from the North where is under the influence of the equatorial low pressure zone, to the South where it is influenced by the subtropical and anti-cyclonic zone. The prominent geological features are the Precambrian crystalline rocks of the Basement Complex, Karoo Sedimentary Rocks, Post Cambrian Volcanic and igneous Rocks and Meso- Kenozoic Sedimentary rocks. The main hydrogeological units correspond to geological units and are: aquifers related to the crystalline basement complex, aquifers occurring in Karoo formations and aquifers related to post Karoo formations [2]. The method employed was the reverse groundwater balance technique for the assessment of potential infiltration factor. As first step the study aims to evaluate the total rainfall received at Mozambique to understand rainfall variability in time by a statistical technique. Monthly precipitations historical series, referred to 23 years of measurements, were available. These records data were collected in meteorological network stations in Mozambique. Afterwards, we carried on the assessment of the effective infiltration action on the basis of an infiltration coefficient evaluated taking the conditions of rock outcropping from the Soil and Terrain database (SOTER) for Southern Africa [3] The intent of the study is to evaluate the groundwater active recharge and how it is sensitive to climate change.