Groundwater Resources Assessment for IDPs camps and Hosting Communities around Nyala Town, South Darfur State, Sudan

Abstract

ABSTRACT Over two million internally displaced persons (IDPs) are present in the three Darfur States. They depend on groundwater from alluvial and fractured basement aquifers as the main source of water supply to secure their daily demands. The study is mainly oriented to investigate the groundwater resources in the IDPs camps and the hosting communities around Nyala Town, which represents one of the main IDPs settlements in Darfur region. The study is based primarily on 10 electronic logger’s records in addition to the manual measurements and the analysis of the existed hydrogeological and hydrological data. The outcome of the present study indicates that only a little amount of the total precipitation replenishes the groundwater aquifers. The alluvial aquifers are vastly replenished through direct infiltration from precipitation and surface runoff. The fractured basement aquifers are characterized by less groundwater storage capacity compared with the alluvial aquifers; they show good fractures conductivities that reflected on the continuous rising of the water table after the rainy season. The current investigations indicate that there are no problems for the camps and hosting communities who depend for water supply from on the alluvial aquifers of Wadi Nyala that is annually replenished by about 13 million cubic meters. Nevertheless, the camps that depend on the fractured basement aquifers are considered vulnerable and subjected to groundwater deterioration. supply in some high populated camps due to the drought and high extraction rates, (Tearfund’s, 2007; UNEP, 2007; UNICEF, 2009). These indicators raise some questions about the availability of the water resources at these vulnerable zones that need more investigations in the short and long run to sustain the water supply for these camps and the hosting communities and for the implementation of the contingency planning. Groundwater deterioration is expected due to the high extraction rates from the limited groundwater storage in water bearing zones, since most IDPs camps are located in basement terrains. In these terrains the aquifers are of limited storage capacity and of direct relation with the prevailing climatic condition, so they are affected by the rates and duration of annual rainfalls. 1.1 The study area Darfur region lies in western Sudan adjacent to Chadian and Central African Republic boundaries. The study area is around Nyala Town in South Darfur State. It is bounded by latitudes; 8o N to 20o N and longitudes 22o E to 27o 30// E. (Fig. 1). This area includes six IDPs camps, namely: Otash, Deraig, Kelma, Sakali, Beleil and El Salam (Fig. 2). The average annual rainfall in Nyala area is about 400 mm with average temperature during summers of about 36°C, decreases to less than 20°C during winters. The temperature shows wide variations through the year and also during the day time. The most important studies conducted in the study area for groundwater exploration and assessment are: WAPS (1982), RTF (2006), Tearfund’s (2007), UNEP (2007) and UNICEF (2009).