Extensão da intrusão salina no estuário do Incomati

Abstract

Saline intrusion is a natural phenomenon that occurs in deltas and estuaries due to interaction between river and sea waters, having a differentiated ecosystem system and sensitive to weather conditions and human action. In the river basin estuary of the Incomáti River, located in the district of Marracuene - this phenomenon has consequences socio-economic due to the existence of fishing and agricultural activities. For this phenomenon which proposed to evaluate the extent of saline intrusion in the Incomáti river estuary for the wet and dry seasons, two campaigns in the Incomati River estuary, one in dry season and another in the wet season of the region where field measurements were made and collecting samples for laboratory analysis at 29 points in the wetlands and canals of the river, where activities such as fishing and agriculture are carried out, and 12 points along of the river in low and high tide conditions. The physicochemical properties were measured in situ at stations along the river every 3 km and at different depths. The highest electrical conductivity values ​​were recorded at the mouth of the estuary, being in the dry season, around 50,333 µS/cm, and in the humic season, around 40,633 µS/cm. A The extent of the saline intrusion recorded in field measurements was 36 km at the time drought and 30 km for the humic season, with salinities of 321 µS/cm being observed, in the area of ​​Matsinane, in the wet season and 363 µS/cm in the area of ​​Eduardo Mondlane, in dry season. Electrical conductivity in the Macaneta wetlands varies significantly during the dry and wet season, with the highest values ​​during the dry season may affect the functioning of the ecosystem in the wetlands of Handle (TRADUÇÃO NOSSA).