AN ASSESSMENT OF THE IMPACTS OF HUMAN ACTIVITIES ON RIVER’S WATER QUALITY: A CASE STUDY OF CHIMVU RIVER

Human activities are recognized as major sources of environmental problems. Worldwide freshwater resources, which provide important ecosystem services to humans as well as aquatic organisms, are under threat from rapid population growth, urbanization, industrialization, agricultural activities as well as domestic activities. Therefore, there is a need to assess and monitor these resources so as to as how human activities are having an impact on them. In this context, the physical and chemical water quality of Chimvu River located in Thyolo district, close to Malawi University of science and Technology (MUST) was assessed with possible contamination from agriculture activities and sand mining. The chemical and physical parameters were assessed at seven sampling sites. In addition, a biomonitoring approach was used where by organism from the river were collected to estimate aquatic ecological condition of Chimvu River using South African Scoring System (SASS). The results showed that some of the measured parameters in some sampling stations did not conform to local as well as international standards of water quality. For example, concentration of dissolved oxygen (DO) in almost all sampling stations were below the recommended level of greater than 8mg/l. Turbidity was found to be at above an agreed value of 50 NTU at sampling point 2 where turbidity value was 63.5 NTU. This is attributed to agriculture activities and sand mining activities which happens along the river’s stretch. Biomonitoring assessment revealed that the river is dominated by pollution tolerant as well as semi-tolerant organisms which indicates that the river is polluted hence not suitable for pollution -sensitive organisms

The study therefore proposes the need for further monitoring of the river where the sampling period should be increased in order to cover the whole stretch of the river

Worldwide freshwater resources, which provide important ecosystem services to humans as well as aquatic organisms, are under threat from rapid population growth, urbanization, industrialization, agricultural activities as well as domestic activities. In this context, the physical and chemical water quality of Chimvu River located in Thyolo district, close to Malawi University of science and Technology (MUST) was assessed with possible contamination from agriculture activities and sand mining. In addition, a biomonitoring approach was used where by organism from the river were collected to estimate aquatic ecological condition of Chimvu River using South African Scoring System (SASS). Biomonitoring assessment revealed that the river is dominated by pollution tolerant as well as semi-tolerant organisms which indicates that the river is polluted hence not suitable for pollution -sensitive organisms

The study therefore proposes the need for further monitoring of the river where the sampling period should be increased in order to cover the whole stretch of the river

The study was conducted in the Chimvu River because of the different human activities taking place within and along the river. The river passes through residential areas as well as agricultural lands, making it important to investigate the possible effects of these activities on water quality. The use of river sand for construction purposes, together with agricultural and domestic activities, justifies the need to assess the physical and chemical water quality of the river. Furthermore, the river is socio-economically important to the population within its catchment; therefore, assessing its water quality is necessary to understand the potential effects of human activities on this important resource. The study area incorporated seven sampling points spaced 800 meters apart to provide adequate spatial coverage along the river and reduce the likelihood of collecting samples from nearby locations with similar water quality characteristics. The study concentrated on activities taking place within and along the boundaries of the river to establish their potential influence on its water quality.

Traditional authority: TA Chimaliro

District: Thyolo

Coordinates: -15.9729, 35.19975