Lake Sibayi variations in response to climate variability in northern KwaZulu-Natal, South Africa

• Published in: Theoretical and applied climatology 2019-07, Vol.137 (1-2), p.1233-1245
• Main Authors: Nsubuga, Francis N. Wasswa, Mearns, Kevin F., Adeola, Abiodun M.
• Format: Article
• Language: English
• Subjects: Analysis; Annual precipitation; Annual rainfall; Annual rainfall data; Anthropogenic factors; Aquatic Pollution; Atmospheric precipitations; Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Catchment area; Change detection; Climate change; Climate science; Climate variability; Climatic changes; Climatology; Correlation analysis; Detection; Earth and Environmental Science; Earth resources technology satellites; Earth Sciences; Image detection; Inflow; Lake catchments; Lakes; Landsat; Landsat satellites; Natural resource management; Natural resources; Original Paper; Precipitation; Probability theory; Rain; Rain and rainfall; Remote sensing; Remote sensing techniques; Remote sensors; Resource management; Restoration; Satellite imagery; Sensing techniques; Shrinkage; Spaceborne remote sensing; Statistical analysis; Surface area; Waste Water Technology; Water demand; Water level fluctuations; Water levels; Water Management; Water Pollution Control; Weather; Weather stations
• ISSN: 0177-798X; 1434-4483
• DOI: 10.1007/s00704-018-2640-0

The optimal management of natural resources like lakes requires understanding the relationship with other environmental elements. Remote sensing techniques using multi-temporal and multi-sensor images for change detection purposes are important in this regard. This study used a combination of approaches to detect changes in the lake surface area of Lake Sibayi in relation to changes in past climates. Delineation of the study area is achieved using WR2012 endoreic maps and Landsat satellite images from 1992 to 2016. Using data from eight meteorological stations, past climate of the lake catchment was investigated. Thereafter, a multivariate correlation analysis is conducted to examine the relationship between the changes in the lake surface area and the changes in climatic (precipitation, temperature) variables and water levels. Results suggest that the lake surface area has decreased by 20% since 1992. There are significant changes in temperatures, while the annual rainfall totals declined significantly. The correlation between precipitation in the catchment and annual water level changes is 0.88. Statistically, significant increases in the water level and precipitation were experienced in 1993 and 2001. SPI analysis reveals that the study area is getting drier and the probability of recurrence of moderate dryness is 10%. The rate at which the lake is shrinking is not solely climatic related, as anthropogenic aspects are also responsible. To prevent further shrinkage of Lake Sibayi, it will be necessary to develop aggressive restoration policies and action plans aimed at maintaining inflows in the face of compounding climate change and water demand. Recommendations of the nature of further studies that can increase our understanding are included.