Characterisation of Agricultural drought patterns using the theory of runs: A case study of Lesotho Highlands commercial dams

Drought is a major environmental problem that affects agriculture, water resources, and communities around the world. In the Lesotho Highlands commercial dams, drought can have a significant impact on agricultural production, water supply, and local livelihoods. Understanding the patterns and severity of drought is crucial for effective water management and agricultural planning. This study aimed to analyse and understand the patterns of agricultural drought in the Lesotho Highlands commercial dams through the use of the Standardized Precipitation Index (SPI) and the theory of runs, as well as various drought parameters. The study used Average Dry Spell Duration, Drought Tendency, Longest Dry Spell Duration, Longest Multi-year Drought, Largest Single Year Drought, Standard Total Accumulative Dry Spell, and Number of Consecutive SPI-values, to provide a comprehensive analysis of the drought situation. The results revealed that the precipitation levels at the four dams were relatively similar, but with a potential increase in precipitation at Muela Dam. The SPI-3 and SPI-6 analyses showed a significant downward trend indicating an increase in dryness in the area. The drought parameters did not show significant differences between the stations/dams, indicating similar levels of drought across the dams. The study recommends regular monitoring of precipitation and drought conditions using the SPI and other water-balance drought indices, development of water conservation and management strategies, use of drought-resistant crops and water-efficient agriculture practices, and increased collaboration among stakeholders for sustainable water management and agricultural resilience.