In Malawi, spate irrigation is hardly known yet it is a key farming practice that would help smallholder farmers to mitigate the effects of climate change. As a rainwater harvesting and flood management system, spate irrigation involves the diversion of rainwater using technologies such as bunds and gabions, masonry or concrete structures. It represents a unique option for the management of scarce water resources in support of agricultural production and rural livelihoods. Spate irrigation is cheaper to invest in than other irrigation technologies such as furrow, ponds and shallow-wells. In this study, Excel and CropWAT softwares were used to analyze crop water requirements and irrigation systems at Madude village in Dowa district. The study has found out that (1) high value drought resistant crops such as cassava are better for spate irrigation; (2) most farmers grow crops with high water requirements hence due to effects of climate change, their water sources are failing to satisfy the needs. (3) a hybrid system of floodwater harvesting and water saving irrigation technologies such as spate irrigation and mulching can improve water productivity. These findings suggest that spate irrigation has potential and could be a way of adapting to the impacts of climate change. Hence, encouraging spate irrigation-capital creation, low-cost operation and maintenance and considering regional diversities can increase the probability of modernizing spate irrigation. The findings also inform the decision on crop choice enterprises in rural areas to enhance food security.

The study of rainfall frequency analysis is important as it guides engineers, policy makers and water planners to design water structures, predict extreme events such as floods or droughts and prepare disaster risk management plans in advance. This paper discussed how Gumbel distribution can be used in analyzing frequency of rainfall in Dowa district. 30 years of rainfall data (1986–2015) for Dowa district was analyzed using Excel and Hydrognomon software applications by employing different statistical analysis and distribution types. The more practical result of this paper was that the 2-year, 5-year, 10-year, 20-year, 25-year and 50-year return periods of maximum monthly rainfall were calculated for the district. It was found out that Gumbel’s distribution is suitable for predicting expected maximum rainfall in the district. From the Gumbel’s distribution using return periods (T) above, the estimated maximum monthly rainfall obtained are: 272.5 mm, 340.4 mm, 385.3 mm, 428.5 mm, 442.1 mm and 484.3 mm respectively. These values are useful for irrigation systems designing, reservoir designing, storm management and water balance modelling in the district. The result of this study can also be used to develop more accurate and reliable models of flood risk management.

Groundwater of good quality is necessary for domestic use and agricultural productivity. The chemical constituents of the groundwater determine its suitability for different usage. Proper analysis (both statistical and geophysical) is needed to analyze water quality parameters such as Hydrogen ion concentration (pH), Electrical Conductivity, turbidity, total hardness, Chloride, Calcium, Magnesium and Sodium. Spatial analysis using inverse distance weighted method in Surfer 12 software was used to prepare the groundwater quality distribution maps. These maps were used to assess temporal and spatial changes in groundwater quality in Lilongwe western zones. The results showed both spatial and temporal variations in groundwater quality in the study area. This study demonstrated that the use of GIS could provide useful information for groundwater quality assessment. This study therefore recommends periodic monitoring and evaluation of groundwater using Geographic information systems (GIS).