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This study reports levels of aflatoxin and fumonisin in maize samples (n = 1294) from all agroecological zones (AEZs) in Malawi. Most maize samples (> 75%) were contaminated with aflatoxins and 45% with fumonisins, which co-occurred in 38% of the samples. Total aflatoxins varied across the AEZs, according to mean annual temperature (P P

Flood vulnerability assessment (FVA) is significant for application to address flood risks in both rural and urban areas in Malawi. Nevertheless, there is lack of FVA framework for application in urban and rural areas. The main purpose of this study was to develop flood vulnerability assessment framework through a comparative study of Lilongwe City and Karonga District in Malawi. Vulnerability was explored through a combination of underlying vulnerability factors (UVFs)-physical-social-economic-environmental and cultural with vulnerability components (VCs)-exposure-susceptibility and resilience. The UVFs and VCs were agglomerated using binomial multiple logit regression model, and Multiple Correspondence Analysis (MCA). The results reveals that except cultural-susceptibility factors (CSFs), all the agglomerated factors contribute to flood vulnerability in Karonga district (KD) and Lilongwe city (LC). The results further show that all the indicator variables in LC have a inertia value at the expected rate of less than 10% while in KD lack of credit unions (0.103), lack of markets (0.499) poverty (0.123) and (0.203); display values that deviate from the expected score of

Many parts of Malawi are prone to natural hazards with varying degrees of risk and vulnerability. This study aimed to quantify vulnerability of the households to flood risks in Karonga District in northern Malawi, specifically in Group Village Headman (GVH) Matani Mwakasangila of Traditional Authority Kilupula. The study used cross-sectional survey and data was collected using a structured questionnaire. This study applied Flood Vulnerability Index and statistical methods to quantify and analyse vulnerability of households in the aspect of exposure, susceptibility and resilience characteristics. Proportional Odds Model also known as Ordered Logistic Regression was used to identify factors that determine vulnerability of households to flood risks. The results show that households headed by females and elders of age (at least 61 years) were the most vulnerable to flood disasters. Households with houses built of mud, thatched and very old with no protective wall were more and most vulnerable to flood disaster in the area. The model also was used to model vulnerability in the respect of exposure, susceptibility and resilience of households to floods. The level of vulnerability was increasing with an increase in the number of households exposed and susceptible to floods. With an increase in resilience to flood disasters, vulnerability level was decreasing. Post analysis was also considered to have predictive margins of vulnerability levels among the villages in GVH Matani Mwakasangila. The likelihoods of vulnerability levels were not significantly different among the villages. However, villages with more exposed, susceptible and not resilience households were most vulnerable to floods in GVH Matani. Therefore, this study recommends that indigenous people and most vulnerable (women and elders) should be included in both Disaster Risk Reduction (DRR) planning and implementation. Their representation should also play a major role, including leadership in national DRR arrangement as a way of increasing resilience to flood disasters.

Climate and land use change (CC and LUC hereafter) are interlinked factors that can lead to river flow regime changes, as well as affecting hydrological extremes such as floods and drought. There is now considerable evidence of CC and LUC in many catchments in Malawi but without corresponding evaluations of their impacts on river flow regimes. Therefore, this study assessed how both factors affect the flow regime of Wamkurumadzi River, a key tributary of the major Shire River in southern Malawi. Land use and hydroclimatic data for the basin were first analyzed for spatial–temporal trends in the historical period between the years 1984 and 2015. The Soil and Water Assessment Tool (SWAT) model was then applied with different LUC and CC scenarios in order to assess their sole and combined impacts on the river flow regime. The model was calibrated and validated using the split sample method from the year 1984 to 1999 and from the year 2000 to 2015. Model performance was acceptable according to the selected evaluation criteria, with the Nash–Sutcliffe (NSE) coefficient of 0.78 and coefficient of determination (R2) of 0.96 during calibration and NSE of 0.93 and R2 of 0.98 during validation. Results of the integrated impacts of LUC and CC suggest a slight increase in river discharge of 0.05 m3/s for the period between the 1980s and 2000s. During the 1980s–1990s, both CC through rainfall decreased and LUC resulted in decreases in the mean river discharges by 1.58 and 0.37 m3/s, respectively. The study also found that CC through increased rainfall in the 1990s–2000s decades saw an overall increase of 1.39 m3/s in mean river discharge, while LUC shows the increase of mean river discharge by 0.25 m3/s. However, the study observed that reforestation efforts in the basin were greatly responsible for the alteration of the river flow regime in the later period. HIGHLIGHTS This article is among few studies undertaken in data-scarce regions applying the SWAT model.; The approaches applied in evaluating the integrated impacts of climate change and land use are very innovative.; The approaches are applicable in other data-scarce regions.; Sheds significant light on remedies to catchment degradation.; Strong potential to influence policy in water assessments and catchment management.

Data scarcity globally has impeded our understanding of hydrological processes. This study was aimed at evaluating skills of models in reproducing past climate in the Shire River Basin (SRB) in Malawi for future climate impact assessments. The study used data, simulated by Global Climate Models (GCMs), participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). A total of 52 models were considered comprising a mixture of models in the Representative Concentration Pathways of RCP4.5 and RCP6.0. The mean annual bias, correlation, extreme precipitation indices obtained from the RClimdex package of R software program and frequency distributions were used to quantify the accuracy of the GCM simulations. On the precipitation indices, emphasis was placed on the frequency indices (number of heavy precipitation days (RR ≥ 10 mm), R10mm, number of very heavy precipitation days (RR ≥ 20 mm), R20mm, number of extremely heavy precipitation days (RR ≥ 25 mm), R25mm, Consecutive Dry Days (RR

Due to climate variability and reservoir regulation worldwide, it is fundamentally challenging to implement holistic assessments of detection, attribution and frequency analysis on non-stationary flood peaks. In this study, we proposed an integrated approach that combines the prewhitening Mann-Kendall test technique, Partial Mutual Information-Partial Weights (PMI-PW) method and Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS) method to achieve reliable non-stationary flood frequency analysis. Firstly, the prewhitening Mann-Kendall test was employed to detect the trend change of flood peaks. Secondly, the PMI-PW was employed to attribute the contribution of climate change and reservoir regulation to non-stationarity of flood peaks. Lastly, the GAMLSS method was employed to quantify the change in flood risks under the non-stationary condition. The applicability of the proposed approach was investigated by long-term (1931-2017) flood series collected from 32 big river catchments globally. The results suggested that global flood trends varied from increasing +19.3%/decade to decreasing −31.6%/decade. Taking the stationary flood frequency analysis as the benchmark, the comparative results revealed that the flood risk in 5 rivers under the non-stationary condition in response to warming climate significantly increased over the historical period whereas the flood risk in 7 rivers in response to increasing reservoir storage largely reduced. Despite the spatiotemporal heterogeneity of observations, the changes in flood peaks evaluated here were explicitly associated with the changing climate and reservoir storage, supporting the demand for considering the non-stationarity of flood peaks in the best interest of social sustainability.Keywords: Flood peaks; Large catchments; Non-stationarity; Frequency analysis*This work was supported by the Research Council of Norway (FRINATEK Project 274310).

© 2019 Elsevier Ltd Malawi experiences frequent floods and droughts and these hydrological extremes kill and displace people and damage infrastructure. In recent years, the trend of these extreme events has increased in frequency and magnitude and has threatened socio-economic development of the country. Analysis of trends and frequency of hydro-meteorological extremes that cause floods and droughts is very vital in understanding the hydrological systems and this may assist in averting disasters associated with those extremes. For extremes extracted from long-term hydro-meteorological records, a significant trend may indicate a shift from the natural changes to the changes induced by human activities on one hand and on the other hand, decadal or multi-decadal oscillations in the occurrence of hydro-meteorological extremes may demonstrate the influence of the (multi-) decadal persistence of the climate system. In Malawi, studies on trends of hydro-meteorological extremes of rainfall, temperature and streamflows are scanty as most studies have focused on the means. This study, therefore, aimed at examining trends and frequency of these hydro-meteorological extremes in the Shire River Basin in Malawi. Daily scale data from 1961 to between 2005 and 2015 were collected from 22 rainfall stations, 12 temperature stations and 10 river discharge station within the study area. The hydro-meteorological extremes were analyzed using annual maximas and annual minimas of the daily hydro-meteorological data. Significance and direction of trends in these extreme indices were examined using the non-parametric Mann–Kendall test statistic. The Peak-Over-Threshold (POT) approach, applying the Generalized Pareto Distribution (GPD) was used to analyze the distribution of the extremes. Study results have shown that temperature extremes have an increasing trend which is significant at 5% significance level. In terms of streamflows, both the peak and low flow extremes have shown a decreasing trend, which is consistent with the decreasing trends observed in rainfall extremes. Analysis of frequency of extreme events has shown that extremely high rainfall events have a high probability of occurrence while streamflow extremes will not occur frequently. These findings have provided key insights that are key in understanding the temporal occurrence of hydro-meteorological extremes in the basin, which are of benefit to the regional water resources planning and development. ispartof: PHYSICS AND CHEMISTRY OF THE EARTH vol:112 pages:91-102 ispartof: location:NAMIBIA, Swakopmund status: published

Food security in Malawi relies on rainfall amount and timing. Because agricultural production is the main source of income for most rural communities, increased frequency of extreme events will increase the risk of production failure—a major threat to food security. Evidence of changing rainfall is reported by farmers and by recent analysis of gauge measurements, but these studies are limited due to small sample size, type of tests, or both. The main goal of this study is to test both statistically significant and robust but less significant changes in rainfall and rainy season for 1981–2018 using a high-resolution gridded dataset (0.05°). We analyzed different indices including onset, length, and cessation of rainy season, number of dry days, and number of extreme events during the rainy season. Our results show that roughly one-third of Malawi has experienced at least one type of significant change in rainfall indices during the study period. For instance, Northern Malawi had ~ 2 fewer extreme event days/decade and an end of season ~ 5 days/decade earlier as well as ~ 5 fewer dry days/decade. For the entire time period, delayed onset varies spatially from 18 to 35 days, number of dry days has decreased 21.6 days, the rainy season has ended 28.8 days earlier in the north and 36 days earlier in the south, and the number of extreme events has decreased 5 to 7 days in many places. The results are heterogeneous spatially and suggest that broad scale forcings are not driving them.

The impacts of climate-related risks on rural-urban linkages and the food systems on which urban settlements depend are poorly understood. This study analysed i) the climate trends for Blantyre City and rural Chikwawa district in Malawi, ii) the sources of foods typically consumed in these locations, iii) the implications of flooding following Tropical Cyclone Idai on urban and rural households interconnected agri-food systems and food security. Although floods were reported to cause both positive and negative effects on food production, food flows between rural and urban areas, and household food security; the negative effects (i.e., destruction of crops, homes and transport routes; higher food prices) outweighed the positive. In both rural and urban areas, poorer households were disproportionately affected resulting in reduced dietary diversity and food intake, shifts to consumption of cheaper foods, and requests for emergency food donations. Given the rapid rate of urbanisation, better understanding of food security amongst urban households is required. Following extreme events such as flooding, special attention needs to be directed to assessing and addressing food availability, access and consumption challenges in both urban and rural areas reliant on interconnected agricultural and food flows, and particularly in poor households.

Access to drinking water remains a challenge in many rural areas in Sub-Saharan Africa. This situation is further compounded by frequent disasters such as floods, which affect water supply infrastructure. However, few scholarly works have examined access to drinking water for rural households vulnerable to floods in Southern Africa. This study analysed the extent to which the 2019 flooding induced by Cyclone Idai affected households’ access to water in Magalasi Village in Chikwawa District in Malawi. Data was collected and analysed following the mixed methods research design in which both quantitative and qualitative approaches were used. The results show that during the floods, households relocated to a nearby school which has solar powered tap water. However, the increased numbers at the camp resulted in a decline in the daily minimum water per capita of 20 L/c/d in about 60% of the households as each tap is meant to carter for 250 people only. Furthermore, the use of the taps was restricted to 8 h (6 am–2 pm during weekdays and 8 am–5 pm during weekends), which coincided with times for farming activities. Consequently, households had to fetch water from a village about 3 km away. However, the alternative water sources were also inaccessible during severe flooding conditions, with intermittent and contaminated water. Considering the health challenges associated with consumption of insufficient and contaminated water, this study proposes construction of more resilient deep boreholes for continuous water supply.

This study explores links between IKS and climate science for flood forecasting in a flood-prone area, affected by Tropical Cyclone Idai, in Malawi. Rural communities’ perceptions of flood trends and risks were collected using household interviews (n = 60), key informant interviews (n = 10) and mixed gender focus group discussions in Chikwawa District. Flood frequency analysis was performed using rainfall and discharge data from nearby weather stations and Mwanza and Shire Rivers. There is a decline in localised rainfall, but increase in flooding from rainfall in upstream catchment. Both communities highlighted reliable IKS (flora, fauna and atmospheric observations) used before the onset of and during the rainfall events for flooding forecasts. However, most of the IK indicators are threatened by environmental degradation and may not be suited to forecasts of patterns or intensity of rainfall at large spatial and temporal scales, such as floods from rainfall in upstream catchment. Therefore, IK indicators may not provide sufficient foreknowledge to respond to climate events such as cyclones. Scientific climate knowledge may provide forecasts at both small and large spatial and temporal scales. Therefore, integration of contextualised IK and scientific climate knowledge can produce robust flood forecasts in the poorly resourced settings.

The impacts of climate-related risks on rural–urban linkages and the food systems on which urban settlements depend are poorly understood. This study analysed (i) the climate trends for Blantyre City and rural Chikwawa district in Malawi, (ii) the sources of foods typically consumed in these locations, (iii) the implications of flooding following Tropical Cyclone Idai on urban and rural households’ interconnected agri-food systems and food security. Although floods were reported to cause both positive and negative effects on food production; food flows between rural and urban areas; and household food security, the negative effects (i.e. destruction of crops, homes and transport routes; higher food prices) outweighed the positives. In both rural and urban areas, poorer households were disproportionately affected resulting in reduced dietary diversity and food intake, shifts to consumption of cheaper foods, and requests for emergency food donations. Given the rapid rate of urbanisation, better understanding of food security amongst urban households is required. Following extreme events such as flooding, special attention needs to be directed to assessing and addressing food availability, access and consumption challenges in both urban and rural areas reliant on interconnected agricultural and food flows, and particularly in poor households.

Lake Malawi in south eastern Africa is a very important freshwater system for the socio-economic development of the riparian countries and communities. The lake has however experienced considerable recession in the levels in recent years. Consequently, frequency analyses of the lake levels premised on time-invariance (or stationarity) in the parameters of the underlying probability distribution functions (pdfs) can no longer be assumed. In this study, the role of hydroclimate forcing factors (rainfall, lake evaporation, and inflowing discharge) and low frequency climate variability indicators (e.g., El Nino Southern Oscillation-ENSO and the Indian Ocean Dipole Mode-IODM) on lake level variations is investigated using a monthly mean lake level dataset from 1899 to 2017. Non-stationarity in the lake levels was tested and confirmed using the Mann-Kendall trend test (α = 0.05 level) for the first moment and the F test for the second moment (α = 0.05 level). Change points in the series were identified using the Mann-Whitney-Pettit test. The study also compared stationary and non-stationary lake level frequency during 1961 to 2004, the common period where data were available for all the forcing factors considered. Annual maximum series (AMS) and peak over threshold (POT) analysis were conducted by fitting various candidate extreme value distributions (EVD) and parameter fitting methods. The Akaike information criteria (AIC), Bayesian information criteria (BIC), deviance information criteria (DIC), and likelihood ratios (RL) served as model evaluation criteria. Under stationary conditions, the AMS when fitted to the generalized extreme value (GEV) distribution with maximum likelihood estimation (MLE) was found to be superior to POT analysis. For the non-stationary models, open water evaporation as a covariate of the lake levels with the GEV and MLE was found to have the most influence on the lake level variations as compared with rainfall, discharge, and the low frequency climatic forcing. The results are very critical in flood zoning especially with various planned infrastructural developments around the lakeshore.

Climate change and variability is threatening agricultural production and adversely affecting the natural resource base, which provides a living for more than half of the world’s poorest people. Farmers have therefore in response, developed coping strategies to adapt to the adverse impacts of climate change. However, most of these strategies have not been successful in some semi-arid areas owing to various challenges, including those that can be attributed to on-farm land and water resources management practices. This study was aimed at assessing the contribution of two different tillage systems (hand hoe and Magoye ripper) in climate change adaptation in agriculture, specifically on maize and sorghum crops in Chikwawa District in Malawi, a drought prone semi-arid area with perennial erratic rainfall pattern. These have been intensified of late by climate change. Three farmers’ fields were used to conduct community participatory research on farm learning activities. Data on maize and sorghum seed germination, seedling quality as well as grain yields were collected and analysed using GenStat. The results revealed that there were no statistically significant differences (p ≥ 0.05) in time taken to germinate, maize plant height and leaf size and number of leaves per plant under both hand hoe or Magoye ripper for both crops. It was however observed that despite the statistically insignificant differences in leaf size and number of leaves per plant, the relative number and length of either maize or sorghum leaves were superior under Magoye ripper tillage system. However, the results show statistically significant differences for grain weight, maize cob circumference, length and stover. In this case, maize yield and stover increased considerably (p ≤ 0.05) under Magoye than hand hoe. These traits therefore, can be used in decision making for the adoption of the Magoye ripper for climate change adaptation in the study area and its up-scaling in Malawi.

The significance of urban agriculture is increasingly being recognised across the globe. Urban agriculture’s contribution to food security and poverty reduction, especially for the urban poor, has received increasing attention in urban policy discourses (Satterthwaite et al. in Adapting to climate change in Urban areas; the possibilities and constraints in low- and middle-income countries. IIED, London, 2007; Mutonodzo in Agriculture in urban planning: generating livelihoods and food security. Earthscan, London, 2009; Mkwambisi in Agriculture in urban planning: generating livelihoods and food security. Earthscan, London, Mkwambisi 2009). The impacts of climate change, climate variability and urban growth reduce the benefits derived from agro ecosystem services in peri-urban areas in most developing countries. Peri-urban areas play a significant role in providing ~80% of the vegetables consumed in urban areas of Malawi. However, the vegetable production is dependent on stream water or residual moisture from wetlands, which are being affected by climate change. This study investigated the viability of multi-stakeholder experimentation with sustainable technologies for improving vegetable production in a peri-urban setting experiencing water shortages due to climate change and variability in the Mulanje district in Southern Malawi. Using a participatory action research (PAR) approach, farmers, researchers, extensionists and village leaders worked together to source, test and evaluate various different horticultural production practices. Over a two-year period, they experimented with technologies such as bag (vertical) gardening, differential use of manure and fertiliser, new crops and crop varieties, seed bed preparation techniques and judicial use of pesticides. Those practices identified as successful in 2011 were replicated in 2012 for further evaluation. In general, the study found considerable improvements in vegetable production resulting from the improved agronomic practices. Further, many farmers found bag gardening more convenient due to reduced irrigation requirements, lower labor demands, all year round seasonal production, ease of access and crop security. Improved quality of produce, earlier harvest and increased total number of harvests of leafy vegetables due to manure incorporation, use of improved varieties and high yields in general were among other advantages that were realised. In addition, the technologies promoted minimal use of chemicals, which resulted in reduced seepage of inputs, thereby maintaining agro-ecosystem health. Most communities in the area have adopted the technologies as strategies for climate change adaptation. Scaling up these practices can therefore improve vegetable supply challenges arising from urbanisation, climate change and variability while reducing impacts on agro-ecosystem services.

Cropland expansion is a common strategy for boosting agricultural production in sub-Saharan Africa (SSA) even though it often leads to economic, environmental, and social trade-offs. Ensuring sustainable cropland use and their management is critical for improving food security and preserving ecosystem services. To develop policies and approaches that support sustainable cropland management at national and sub-national scales, there is a need to understand the spatial distribution of cropland expansion (/loss), and any resultant changes in cropland productivity. This is especially important in SSA countries such as Malawi, where spatially explicit assessments of changes in cropland area and cropland productivity are lacking. To address this gap in Malawi, we used multi-source satellite data and socio-economic data, combined with satellite image classification and trend analysis, firstly to quantify spatial changes in cropland area and productivity, and secondly to evaluate potentially available cropland for future expansion. We found evidence of unsustainable cropland use in Malawi, which was demonstrated by: (a) rapid cropland expansion between 2010 and 2019 (increase 8.5% of land area), characterized by an expansion of crop farming into upland areas which indicate increased land scarcity in Malawi; (b) limited potential for future expansion, as approximately only 5% of the total land remained as potentially available cropland (corresponding to 4671 000 ha); and (c) an overall reduction in cropland productivity and a prevalence of increase in soil erosion. Our findings underscore the urgent need for taking measures to promote sustainable cropland use, including by protecting current cropland from further degradation (e.g. Southern Malawi) and improving cropland use planning (e.g. Northern Malawi).

This study presents the first national-scale assessment of temporal variations in the Base Flow Index (BFI) for watercourses in Malawi. A proxy indicator of groundwater discharge to rivers, the BFI is a measure of the ratio of long term baseflow to total river flow and is a key parameter for sustainable water resources management. The smoothed minima technique was applied to river flow data from 68 river gauges across Malawi (data records ranging from 11-64 years). The long-term average annual BFI for each gauged site was determined, as well as seasonal values of BFI. The Mann Kendal (MK) statistical test was used to identify trends in the BFI. Average annual BFI was 0.57, average wet season BFI was 0.52 and average dry season BFI was 0.97. This indicates that 57%, 52% and 97% of the total river flow is derived from groundwater and other stored sources in the annual, wet and dry season periods respectively. These results show that baseflow in Malawi follows a seasonal pattern with minimal differences between the average annual and average wet season BFI; however, significant increases are generally seen in the dry season BFI. The results also found long-term behavioural changes in BFI across all periods. Annually, 74% showed no trend, 10% showed an increasing trend and 16% showed a decreasing trend. The wet season trends showed similar values with 66% showing no trend, 16% showing an increasing trend and 18% showing a decreasing trend. In contrast, for the dry season, 93% showed no trend, 1% showed an increasing trend and 6% showed a decreasing trend. The dataset determined in this study can support sustainable water resources management in Malawi and contribute to measuring its progress towards Sustainable Development Goal 6.

In many developing countries, hydro-meteorological data is scarce due to dysfunctional or non-existent monitoring networks. Where available, such networks are not normally at the desired temporal and spatial scales. Studies in Malawi have shown variations of weather systems at relatively low spatial scales. Such variations, typical of tropical weather, entail a need for increasing the density of the hydro-meteorological monitoring networks for effective monitoring. This study is aimed at improving our understanding of hydro-meteorological processes in the Lake Chilwa Basin, a socio-economically important ecosystem in Malawi with a population of 1.6 million. The study used historical data of rainfall, river discharge and lake levels from old and new monitoring networks installed under the Lake Chilwa Basin Climate Change Adaptation Programme (LCBCCAP). The discharge data were also applied in regionalization to understand the frequency and magnitudes of floods and low flows. The role of Indigenous Knowledge Systems (IKS) in climate change adaptation was investigated through community engagement. The results have shown a declining trend of annual rainfall, river discharge, lake levels and shifts in rainfall onset and cessation. The quantiles of low flows and floods developed in the study can be used in estimating these hydrological extremes in the ungauged parts of the basin. Lastly, a need was identified to validate the various IKS used by the communities with empirical data.

Estimation of the spatial and temporal characteristics of key water balance components in data scarce regions is a large challenge worldwide. This paper presents the derivation of the 30-year surface water balance components (rainfall, temperature, potential and actual evapotranspiration (ETp and ETa) runoff). Monthly rainfall and mean temperature from 28 synoptic stations in Malawi during 1971–2000, together with soil moisture capacity extracted from the International Geosphere-Biosphere Programme Data Information Services (IGBP-DIS) Global Gridded Surfaces of Selected Soil Characteristics database at 0.5° × 0.5° grid resolution were used as model input. Ordinary Kriging was applied to examine the spatial distribution of the components using a 0.5° × 0.5° grid resolution. Temporal trends were investigated using the Mann–Kendall test at α = 0.05 significance level. The results showed: (1) an area of high rainfall, ETa and runoff areas located in the south east and north east highlands and decreasing westwards. Temperature and ETp were highest in the lower Shire River valley and along Lake Malawi; (2) Mann–Kendall trends suggested statistically significant positive trends in mean annual temperature and ETp and declines in annual rainfall, ETa and runoff, though their trends were not statistically significant. The contrasting trends ETp and ETa are a manifestation of the complementary relationship. The decline in rainfall coupled with temperature increase suggests that Malawi became more water-limited during 1971–2000.

In Malawi, production from subsistence rain fed agriculture is highly vulnerable to climate change and variability. In response to the adverse effects of climate change and variability, a National Adaptation Programme of Action is used as framework for implementing adaptation programmes. However, this framework puts limited significance on indigenous knowledge systems (IKS). In many parts of the world, IKS have shown potential in the development of locally relevant and therefore sustainable adaptation strategies. This study was aimed at assessing the role of IKS in adaptation to climate change and variability in the agricultural sector in a rural district of Chikhwawa, southern Malawi. The study used both qualitative data from focus group and key informant interviews and quantitative data from household interviews and secondary data to address the research objectives. The study established that the local communities are able to recognise the changes in their climate and local environment. Commonly mentioned indicators of changing climatic patterns included delayed and unpredictable onset of rainfall, declining rainfall trends, warming temperatures and increased frequency of prolonged dry spells. An analysis of empirical data corroborates the people’s perception. In addition, the community is able to use their IKS to adapt their agricultural systems to partially offset the effects of climate change. Like vulnerability to climate change, IKS varies over a short spatial scale, providing locally relevant adaptation to impacts of climate change. This paper therefore advocates for the integration of IKS in programmes addressing adaptation to climate change and vulnerability. This will serve to ensure sustainable and relevant adaptation strategies.

The headwater catchments of the Rivirivi River basin in Malawi play a vital role in meeting downstream water requirements. In recent years, the Rivirivi River flow regime has experienced changes in its hydrological regime, including an increased number of zero-flow days. This study was aimed at investigating some of the causes of these changes. Water quantity indicators were assessed through flow duration analysis of the river flow regime behavior before and after the introduction of the traditional water allocation practices and dam construction. Further, a desktop reserve model was applied to estimate the environmental water requirements. Anthropogenic land use induced change patterns were investigated by time series analysis of satellite imagery and their potential effect on water resources were inferred. The results indicate that there was a considerable difference in average annual stream flow between two identified main periods (between 1963–1983 and 1984–2004) and zero flows increased from 5% to 12%. In addition, the area experienced a 65% reduction in forest cover from 1992 to 2008 which resulted in increased high flow index by 16%. Furthermore, the ecosystems need approximately the range of 35–40% of the MAR to be maintained at Class A and the range of 9–13% of MAR for class D. The results suggest that anthropogenic activities have negatively affected low flow environmental flows requirements by increasing zero flow days in Rivirivi River catchment. However, total water usage remains below the river’s MAR and the river can meet all water needs with proper management of the river flow regime.

This study investigates groundwater discharge to rivers in the Shire River Basin, Malawi, using the base flow index (BFI) approach. The BFI represents the baseflow component of a river and is often used as a proxy indicator of groundwater discharge to a river. The smoothed minima method was applied to river flow data from 15 gauges in the Basin (ranging from 1948 to 2012) and the Mann-Kendall (MK) statistical test was used to identify trends in the BFI. The BFI results indicate that groundwater plays an important role in contributing to river flows in the SRB, especially in the dry season. Expressing the BFI as a percentage, these values indicate that annual groundwater discharge to the river’s ranges from 19% in the Rivirivi River to 97% in the Shire River. Seasonally, minimal difference was found between the annual and the wet season BFI. Generally, the dry season BFI was higher than those of the wet season with most rivers increasing to >75%. Groundwater data supported the seasonal fluctuations identified in the BFI data, however, there were no groundwater monitoring boreholes in close proximity to any of the river gauges for in-depth analysis. The results also showed long term trends in the BFI data indicating behavioural changes in the river baseflow and groundwater discharge. In some areas, the declines in BFI indicate that groundwater discharge has been reducing over time due to declines in groundwater levels. This is a concern for the sustainable management of water resources in the Basin. The findings of this study provide important new knowledge on the seasonal and long-term behaviour of groundwater discharge to rivers in the Basin which will be crucial for supporting sustainable water resources management practices. The results will be particularly useful to the new National Water Resources Authority within the Malawian Government, who will oversee catchment management plans.Keywords

The projected impacts of climate change and variability on floods in the southern Africa has not been well studied despite the threat they pose to human life and property. In this study, the potential impacts of climate change on floods in the upper Kafue River basin, a major tributary of the Zambezi River in southern Africa, were investigated. Catchment hydrography was delineated using the Hydro1k at a spatial resolution of 1 km. The daily global hydrological model WASMOD-D model was calibrated and validated during 1971–1986 and 1987–2001 with the simple-split sample test and during 1971–1980 and 1981–1990 with the differential split sample test, against observed discharge at Machiya gauging station. Predicted discharge for 2021–2050 and 2071–2100 were obtained by forcing the calibrated WASMOD-D with outputs from three GCMs (ECHAM, CMCC3 and IPSL) under the IPCC’s SRES A2 and B1 scenarios. The three GCMs derived daily discharges were combined by assigning a weight to each of them according to their skills to reproduce the daily discharge. The two calibration and validation tests suggested that model performance based on evaluation criteria including the Nash–Sutcliffe coefficient, Pearson’s correlation coefficient (r), Percent Bias and R 2 was satisfactory. Flood frequency analysis for the reference period (1960–1990) and two future time slices and climate change scenarios was performed using the peak over threshold analysis. The magnitude of flood peaks was shown to follow generalised Pareto distribution. The simulated floods in the scenario periods showed considerable departures from the reference period. In general, flood events increased during both scenario periods with 2021–2050 showing larger change. The approach in our study has a strong potential for similar assessments in other data scarce regions.

This study evaluated the performance of the Food and Agriculture Organization (FAO) Penman–Monteith (PM) reference evapotranspiration (ET0) method for various limited data scenarios in southern Malawi. The study further evaluated the full data PM method against the radiation-based Priestley–Taylor (PT) and the temperature-based Hargreaves (HAG) methods, which are less data-intensive approaches commonly used to estimate ET0 in data-scarce situations. A comprehensive daily climate dataset observed at the Nchalo Sugar Estate in southern Malawi for the period 1971–2007 was the basis of the study. The results suggested that lack of data on wind speed and actual vapour pressure did not significantly affect the PM ET0 estimates. However, the estimation of radiation using various combinations of observed wind speed and relative humidity all resulted in significant deviations from the PM ET0. Further, the HAG and PT methods significantly underestimated the PM. However, the PM method computed with estimated climate variables instead of observed climate variables still outperformed both the PT and HAG methods if their original parameters and estimated radiation were used. Thus, new monthly parameters for the PT and the HAG methods are proposed for more accurate daily ET0 estimates.

This paper provides a comparison of two widely used global precipitation datasets in southern Africa: Tropical Rainfall Measuring Mission (TRMM) and Water and Global Change (WATCH) Forcing Data (WFD). We also evaluate the performance of the water and snow balance modelling system (WASMOD-D) in a water balance simulation of 22 gauged basins over the southern Africa region. Water balance for southern Africa was simulated using the two global datasets as input with regionalized model parameter values. The results reveal that the special variation patterns of mean annual precipitation from TRMM and WFD datasets and temporal changing trend are similar in southern Africa. However, they are quite different in terms of probability distributions. Simulation of WASMOD-D based on two datasets in southern Africa results in model performances of above 0.5 for Nash–Sutcliffe (NS) values, below 10% for volume error (VE) values and a good reproduction of the observed flow duration curves for the majority of the basins. Finally, WFD data which have been bias corrected were observed to outperform TRMM data in southern Africa. The approaches and results described in this study contribute to the limited literature on regional hydrological modelling in the data-scarce region of southern Africa.

Climate change and variability are a threat to sustainable agricultural production in semi-arid areas of Malawi. Overdependence on subsistence rain-fed agriculture in these areas calls for the identification of sustainable adaptation strategies. A study was therefore conducted in Chikwawa, a semi-arid district in southern Malawi, to: (1) assess community’s perception of a changing climate against empirical evidence, (2) determine their local adaptive measures, (3) evaluate the potential of irrigated agriculture as an adaptive measure in household food security and (4) challenges over access to available water resources. The study employed focus group discussions and key informant interviews to assess people’s perceptions of climate change and variability and their desired interventions. To validate the people’s perceptions, rainfall and temperature data for the period 1960–2010 were analysed. A participatory complete randomised experimental design in both rain-fed and dry season–irrigated conditions was conducted to assess a maize cropping system that would improve adaptation. The study established persistent declining yields from rain-fed production in part because of perennial rainfall failure. In response, the community has shifted its focus to irrigation as an adaptation strategy, which has in turn triggered water conflicts in the community over the control of the resource. Water legislation however fails to adequately provide for rules governing sharing of water resources between various stakeholders. This article therefore recommends development of an appropriate institutional framework that forms a strong basis for equitable distribution of water for irrigation in areas most vulnerable to extreme climate events – including droughts and floods.Keywords: Food Security; Climate Change and Variability; Rainfall Variability; Irrigation; Water Resources; Governance Crisis

Groundwater resources in some parts of the lower section of the Shire River valley, Malawi, are not potable for rural domestic water supply due to high salinity. Knowledge of spatial variation of water quality is essential in locating and sustaining usable water supplies. In this study, a comprehensive assessment of the quality of groundwater from the area has been conducted to establish a spatial variation of major ions and general groundwater quality. World Health Organisation (WHO) guidelines for sodium (200 mg/l), chloride (250 mg/l), sulphate (250 mg/l), magnesium (30 mg/l) and calcium (75 mg/l) in drinking water were exceeded by 42%, 29%, 15%, 70% and 53% for all groundwater samples, respectively. The concentrations of analysed solutes are very wide in range, suggesting that the hydrochemistry is controlled by several intermixed processes such as saline water mixing and water–rock interaction. Based on the interpretation of the cumulative probability curve for TDS content, groundwater samples are grouped into three groups, as follows: (1) Group 1 waters (51%) that are relatively poor in Cl−, representing fresh groundwater affected mainly by weathering reactions; (2) Group 2 waters (45%) relatively enriched in Cl−, indicating considerable effects of rock-water interaction and mixing with saline water; (3) Group 3 waters (4%) enriched in Cl−, representing the saline groundwater resources. High total hardness (TH) and total dissolved solids (TDS) (in several places) render the groundwater, in large sections of the study area, unsuitable for domestic and irrigation purposes. Results reported in this study provide baseline data towards the utility of groundwater resources in the area.

Rainfall extremes often result in the occurrence of flood events with associated loss of life and infrastructure in Malawi. However, an understanding of the frequency of occurrence of such extreme events either for design or disaster planning purposes is often limited by data availability at the desired temporal and spatial scales. Regionalisation, which involves “trading time for space” by pooling together observations for stations with similar behavior, is an alternative approach for more accurate determination of extreme events even at ungauged areas or sites with short records. In this study, regional frequency analysis of rainfall extremes in Southern Malawi, large parts of which are flood prone, was undertaken. Observed 1-, 3-, 5- and 7-day annual maximum rainfall series for the period 1978–2007 at 23 selected rainfall stations in Southern Malawi were analysed. Cluster analysis using scaled at-site characteristics was used to determine homogeneous rainfall regions. L-moments were applied to derive regional index rainfall quantiles. The procedure also validated the three rainfall regions identified through homogeneity and heterogeneity tests based on Monte Carlo simulations with regional average L-moment ratios fitted to the Kappa distribution. Based on assessments of the accuracy of the derived index rainfall quantiles, it was concluded that the performance of this regional approach was satisfactory when validated for sites not included in the sample data. The study provides an estimate of the regional characteristics of rainfall extremes that can be useful in among others flood mitigation and engineering design.

The Linthipe and Songwe River Deltas are found to the extreme southern and northern parts of Lake Malawi respectively within the East African Rift System. They occur in contrasting tectonic and climatic settings of the rift-valley half-graben structure. The sub-aqueous part of the Songwe Delta consists of relatively finer grained sediments than the Linthipe but is relatively poorly sorted. The composition of sediments within the Songwe Delta shows significant amounts of sedimentary and volcanic lithic fragments which are lacking in the Linthipe. On the other hand, ferromanganese nodules were recovered in the Linthipe Delta at water depths of 80–100 m but were not recovered in Songwe Delta at similar water depths. The finer grained facies of the Songwe Delta suggests a more prograded delta than the Linthipe. However, its poorly sorted sediments are most likely due to the heterogeneous geology of the source area; higher and faster depositional rates due to climatic influences. The lack of Ferromangenese nodules in the Songwe Delta is probably due to the sand-mud facies boundary which occurs at shallower depth. The higher proportion of Total Organic Carbon (TOC) in higher the Linthipe Delta is probably related to high rates of environmental degradation such as deforestation and agricultural activities in the riparian catchment basin. This is in contrast to the Songwe catchment basin where the levels of anthropogenic disturbance are less and climate, geomorphology and the heterogenous character of the source rocks seems to play a major role in the sedimentation processes.

This paper presents the methods, procedure and results in studying spatial and temporal characteristics of rainfall in Malawi, a data scarce region, between 1960 and 2006. Rainfall variables and indicators from rainfall readings at 42 stations in Malawi, excluding Lake Malawi, were analysed at monthly, seasonal and annual scales. In the study, the data were firstly subjected to quality checks through the cumulative deviations test and the standard normal homogeneity test. Spatial rainfall variability was investigated using the spatial correlation function. Temporal trends were analysed using Mann–Kendall and linear regression methods. Heterogeneity of monthly rainfall was investigated using the precipitation concentration index (PCI). Finally, inter-annual and intra-annual rainfall variability were tested using normalized precipitation anomaly series of annual rainfall series (|AR|) and the PCI (|APCI|), respectively. The results showed that (1) most stations revealed statistically non-significant decreasing rainfall trends for annual, seasonal, monthly and the individual months from March to December at the 5% significance level. The months of January and February (the highest rainfall months), however, had overall positive but statistically non-significant trends countrywide, suggesting more concentration of the seasonal rainfall around these months. (2) Spatial analysis results showed a complex rainfall pattern countrywide with annual mean of 1,095 mm centred to the south of the country and mean inter-annual variability of 26%. (3) Spatial correlation amongst stations was highest only within the first 20 km, typical of areas with strong small-scale climatic influence. (4) The country was further characterised by unstable monthly rainfall regimes, with all PCIs more than 10. (5) An increase in inter-annual rainfall variability was found.

Subsistence rain fed agriculture underpins rural livelihoods in the Sub Saharan Africa. The overdependence on rainfall suggests the need for more reliable climate and weather forecasts to guide farm level decision making. Traditionally, African farmers have used indigenous knowledge (IK) to understand weather and climate patterns and make decisions about crops and farming practices. However, increased rainfall variability in recent years associated with climate change has reduced their confidence in indigenous knowledge, hence reducing their adaptive capacity and increasing their vulnerability to climate change. To address this problem, researchers are advocating the integration of indigenous knowledge into scientific climate forecasts at the local level, where it can be used to enhance the resilience of communities vulnerable to climate change. A study was therefore conducted to establish commonly used IK indicators in weather and climate forecasting and people’s perceptions of climate change and variability in Nessa Village, Southern Malawi. We further compared the people’s perceptions on climate change and variability with empirical evidence from a nearby weather station during 1971–2003 and the major constraints that the people face to fully utilise conventional weather and climate forecasts. Our results show various forms of traditional indicators that have been used to predict weather and climate for generations. These include certain patterns and behaviour of flora and fauna as well as environmental conditions. We further established that the peoples documentation of major climatic events over the years in the area agreed with the empirical evidence from the temperature and rainfall data. Overall, rainfall in the area has reduced since 1971 with increasing temperatures. The people were however of the view that current scientific weather and climate predictions in Malawi were not that useful at village level because they do not incorporate IK.

Irrigation is a major coping strategy in many areas experiencing unreliable rainfall distribution and pattern for rain fed agriculture. The benefits of irrigation may however be challenged by its potential to increase malaria incidences through creating breeding grounds for malaria vectors. This study compared malaria trends from archived malaria records in the rainy season and the dry season in Mbewe Extension Planning Area (EPA) in Chikhwawa District, Malawi. This is an area where irrigation has been intensified as a means of coping with floods and drought effects, which often result in crop destruction and failure. Data of monthly incidences of malaria from 2002 to 2009 from Ndakwera Health Centre in the area were used. Rainfall data for the area from 1971 to 2008 were also used. Mwanza River discharge from 1951 to 1992 was considered. Rainfall data were lagged to four months taking into consideration the breeding period of malaria vectors and the incubation period for malaria in human host. We assessed correlation between rainfall and malaria using data of 2004–2009, by fitting a generalised linear model to the data via an over-dispersed Poisson model. The highest malaria cases corresponded with the rain season. Malaria cases in the dry season, when irrigation is implemented, were low. The Pearson correlation coefficient for the monthly rainfall and discharge was not statistically significant at 0.34 ( p > 0.05). The results suggest that direct contribution of the rainfall to flooding in the area is minimal and the floods experienced are generated in the upstream areas. Further, the malaria pattern was mainly associated with the rain season flooding and not irrigation.

Annual rainfall series and annual base flow series (1954–1998) derived from the annual river flow series for the Mulunguzi river in Malawi were analysed using the non-parametric Mann–Whitney Pettit and Mann–Whitney–Wilcoxon statistics to detect any trends and variability patterns. A general decline in rainfall, with alternating wet and drier years was detected since 1954. The variation pattern mainly followed the El Nino and Southern Oscillation and the La Nina episodes. Two rainfall change points were detected at 1965 and 1979 after which the rainfall declined. The rainfall trend and variation pattern was evident in the base flow series, indicating a strong correlation between the rainfall and base flow series. This strong correlation means that the Zomba mountain aquifer, the source of the Mulunguzi river mainly depends on rainfall for recharge. Hence all water resources development and planning activities in the catchment area should take into consideration the effects of climate variability on water yield.