The Trends and Effects of Flood Occurrences in the Shire River Basin in Chikwawa District of Malawi: A Historical Perspective (1980 - 2019)

Abstract

Purpose: The purpose of this study was to examine historical trends in flooding in Malawi’s Shire River Basin (SRB). The basin is prone to severe flooding and most affected in the country. For many years, flooding has posed a significant threat to communities in and around the basin. Therefore, the main objective of the study was to document the historical perspective of flood occurrences in terms of frequency and impact in the Shire River Basin of Chikwawa District, Malawi, from 1980 to 2019. Methodology: A mixed survey design was used for the study. Both random and purposive sampling were used to identify participants. A total of 384 respondents took part in the study. The study collected both primary and secondary data. Primary sources of data were collected using household surveys, interviews with key informants, and focus group discussions, while secondary sources of data were collected using documents from both non-governmental and Malawian governmental departments and agencies (MDAs) as well as existing literature. Data from focus group discussions (FGDs), interviews with community elders (CEIs), and key informant interviews (KIIs) were recorded in Chichewa with a voice recorder, transcribed in Chichewa, and then translated into English. Household survey data were processed using Statistical Package for Social Scientists (SPSS) version 25 and secondary data were converted to time series data and then analysed using STATA software to produce charts and graphs. Findings: The results showed that all three hydrometeorological extremes (mean annual temperature, average rainfall and baseflow index) increased, suggesting that both the intensity and frequency of flooding in the Shire River Basin of Chikwawa District were also increasing in absolute terms. People’s perceptions of flooding showed that the Shire River Basin in Chikwawa District experienced excessive flooding every 5 years. This 5-year cycle was, among other factors the result of climate change and forest loss in the study area, leading to an increase in river sedimentation. Recommendations: This article found that the local people in the Shire River Basin of Chikwawa District will always live with increasing levels of flooding. Therefore, they should be proactive in flood management and understand the process as an ongoing activity for future risk assessment. Analysing the history of river basin flooding is important as it helps the Malawi's Department of Disaster Management Affairs (DoDMA) officials to be alert and estimate the time frame for the next flood in the Shire River Basin of Chikwawa District to strengthen the flood forecasting accuracy.