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Current and Future Hydrometeorological Hazard Analysis and Mapping using Historical Data In A GIS Environment By …
Background • Hydrometeorological hazards, such as floods, droughts, and landslides, pose significant threats to human populations, infrastructure, and the environment. • The frequency and severity of these events are expected to increase due to climate change, making it essential to develop effective strategies for hazard analysis, mapping, and mitigation. • Geographic Information Systems (GIS) offer a powerful tool for analyzing and visualizing hydrometeorological data, allowing for the identification of high-risk areas and the development of targeted adaptation measures. • Historical data, including precipitation records, and remote sensing imagery, provide a valuable resource for understanding past hazard events and predicting future occurrences. • By integrating historical data with GIS mapping and analysis, this research seeks to enhance our understanding of hydrometeorological hazards and support the development of effective mitigation and adaptation measures.
Problem Statement • Despite advances in hydrometeorological monitoring and prediction, the frequency and severity of floods, droughts, and landslides continue to increase, resulting in significant economic losses and human suffering. • The lack of effective hazard analysis and mapping tools, particularly in data-scarce regions, hinders the development of targeted adaptation measures, exacerbating the vulnerability of communities to these events.
Objectives • To develop a comprehensive framework for analyzing and mapping hydrometeorological hazards using historical data in a GIS environment. • To create detailed hazard maps and vulnerability assessments for Zimbabwe. • To evaluate the effectiveness of using historical data in a GIS environment for predicting future hydrometeorological hazard events.
Methodology Flood Risk Mapping Inputs • SPI Wet, Slope, Elevation, Seismology, LULC & Soil Type. Flood Risk Profile Map Overlay Reclassify Hydro-met Risk Profile Map Drought Risk Mapping Inputs • SPI Dry, Slope, Elevation, Seismology, LULC & Soil Type. Drought Risk Profile Map Overlay Reclassify
Precipitation Anomaly Spatial Analysis Mean Wet SPI Anomaly Map ( 1981-2021) Mean Dry SPI Anomaly Map ( 1981-2021)
Flood Vulnerability Profiles For Zimbabwe Past Flood Vulnerability Profile Current Flood Vulnerability Profile
Drought Vulnerability Profiles For Zimbabwe Past Drought Vulnerability Profile Current Drought Vulnerability Profile
Hydro-met Vulnerability Profiles For Zimbabwe Hydro-met Vulnerability Profile Map Non Hydrometeorological Hazard Influencing Thematic Layers (Digital Elevation Map (a), Slope Profile Map (b), Seismological Profile Map (c), LULC Map (d) and Soils Type Profile Maps (e)
Future Drought Vulnerability Profiles Using Different Emission Scenarios
Future Flood Vulnerability Profiles Using Different Emission Scenarios
Current and Future Hydrometeorology Vulnerability Profiles Using Different Emission Scenarios
Results • Low lying areas in the North West and South Eastern parts of Zimbabwe are more susceptible to hydrometeorological hazards. • The central parts are less susceptible to hydrometeorological hazards. • 6 hydrometeorological hotspots were identified (Chiredzi, Chimanimani, Chipinge, Gokwe, Binga, and Beitbridge), which all lie in the NW and SE parts of the country. • On average, all the identified hotspots show a generally increasing trend in precipitation. • These hydrometeorological hazard events have return periods of about 2 years for moderate events and 7 years for extreme events.
Results • Moderate events have a lesser return period meaning they occur more frequently while extreme events have a larger return period. • A greater portion of the country is under low (48.4%) to moderate (30.4%) classes of hydrometeorological hazard profile, compared to the areas under higher risk (19.5%) or very high risk (1.7%).
Findings: • 1. Historical data analysis revealed that Zimbabwe has significant areas which are prone to hydro met hazards occurrences. • Spatial analysis identified high-risk areas for drought and flood hazard occurrences which can be used for targeted mitigation and adaptation efforts. • 3. Climate change projections indicate an increase in extreme precipitation events, leading to more frequent flooding in the extreme northwestern and southeastern parts of Zimbabwe. • 4. The central parts along the central watershed are likely to increase a decrease in precipitation due to climate change.
Recommendations • Upgrade drainage infrastructure and build flood resilient infrastructure in the flood prone areas due to the expected increase in precipitation amounts. • Implement floodplain management strategies, such as zoning regulations and flood control measures. • Conduct regular flood risk assessments and update maps accordingly. • Implement reforestation and soil conservation measures to reduce landslide risk. • Conduct regular slope stability assessments and monitor high-risk areas. • Implement water-saving measures and efficient irrigation systems. • Improve current drought ealy warning systems and monitor water levels. • Promote water harvesting and storage infrastructure. • Conduct regular vulnerability assessments and update adaptation plans accordingly. • Engage with local communities, policymakers, and stakeholders to raise awareness about hydrometeorological hazards. • Collaborate with stakeholders to develop and implement effective mitigation and adaptation strategies..
