Hydroenvironmental Impacts of Extreme Events in Anambra State, Nigeria

Anambra State of Nigeria as well as other neighboring States suffer from major extreme events that pose much negative effects on the total environment of land and water. Climate change associated with high temperature, heavy rainfall flooding, gully erosion and landslides results in deterioration of water quality and degradation of the land environment. Over 750 active gully erosion sites have been identified in Anambra State, Nigeria with depth of over 75m and width of over 20m in some places. The dimensions of the gullies increase with each rainy season silting surface water bodies and exposing shallow aquifers. The extreme event of gully erosion and landslide exacerbate water scarcity in the area with implications on food security. The main causes of extreme events in the area include runoff concentration, groundwater flow, and vulnerable soil exposure by man as well as poor environmental sanitation. Many varieties of plant and animal species and wildlife have been terminally-lost; by which all losses affecting parts of the Tropics of African countries are trending fast to an emerging regional biotic extinction within this Holocene times. The present attitude by governments and people of all affected areas is of a laissez-faire attitude as attempts in the past have been unsuccessful. For sustainable development associated with adequate water supply and food security, dumping of refuse along river channels should be prohibited. Cultural methods of gully erosion control by planting plantain and bananas along the floodplain should be introduced while improved farming practices encouraged. Inadequate awareness of effects of human activities on both floodplain and river channels contribute to misuse of these areas. Therefore, there should be general enlightenment campaign on the dangers posed by gully erosion and human activities that promote them. Efforts should also be made by relevant authorities to enact a law against location of engineering structures on waterways.