COASTAL EROSION ALONG LAGOS COASTAL COMMUNITIES: A CALL CREATION OF STATE OWN COASTAL MONITORING DEPARTMENT

 

For some of us that come from coastal communities and riverine areas of Lagos, how do we tell our children that our beaches and waterfront are usually full of coconut tree and mangrove of various species of plants?

Coasts host a huge number of different biomes, with these ecosystems hosting an extensive host of different species of the flora and fauna nowhere else to be found. While globally seen large parts of the coastline are still untouched by human presence, ever increasing pressure is put on them by rising alteration of natural characteristics. Globally, more than 40% of people live within 100 km of the coast and this number is set to increase further. Many settlements are concentrated within 5km of the coastline; population densities at the coast are around three times higher than the global average and twenty-one of the 33 world’s megacities are located on the coast.

Coastal erosion is a natural occurrence, the rate of which would vary depending upon the kinetic energy of the waves, itself determined by weather and astronomical factors and upon the resistance of the coastline, as influenced by geology and morphology. However, abnormal and accelerated erosion rates are mainly due to extreme weather condition. Coastal erosion is already happening, has been happening for at least some decades now, and is threatening coastal communities, livelihoods, and ecosystems. According to Bentum, K.M. (2012): The wave climate at Lagos consists of persistent, high-energy swell waves, which reach the coast of Lagos with a mean direction of 188°. Hereby, a mean eastward longshore sediment transport of roughly 600,000 m³/year to 700,000 m³/year is induced. It has been assumed that this longshore sediment transport rate was approximately constant over the years. In general, the whole Lagos coast suffers erosion due to the high rates of relative sea level rise.

However, the impacts of climate change such as a higher probability for extreme weather events and advancing sea level rise will exacerbate coastal erosion and its effects. Hence, the costs due to this phenomenon will also most likely increase in the future unless suitable steps are taken to combat it and protect human developments where possible. Besides destroying buildings, coastal erosion also impairs the human developments along the coast such as ports or industrial sites. Presently, the erosion is further growing eastward. Evidence is available on the rate of erosion especially in the Ibeju-Lekki axis of the State. Induced by the Eustatic sea level rise combined with soil subsidence. The rates of subsidence are high, due to natural dewatering and compaction of the soil but also due to human-induced water extraction in coastal zone.

Lagos coastal communities are presently faced with new challenges of battling with development, naturally and anthropogenic included coastal erosion and the ever present sea level rise. The time is right for us to develop a state own coastal monitoring system. The fast growing coastal communities in Lagos will be contributing huge revenue to the State and Nation in general. It is expedient for us has people, business community and government to set up coastal monitoring system that will tackle both natural and anthropogenic environmental threats and challenges.