**2. Coastline geomorphology of the region**

The Nigerian coastline is separated into four physiographic zones, as described by Fabiyi [4]. The sections include: the Strand Coast, the Niger Delta Coast, the Barrier-Lagoon Coast and the Transgressive Mud Coast. Each of the sections is associated with differing erosive activities, resulting from anthropogenic and natural factors as explained thus;

#### **2.1 The Barrier-Lagoon coast**

This complex is located in the Lagos State axis of Nigeria's coastline. It is predominantly made up of coarse sand beach, which allows easy drains of excess flood water and allows it to percolate. This easily flows back into the sea in few days.

#### **2.2 The Niger Delta coast**

The Niger Delta coast is predominated by fine beach sand and Mangrove forest. It is characterized by intense flooding around the communities and in some elevated areas, the vegetation is rain-fed deltaic. This is found along Delta, Akwa Ibom and Rivers States of Nigeria coastline.

*Climate Change and Anthropogenic Impacts on the Ecosystem of the Transgressive Mud Coastal… DOI: http://dx.doi.org/10.5772/intechopen.105760*

## **2.3 The strand coast**

It is the most eastern section of Nigeria coastline with a lot of vegetation (mostly Nypa Palms'- Nypa fruticans) which holds the fragile beach and acts as a barrier to ocean flooding. The beach is fronted by flat beaches and changes into a beach ridge plain. It is located at the Cross River axis of Nigeria coastline.

#### **2.4 The transgressive mud beach or Mahin mud coast**

This is located at the Ondo State axis of Nigeria coastline. It is composed of vegetated bluff, mud and flat marsh forming a transgressive mud beach. The area is characterized by a lot of floods trapped in the mud creeks, remaining there for days. Making it vulnerable to coastal flooding, thereby paralyzing activities in the affected communities. During the summer, it is left with mud cracks, formed from dried saturated mud (**Figure 1**).

Ondo State coastal plain (Transgressive mud coast) is narrow (about 700 m wide), unlike other coastal plains that have extensive mangrove swamps, lagoons and raised beaches. Freshwater swamp, lacustrine marshes and an intricate network of interconnected creeks backed the coastline by about 30–60 km wide freshwater marshes [5]. This, therefore, constitutes a fragile buffer zone between the Atlantic Ocean menacing wave and the tranquil freshwater swamp. Massive incursion of the sea into the inland swamps occurs as a result of extensive breaching into the coastal plain, leading

**Figure 1.** *Mud beach (A) and Mud crack, formed from dried saturated mud (B).*

#### **Figure 2.** *Coastline recession in Ayetoro (A) and Awoye (B) communities resulting from massive incursion of the Atlantic Ocean.*

to economic loss and threat to national security. One of the most important implications of massive incursion of the Atlantic Ocean is the coastline recession in Ayetoro and Awoye communities (**Figure 2**).
