Application of Geo-Bag and Cement Concrete Blocks in Riverbank Erosion Control: A Study of Satkhira Koyra

Riverbank erosion is a significant natural disaster that is prevalent in the deltaic regions in Bangladesh, resulting in loss of land, crops, and settlements. This research work is concentrated on the Satkhira Koyra area and is oriented towards a comparative assessment of the functionality of geo-bag and cement concrete (CC) blocks for erosion control purposes. The results showed that a geogrid could be used on the riverbank slope for more soil stability. The proposed approach is that the geogrid is used as a base layer for the slope. The sand-filled geo-bags are more cost-effective with this combination. Field monitoring and hydraulic model testing were used to identify their performance under natural flow conditions. Lined with geotextile fabric and filled with sand, the geo-bags were located in the most susceptible riverbank areas. The empirical results showed that the geo-bags provide the same levels of hydraulic resistance as those provided by CC blocks, but with substantial economic benefits and installation accomplished by local labor. When used in combination with a geogrid base layer, the geo-bag construction ensured excellent slope stability and allowed the establishment of natural vegetation, thus contributing to an environmentally friendly restoration. While CC blocks remain the optimal solution for high-value structures, the combined geogrid and geo-bag system offers a more flexible, cost-effective, and environmentally friendly alternative for stable erosion protection.