During the monsoon, extensive riverbank spills and riverbank erosion are typical. Riverbank erosion mainly occurs due to the braided nature of rivers in Bangladesh, and is further aggravated by heavy rainfall, particularly upstream, and increased water flow. Most recently, due to climate change, the rate of riverbank erosion has drastically increased, resulting in sudden collapse of riverbanks and devastation of whole Unions and Upazilas.
Every year, riverbank erosion leads to millions of people being affected as it results in damage and loss of crops, cattle, housing structures, and farmland. Additionally, it erodes away public infrastructure and communication systems. The unpredictable shifting behavior of the rivers and their encroachments not only affect the rural floodplain population but also the urban growth centers and infrastructures.
According to the Bangladesh Water Development Board (BWDB) the most erosion prone districts are Bogra, Sirajganj, Kurigram, Lalmonirhat, Gaibandha and Rangpur, in the country’s north, and Chandpur, Manikganj, Rajbari Shariatpur, and Faridpur in Dhaka zone, with Tangail and Jamalpur in Mymensingh zone, and the coastal areas of Patuakhali. The most erosion prone area in Bangladesh is Sirajganj, which faced a total land erosion at a rate of 622.2 ha, according to a CEGIS study in 2009 (Unnayan Onneshan 2012).
Bank lines of the Padma River are particularly unstable. The Padma is wide with major erosion occurring along the left bank near Harirampur upazila of Manikganj district, where an acute erosion problem exists (Banglapedia 29/01/2015). Most recently, the right bank of the Padma has also come under threat of extreme erosion, particularly in Naria upazila of Shariatpur district.
Humanitarian and Operational constraints
Eroded roads are likely to make accessing affected people difficult and increase the time taken to reach affected areas. As affected population becomes scattered, it may be difficult to locate beneficiaries. Limited information is available on further constraints to access. Due to the sudden onset nature of this particular erosion, the road situation may change rapidly during the time of planning operations.