River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss...River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.展开更多
River bankline migration is a frequent phenomenon in the river of the floodplain region.Nowadays,channel dynamics-related changes in land use and land cover(LULC)are becoming a risk to the life and property of people ...River bankline migration is a frequent phenomenon in the river of the floodplain region.Nowadays,channel dynamics-related changes in land use and land cover(LULC)are becoming a risk to the life and property of people living in the vicinity of rivers.A comprehensive evaluation of the causes and consequences of such changes is essential for better policy and decision-making for disaster risk reduction and management.The present study assesses the changes in the Brahmaputra River planform using the GIS-based Digital Shoreline Analysis System(DSAS)and relates it with the changing LULC of the floodplain evaluated using the CA-Markov model.In this study,the future channel of the Brahmaputra River and its flood plain’s future LULC were forecasted to pinpoint the erosion-vulnerable zone.Forty-eight years(1973–2021)of remotely sensed data were applied to estimate the rate of bankline migration.It was observed that the river’s erosion-accretion rate was higher in early times than in more recent ones.The left and right banks’average shifting rates between 1973 and 1988 were -55.44 m/y and -56.79 m/y,respectively,while they were-17.25 m/y and -48.49 m/y from 2011 to 2021.The left bank of the river Brahmaputra had more erosion than the right,which indicates that the river is shifting in the leftward direction(Southward).In this river course,zone A(Lower course)and zone B(Middle course)were more adversely affected than zone C(Upper course).According to the predicted result,the left bank is more susceptible to bank erosion than the right bank(where the average rate of erosion and deposition was -72.23 m/y and 79.50 m/y,respectively).The left bank’s average rate of erosion was -111.22 m/y.The research assesses the LULC study in conjunction with river channel dynamics in vulnerable areas where nearby infrastructure and settlements were at risk due to channel migration.The degree of accu-racy was verified using the actual bankline and predicted bankline,as well as the actual LULC map and anticipated LULC map.In more than 90% of cases,the bankline’s position and shape generally remain the same as the actual bankline.The overall,and kappa accuracy of all the LULC maps was more than 85%,which was suitable for the forecast.Moreover,chi-square(x^(2))result values for classified classes denoted the accuracy and acceptability of the CA-Markov model for predicting the LULC map.The results of this work aim to understand better the efficient hazard management strategy for the Brahmaputra River for hazard managers of the region using an automated prediction approach.展开更多
文摘River bank erosion is a natural process that occurs when the water flow of a river exceeds the bank’s ability to withstand it. It is a common phenomenon that causes extensive land damage, displacement of people, loss of crops, and infrastructure damage. The Gorai River, situated on the right bank of the Ganges, is a significant branch of the river that flows into the Bay of Bengal via the Mathumati and Baleswar rivers. The erosion of the banks of the Gorai River in Kushtia district is not a recent occurrence. Local residents have been dealing with this issue for the past hundred years, and according to the elderly members of the community, the erosion has become more severe activities. Therefore, the main objective of this research is to quantify river bank erosion and accretion and bankline shifting from 2003 to 2022 using multi-temporal Landsat images data with GIS and remote sensing technique. Bank-line migration occurs as a result of the interplay and interconnectedness of various factors such as the degree of river-related processes such as erosion, transportation, and deposition, the amount of water in the river during the high season, the geological and soil makeup, and human intervention in the river. The results show that the highest eroded area was 4.6 square kilometers during the period of 2016 to 2019, while the highest accreted area was 7.12 square kilometers during the period of 2013 to 2016. However, the erosion and accretion values fluctuated from year to year.
文摘River bankline migration is a frequent phenomenon in the river of the floodplain region.Nowadays,channel dynamics-related changes in land use and land cover(LULC)are becoming a risk to the life and property of people living in the vicinity of rivers.A comprehensive evaluation of the causes and consequences of such changes is essential for better policy and decision-making for disaster risk reduction and management.The present study assesses the changes in the Brahmaputra River planform using the GIS-based Digital Shoreline Analysis System(DSAS)and relates it with the changing LULC of the floodplain evaluated using the CA-Markov model.In this study,the future channel of the Brahmaputra River and its flood plain’s future LULC were forecasted to pinpoint the erosion-vulnerable zone.Forty-eight years(1973–2021)of remotely sensed data were applied to estimate the rate of bankline migration.It was observed that the river’s erosion-accretion rate was higher in early times than in more recent ones.The left and right banks’average shifting rates between 1973 and 1988 were -55.44 m/y and -56.79 m/y,respectively,while they were-17.25 m/y and -48.49 m/y from 2011 to 2021.The left bank of the river Brahmaputra had more erosion than the right,which indicates that the river is shifting in the leftward direction(Southward).In this river course,zone A(Lower course)and zone B(Middle course)were more adversely affected than zone C(Upper course).According to the predicted result,the left bank is more susceptible to bank erosion than the right bank(where the average rate of erosion and deposition was -72.23 m/y and 79.50 m/y,respectively).The left bank’s average rate of erosion was -111.22 m/y.The research assesses the LULC study in conjunction with river channel dynamics in vulnerable areas where nearby infrastructure and settlements were at risk due to channel migration.The degree of accu-racy was verified using the actual bankline and predicted bankline,as well as the actual LULC map and anticipated LULC map.In more than 90% of cases,the bankline’s position and shape generally remain the same as the actual bankline.The overall,and kappa accuracy of all the LULC maps was more than 85%,which was suitable for the forecast.Moreover,chi-square(x^(2))result values for classified classes denoted the accuracy and acceptability of the CA-Markov model for predicting the LULC map.The results of this work aim to understand better the efficient hazard management strategy for the Brahmaputra River for hazard managers of the region using an automated prediction approach.
