River course changes are a natural process that occurs on the Earth’s surface. Major factors influencing bank and channel shifting are rainfall, geomorphological and geological structure, slope, and relief. During the monsoon period from May to August is the time of peak precipitation for the state of Assam in India, causing the alluvial channel to reach its high-water level, thereby leading to flooding and bank erosion. Assam is highly flood- and erosion-prone, resulting in many floodplains due to bank erosion in the Nalbari District. The current study focuses on the spatiotemporal change detection of the Pagladia River and its impact on the physical and socioeconomic environment. Changing channel patterns are evaluated with the help of remote-sensing data, processed using GIS software. The study primarily emphasizes shifting patterns of the Pagladia River from 1991–2023 and notes the land use/land cover (LULC) changes of the study area. As the course of the river changes, the location of the floodplains of Nalbari also shifts, causing loss of agricultural land and infrastructure. The present study found that the highest shifting took place from 1991 to 2001. In cross-section 11, total shifting was recorded at 1030 m on the right bank. Similarly, in 2001–2010, cross-section 17 recorded the highest shifting, which is 1585 m on the right bank. The study is significant for future analysis to propose suitable remedial measures.