Sand mining is a growing environmental and socioeconomic concern worldwide. As urbanisation and infrastructure development continue to increase, the demand for sand has skyrocketed. When mined on or near rivers, it alters the river's pathway, eroding riverbanks, damaging housing, infrastructure and livelihoods. This thesis examines the role of sand mining in the river-delta system, by examining the influence of dredging duration, dredging intensity, location and pit size on the river delta system.

A 2-dimensional depth averaged Delft3D model is made. Here a river-delta system is modelled and run for 600 years. Over the last 100 years, different sand mining scenarios have been modelled. With varying duration, intensity, locations, and pit geometry, each of these scenarios is then analysed using various method of analyses. Though changing the dredging scenarios, changes the downstream morphology and hypothe-
sised trends—such as pit migration, increased erosion, and reduced delta growth—were partially
observed. Furthermore, in the five scenarios, dredging influenced the river-delta system in complex, non-linear ways.

Some configurations (e.g., 30-year duration, 5.0x intensity, 200 m width) led to pronounced short-term changes, but long-term outcomes returned toward control-like conditions. In general, the results highlight high internal variability and limited predictability based solely on single dredging parameters. It is recommended to include a cluster of slightly varied control scenarios in future research to distinguish the effect of dredging from the natural variability of the river.