Which risk increases when natural levees block an oxbow lake's connection to a river?

💡 Explanation

When levees cut off an oxbow lake, stagnant water conditions develop because there is no continuous flow or flushing from the river, promoting nutrient accumulation and algal blooms which drive eutrophication. Therefore, increased eutrophication results, rather than the other changes to groundwater, sedimentation, or stream flows which depend on hydraulic connectivity.

• Which process causes the formation of distributary channels on an alluvial fan?
• Which effect accelerates coastal erosion when sustained offshore winds induce upwelling?
• Which risk intensifies when poorly consolidated alluvial sediments are saturated by heavy rainfall?
• Which mechanism initiates downwelling when surface water density substantially increases in polar marine regions?
• Which mechanism causes Benioff zone earthquake frequency pattern during oceanic plate subduction?
• Which mechanism causes the deflection of fast-moving air streams by the Coriolis effect?