This landform results when water exists a constricted channel and loses velocity.

When water exists a constricted channel and would lose velocity the answer would be alluvial fan. It is a fan or a cone in shape deposit of sediments that are cross and also built up by streams. If there is a fan built by debris it is called debris one.

Air pollution: “combustion results in gases such as nitrogen oxides, nitrogen dioxide and particulates. the main causes of air pollution include transport, domestic combustion and industrial processes. pollutants from these sources can cause problems in the immediate vicinity and a distance away.”