Urban floods are mainly caused by

Urban floods are mainly caused by blockage of drains and waterways. Urban areas are characterized by a large number of buildings, roads, and other infrastructure, which can obstruct the natural flow of water. When it rains, water cannot drain away quickly, leading to the blockage of drains and waterways. This can cause water to accumulate and lead to flooding in urban areas. Other factors, such as the construction of dams and barrages, clearance of vegetation on farmlands, and establishment of shelter belts, can also contribute to urban flooding by altering the natural flow of water. However, the blockage of drains and waterways is the main cause of urban floods.