Children play in an underpass filled with rainwater in Karachi. ─ AP
Population density and proximity to urban centres significantly alter the dynamics and complexity when it comes to urban flooding. However, flood-related data is usually not classified between rural and urban areas, presenting a serious challenge for policymakers.
Direct impacts from major flooding events, such as the recent urban flooding seen in Karachi and Lahore, represent the biggest risk to life and property. The loss of human lives as a result of flooding has a disproportionate impact on the poor and socially disadvantaged, particularly women and children.
The indirect, and long-term, effects such as disease, increased burden on a crumbling healthcare infrastructure, malnutrition and food insecurity, reduced education opportunities and loss of livelihoods can continue for years down the road, particularly when the hardest hit are those who are barely able to eat two meals a day.
Such impacts are hard to identify immediately in the aftermath of a disaster, and harder still to quantify and value. Beyond the erosion of communities to withstand any unforeseen hazards, and set-backs to development in general, indirect impacts of floods place the disadvantaged at a further disadvantage.
Urbanisation, a defining feature of demographic growth and development, compounds flood risk. While urban growth is welcomed as a harbinger of development, an ill-planned and poorly managed process increases flood risk due to unsuitable land use.
When cities and towns swell outwards to accommodate larger populations, large-scale urban expansion takes place in the form of unplanned development in floodplains and flood-prone areas. A majority of urban population growth and spatial expansion occurs in densely-populated, low-income settlements, slums or squatter settlements.
Nearly half of Karachi’s population, for example, lives in slums, many of which are built atop waterways and on, or along, the beds of natural drainage channels and seasonal rivers, leading to widespread devastation as a result of flooding.
These localities are scattered throughout urban areas, from the city-centre to peripheral, suburban or peri-urban areas; and typically lack adequately constructed housing, infrastructure and service provision, thereby exacerbating the effect of heavy rainfall, flooding and associated impacts; and ensuring that the poor and marginalised are left off far worse than before.
Also read: Exploring why Karachi's rainwater has nowhere to go