#SoilSealing #UrbanErosion #UrbanRunoff

Runoff refers to water that falls on the soil but fails to be absorbed. Urban runoff creates problems. According to E.J. Plaster, "It [urban runoff] increases downstream flooding, introduces pollutants such as phosphates and herbicides into surface water (such as lakes and rivers) and reduces the amount of water available to recharge groundwater supplies."

Clearly, a huge percentage of our urban soils are cemented. Thus, the capacity of soil to store water, specifically rainwater, is hampered. No matter how huge we build our drainage systems to be, they just cannot absorb as much water as vegetative soils can! (Not to mention that climate change is taking its toll on us!) This problem can be referred to as one of the effects of "soil sealing". Not only can soil sealing cause flooding, it could also degrade soil quality and disrupt life cycles in the Earth's biosphere.

So what can we do about it? we can try:

• Using permeable pavements
• Adapting roof water harvesting
• Incorporating green roofing into our homes
• Desealing of areas which are already soil-sealed

"Permeable pavements allow water to infiltrate into the soil– so those important interactions between soil, water and air can happen - at least to some degree." << better than totally sealing soil, right?

"Roof water harvesting is collecting and discharging rain water from building roofs - and also compensates for sealing. "

"Green or living roofs are building roofs that are partially or completely covered with a growing medium and vegetation. Green roofs put a new living ecosystem on top of the buildings and can be a great way to partly compensate for the negative effects of soil sealing. "

"Green roofs offer many benefits such as reduced roof temperature (thus lowering cooling loads in the building), and absorption of rainwater that would otherwise enter the storm sewer system."

"De-sealing of areas is also possible. However, the restoration of soil functions takes a lot of time."

P.S. I am not against development, I am advocating for sustainable development.

References:
Sustainable Soil Management: Soil for life | WageningenX -  Soilx
Soil Science and Management, 5th Edition, Plaster, Edward J.


Image sources:
> DengodaJorden.Se
http://www.dengodajorden.se/2016/12/05/world-soil-day/
> Sustainable Soil Management: Soil for life | WageningenX -  Soilx
> Tip of the Mitt Watershed Council
https://www.watershedcouncil.org/permeable-pavers.html
> Kortright
https://tour.kortright.org/tech/permeable-pavements
> RainManSpeaks from Bangalore
http://rainmanspeaks.blogspot.com/2014/07/go-ahead-hit-roof.html
> Urban Gardens
http://www.urbangardensweb.com/2013/01/19/will-detroit-get-worlds-largest-urban-farm/

[Links subject to change because of the volatile nature of websites]