Effects of Urbanization on Environment
the sex of urbanization on the environment is a lesson plan developed by John Bunce and has been modified by Jerry Spencer the content in this blog focuses primarily on the detrimental increase of impervious surfaces on the growing an urban environment this blog was made possible through the NSF-funded photo knowledge and science classroom projects at Ohio
University
have you ever witnessed a garden move in the middle of a city probably what a building coated in the grass or putting green on top of a building why would we ever plan a garden on the top of a roof what is this madness these token a structures are known as green roofs
they can greatly reduce the impact of human activity on the environment a green roof is essentially a garden planted on the top of a building or urban structure instead of using typical roofing materials green roofs are composed of a series of layers including a vegetation and soil layer instead of in synthetic plastic
Warren airs underneath the vegetation for drainage filtration and insulation purposes these Roos enhance environmental conditions in urban environments by reducing runoff volumes from rain events helping to filter contaminants in rainwater providing
insulation from noise absorbing excess heat increasing the lifespan of roof structures and being generally pleasant to look at however they are more expensive than traditional roofs as they require additional building materials engineering and maintenance this augmentation of the urban landscape with greenery is a common
the technique to reduce the effects of urbanization on our environments urbanization relates to the growth and development of cities but why might people be more inclined to move to urban areas in the past and today people flock to cities in hopes of economic opportunity a majority of u.s. population
now resides in urban environments cities provide a wealth of resources and a sense of opportunity which is lacking in rural areas this growth of urban centers is largely accelerated by gains and transportation planning or personal vehicles and roadways allow for quick movement of people and resources better transportation systems may ultimately lead to
what is known as urban sprawl people are now able to commute the cities and personal vehicles and they are therefore able to reside outside of urban centers while still reaping the benefits of urbanization urban sprawl can be defined as the growth of low-density developments on the edges of cities and towns
these developments include things like suburbs and small towns outside of larger cities urban sprawl may eliminate usable agricultural lands result in increased impervious surfaces worsen traffic congestion increased greenhouse gas emissions increase the number of people
living in suburbs and destroy wildlife habitats a large concern of urban sprawl on the environment deals with the interruption of the local hydrological cycle by impervious surfaces impervious is defined as not allowing entrance or passage something which is impenetrable of the three third surfaces shown which ones are impervious and which ones that are previous how do these surfaces relate to urbanization take a moment to think about these questions and share your thoughts
with others in your class try to think of other surfaces or core materials which are impervious you may pause the blog here to discuss both these images the pavement and roof shingles would be considered as impervious surfaces and the grass would be considered as a pervious surface if you've ever observed the street during a larger rain event next to the curve
you might notice rainwater flowing downhill in a little stream channel in a natural environment with lots of pervious surfaces water is able to penetrate through the ground and collect in aquifers underground we will now conduct a simple lab experiment to study the effects of impervious surfaces on the environment
you will work in small groups to build a land surface model using a sloped paint tray wire mesh and sponges as shown in the picture on the right then you will test several different materials by simulating a rain event while conducting the experiment try to think about what each material might represent in either in urban or natural environments read
The Associated handout for more details now you can pause the video here to perform the experiment before moving on with the rest of this blog an increase in the number of impervious surfaces leads to increase the amounts of runoff runoff is water from rain events flowing over the grounds
eventually collecting into streams rivers or groundwater surfaces in an urban environment runoff volumes are increased dramatically because water is not as able to be stored underground this leads to an increased risk of flooding in urban environments the local hydrology of an urban environment is effectively driven by runoff whereas
a natural environment is driven by infiltration of rainwater into the grounds a runoff driven environment is more susceptible to water pollution when water in an urban environment runs over an impervious surfaces it tends to pick up the pollutants which have been deposited by the people living there to some degree gasoline oil lawn fertilizers pesticides and trash all get swept away by runoff and carried to
the intercepting streams or odd water sources without a sizable amount of land cover for water to penetrate through these pollutants are not able to be effectively removed by natural filtration and thus become concentrated the effects of water pollution may become intensified by air pollution as the two are interrelated to some degree eutrophication is a prime example of the pollution of aquatic ecosystems stemming from urban water runoff eutrophication begins when runoff picks up excess nutrients from the deliberate spring of fertilizers for agriculture or personal lawns and gardens fertilizers are rich in the phosphorus and nitrogen by supplying plants
these nutrients fertilizers allow for rapid plant growth as you may expect these nutrients bolster the growth of algae in the same way nutrient loadings the streams via runoff accelerates the gross growth of algae which can then block sunlight from reaching other aquatic organisms when the algae eventually die and deposit on the bottom of a river or lake bacteria which decompose the dead algae remove oxygen from the water column and effectively kill organisms
which rely on oxygen to survive this leads to dead zones where aquatic organisms are not as able to thrive in order to mitigate or reduce the negative effects of urban runoff and aquatic ecosystems it is necessary to make a compromise with Mother Nature to do this engineers and construction companies typically implement mitigation features into infrastructure design mitigation efforts may include things like egoism solar or renewable energy resources repurposing municipal wastes incorporating urban gardens or green roofs into new and pre-existing infrastructure using Zoning to protect
the agricultural landscape from urbanization in allotting tax breaks for implementing environmentally-conscious practices an example of a common mitigation practice that you may be somewhat familiar with is the stormwater detention basin these basins are sometimes they require and for businesses for developers in rural areas stormwater detention basins are tied to the downspouts of a building structure and reduce runoff volumes in a similar manner to green roofs by holding rainwater in a pond like structure you know slowly allowing it to infiltrate into the grounds typically these basins are designed to collect and hold all potential rent rainwater runoff the results from the development of a building site weed for the Leadership in Energy and Environmental Design
is a nationally recognized green certification organization under the United States Green Building Council which uses a 110 point scale to determine how green a building it is points are assigned to buildings based on several categories these categories include whether the building uses water efficiently is located at a sustainable site is energy efficient produces few emissions use environmentally conscious materials or resources in this construction and that's good indoor environmental quality buildings with the highest ratings receive a platinum rating while we design is not enforced at this time
it is slowly gaining a foothold in the minds of engineers architects and construction companies in the design of buildings and structures a good example of a Platinum rated building is station number 12 in Madison Wisconsin this building utilizes a geothermal system for heating and cooling a green roof solar heating panels for hot water needs xeriscaping that reduces the amount of high maintenance turf and the landscaping in a stormwater collection system for general
non-potable uses such as for landscape irrigation and flushing toilets to summarize urbanization and urban sprawl negatively impact the environment in a number of different ways because of a large percentage of impervious surface cover in urban environments rainwater runoff volumes
the streams tend to increase and may lead to dramatic consequences like flooding pollution associated with urban landscapes enters the aquatic environment through runoff into streams lakes and rivers eutrophication is an example of aquatic ecosystem collapse due to runoff of excessive nutrients from fertilizers for I qualms and Gardens we can use green roofs urban gardens improves us dorm water detention structures and environmentally conscious designs like weed buildings to mitigate the impact of urban runoff on our environments.
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