Question

1. Urban sprawl can have some negative impacts on the environment with respect to use of resources, land use, andpollution. Choose ONE of these three aspects and EXPLAIN why having large areas of suburbs rather than densely populated urban areas can have a negative environmental impact.

2. Advancements in agriculture have decreased the percentage of the human population that is malnourished, even as the human population has dramatically increased. However, this success has not been without a price.  CHOOSE TWOof the three advancements listed below, and fully EXPLAIN one way that this practice can negatively impact the ENVIRONMENT (not just humans). (Note: if you answer all three, please indicate which two you want to be graded. Otherwise I will grade the first two that are answered.)

Use of inorganic fertilizers

Use of pesticides

Use of transgenic crops

Answer 1

(1)Sprawl can be defined as "low density development beyond the edge of service and employment ,which seperates where people live from where they shop,work,recreate and educate-thus requiring cars to move between zones."

In context of pollution,

Urban areas produce less greenhouse emmisions per person than other areas,sprawling suburbs that surround them produce enough green house gas per person to essentially cancel benefits of urban centres.The reasons for this are:-

(a)MORE PEOPLE LIVING IN LESS AREA:- There is negative inverse relation in population and average carbon footprint.

(b)Suburbs sprawl outwards to miles,residents drive much more often,releasing large amounts of greenhouse gases.

(c)LARGER HOMES FOR LESS MONEY:-Suburbs offer larger homes for less money,they spend huge amounts of energy heating and powering their larger homes.

The suburbs surrounding a city cancels its benefits contributing more to pollution.

(2)Use of inorganic fertilizers in agriculture has negative impact on environment.Most problem occur when they are overused or applied incorrectly leading to following situations:-

(a)SALT ACCUMULATION:-overuse of fertilizers can lead to accumulation of salt in the soil,which hinders the absorption of water by the plants eventually plants use more energy to draw water causing them to wilt.Also plants are sensitive to high salinity.

(B)RUN OFF:-Some fertilizers wash away in rain and pollute streams,ponds and other water bodies causing destruction of aquatic organisms.

(C)PLANT DAMAGE:-If fertilizers come in contact with plant parts such as leaves it can cause leaf scorching.Decreased growth,Defoliation,Wilting are some of the negative effects.

(D)LEACHING:-The fertilizers which are inaccessible to plants leach and reach the underground water.

(e)pottasium and phosphorus build up on the surface of soil,hence decreasing the soil pH and availability of other nutrients to the plants.

Use of pesticides causes many ill effects as follows:-

(a)pesticides can be blown by wind while spraying causing air pollution.

(b)pesticides can leach,run off or pollute water bodies while spraying.

(C)It can pollute ground water by leaching.

(d)It effects soil fertility and essential soil micro-organisms.

(e)Pesticides can cause reduction in nitrogen fixation by leguminous plants by interfering the interaction among rhizobium and root nodules.

(f)They can lead to serious health hazards in animals such as cancer and many neurological disorders if consumed.