• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Evaluate the role of hard and soft engineering strategies in managing rivers

Extracts from this document...

Introduction

´╗┐Evaluate the role of hard and soft engineering strategies in managing rivers Libby Flynn 12F Hard engineering strategies tend to be the more expensive strategies, and can also cause a negative impact on the landscape and environment. Channelization of the river channel removes meanders to reduce the length of the river so the water flows faster downstream. The faster flowing water washes away sediment that has accumulated on the river bed minimising the risk of flooding, as well as the flow of the water deepening the river which means there is an increase in the capacity of the river, also reducing the risk of flooding. However, this strategy can cause problems further downstream as there is an increase in the speed and discharge, so areas that do not have flood defences are more vulnerable and the risk increases. This is also a very expensive method and a lot of resources and manpower are required. An example of where this particular strategy has been used is the Kissimmee River in Florida, where the river channel was shortened from 103 miles to just 56 miles in length. ...read more.

Middle

As well as this, dams and water control structures are very expensive to build and require a lot of resources and so are not always economically sustainable, which can be seen from the construction of seven dams in Bangladesh, costing approximately $30-40billion and would take forty years to build. They would then need continuous maintain which would also be costly, putting great strain on the government. They can also be seen as socially unsustainable as people can be forced to move off their land if it is to be used to store the water. Overall, measures such as dams and water control features are effective at holding back the water and regulating flow yet they are expensive and not always sustainable. Embankments are raised banks along the river, enabling it to increase its capacity and deepening the channel, meaning more water can be held in the river before it reaches bank full discharge and floods. 7500 km of flood embankments have been built in Bangladesh since 1947 and have been effective at holding back smaller floods. ...read more.

Conclusion

Land has different building controls depending on how far from the river the buildings lie. The land next to the river is unused land and as the distance from the river increases so does the value and land quality, as these are areas less likely to flood. However, this is not always effective as they can be ignored and do not actually prevent flooding, just help to lessen the impacts. They can also cause problems as people who live in high-risk zones will face a rise in insurance prices. Afforestation is economically sustainable as it is not too expensive, environmentally sustainable as it creates habitats and therefore can help increase biodiversity and socially sustainable as it does not affect anyone. However, it is not always effective as it takes years for the trees to grow and they only intercept a certain amount of rain so will not prevent extreme floods. Overall, hard engineering strategies such as embankments, water control features, dams and channelization are more effective than soft engineering strategies such as washland areas and land use zoning. However, hard engineering strategies tend to be a lot more expensive and costly to the environment. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Environmental Management section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Environmental Management essays

  1. Managing change by managing risk

    Perhaps the most familiar instance of this kind of change is the change or version control aspect of information system development projects. However, these internal changes might have been triggered by events originating outside the organization, in what is usually termed "the environment."

  2. Critically evaluate the view that understanding the multi-disciplinary nature Organisational Behaviour is essential to ...

    However, some recommendations can be drawn from the above text, to provide support to the initial statement that understanding multi-discipline organisational behaviour is essential to the effective management of both people and operations in organisations. However, whatever the balance between philosophy and science, knowledge of management theory will help with the complexities of management.

  1. positives and negatives of flooding

    people had to climb trees to evade the floods but over 150 000 people were drowned and 500 000 cattle were lost along with vast damage to settlements, electricity, roads and fishing. Deforestation is another big factor that is negative as this destroys trees that are vital for the world

  2. Climate Change, sea level rises and engineering Hull for the future. In areas ...

    Some of this radiation is reflected back from the earth's surface into space at a longer wavelength. Greenhouse gases in the Troposphere such as carbon dioxide, absorb some of this long wave radiation and radiate it back again towards the earths surface.

  1. Thailand Highways Management Project

    The implementation of the pilot project requires the private sector contractor involvement in conducting the road rehabilitation of 10 km and the annual maintenance of 15-20% per annum as well as routine maintenance for 5 years of the assigned 300 km in each region.

  2. Is the Panama Canal Sustainable?

    There is very little seasonal variation in temperature but there are large seasonal fluctuations in rainfall. The humidity chart shows that the humidity is also high throughout the year, peaking between June and November, but only varying by 9% over the whole year.

  1. A report concerning new business development in the local area, which is the Paddington ...

    The developers are aware of this fact and they are also hoping it will be reduced once the development has been finished. * There are some damaged sites as a result of the development, as some buildings had to be knocked down, eg NWCS, which is ending in a change in the environment that not many people are happy about.

  2. Sustainable construction.

    Fossil fuels are a non-renewable source of energy, which means that once they are used up there are no more. We need to change the way we live our lives and we need to make a dramatic change in our choice of energy source.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work