Hard & Soft Engineering
Flood Control - Hard & Soft Engineering Techniques Rivers are a natural flow of water, and since the beginning of time, humans have tried to harness the energy of rivers and change their direction. This interference often leads to flooding. Sometime when a river floods it becomes necessary to intervene with its course and use modern techniques to reduce the risk of flooding and to ensure the passage of water flows downstream and away from the affected area as quickly as possible. Hard Engineering Techniques Below are diagrams explaining some commonly used hard Engineering Techniques: Revetments. Brick, concrete, wooden pile, sheet steel, rock or wire mesh structures designed to reduce bank erosion and to prevent meander development and thus to protect homes and farmland from erosion. Wing Dykes and training walls. These built out from the bank towards the centre of the channel in order to direct the fastest river current or thalweg away from the bank. This decreases bank erosion and increases the river's velocity in the centre so that it erodes a deeper, navigable channel, which is self-dredging. Channelisation. This is where the river is straightened out bout in terms of its course and in terms of its bed and sides. This is done to reduce the friction that sides have on the water and this in turn increases the water velocity. A faster flowing river also prevents
Hard & Soft Engineering Coastal Management Case Studies
Hard & Soft Engineering Coastal Management Case Studies Hard Engineering - Coastal Management - Isle of Wight The Isle of Wight has 65 miles of spectacular coastline, 28 miles of which are designated Heritage Coast. This varied coastline is one of the Island’s main assets. The Isle of Wight has four coastal defence options: . Hold the Line – retain existing coastline – maintain current deference’s, upgrade or install new ones 2. Do nothing but monitor – it may not be technically, environmentally or economically possible to do coastal defence work 3. Retreat the line – this is used to manage the rate and process by which the coast retreats 4. Advance the line – build new defences seaward, in front of the land, to protect the land behind Monks Bay * Cliff failure after the 1990/91 severe storms gave motivation to upgrade coastal defence * Offshore breakwater, six rock groynes and rock revetment * This reinforced the existing sea wall – 25,000 tonnes - Norwegian granite * Beach nourishment was used – 40,000 m3 of sand * Re-profiling the slope and installing land drainage * This was to reduce the risk of Mass Movement Cost-benefit analysis – value of property exceeded £1.4 million cost * Completed in 1992 * £1.4 Million - but value of property exceeded this * Sediment in groyne has been a problem, as some has overtopped the rock
Genetic engineering: techniques, benefits and risks
Genetic engineering: techniques, benefits and risks David Farrell What is genetic engineering? Genetic engineering is the transfer of a gene from one organism to another. This transfer is from donor to recipient. It is also the scientific alteration of genetic material in a living organism. Genetic engineering is a relatively new and fast moving technology which has the potential for limitless possibilities in influencing the genetic make-up of human genes. However there are certain ethical opposition that genetic engineering has had to face. Genetic engineering involves moving a specific gene from one organism to another, cross breeding however involves moving hundreds if not thousands of genes from one organism to the other. Common techniques used in genetic engineering Recombinant DNA Uses plasmids and viruses to insert foreign genes into cells an example of this is bacteria being given the human insulin gene so that when the bacteria multiplies it creates insulin. This means that diabetes can be treated better then before and many people have been saved from diabetes thanks to genetic engineering. Viruses can also be used as a vector by adding a new gene to the genetic material of the virus. Microinjection This is a simple procedure where the recipient is simply injected the new gene, however sometimes the injected cells find the host cell genes and incorporates
Sea Defence. Which is better: hard or soft engineering?
Which is better: hard or soft engineering? Hard engineering options tend to be expensive, short-term options. They may also have a high impact on the landscape or environment and be unsustainable. Hard engineering is the controlled disruption of natural processes by using man-made structures. An example of hard engineering is a sea wall, these walls are built on the edge of a coastline and made to protect the base of cliffs and also to limit the amount of coastal erosion on a cliff-face were land is being absorbed by the sea. These walls could also prevent coastal flooding. This type of hard engineering is good as it has many aspects and is effective. Disadvantages of creating a sea wall are that it is very expensive to build; the curves in the sea wall reflect the wave's energy back to into the sea, therefore the waves remain powerful. Another disadvantage is that the walls erode after time and the cost of maintenance is high. Another example of hard engineering is groyne, a groyne is a wooden barrier built at a right angle to the beach. Groynes are built to prevent the movement of beach material along the coast by long shore drift. This allows the build-up of a beach; beaches are a natural defence against erosion and also an attraction for tourists. Disadvantages of building a groyne are that it can be seen as unattractive and is also costly to build and maintain. A
Referring to examples, explain why sustainable solutions to flood control are increasingly preferred to hard engineering.
Referring to examples, explain why sustainable solutions to flood control are increasingly preferred to hard engineering There are a number of reasons why sustainable answers to flood control, or soft engineering, are preferred better than hard engineering, in other words, non-sustainable methods. Firstly these terms need to be stated. Sustainability is when improving it for the present, but also to create a better environment for the future generations as well carries out development. Soft engineering is when people try to work with the environment by using ecological materials. This is so there is minimal impact on the environment. These methods try to create a balance by using more natural resources. Hard engineering is the opposite, as it uses resources like concrete, and it does not provide a sustainable environment for the future. A case study of where hard engineering has been used is the River Mississippi. This river has had extensive hard engineering done on it. For example, channelisation took place by straightening all the meanders and thus making it over 250km shorter. Also many dams were placed along the river in order to hold back the water and therefore provided flood control. Even though this channelisation worked upstream, the water continued to flood downstream, causing just as many problems and damage. This is why hard engineering is seen as
"The 1993 Mississippi floods were caused by hard river engineering" Discuss this statement.
"The 1993 Mississippi floods were caused by hard river engineering." Discuss this statement In 1993 the Mississippi River, whose mouth is located near New Orleans in South of the USA, flooded causing $15 mil worth of damage. Around 50 people were killed in the disaster as 18 thousand square metres of the States were covered in overland flow in North America's worst flood. In normal conditions, every spring the river fills up draining half of the country's water, and floods are common so to aid this, American governments set up various 'hard engineering' schemes to control the water. Examples of this type of engineering feature the construction of artificial levees to prevent the river from overflowing, and the building of over 200 reservoirs in an attempt to hold back large amounts of water. The instalment of wing dykes to improve transport through river dispersion was also used, and the interference of hard engineering has been seen as one of the leading causes for the worsening of the 1993 floods . It can be argued that a lot of the hard engineering work done on the Mississippi river actually made the consequences of the flood a lot more severe than if the river had been left to take its natural course. Artificial levees, which make up over 500km of the Mississippi's banks can be seen to greatly enhance the flood damage rather than reduce it. These are extensions to
Evaluate the role of hard and soft engineering strategies in managing rivers
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. Two thirds of the floodplain was destroyed and due to the river’s increased velocity many species of fish were unable to survive and began to die out, causing problems low down on the food chain which resulted in a negative impact on surrounding ecosystems. Containing some of the discharge of a river via
Continued spending on hard engineering coastal defences cannot be justified in geomorphological, economic or environmental terms.
Coastal Hazards and Management "Continued spending on hard engineering coastal defences cannot be justified in geomorphological, economic or environmental terms." Hard Engineering: In civil engineering of shorelines, hard engineering is generally defined as the use of concrete break walls or steel sheet piling to stabilize shorelines and achieve safety.1 Soft Engineering: Soft engineering is the use of ecological principles and practices to reduce erosion and achieve the stabilization and safety of shorelines, while enhancing habitat, improving aesthetics, and saving money. Soft engineering is achieved by using vegetation and other materials to soften the land-water interface, thereby improving ecological features without compromising the engineered integrity of the shoreline.2 The two problems associated with coastal hazards are: ) Erosion and loss of land and property to the sea 2) Coastal flooding These two problems are a headache to the people living near the coastline. Many solutions have been suggested. Their property is eroded away by the sea, into which they have invested a lot of money. Along with property, normal landscape is eroded away which is quite valuable to hotel owners. The place attracts a lot of tourists thus generating a lot of profit for hotel and restaurant owners and other local businesses. This can be seen in the Estoril Coast in Portugal,
Genetic engineering.
Genetic engineering The use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biological products. The techniques include the use of hybridomas (hybrids of rapidly multiplying cancer cells and of cells that make a desired antibody) to make monoclonal antibodies - an antibody that is mass produced in the laboratory from a single clone and that recognizes only one antigen, gene splicing or recombinant DNA, in which the DNA of a desired gene is inserted into the DNA of a bacterium, which then reproduces itself, yielding more of the desired gene; and polymerase chain reaction - laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA which makes perfect copies of DNA fragments and is used in DNA fingerprinting - any of several similar techniques for analyzing and comparing DNA from separate sources, used especially in law enforcement to identify suspects from hair, blood, semen, or other biological materials found at the scene of a violent crime. It depends on the fact that no two people, save identical twins, have exactly the same DNA sequence, and that although only limited segments of a person's DNA are scrutinized in the procedure, those segments will be statistically unique. Genetically engineered products
Genetic Engineering
Suzanne Bembridge Genetic Engineering Scientific study, ethical considerations, and the pursuit of a better human destiny, are the foundation for genetic engineering. But what is genetic engineering and why is there so much ethical controversy? Genetic engineering as defined by Pete Moore 1 "is the name given to a wide variety of techniques that have one thing in common: they all allow the biologist to take a gene from one cell and insert it into another". The structure of every living thing is determined by its genes. A gene is a chemical code which contains an instruction for the body to express a particular attribute such as eye colour, skin pigment or height. Each gene is made up of a segment of DNA (deoxyribonucleic acid). Scientists are able to extract DNA from any organism and can then isolate a specific gene through the use of restriction endonucleases, which cut DNA strands at specific points. The gene is then copied and folded and transferred to another organism. Genetic modification has gone on for years through traditional plant and animal breeding techniques. Genetic engineering allows the transfer of a gene from any source (transgenic manipulations). This creates safety, environmental, social moral and ethical concerns for many people. According to Ron Epstein 2 most of genetic engineering happens in the agricultural sector. Plants are genetically
