Strategy of Channelization in River Systems

Strategy of Channelization in River Systems The purpose of this essay is to analyze the strategy of channelization in river systems in order to reduce flooding, and other purposes such as navigation. Also the importance of channel forms and the value of the systems approach are evaluated within this essay when considering the pros and cons of restoration activities and whether these schemes are beneficial to the environment. Overall this essay will look at the environmental degradation caused by channelization and determine whether channelization is the most beneficial strategy in reducing flooding or are there alternatives that lead to less environmental degradation. Channel forms: Channel forms help humans comprehend the behaviour of rivers. This is vital as one can foresee how rivers may be affected by various changes and restoration schemes. Thus, the ability to protect and restore river health is enhanced. Channel forms are regulated by convoluted interactions between profuse environmental variables. This is why the systems approach is a useful method when analysing channel systems, as it does not just look at one variable but all of the linked variables involved. Even with this system shaping channel forms is highly dependent on geology; directly and indirectly over a prolonged period. Human interactions have also had an impact on the change of channel form for instance channelization (Water and river commissions, 2002). Channelization and its implementation: Human interaction with river systems is both the reason why channelization was implemented for example as a result of flooding and the cause of environmental degradation of the river systems. Humans interact with river systems in many ways and have impacted flooding of river channels due to increased population pressure, which has put a growing demand on water supply systems leading to environmental degradation. Deforestation around river channels have also increased flooding as deforestation impacts the interaction between precipitation and the drainage basin response. Due to increased awareness of river behaviour and dynamics new strategies were implemented and overtime humans modernised engineering structures and built broad structures to control and regulate river flows, such as channelization. Channelization according to Brookes is a type of â€Å"river engineering whereby the natural river channels are modified to control flooding, drain wetlands, and improve river channels for navigation, control stream-bank erosion and to improve river alignment† (Brookes, 1988). River channelization has seven types of alterations (Gregory, 2006). These are â€Å"(1) re-sectioning and realignment, (2) Dredging, (3) Snagging and clearing, (4) Levees or artificial embankments, (5) Bank protection, (6) Bed protection and (7) River training† (Charlton, 2008). An example where these alterations have been implemented is during the channelization of the River Raba in Carpathians, Poland (Wyzga, 1993). However, these engineering structures tend to have a large impact on river and the natural ecology and hydrology of the channel system. For years humans have interacted with channels and altered the natural geology of the systems and thus have lead to severe impacts on the â€Å"physical, chemical and ecological condition of the channel systems† (Brookes, 1988). The impacts of channelization usually involve the alteration of river hydraulics and the decrease of instream habitat. Other impacts discovered as a result of these alterations include increased water temp, erosion, elimination of bankside habitat. These impacts can cause severe environmental degradation (Gregory, 2006). Environmental degradation: The deterioration of systems within the environment by either natural or human influence is considered environmental degradation and as channelization alters the natural river system it leads to extreme environmental degradation. Impacts on the environment associated with human interference are usually quite complex and are mostly long term effects. Nevertheless, few studies have been conducted on the long term effects of channelization (Brooker, 1985). Swales (1982a) however inspected several environmental effects on channel engineering systems, in particular the impact on stream habitat and discovered that channelization has a major impact on instream and bankside habitat (Brooker, 1985), as well as the hydrology, aspects of flow and suspended sediment within river systems (Wilcock, 1991). Effects of channelization can also occur downstream in a channel system which broadens the extent of ecological disturbance (Brooker, 1985). The increase of flow velocity and its carrying capacity as a result of shortening and straightening the channels has an immediate ecological effect on instream habitat as many ecosystems need particular conditions in terms water velocity (Gore, 1978). This destruction within the channel systems leads to erosion of bankside vegetation which increases sediment loads in the channel (Keller, 1976; Karr and Schlosser, 1978). Sediment loads in channel systems are usually low (Lewin, 1981), however, in channelized rivers se the loads are increased as bed/channel wall sediments are scraped up. This release of sediment has major effects on the ecology of the river (Wilcock, 1991) as removal of bankside vegetation leads to temp changes and in results affects the ecosystem as well as reducing energy flow (Brooker, 1985). In some cases channel slopes have also seen as increase whilst channel roughness is seen to reduce. An example of environmental degradation was shown in Gregory (2006) which involved the Channelization of the Blackwater River in Johnson County, Missouri. This channel was shortened in 1910 in order to reduce flooding by deepening and widening the channel by â€Å"up to four times its original size† (Emerson, 1971). This subsequent lowering and increase of channel width lead to increased erosion in the river system, also bridge repairs have had to be carried out and there has been a severe loss of farmland. â€Å"Downstream reduction in channel capacity has caused suspended sediment in turn increased flooding rather than reducing it due to termination of dredging† (Emerson, 1971). Alternatives: Channelization was initially implemented to straighten and shorten river channels to reduce flooding. It was also implemented to decrease flow velocity and prevent flooding, however, this lead to environmental degradation which resulted in the depletion of instream habitats and depleted drainage function. As channelization has had problems leading to environmental degradation, alternative channel schemes have been developed to enhance water quality functions whilst preserving drainage function and lessening environmental degradation (Evans, Bass, Burchell, Hinson, Johnson and Doxey, 2007). There are many alternatives to channelization that environmentalists could install; one such method is stream renovation which has been implemented on â€Å"streams in Charlotte, North Carolina† (Nunnally, 1978). Unlike channelization stream restoration aims to decrease the risk of flooding and drainage problems â€Å"by employing channel design guidelines that do not destroy the hydraulic and morphologic equilibria that natural streams possess† (Nunnally, 1978). Minimal straightening which promotes bank stability by leaving trees is employed in this scheme. Also the reduction of channel reshaping and the use of bank stabilization techniques are used here to reduce flooding and control erosion as well as sedimentation problems (Nunnally, 1879). Other alternatives involve the formation of in-stream wetlands and â€Å"lowering of the floodplain to reconnect the channel with the floodplain, redesign of channels using natural channel design principles, and establishment of conservation easements† (Evans, Bass, Burchell, Hinson, Johnson and Doxey, 2007). Restoration: Recognising channel forms and understanding how they behave and change is crucial for managing and protecting channel systems, especially for river restoration activities. Due to severe environmental degradation restoration schemes have been implemented. Though, it is not known whether these schemes are beneficial. Restoration activities generally improve bank stabilization (Florsheim, Mount, and Chin, 2008) and have positively increased depth and flow variety and velocity as well as increasing habitat diversity in channel systems (Pretty, Harrison, Shepherd, Smith, Hildrew and Hey, 2003). Other benefits include the protection of infrastructure around river channels, and in relation to instream habitat it guarantees overall ecological system. Restoration schemes allow the natural process in the channel systems to redevelop and surrounding landscapes to restore. Restoration schemes are constructive in counteracting the environmental degradation caused by channelization; yet there are a few cons. For instance natural processes may not necessarily be enhanced. Also a clear understanding of channel process is important in implementing these schemes, as they may sacrifice natural conditions in order to protect infrastructure. Restoration schemes are extremely expensive and very complicated therefore it is generally impossible to remove all human influences meaning restoration may not lead to higher biological diversity. Channelization is commonly used to prevent flooding of channel systems; however, it has been found that the adverse impacts created by channelization projects far outweigh the benefits they intend to create. It is for this reason that alternative strategies are being developed so that in the long run creates less environmental degradation. The use of the systems approach is important as the use of all variables regulated by channel forms is necessary in making the new strategies environmentally acceptable. Also increased knowledge of channel systems and its dynamics have helped better restoration schemes and thus leading to the recuperation of many already channelized systems.

The Destruction of the Rainforest :: Environment Environmental Science

The Destruction of the Rainforest The purpose of this paper is to inform the reader of the destruction of the rainforest. In my paper I discuss many aspects of the rainforest. I explain what the rainforests are, and give a brief summary of the importance of the rainforests. I also give a description of the destruction of the rainforest, and how a person can help to save the rainforest. The rainforests are disappearing acres per minute, a number that grows so quickly it would be impossible to cite here because it would be outdated within a week. The rainforests are home to over half of the entire species of the world, which are being destroyed with the rainforests. Unlike the rainforest itself, which may appear to grow back, it will never be the rainforest it once was, and the species that were killed will never return again. Many of the species that have not yet been discovered may very likely cure cancer, AIDS, and many other diseases and viruses of today. If the rainforests disappear so will most of the population of the world. By the end of my paper the reader will know more about the horrifying destruction of the rainforest and how we can all work together to stop it. There are two different types of rainforests: tropical and temperate. Tropical rainforests are found in 85 countries around the world. They are located near the equator, where temperatures stay above 80 degrees Fahrenheit year round. These dense, damp forests occur in Latin and South America, Africa, and Southeast Asia. Although they (tropical rainforests) cover just seven percent of the earth’s surface they can provide habitat for 50-90 percent of its animal species. In 1990, tropical rainforests totaled some 1.7 billion hectares (Forest Alliance of British Columbia, 1996). Half of the world’s rainforests lie within the borders of Brazil, Indonesia, and Zaire. Tropical rainforests have 3 layers: the forest floor, the understory, and the canopy. The forest floor has soil and is home to mainly insects although large mammals like gorillas and jaguars are also found there. Many smaller animals, including anteaters, lemurs, and tree kangaroos live in the understory. This is also where many small trees and shrubs are found.

Recount Mother’s Day

Yesterday was indeed a very busy and special day for our family. It has been a family tradition to celebrate Mother’s day with the entire family and with each one of us excitedly prepared with a gift and a letter for our Mum. Dad led the different activities lined up for the day. Everyone actively participated and contributed, which made the celebration truly meaningful and memorable. We made sure we have shown our love, appreciation and gratefulness to the one woman who painstakingly brought us in this world and nurtured us with unconditional love, guidance, and undying support. Mum was still asleep when we scattered our gifts and letters cut out in different colours, shapes, and sizes by her bedside early in the morning. We then prepared breakfast consisted of steamed rice, fried eggs and sauteed tuna and bread. We squeezed fresh oranges to give her the freshest and healthiest breakfast just the way she does every day for all of us. We capped her breakfast delight with beautifully assembled fresh strawberry with classic yoghurt, her favourite dessert. When Mum woke up, she was greeted with a kiss from Dad and a happy mother’s day hug. Mom read the letters and opened the presents. There was a big grin on her face when she opened my little brother’s gifts which are chocolate balls from the baptism party we went the night before. Same with my little sister who gifted Mum with the baby in a cradle also from the baptism party but both gifts were artistically wrapped in their personally cut out big hearts giving it their personal touch. My sister and I bought Mum a heart pendant. Dad treated Mum to a lunch at the Adelaide Casino after watching Pacquiao and Mosley fight there, while we children stayed at Urbanest, a cool students’ accommodation place across Adelaide Casino and baked macaroons there. We had early dinner with my Dad’s fellow Filipino scholars. After having dinner, we then went to church and headed home after. Mum thanked us with kisses for the wonderful break from her daily routine of unselfishly attending to all our needs first over hers. I reflected on the day’s event and truly believed it was proper to pay tribute to all the mothers around the world for everything that we are, it was especially so because of our Mums.

Chinas Treatment of Its Growing Elderly Population

Chinas famous one-child policy had an aftereffect of creating a larger elderly population. Westerners often hear about how much regard the Chinese have for the elderly, but as China grows old, a number of challenges potentially await the emerging superpower. With this review of the elderly in China, better your understanding of how old people are treated in the country and the impact of a rapidly aging population there. Statistics About the Aging Population   The population of the elderly (60 or older) in China is about 128 million, or one in every 10 people. By some estimates, that puts Chinas sheer number of senior citizens at the largest in the world. It is estimated that China could have up to 400 million people over 60 years of age by the year 2050. But how will China address its masses of senior citizens? The country has changed dramatically in recent years. This includes the changing of its family structure. In traditional Chinese society, the elderly used to live with one of their children. But today more and more young adults are moving out, leaving their elderly parents alone. This means that the new generation of elderly people may not have family members to tend to their needs, as young people in the country traditionally have.   On the other hand, many young couples are living with their parents because of economic factors and not because of tradition. These young adults simply cannot afford to buy a house of their own or rent an apartment. Experts say family-based care is now impractical because most middle-aged children have little time to take care of their parents. So, one of the things the elderly have to face in 21st century China is how to live out their twilight years when their families cant take care of them. Older people living alone is not an anomaly in China. A nationwide survey found that about 23 percent of Chinas seniors over the age of 65 live by themselves. Another survey conducted in Beijing showed that fewer than 50 percent of elderly women live with their children. Housing for the Elderly Since more and more elderly  live alone, homes for the elderly arent enough to meet their needs. One report found that  Beijings 289 pension houses could accommodate only 9,924 people  or 0.6 percent of the population above age 60. To better serve the elderly, Beijing adopted regulations to encourage private and foreign investment in homes for the elderly.   Some officials believe that the problems facing Chinas elderly can be solved through combined efforts from family, the local community, and society as a whole. Chinas goal is to establish a support network for senior citizens that provides medical care and helps them avoid loneliness through scholarly pursuits and entertainment. The network would also encourage  senior citizens to continue serving society after retirement age by using the knowledge theyve acquired over the years. As Chinas population ages, the nation will also have to take a hard look at how this shift will affect its ability to compete on the world stage.