River engineering involves methods that target in modifying a change in the course of a river. The reasons could be diverse, from protecting wetlands to ensuring that navigation is possible for boats along certain courses. River engineering brings in experts from different streams like geology, ecology, hydrology and civil engineering. Environmental concerns are rife about rivers and the consequences that come by when constructions are made on it or that which change their courses. Hence, the ultimate goal of any river engineering project needs to be protective of a river and its surrounding environment.
Humans have interfered with river courses for different reasons and in an ad hoc manner from time immemorial. When irrigation was started or when settlements faced the danger of flooding, such practices were made in an ad hoc manner. Today engineering of a river course takes on a more scientific and comprehensive view of the related river system and consequences that would come by when the course of a river is tampered with. Engineers are often asked to work on diverting a river’s course when flooding causes much damage and lives. There might be environmental issues that are being faced which could also require reverse engineering to be done in order to get back a previous natural river system.
The crew that is involved in river engineering first devise a plan as per the goal that has been discussed and sanctioned. Weather patterns, current river course, materials that form the river bed and geology of the surrounding river habitat need to be surveyed. The changes that are being thought about include the effects that would be in surrounding regions and human settlements. Any diversion also affects the animal population in the present habitat as a river provides food and other forms of sustenance to animals. Bringing about obstructions or barrier would also pose a problem to fishes and other aquatic animals that live in a river system.
Once these issues are looking into and possible effects identified, the site evaluation is then successfully concluded. A proposal is then put forward by the engineering team. There might be a consensus about what can be done and whether a project being considered would have too many harmful consequences. Once the regulatory agencies approve a river engineering project then commences. The activities that are involved in engineering a change in the course of a river include dredging to make the river bed deeper or straightening the river course. Often, water diversion is done when certain areas are adversely affected by repeated flooding.
There have been several benefits seen from river engineering projects. With the increase of communities around river systems, the control of river waters by embankments, dredging operations or diversion are necessary in order to protect from natural calamities like flooding. Dam constructions when effectively done by objective river engineering practices help overcome the adverse side effects like loss of water in certain areas, disruption of aquatic life and others while enhancing other benefits like the generation of hydroelectricity and navigation channels.
River rock landscaping is a concept that extends to the domestic concept of landscaping from the river systems. Again, river rocks are also sourced for creating driveways, mailboxes, and gardens. They can be used to create borders around outbuildings, ponds, and lawns. River rock landscaping helps to control the growth of weeds and grasses around areas like drainpipes, carports, flagpoles, and mailboxes. These can be under canopies as well as placing on patios and decks.
River rocks can come to form a flower garden in your home or a small footpath if you wish so. These rocks are also used for creating or mimicking a dry riverbed area which can be great by the sides of a lawn. Usually, pea gravel is used for river rock landscaping.
If you are creating a pond in your garden, try using river rocks that can be spread out by the edges. This helps to create a natural water body look and feel. These could also line the bottom of a man-made pool or pond. Often these rocks are re-aligned with the edges of streams and other water bodies to make the areas less mushy or muddy. They are good for lining bottoms of waterfalls as well as this helps to reduce erosion of the soil. The rocks can also be used to inhibit soil depression from being formed around drain pipes.
River rocks can work for your home in different ways. These could act as a border along your flower patches or could be kept scattered around the edges of your garden. They also help to prevent the growth of weeds. You could layer on river rocks around flagpoles, birdhouses and mailboxes hat eliminate the growth of grass or weeds around such areas. The same concept is applied around drain pipes as well.
River rock landscaping has used in building home foundations as well. This helps to prevent home foundations from being eroded easily by debris or dirt as well as water splashing against the walls. They are often used with mortar to create patios, steps, sidewalks, and driveways. They are inexpensive and used for paving surfaces like carport canopies. Even in playgrounds, the use of river rocks is common. The stones act as a base around several playground equipments. They prevent the growth of weeds in unwanted areas of such garden spaces. They are also used as a base for large rocks or boulders. The sourcing of river rocks is usually done from nearby water bodies but should be done in a sustainable manner.
China’s river waters are often thought to suffer from polluting factors, but that is not the only country in Asia that might be contaminating waters of the rivers. In fact, most countries in Southeast Asia are facing the challenges of preventing chemical pollution from getting into their river waters. There are environmental threats that are most prevalent in countries like Sri Lanka, India, Pakistan, Cambodia, and others.
A recent discovery was made in the Chenab and Ravi rivers in Pakistan. It was determined that sediments being brought in by these tributaries to the Indus river contain persistent organic pollutants or POPs as well as organochlorine pesticides or OCPs as well as polychlorinated biphenyls or PCBs.
POPs are pollutants that are not biodegradable. These affect the areas where they are deposited as they linger in such places. PCBs on the other hand, are carcinogenic and toxic. They are banned from landfill areas, but they still manage to get into the river waters from where they get into the oceans. PCBs can affect our nervous system, endocrine, and reproductive systems. It was banned in US long time back, but the developing and third world countries still use them as do private companies. A study was done of the Mangla Lake in Pakistan, a water reservoir that is used for swimming as well as fishing. Here heavy metal levels were found in the water.
It is not only industrial sources that cause pollution in river waters. Agrochemicals are used by farmers in most Southeast Asian countries as part of Green Revolution, techniques used to grow crops without putting in much effort. Agrochemicals pollute the soil and then find their way into rivers, lakes and stream waters. That is how they get into our food as well.
There has been seen rising in kidney diseases in countries like Sri Lanka and India. Male farmers are found to have been suffering from such condition between the ages of 30 to 60 even if they do not have precursor conditions like diabetes or high blood pressure. These can be attributed to environmental pollution caused by the use of agrochemicals like DDT. Such substances have been banned from use in developed nations, but stricter restrictions need to come by for developing nations. These countries would be seeing a rise in carcinogenic diseases for a long time if the right steps are not taken.
There are several long rivers to be found all over the world, but it can be difficult to determine what the length of a river is exactly. Many rivers usually join to form a river system, but it is often difficult to determine the origin of a single river. In most cases, the length of a river is measured from the headwaters that are located the farthest distance from the mouth of a river. In certain instances, the source of a river is usually on a tributary that has a different name than the main river.
The Nile is one of the longest rivers of the world that is known to cover ten countries. The Nile River winds through Egypt, Burundi, Democratic Republic of Congo, Eritrea, Kenya, Ethiopia, Rwanda, Tanzania, Sudan and Uganda. On the other hand, Mississippi is a river that flows through only a single country.
The Amazon is the second-longest river in the world, and it is known to carry the maximum volume of water as compared to any other river. The Amazon system comprises of the second and third longest rivers which are Madeira and Purus. These two rivers also form part of the Mississippi and Missouri system.
If you look at the Australian sub-continent, this part of the world does not have a single river that would count among the top twenty in the world. The longest river here is the Murray River which covers about 1475 miles. The river system comprising of the Murray and Darling comprises a length of 2094 miles that make it to the list of the top 20 rivers. Among other longest rivers, there are three in Africa and one in Europe. The Volga and Danube are the longest rivers of Europe, while the remaining long rivers belong to the Asian subcontinent.