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What is AQUATIC WEED HARVESTER? What does AQUATIC WEED HARVESTER mean? AQUATIC WEED HARVESTER meaning – AQUATIC WEED HARVESTER definition – AQUATIC WEED HARVESTER explanation.
Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license.
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An aquatic weed harvester, also known as a water mower, mowing boat and weed cutting boat, is an aquatic machine specifically designed for inland watercourse management to cut and harvest underwater weeds, reeds and other aquatic plant life. The action of removing aquatic plant life in such a manner has been referred to as “aquatic harvesting”.
Water is an important resource and in many countries, waterways are increasingly clogged by aquatic plant growth. This is particularly so in tropical countries where warmer water means the plants grow more quickly, and increasing run-off of fertilisers and effluent has exacerbated the problem. Irrigation ditches and pumps can become overgrown with vegetation, power station and factory water intakes can get blocked, boats can get hindered, fish stocks can be disrupted, and water moves more slowly, resulting in greater evapotranspiration and a greater risk of flooding. In some large irrigation projects in India, canals have become so overgrown with vegetation that water flow has been reduced to a fifth of its previous amount. In Bangladesh, floodwater has washed mats of water hyacinth onto paddy fields, overwhelming the emerging rice crops. Small fish can become entangled in excessive algal growth.
Rice is the main aquatic plant grown for human food, but smaller areas of watercress and water chestnut are also cultivated. In their native environments, aquatic weeds are part of a balanced ecosystem, and it is mainly introduced species of water plant that become invasive and cause problems by congesting water bodies. The worst culprits, found in both temperate and tropical waterways, are floating plants such as water hyacinth, water lettuce and Salvinia, fully submerged rooting plants such as Hydrilla and water milfoil and rooting plants that reach the surface such as cattail, papyrus, bulrush and reed.
Weed cutting boats are developed to enable the maintenance of canals, lakes and rivers and to remove excessive aquatic life such as algae and other plants that may negatively affect a waterway’s ecology. Mechanical harvesters are large floating machines that have underwater cutting blades that sever the stems of underwater plants, gather the weeds and raise them on conveyor belts, storing the vegetation on board in a hold. Periodically this is discharged to a barge or an onshore facility. The harvested product can be composted, sent to a landfill site or used in land reclamation. In developing countries aquatic vegetation may be harvested by hand or by net from the shore, cut and harvested by boat and lifted ashore by hand, crane, pump or conveyor system. The harvested vegetation may be used for the feeding of livestock. To reduce the high moisture content and to make it easier to transport, the weed can be chopped and pressed. Other uses to which the harvested vegetation can be put include ensiling the material for livestock fodder, adding it to the soil as a bulky organic fertilizer, manufacturing the raw material into pulp, paper or fibre, and fermenting it to produce methane for energy production.
Mechanical harvesters can be effective at clearing aquatic weeds but the machines are expensive and the process may need to be repeated several times in a growing season. Small fragments of weed remain in the water and may spread to other locations thereby aiding in the dispersal of invasive species. Some areas may be too shallow for the mechanical harvester and it may be unable to access restricted locations. Submerged tree stumps can damage the machine. An alternative to mechanical harvesting is the use of herbicides, which are easy to apply and less expensive, but may have unwanted impacts on the environment.
What is AQUATIC WEED HARVESTER? What does AQUATIC WEED HARVESTER mean?