What is it?
Waterlogging is the lower in land productivity through the rise in groundwater close to the soil surface, and also where the water table rises above the surface. The raised water table results in the soils becoming waterlogged and air spaces in the soil are filled with water, and plant roots, in effect, suffocate from the lack of oxygen, limiting plant growth in those areas.
Where does it occur?
Waterlogging occurs where bad irrigation methods are used and in poorly drained soils where water can't penetrate deeply. For example, there may be an impermeable clay layer below the soil. It also occurs on areas that are poorly drained topographically. Worldwide, about 10% of all irrigated land suffers from water logging. Currently Victoria has 1.8 million ha affected by waterlogging. Waterlogging occurs mostly on flat floodplain areas or gently sloping landforms with high rainfall and red duplex or heavy clay soils.
What causes it?
Water logging is caused by excessive irrigation on poorly drained soils, i.e. water enters the soil faster than it drains away. It occurs even worse where there is compaction of subsoil layers; where water quickly enters the topsoil but is then blocked by a water-resistant clay layer, which may occur naturally or may be induced through excessive use of agricultural machinery. Irrigation water and/or seepage from canals eventually raise the water table in the ground.
What are the impacts?
Water logging causes:
· Damage to the soil structure.
· Suffocation of Plant roots.
· Fall of productivity by about 20% in those areas affected.
The water moves at a faster rate since there is nothing to absorb the water, which could cause flooding.
Darcy’s law provides an accurate description of the flow of ground water in almost all hydrogeological environments. Henri Darcy established empirically that the flux of water through a permeable formation is proportional to the distance between top and bottom of the soil column.
Have you ever wondered why little rain can cause drastic floods? Why rainwater doesn't just stay in one place, it goes with the force of gravity? If you have, you’ve thought about a cycle called runoff. Runoff can be negative and positive. It can cause floods, or water your crops.
Beaver ponds generally slow the water flow from drainage areas and alter silt deposition, which creates new habitat. During drought conditions, beaver ponds create water holes for livestock and wildlife, particularly wood ducks. However, their engineering feats cause problems when they flood homes, roads and croplands, dam canals, drainages and pipes, which inhibits water control, girdle and fell valuable trees and flood valuable trees, causing them to die after prolonged flooding.
There are numerous stages that take place simultaneously in the hydrologic cycle and this includes evaporation. This is when the water alters from a liquid state into a gas. The damp air from the water rises into the atmosphere and when it cools, the vapor condenses and shapes into clouds. But those billows are not the only form the vapors make; it can also materialize as dew, fog and mist, which blanket the Earth, characteristically on a rainy or humid day. Evaporation takes place when water changes from a liquid state into a gaseous state, and ascents out of the pores of the earth and into the atmosphere as a vapor (“How”). While evaporation is taking place, condensation is also occurring. When the temperature in the air plunges, the clouds become heavy and as a result they relieve themselves of the extra weight, which is called precipitation. This produces rain, hail, snow and sleet, conditioned upon the temperate. As the precipitation falls, it enters the surface of the ground and percolates into the soil, which is called infiltration. The more porous the land is, the more the infiltration can take place. However, the ground cannot hold all of that water and floods. The excess rainfall, which is also called runoff that has not been absorbed makes its way into bodies of water, such as small ponds, rivers, lakes and parts of the ocean (“Summary”).
Infiltration: This occurs when sewer lines are placed below the water table or when rainfall goes
rains down on us from the sky which then either enters the soil or joins with a larger body
Whenever there is an increase of CO2 in the atmosphere, plants respond by reducing stomatal conductances, hence, water loss is reduced. This result in greater soil moisture content in ecosystems rich with CO2, this increases plant growth
...management than scarcity of that resource. In some cases up to 50% water in urban areas, and 60% of the water used for agriculture is wasted through evaporation and loss. Logging and land conversion to yield to the demands of human beings have been reduced to half the world's forests, which has increased soil erosion and water scarcity.
When a plant reaches this condition it is said to be fully turgid. This turgor is essential for support in the plant, as the plant would wilt if it lost water. The term water potential is used to describe the force acting on water molecules in a solution, when separated from pure water by a membrane, which only allows water to pass through it. This is a measure of the potential of water molecules to move from a region of a certain water molecule concentration to another region of lower water molecule concentration. Water will move from a region of higher water potential to one of lower water potential.
The tissue would gain in mass and length and will become turgid and sabotaging. If plant tissue has a higher water potential than
Effect of overburden pressure. Soils of same density will give smaller count near ground surface.
If the gradient is steep (like the example on the right) then this can indicate that the amount of rainfall becoming overland flow is very high, the result of this is that all the water reaches the river very quickly and all in a short period of time, this gives the immediate steep ascending limb on the hydrograph. Reasons for large amounts of rainfall becoming overland flow can be little vegetation and maybe impermeable rock below the surface. Being impermeable rock, the water cannot infiltrate through this and become ground water, instead it flows over the ground to the river. Urban development and agricultural practices contribute to overland flow.
cause a greater amount of evaporation from lakes, rivers, and oceans. In some areas this could be