Enumerate human actions that affect the processes of the water cycle on Earth

Water Cycle The repeated movement of water on the earth by evaporation, precipitation and runoff under the action of solar radiation and gravity, also known as the water cycle and hydrological cycle. The water cycle is one of the most important and active material cycles in a geographical environment.

Water Cycle Process The three-state (solid, liquid, gaseous) transformation characteristics of water are the internal causes of the water cycle, and solar radiation and gravity are the external causes or driving forces of this process. The sun radiates a large amount of heat energy into space, and the total heat that reaches the earth is about 23 The water consumed on the surface of the ocean and land evaporates, and an average of 5,000 cubic kilometers of water enters the atmosphere through evaporation every year, and returns to the sea and land through precipitation. The water cycle process usually consists of 4 steps:

Evaporation, which refers to the evaporation of water from the surface of the ocean and land by solar radiation, and the evaporation from the surface of plants into water vapor, which becomes part of the composition of the atmosphere; Water vapour transport refers to the transport of water vapour from one area to another with the air flow, or from low altitude to high altitude; Condensate precipitation refers to the condensation of water vapor entering the atmosphere under appropriate conditions and falling in the form of rain, snow and hail under the action of gravity; Runoff refers to the precipitation in the process of falling, in addition to the evaporation of a part of the return to the atmosphere, the other part of the water through plant interception, infiltration, filling and ground retention water, through different ways to form surface runoff, surface flow and underground runoff, into rivers, into lakes and seas.

There are two types of water cycles: large water circulation and small water circulation. The water circulation, that is, the circulation between land and sea. The water vapor evaporated from the ocean is carried over the continent by air currents, condenses and falls to the surface in the form of precipitation.

Part of it seeps into the ground and is converted into groundwater; Some of it was evaporated into the sky; The remaining water flows along the surface to form rivers that flow into the ocean. The water cycle, which is the vertical exchange of precipitation and evaporation in the oceans or continents. These include two local water cycle processes: the ocean circulation (marine internal circulation) and the terrestrial circulation (inland circulation).

Water Cycle Speed The total amount of water on Earth that participates in the water cycle is about 5,000 cubic kilometers (1,130 mm of water depth) each year. The total amount of water in the troposphere of the atmosphere is about 10,000 cubic kilometers (equivalent to a depth of 25 mm). This water is replaced about 45 times a year on average by evaporation and precipitation, i.e. a renewal period of about 8 days.

The renewal period of river runoff is about 16 days. Marshes and lakes have a longer cycle of 5 and 17 years, respectively. Other bodies of water have a longer renewal period, with 1,400 years for deep groundwater, 25 years for oceans, and 9,700 years for polar glaciers.

It can be seen that the circulation speed of different water bodies varies greatly.

Groundwater pumping, deforestation, artificial rainfall, and many more, the list goes on.

Construction of dams, pumping of groundwater, deforestation, artificial rainfall.

Building dams, pumping groundwater, and so on.

Similarly, reservoirs and dams are built to generate electricity, such as the Three Gorges Dam. Of course, there are negative aspects to these examples, and there are many situations that cannot be assessed when they do not occur. For example, when a dam is built, the water level of the river downstream of the dam is lowered, and the groundwater level on both sides of the river is also lowered.

The water cycle refers to the change of state of water in different parts of the earth to another place on the earth by absorbing the energy of the sun. For example, moisture from the ground is evaporated by the sun into water vapor in the air. Whereas, the state of water on earth includes solid, liquid, and gaseous states.

Most of the earth's water is found in the atmosphere, on the ground, underground, in lakes, rivers and oceans.

Water moves from one place to another through physical processes such as evaporation, precipitation, infiltration, surface flow and underground flow. Like water flowing from a river to the ocean.

Effect. Natural factors mainly include meteorological conditions (atmospheric circulation, wind direction, wind speed, temperature, humidity, etc.) and geographical conditions (topography, geology, soil, vegetation, etc.). Human factors also have a direct or indirect impact on the water cycle.

Changes in the spatial and temporal distribution, intensity, and total amount of precipitation, the migration of rain bands, and the changes in temperature, air humidity, wind speed, and solar radiation forcing directly affect the formation of soil water, evaporation, and runoff. Due to climatic factors, there are significant differences in the terrestrial water cycle between humid climate zone, semi-humid climate zone and arid and semi-arid region in China.

Human activities are constantly changing the natural environment and influencing the processes of the water cycle more and more strongly. The construction of reservoirs, the excavation of canals, channels, and river networks, and the development and utilization of groundwater in large quantities have changed the original runoff route of water, causing changes in the distribution of water and the movement of water.

The development of agriculture and the destruction of forests have caused changes in processes such as evaporation, runoff, and infiltration. Air pollution and the heat island effect in urban and industrial and mining areas can also alter the water cycle in the region.

The links of the water cycle include: evaporation, water vapor transport, precipitation, surface runoff, underground runoff, etc.

Humans mainly affect surface runoff, such as diversion for irrigation, construction of reservoirs, and water transfer across river basins.

It can also affect water vapor transport and precipitation, such as artificial rainfall.

It can also affect underground runoff, such as artificial recharge of groundwater in the rainy season, pumping groundwater for irrigation, etc.

It can also affect evaporation, such as afforestation and reservoir repair, which can increase the amount of water vapor in local areas.

But the main thing is to affect surface runoff.

Human activity is onWater cycleThe impact is reflected in two ways.

The most important aspect is that due to the changes in the chemical composition of the atmosphere due to human production and socio-economic development, the significant increase in the concentration of greenhouse gases such as CO2, CH4, CFCS, etc., which changes the radiation balance of the earth's atmospheric system, leads to the increase of temperature, the increase of global precipitation, the increase of evaporation and the acceleration of the water cycle, as well as the changes of the regional water cycle. The time scale of this change can last from decades to centuries.

Another human activity is mainly on the underlying surface of the watershed.

For example, changes in the terrestrial water cycle caused by land use changes, farmland irrigation, agricultural and forestry reclamation, deforestation, the expansion of the area of impervious layers of urbanization, the development and utilization of water resources, and changes in the ecological environment. The effects of such human activities, although localized, tend to be intense, and sometimes extend to larger areas.

Which part of the water cycle is affected by humans?

The water resources used by human beings are mainly surface water and shallow groundwater with low development and utilization costs, so the most affected link by human activities is surface runoff.

Human production and life are mainly concentrated on the surface, and the most influential part of human activities is to affect the surface runoff environment by affecting the water of rivers and lakes, building reservoirs, and transferring water across river basins. South-to-North Water Diversion.

By changing the surface runoff and thus changing the spatial distribution of water, the main link it affects is surface runoff.

Due to the changes in the chemical composition of the atmosphere due to human production and socio-economic development, the significant increase in the concentration of greenhouse gases such as CO2, CH4, CFCs, etc., has coincidentally changed the radiation balance of the earth's atmospheric system and caused the temperature to rise, and the global precipitation has increased.

Water cycleIt is a multi-link natural process, and the global water cycle involves evaporation, atmospheric water transport, surface water and groundwater cycle, as well as various forms of water storage, precipitation, evaporation and runoff are the three most important links in the water cycle process, and the water cycle pathways composed of these three determine the global water balance and the total water resources of a region.

Evaporation is one of the most important links in the water cycle. The water vapor produced by evaporation enters the atmosphere and moves with atmospheric activity. Water vapour in the atmosphere comes mainly from the oceans, and some also from evapotranspiration from the surface of the continents. Atmosphere.

The circulation and suffocation of water vapor is a cyclical process of evaporation, condensation, precipitation, and evaporation. Water vapor over the ocean can be transported to the land to condense precipitation, which is called extraneous water vapor precipitation. The direct condensation of water vapor over the continent is called internal water vapor precipitation. Total precipitation in a place.

The ratio to external water vapor precipitation is called the water cycle of the place.

Coefficient. The global atmospheric moisture exchange cycle is 10 days. Water vapor transport is one of the most active parts of the water cycle.

The cycle consists of three major cycles, namely: 1) the offshore water cycle.

Ocean water is evaporated and brought to the air, where it is returned to the ocean through precipitation. It is the main body of atmospheric precipitation, accounting for more than 90% of the total precipitation.

2) Hydrothermal cycle between land and sea – ocean water evaporates to the sky above the ocean, reaches the land through water vapor transport, reaches the land surface through precipitation, and then returns to the ocean through surface runoff (rivers, rivers, lakes, seas) and underground runoff (groundwater). It allows for the continuous recycling of land water. So terrestrial water is a renewable resource.

3) Inland water cycle – terrestrial water through evaporation and plant transpiration.

It is carried to high altitude and returned to land through the precipitation process. It is mainly found in inland areas.

Function: 1. Regulate air humidity.

2. Lowers the temperature of the surrounding environment.

3. Absorbing and reflecting the sun's rays is conducive to improving the microclimate of the region.

4. Storing water and avoiding or reducing flood disasters.

In the sea and land circulation.

, the water cycle that is most affected by human activities.

The link is surface and underground runoff.

The water cycle can be divided into inter-sea circulation, grinding section such as offshore internal circulation, and onshore internal circulation. The main links of the water cycle combustion ring are: evaporation, precipitation, water vapor transport, surface runoff, infiltration, underground runoff, plant transpiration, etc.

The most affected part of the water cycle by human activities is surface and underground runoff.

Human activities have an impact on the water cycle, and the following statements are correct: b. the construction of reservoirs to alter the temporal variation of surface runoff; c. Afforestation can slow down the seasonal variation of surface runoff.

The construction of reservoirs mainly affects the dismantling posture of surface runoff and changes the temporal variation of surface runoff. Afforestation can increase infiltration, improve the local microclimate, and slow down the seasonal variation of surface runoff. Large-scale deforestation reduces groundwater runoff and increases surface runoff.

Effects of the water cycle:

Natural factors mainly include meteorological conditions (atmospheric circulation, wind direction, wind speed, temperature, humidity, etc.) and geographical conditions (topography, geology, soil, etc.), and human factors also have direct or indirect effects on the water cycle.

Changes in the spatial and temporal distribution, intensity, and total amount of precipitation, the migration of rain bands, and the changes in temperature, air humidity, wind speed, and solar radiation forcing directly affect the formation of soil water, evaporation, and runoff. Due to climatic factors, there are significant differences in the terrestrial water cycle between humid climate zone, semi-humid climate zone and arid and semi-arid region in China.

The water in the ocean is evaporated by the sun's heat to form clouds, which are blown away by the wind, and when cold, ice crystal droplets are formed, and when they fall, they form rain, and part of them fall on land, and part of them fall on land.

Follow the river into the sea.

It's a cycle.

Offshore Internal Circulation: Ocean Evaporation - Differential Beam Water.

Inland circulation: evaporation - precipitation.

Great circulation between land and sea:

Ocean evaporation – water vapor transport – 1

Plant transpiration Ground evaporation--2

Precipitation - Groundslip runoff - Ocean.

Precipitation - infiltration - Underground runoff - Ocean.