How are humans affecting the water cycle?

Question

Water moves from ocean to air, onto land, to lakes and streams and groundwater, back to the sky and ocean, in a continuous cycle. In the past, water was considered to be a renewable resource. Today, in many parts of the world, water has become a non-renewable resource. Discuss some ways in which humans are affecting the water cycle.

Answer 1

They are the worst humen, affecting water cycle....in journals--famous Institutes..

Answer 2

Humans are taking many medications that have started to appear in detectable quantities in drinking water...watch out, there's viagra in that water!

also, with every new parking lot and building, there is an increase in surface runoff.  This results in pollutants washed into a water system.

Answer 3

Wow, you've gotten a lot of bad info so far.

Agriculture and reforestation are both pretty essential to human life, unfortunately both consumer large quantities of water. The good news is - there's a water cycle here on planet Earth. Sea water evaporates, goes into the atmosphere, condenses into clouds, moves over land and falls as rain. It's not like it's forever trapped in the ocean!

As for rivers and lakes being polluted. Yes, they should be cleaned up even more but they're already much cleaner than they were in the 70s when the Clean Air and Clean Water Acts in the US were implemented. I think anyone who dumps chemicals or raw sewage into a waterway should be imprisoned but at least we're going in the right direction.

Putting salt into a landfill isn't going to leech into the ground water, the salt will sit on top of the soil where it's placed.

I for one think flush toilets are pretty handy and I know that most Africans would love to own one. You could advocate not using drinkable water but grey water for flushing but you won't convince me to go back to the days of outhouses.

Bydrerule: please explain how ice melting can possibly reduce freshwater supplies. Most of that water has been in a glacier for thousands or millions of years, thus it's been out of circulation. When it melts it rejoins the water cycle where it can evaporate and drop as fresh clean rain. The idea that anything on Earth is lost forever is naive, seawater is still water and after it evaporates...well, read the above.

The Earth has been largely jungle in the past, mostly ocean and largely desert, depending on the epoch. Saying humans have caused desertification is simplistic and if you think the people in Africa or Mongolia are mismanaging their land and making their deserts grow, go talk to them.

I agree with your point on recycling grey water for sewage but that will require changes to building codes nationwide. As for cisterns, you're actually taking water out of circulation when you do that so some areas prevent it because some people store 1000s of gallons of water for some reason.

Desalinization is currently too expensive to be practical but if someone develops a cheap energy source that may change. There are a lot of intriguing ideas on the horizon from hydrogen fuel cells, improved nuclear reactors, to eventually fusion power. That would simplify things a great deal but in some areas the damage is already occurring and the water is in short supply.

As for the US, we could build a nationwide canal system as was discussed in the 19th century. They wanted it primarily for transportation but we could use it to transport water from areas that have too much to areas in short supply. It would be very expensive but probably not much more than the interstate highway system and could run parallel to or underneath those roads. It would be much cheaper than trying to truck water into areas that need it and much better than just wringing our hands about lack of rainfall.

Here's a link if you want to help people living in the developing world gain access to purified drinking water. Each sachet costs 10 cents, is given free to the needy and can purify 10 liters of water.

Answer 4

A long winded answer also giving solutions .

BUT YOU ARE WRONG ONLY THE COASTAL RAINS COME FROM THE SEAS ,THE REST COMES FROM PRECIPITATION FROM THE FORESTS.(they can measure the salt content in the rain water and  the further inland we go the less clouds are from ocean evaporation)

IT IS THE TREES THAT KEEP THE RIVERS FLOWING

Farmers pump to much from the rivers for irrigation,More and everywhere.more people use water and also contaminate it

In many places people die of the lack of uncontaminated water or even any water and will end u killing for it if they don`t already..

Now with the melting  ICE we are loosing 75% of all sweet water supplies on the planet.

25% of the planets surface is land

75%of the surface is SALT water ,and it is rising

------------------------------...

97%of the Earths water is salt

fresh water is only 3% of all the Earths water

most of it is beyond out reach

now much ice is melting and running into the seas fresh water lost for ever.

STORAGE or Location of % of the fresh water

ice and glaziers 74%

groundwater 800 meters + 13.5 %

groundwater less than 800meters 11.o%

Lakes 0.3%

soils 0.006%

Atmospheric in circulation 0.0035%

rivers 0.03%

frozen land or permafrost is not included and represent an unavailable storage of 40%

so of the 3% about 11.6 ,is easily available to us ,in rivers, lakes and ground water surface aquifers,more and more of this is becoming contaminated

overpopulation of an extra 70 million people a year (increasing all the time )and expanding agriculture ,which uses 70% of available potable water supplies ,has brought the good(sweet) water supplies to critical levels ,some countries have been in trouble already quite a while .

Now climate change and desertification, because of irresponsible agriculture ,overgrazing and deforestation is damaging world fresh water production .

It is a good reason for concern and if we do not rectify matters by changing agricultural methods ,

reforest ,stop deforestation,

become more economic with water use ,

stop producing more people ,

stop wasting and contaminating water,

we will be in serious trouble all round

and could end up looking like Mars.

I am sure this will fall on deaf ears but these are some of the things we can do

to conserve water use

EFFICIENT WATER USE

IN THE HOUSE

one can connect the sink straight to the toilet cistern and so use the water twice ,first to have a shave and then to flush the toilet

also if you bend the ball valve you can regulate the level of the cistern

Always have your Grey water and Black water separate,so that the sink and shower water goes directly into the garden saving on irrigation and at the same time ,making the sewage smaller and easier to deal with ,

This also goes and irrigates the garden but via a cistern of two compartments and a French drain ,on which you plant trees,

HAVE DRUMS OR A POND COLLECT WATER FROM THE ROOF OF THE HOUSE

And cars can be washed with rain water ,it does not have to be drinking water.

ON THE LAND

Only use small tractors for initial shaping and earth works

then preferably no till methods

Or use deep chisel plows sparingly to minimize disturbing the

top soil further so that organic structures remain intact and continue working ,building soil.

Do not use heavy machinery which compacts the soil and will raise salt content to the surface do not have too many Cows

which will do the same

Compacted soil does not absorb much water.

Economic systems of irrigation, like drip irrigation

and water harvesting design, using a lot of stone walls ,that condense water in the night

and planting leafy plants ,for the same purpose,

Building wind breaks ,to counter act the drying effects of the wind and farm towards Aggro forestal ,using as many trees as possible to limit evaporation .

Using shade nets before we have tree cover

and use MULCH

By cutting down the weeds before they produce seeds and leave them where they fall.

They will cover the ground add even more organic matter on top,(you can use saw dust,leaves green or dry),

Plant big leafed plant around the plots to use for mulch

Conserve soil by using compost,,Utilize all manure from the farm,

Plant DIVERSE,in guilds and companion planting to spread the chemical requirements and releases to preserve soil balance,

Have some tall scattered shading trees at intervals to break the suns rays.

And when you plant make a little space and plant in the mulch.this is the easiest quickest and by far most beneficial way(for the quality of you soil)to prepare the land for planting.

To prevent weeds from coming all you have to do it turn out the lights,you can even use cardboard or black plastic(this is good for strawberries because they will rot if they touch humid ground,and the bugs can get to them).

The humidity is preserved underneath and promotes the development of worms(there exists no better compost than their excrements)and a variety of micro biotic life which together within the mulch produce more topsoil.

The mulch also keeps the ground temperature even and guards against the impact of the rain ,which would other wise brings salt to the surface if on unprotected land.

Mulch also prevents the soil from drying out because of the sun and,wind erosion.

WATER HARVESTING

We should not only conserve Water ,we should also collect it when it rains ,make your lawn and garden receptive to absorb water ,like a giant sponge.

As far as catching rain is concerned ,we do this all the time ,and have done so already since Babylonian times,and is a part of the more advanced Agriculture,that existed with the Egyptians,,Moors, Arabs and probably many more

Central ,and South American indigenous people had this idea coupled to their pyramids ,catching the water of the slopes and leading it into tanks or onto the fields .

And many others ,today we call this WATER HARVESTING.

Only Modern Man is totally extravagant with the rain water given ,and complains of the wetness ,letting it run off into the rivers lost forever ,With out even attempting to hold on to it .

And then later complains of not having water ,when times are dryer

So initial energy on Extensive earth works to shape the land to be receptive to water absorption,is to be recommended.

Make terraces when farming on slopes

use living and any other type of barriers on steep slopes to collect and contain any organic material that is about and mobile

In Permaculture the rule is to harvest water to the point of Zero runoff.

This means that all of the rain that falls on an area is absorbed by the terrain and not a drop leaves it.

By building dams,ponds or Swales, with inter connecting ditches,

Bio swales to absorb water

http://answers.yahoo.com/question/index;...

If there are enough of these ;the places ,where before ,the rain water ran over the ground into the rivers and on to the sea ,in a matter of hours or days.

It now runs into absorbent dams or Swales and saturates the ground and eventually reaches subterranean water deposits ,taking many months to do so.

Or it fills up ponds that can be used for Aquaculture.

And so a convex situation that repels water is transformed in a concave ,absorbent one and turning the area in to a sponge.

The more holes the better and if they do not hold the water but leak ,the water is not lost it is in the ground for months

In Spain and Portugal ,which still display many examples of the conquering Moorish influence one can find many remnants of Water harvesting,such as Aqueducts and tanks underneath the patios ,which collect the rain water from the roofs ,to be used in dryer times.

In Arabia ,on a large scale ,land has been shaped to catch and lead,rain water into sandy areas or to agricultural lands.sand is almost as good as dams because it absorbs water and holds it.

Here in Mexico we collect the rainwater in our school for sustainable agriculture,but it is too near Acapulco to trust the rain water for drinking ,and this holds true for most places ,so we use it for irrigation.The rain water from a gutter runs via a filter into a tank.

In Europe in my parents house ,when i was young ,we had a rain barrel,where the water from the gutter ended up .

this was usual in those days ,but i have seen few in modern times.

We can use this concept also in other ways ,

for example the roof water from the rain,via a ditch can run trough the chicken house ,cleaning it and end up fertilizing the vegetable plot

(this is called the creation of energy flow).

This water used to be Ok in times gone by before Air pollution ,

Today i would recommend it only for washing and irrigation

For more information on Water Harvesting

read The Permaculture designers manual by Bill Mollison,which cost about 40 dollars.

and is the best all round book you can get,on Environmental design,.(tagiari publishing, [e-mail])

Answer 5

If anything it would be increasing due to the fuels we are burning. It produces CO2 and water vapor.

Answer 6

Of all the water in the world there is about .003% available for use for humans.  With that small amount of water, most of of it comes from the groundwater resources.  The groundwater has a natural cycle of replenishing itself.  But humans are withdrawing the water faster than it is replenishing itself.  In many cases the groundwater is holding the land up and when it is being depleted land literally sinks, as is the case of Mexico City.  As for streams and rivers, they clean themselves naturally of pollutants.  But humans throw so many pollutants into running water that it makes it virtually impossible for the water to natually clean and replenish itself.  Lakes have a much more difficult time filtering itself of pollutants,so once it a lake is polluted, it is near impossible for it to clean itself.  Also a lot of landfills filled with biohazardous materials are leaking into the ground and polluting the groundwater where we get most of the water we use.  There are some solutions such as desalinization that turns salt water into clean fresh water, but that only does a little water at a time certainly not enough to sustain the world and it takes a lot of energy and the we have no where to put the solid salt after the desalinization process takes place because if we throw away the salt in some landfill, then that will penetrate the earth and salinize what fresh water we have left in our groundwater stores.  We are wasting water and needlessly too.  (An average African uses about 1.5 gallons a day... that is about the same amount of water it takes to flush a toilet.)

Answer 7

the deforestation is the maojr cause for the imbalance of the water cycle

also the over exploitation of the underground water resources is another major factor

the pollution too has adverse effects on watercycle

the pure water vapour is getting converted into acid rain in some places

Answer 8

Humans have managed to increase areas of drought and erosion.

I think they have increased ocean heat and total rain as well.

More and more people seem to agree.

But there are holdouts, including some scientists.

People who truly understand the situation are ABLE to make ACCURATE predictions based upon their understanding.

Those who really do NOT understand, albeit they may claim to understand, are NOT able to make such ACCURATE predictions.

So, when you seen rivers cresting and floods overwhelming in the next few months, think about me and what I have said.

I also have a blog:

Nunitak's Weather Blog

http://360.yahoo.com/ki_te_moana

Pls note the accurate prediction of 2007--2008 Heavy Winter Snow, made well ahead of time.  See the Tag Cloud, down the left margin in the blog.  You will also find other predictions in there...

Not only about the Weather, as a true understanding is good for many other topics.