How do floods and droughts form? and what causes them to form?

Question

I want to know how floods and droughts form and what causes them to form....please

Answer 1

if God is in control he should be shot for being the most incompetant god earth has ever had judging by his track record

that is 2 big questions
here is FLOODS

forrests act as sponges
they absorb 60% of all rainfall and the rest that flows over the ground is slowed down and filtered by the trees

the rest 40% is called thru fall and it is a different quality of water enriched with sugars and excrements of insects etc.

when the trees are removed the 100% of the rain flows quickly over the ground in to the streams and rivers picking up speed and arives down stream far to quickly.and far too much

this is the cause of most floods

in the past people also made straight cannals which have the same effect ,

rivers and streams are always winding throwing water against the absorbing banks ,in straight cannals too much water too fast arrives down stream also causing floods .

but draining of wetlands and deforestation with the subsequent farming ,have removed these natural safeguards.


WATER MANEGEMENT AND HARVESTING

Any given landscape tends to be convex shapes that guide the water floes into creases which becomes ravines and then streams and rivers

we must reverse the effect and build a series basins that absorb water intead of repelling the water and draining the lands ,so that the whole place becomes like a sponge

Making terrazes is part (slightly concave )is part of this concept

the best long term safe guards,are as many dams as posible in a catch ment area most of the dams to be porrous ,so that the water is redirected into the ground instead of over it .
this suplements surface aquifers and brings up ground water levels ,
the water still reaches the rivers ,but much slower and for far longer (by many months)ensuring more constant river levels .

when all of the rain water is redirected into the ground before it reaches the rivers ,this is called zero run off ,and the whole concept is called water harvesting

large blocking dams in catchment areas are very bad they always end up full of silt ,they interupt natural ecosystems and fish movements ,and change the country side ,somebody always being the looser and big companies profit by the power they provide

the numerous small dams like,saddle dams ,(between mountainpeaks),horseshoedams (mountain slopes)and turkey nest dams(on the straights),are the only reasonable ,eco friendly and water efficicient solutions in the big picture in the end .

more ways are to build contour swales that absorb water and accomodate excess ground flow in huge rainfalls


DESERTIFICATION

Many of the Desserts on this planet result from human intervention.
the Building of the Spanish Armada deforrested Spain
the Phoenician trading fleet turned Lebanon in a dessert
Ghenges Khan put everything to the sword and torch, then filled the wells with sand,
the sun finished of the job and whole countries turned to wastelands.
He would have been envious of the effects of modern day farming.

Slash and burn destroys the protective vegetation (which helps to form the soil ),
leaving it open to the Sun ,and then ,wind and, water erosion.
The Plough turns the soil ,killing micro-biotic life (essential to soil building) and accelerates the drying out .
Pressures of the :vehicles, cattle and rain impact brings the salt to the surface.

Mono cultures ,aided by chemicals Exhaust and pollutes the soil .
Adding to this the effects of overgrazing has resulted in large scale desertification.

Each year billions of tons of topsoil are blown or washed away by storms.
Arable lands and their farms are lost all over the globe. Many farmers sons abandon farming and head for the cities.

Northern China is drying up, what once were millions of food producing people,
are now hungry refugees ,running for their lives from the all consuming dust storms.

some solutions

SOIL PRESERVATION

the first concept to prevent desertification is always to conserve the trees and to maintain moisture ,which can be enhanced by waterharvesting ,

which simply means to catch and retain any rain fall that happens in that place by building as many dams as is possible, and so efectively turn the place into a sponge .

the water will not always be visible ,but all the same is absorbed by the ground ,and is now moving at a much slower speed ,sometimes taking months to leave the area before it ends up in subteranean water deposits or helps feed the streems and rivers , meantime your trees have been using it.

a tree builds its own soil ,in its life time,by the leaves it discards ,--we improve on that by mulching

MULCH
cut down the weeds before they produce seeds and leave them where they fall,they will cover the ground and put even more organic matter on top,you can use saw dust,leaves green or dry,and when you plant make a little space and plant in the mulch.

this is the easiest quickest and by far most benificial way(for the quality of your soil)to prepare the land for planting

what you do is to cover the ground with mulch which is the same principal as compost but it includes the whole garden surface
the top part of the soil where the topsoil is being produced houses a world or microbiotic life.

Mulch is organic material green or dry that covers the ground,the thicker the better the composting process will turn it in to black topsoil
an exelent mulch is forgotten or old bales of whatever ,straw or hay or alphalfa

the humidity is preserved underneath and promotes the devellopment of worms(their exists no better compost than their excrements)and a variety of micro biotic life which together with 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 surfave if on unprotected land

Mulch also prevents the soil from drying out because of the sun and, lay it open to wind erosian.

do not use chemicals because the water will wash them into the ground and if enough people did that, you would be guilty of helping to contaminate subteranean water suplies that other people could be pumping up to drink

to find out more about Water harvesting and soil manegement I recommend:
the designers manual by Bil Mollison,which cost about 40 dollars.tagiari publishing, [e-mail])

some other writers that are on the internet are
david Holmgren
Larry Santoyo
Kirk Hanson

Masanobu Fukuaka has written ,
One-Straw Revolution
The Road Back to Nature
The Natural Way of Farming
http://www.context.org/iclib/ic14/fukuok...
http://en.wikipedia.org/wiki/masanobu_fu...

Simon Henderson
and Bill Molisson.

a representitive of the concept in USA is
Dan Hemenway at [e-mail]
[e-mail]
http://barkingfrogspc.tripod.com/frames....
http://csf.colorado.edu/perma/ypc_catalo... Source(s) i am a Permaculture Consultant for the department of Ecology for the regional government in Guerrero Mexico
http://spaces.msn.com/byderule

Answer 2

It is not under the control of man. GOD is in control.