Which of the following human activities can increase the risks of flooding?

Deforestation and Cultivation

Explanation:

First I am going to give the definition of deforestation:

Deforestation is basically the removal of trees.

The removal of trees leaves leaves very little vegetative cover to hold heavy rain fall. This is why mudslides and things happen. When the land is clear and flat, the water keeps on going instead of going into the soil. That water that keeps on going is called runoff water. If we planted trees by the rivers, that could take down the height of the floods in towns by 20%

At first I was going to say widening rivers, but that is a way to manage river water. When we lengthen the river, it is so that the water can take more time to reach the river canal.

Definition of Cultivation: The production of food by preparing the land to grow crops (especially on a large scale) animal husbandry - breeding and caring for farm animals. agriculture, tree farming - the cultivation of tree for the production of timber.

I was also going to say Cultivation. Over-cultivation is the excessive use of farmland to the point where productivity falls due to soil exhaustion or land degradation. Now this is actually why we have floods in the USA. The soil cannot soak up any water, therefore the water over flows and that is when a flood starts to happen.

I know this took some time but hope I could help :)

the answer is

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-