A hazard is any source of potential damage, harm or adverse health effects on something or someone under certain conditions. However, hazard is not the actual harm, it has the potential to harm.

Risk is the chance or probability that a person will be harmed or experience an adverse health effect if exposed to a hazard.

For example, there is a well in my garden which is polluted and full of bacteria. There is no risk to me if I don’t drink it. If I drink it then my vulnerability ( the immune system) plays is role if my constitution is strong or week.

For your question you need to calculate the exposure to that hazard which is the probability of me drinking the contaminated water from the well in my garden. Then you need to multiply this the probable level of bacteria and if that level is large enough to cause harm. The level of bacteria which could cause harm depends on the vulnerability. For instance an old person is more vulnerable than a young one.

First determine, the probability of the hazard you have in mine to cause harm. After than you can determine the conditional probability of harm, which risk.

If the word danger refers to threat, the equation that relates the threat, risk and vulnerability is:

R = T * V

-R = risk index

-T = threat index

-V = vulnerability index

Therefore, if the vulnerability is very low, the risk will be very low (if the vulnerability or threat is 0 the risk will be 0). If the vulnerability or threat is high, the risk is also high. If the vulnerability is low, and the threat is high or vice versa, the risk will be high or low depending on what values have the threat and vulnerability.

The equation of the disaster is: 

Disaster = threat * vulnerability / social preparation

 Dear Mr. Sirous Yasseri,

thanks a lot!

 Dear Mr. Daniel Tecles,

thanks a lot!

When we discuss this terms related to landslides, susceptibility to sliding depends mainly on the natural prerequisites that can lead to sliding. So the level for  vulnerability and hazards are connected, while risks are dependet on the exposure of materials goods and human lives to sliding influences.

 Here is a summary Power Point on the risk as a multidisciplinary space problem or on the data used for the analysis of risk, among other requirements. That will help you understand the mathematical model formulated above. The text is in Spanish. I hope you will be useful.

https://www.itc.nl/external/unesco-rapca/Presentaciones%20Powerpoint/03%20Introduccion%20Amenaza%20Vulnerabilidad%20y%20Riesgo/Introduccion%20Amenaza%20Vulnerabilidad%20y%20Riesgo.pdf

Dear Professor Bashkim Mal Lushaj 

You asked: What is the ratio between hazard and risk when the vulnerability is at very low,low levels, medium and high?

Vulnerability is what makes a hazed risky. When Vulnerability is near zero so is the risk. When the Vulnerability is near one, risk is the probability of that hazard to occur. 

We must consider the trio of hazard, vulnerability and likelihood. 

Do you agree with me?

Dear Dr. Sirous Yasseri,

Yes, I asked: What is the ratio between hazard and risk when the vulnerability is at very low,low levels, medium and high? Your answer was: "Vulnerability is what makes a hazed risky. When Vulnerability is near zero so is the risk. When the Vulnerability is near one, risk is the probability of that hazard to occur". 

Yes, we must consider the trio of hazard, vulnerability and likelihood. 

You asked me: "Do you agree with me"? My answer, yes, I agree you. Thanks a lot for your opinions given to us, as a working group!

 Dear Dr. Sirous Yasseri,

I have worked for risks some times before with a project, and concretely with theme: "Training and workshops on: “Risk Management on projects of the concessions and public private partnership in Albania”, in ResearchGate is shown in Albanian language, you can see it. In near furture I will translate it in English language, and I promise you that I will send to you before to publish it. Thanks a lot again!

 Dear colleague, Mr. Daniel Tecles,

it is my pleasure to thank you very much for your very nice work sent to us!

Have a nice weekend!

Sincerely, by our group

Prof. Dr. Bashkim Mal Lushaj

I look forward seeing you publication in English. 

The only things which I have read (in translations) are  writings of  ismail kadare as well as one of your papers. 

Dear Dr. Sirous Yasseri,

Today I received one of the most attractive messages as Albanian intellectual during my career from you, dear Dr. Sirous Yasseri, and concretely: "I look forward to seeing you publication in English. The only things Which I have read (in translations) are writings of Ismail Kadare as well as one of your papers". I thank you very much big big respect given to me, when you have read the writings of our Great Albanian Writer, Mr. Ismail Kadare!

I thank you very much again!

Yes, in near future my works will be in English language.

Have a nice weekend! Sincerely,

Dear Dr. Sirous Yasseri, Dr. Milorad Jovanovski Mr. Daniel Tecles,

thanks a lot again!

Have a nice weekend! Sincerely, 

Hi,

I do often follow the equation mentioned by Daniel (R = T * V) in my works. Bu I always have considered that it is not useful when one of the two terms is extremely high, especially V. For example: acoording to some works, the probabilty of Antarctica ice melting is lower than 1%.

But if we put that value in the equation, cities like NY or London, or complete countries would be totally covered by water. So are we commiting a mistake when we are not facing that rare hazard, or is there a problem in the concept o risk when vulnerability values are extremely high?