There is no minimum number of stations required for MK and SS analysis. You're going to end up doing the analysis per station. When you're done, you combine your results for the different stations for easy visualisation and comparison.

I have a paper where I applied these tests on my profile, perhaps you want to read it. I used a software I got from one Fitsum YouTube tutorial. It was helpful. You can search YouTube too for assistance.

Dear Dr. Isaac Oluwatimilehin

Really thank you for your nice and valuable explanations!!!

Therefore, we can do Trend Analysis for a specific location, and also Variability Analysis too.

But, my worry is:

are the Trend and Variability analysis we are doing

a ) for the changes of climatic elements of that specific location, or

b) to compare variability and differences among locations?

c) what are we comparing? different locations or what?

• Then, what do the trend and var. indices, e.g. CV, sta. dev, etc. tell us?
• Could you please send me your paper? I want to read it.

STAY BLESSED!!!

Alem

Dear Alem,

Principally I agree with Isaac. Generally speaking, the number of separate time series (i.e. number of stations) has nothing to do with the applicability of the MK test and Theil-Sen slope estimator. It could influence, eventually, the spatial representativeness of the obtained results. See the following two articles for the

application of both methods for meteorological purposes:

Chervenkov, H., Slavov, K. (2017) Theil-Sen Estimator for the Parameters of the Generalized Extreme Value Distributions: Demonstration for Meteorological Applications, Compt. rend. Acad. bulg. Sci., Vol. 70, No 12 pp. 1701-17010

(available in RG in public full-text)

and this with:

DOI: 10.2478/cait-2020-0069

Regards: Hristo

Dear Hristo Chervenkov , thank you so much for your response and for sharing valuable references.!

But, maybe due to the fact that I am still going deep into the subject matter, the following are not clear for me.

1) Do we just do the climate analysis for a location (using 30 years of data) then say there is variability overtime or not? Then, it is only TEMPORAL ANALYSIS

2) Or, do we compare the climate changes of different locations and say there is high/low variability for location 'a' than 'b' or 'c' etc.? Then, it is only SPATIO ANALYSIS

3) then, what do we want to do with a title saying "the Spatio-temporal analysis of

climate variables?

So, according to Dr. Hristo Chervenkov (as stated above), MKT and SST estimators work for only time-series data. Is that?

Thank you for your understanding!!

Alem

It depends upon the size of your study area. How big is your area?

Technically, it doesn't matter the number of stations to use in MK, but coverage of the gauge network and length of record will have an impact on the physical meaning of your result.

Dear Dr. Tesfay Gebretsadkan G., so nice to hear from you!!! And how r u?

Thank you for your valuable suggestion.

I have 30 years of climate data. I want to do both spatial variability and temporal trend. My worry was on the spatial variability with five locations (if it is feasible or not).

Ok. I'll get back to you for further clarifications.

Stay Blessed!!!

Alem

check your inbox

Dear Emnet Negash, thank you so much for sharing such a valuable reference.

STAY BLESSED!!

Alem

I also agree with the comments above. There is need to test for first order autocorrelation (AR(1)) before applying the Mann-Kendall test. Use the Modified Mann-Kendall.

Dear Dr. Charles Bwalya Chisanga really thank you for your important suggestion.

Also nice to hear from you. I've read most of your interesting and valuable modelling research papers, MSc, PhD!!!

STAY BLESSED!!!

Alem

Dear Alem Redda,

MK and SST analysis doesn't depend upon number of stations that you are taking, only depend upon how many years you are considering. For example, if you have 30 years data from one station then you are free to use MK and SST analysis to find out the trend and variability of the meteorological parameters, but more years data may give you more precise result. Although, one station data only show you variability over a small area not for whole region. So, if your looking for whole region then you have to consider several number of stations.

Dear Dr.Saurabh Verma Saurabh Verma

Really thank you for your clear and concise suggestions.

You made me feel nice. For the TEMPORAL (time) trend analysis of rainfall, what you said is alright.

But, what if we are to deal with SPATIAL (location) analysis? I mean, if we are to compare variability among locations, how many locations should we have at least?

Thank U for understanding my concern.

STAY BLESSED!!!

Alem

Dear Alem,

If you want to compare variability over the locations then you should have at least two locations with several years of data (more than 20 years).

Dear Dr. Saurabh Verma

Thank you so much!! I was desperately in need of this answer.

Therefore,

• for SPATIAL (variability over the locations) analysis, at least 2 locations with min. of 20 years of climate data.
• for TEMPORAL ana., at least 30 years of climate data.

Sir., if you have any references (for the variability over the locations), would you please share them with us!!

Wish you all the best this life can deliver, today and always!

Alem

Dear Alem,

I think these papers would help you significantly:

Article Influence of climate variability on land degradation (desert...

Article Climate Variability Impact on the Spatiotemporal Characteris...

Article Analysis of Rainfall Trends and Its Relationship with SST Si...

Regards,

Saurabh

Yes proceed this is okey especially if stations are multi locations

Dear Dr. Saurabh Verma, thank U for ur valuable docs. Well noted!!!