In this video, I have clearly shown the steps required to calculate SPEI and SPI indices using SPEI package in RStudio. #pleasesubscribe #sharingiscaring
Hello Mr. Fitsum, your videos are very useful! I would like to ask you,could you make video about statistical downscaling in R (package ClimDown) and how to prepare data for such kind of analysis in different format (netcdf and so on). Thank you in advance!!!
Hello Mr. Fitsum, i love your videos they are very useful! I would like to ask you, how can i plot my SPI results, in this video you made it to the SPEI. i would aprecciate if you can help me, greetings from Colombia.
Hallo Fitsum, in your example, it only shows for one latitude point. But in real sense, you will be having multiple altitudes. How do you compute this given varying altitudes?
Thank you very much for the video, it was extremely helpful. I have a question regarding computing SPEI when dealing with multiple locations. Appreciate if you could provide some guidance on how to do this.
Hello Fitsum how are you? I am working on preparing SPEI map for multiple stations using R studio, provided that I have monthly precipitation, minimum and maximum temperature for 500 Geographic coordinates?
Hello sir. I have plotted the SPI graph using plot(spi(ts(data$prcp, frequency = 12, start = c(1957,1)), scale = 1)) to get years on the time axis of the graph. But I noticed that there are also some grey lines in between the blue and red lines. Are these grey lines normal? Also, I have obtained 1-month SPI values which are exactly equal to zero for about 10 months in the same year and this has happened in multiple years. I wanted to ask if this is possible? Thank you.
hellos sir. I want to ask you some questions, how do yo know the value of gamma, beta and alpha for the SPEI calculation? Is the values for the gamma, alpha and beta is the same with SPI? Did you set up the value of gamma, alpha and beta manually in the R studio. Thank you in advance sir
hello! Sir, thank you for the video! But I have a question when i calculated SPEI, i got a -inf instead of results only for 1 year. I ve checked datasheet, and there everything is OK. Why have i gotten -inf? tnx
Thank you so much! I am curious If it is possible to calculate SPI and SPEI easily in raster format. Please, could you share If you know some tools/softwares for that?
@@danielcantor6166 Thank you for your reply. Could you please explain what should I do with dplyr? Maybe you have some manuals. My mail is zhanassyl.kz@gmail.com
Fistum its really good jobs; perhaps I learn most from you. I really appreciate if you are able to convert time scale from (5, 10,15,20,25) to for an example (1981,1982,..., )so we can clearly identify which year is drought and which year is not, otherwise its little difficult to interpret the results from the graph
For a video example: To plot a graph for SPEI-1 type the following command, Plot(spei(ts(Addis$CWBAL,freq=12,start=c(1985,1)),1,ref.start=c(1985,1),ref.end=c(2017,1))) "ts" is time series "Addis" is station name "CWBAL" is climatic water balance (Addis$PRCP-Addis$PET) "freq" is frequency which is twelve months
@@NEXTLevelGISRSfitsalem, i have been able to plot all my scales 1,3,6 and 12 months, but when i tried plotting using this command to put the numbers in years.. by typing this command Plot(spei(ts(standp$CWBAL,freq=12,start=c(1982,1)),1,ref.start=c(1982,1),ref.end=c(2018,1))) the error message is Error in Plot(spei(ts(standp$CWBAL, freq = 12, start = c(1982, 1)), 1, : could not find function "Plot" i pray you respond
Hello sir. Thank you for your video. Can I ask if I need to calculate the SPI so my data only consist of the precipitation data. And i uploaded the data set, the spi (file name$PRCP,3) but the outcome is NA. Anyone can help me? Thank you in advance! :)
Hi In the results, the number appears large, such as -9.869182e-01 How do I get rid of this round(spei3_tho,digits=4) Error in round(spei3_tho, digits = 4) : non-numeric argument to mathematical function
E+01 means moving the decimal point one digit to the right, E+00 means leaving the decimal point where it is, and E-01 means moving the decimal point one digit to the left. Example: 1.00E+01 is 10, 1.33E+00 stays at 1.33, and 1.33E-01 becomes 0.133.
Hi. I get this warning when I type the formula: [1] "Calculating the Standardized Precipitation Evapotranspiration Index (SPEI) at a time scale of 3. Using kernel type 'rectangular', with 0 shift. Fitting the data to a Gamma distribution. Using the ub-pwm parameter fitting method. Checking for missing values (`NA`): all the data must be complete. Using the whole time series as reference period. Input type is vector. No time information provided, assuming a monthly time series." Can you help me please? Thanks.
Nice Video. But How do I calculate SPI to get results for each year. This procedure gives results per month per year, but I want SPI per year NOT per month. What should I do?
@@NEXTLevelGISRSfitsalem Do you mean that since my hydrological year starts in October and ends in September the following year, I could extract the SPEI values for the month of September in each year to get the SPEI values at annual time scale? I want the final output to be like this: Year SPEI 1990 xx 1991 xx 1992 xx I have seen the SPI package in R gives the results in the above format, but the problem is that I cant use it since it does not calculate SPEI
@@NEXTLevelGISRSfitsalem Am asking about the time, is it possible to change years (as your data starts from 1985) to read from 1985 instead of the SPEI to read time in 5 years intarval (5,10,15)?
@@thavhanyedzahumbulani3931 Yes it is possible. For example if you want to plot SPEI-1 graph which starts from 1985 and ends in 2017, type like this: plot(spei(ts(name af your data$PRCP-name af your data$PET,freq=12,start=c(1985,1)),1,ref.start=c(1985,1),ref.end=c(2017,1)))
how to fix "Calculating reference evapotranspiration using the Hargreaves method. Using latitude (`lat`) to estimate extraterrestrial radiation. Checking for missing values (`NA`): all the data must be complete. Input type is vector. Assuming the data are monthly time series starting in January, all regular (non-leap) years."
Error in read.table(filename, header = TRUE) : 'file' must be a character string or connection I am getting this error. Can you please help me on this?
