How to produce rainfall maps

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How to produce rainfall maps

Stefano Sofia
Dear R users,
I need to produce rainfall maps using R.
I know that this is possible, I looked though the web, I found the example below reported (the author is Andrew Tredennick).
I would ask you if this is the most performing way to make rainfall maps; if yes would someone be able to give me an example of how file.asc and pointfile.csv should be? If no would somebody please show me another way providing a small example?

Thank you for your help
Stefano


library(raster)
library(ggplot2)

#open ASCII file using �raster� command, which converts the ASCII to a raster object
map <- raster(�/your/path/to/file.asc�)

#convert the raster to points for plotting
map.p <- rasterToPoints(map)

#Make the points a dataframe for ggplot
df <- data.frame(map.p)
#Make appropriate column headings
colnames(df) <- c(�Longitude�, �Latitude�, �MAP�)

#Call in point data, in this case a fake transect (csv file with lat and lon coordinates)
sites <- data.frame(read.csv(�/your/path/to/pointfile.csv�))

#Now make the map
ggplot(data=df, aes(y=Latitude, x=Longitude)) +
geom_raster(aes(fill=MAP)) +
geom_point(data=sites, aes(x=x, y=y), color=�white�, size=3, shape=4) +
theme_bw() +
coord_equal() +
scale_fill_gradient(�MAP (mm/yr)�, limits=c(0,2500)) +
theme(axis.title.x = element_text(size=16),
axis.title.y = element_text(size=16, angle=90),
axis.text.x = element_text(size=14),
axis.text.y = element_text(size=14),
panel.grid.major = element_blank(),
panel.grid.minor = element_blank(),
legend.position = �right�,
legend.key = element_blank()
)



         (oo)
--oOO--( )--OOo----------------
Stefano Sofia PhD
Area Meteorologica e  Area nivologica - Centro Funzionale
Servizio Protezione Civile - Regione Marche
Via del Colle Ameno 5
60126 Torrette di Ancona, Ancona
Uff: 071 806 7743
E-mail: [hidden email]
---Oo---------oO----------------

________________________________

AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu� contenere informazioni confidenziali, pertanto � destinato solo a persone autorizzate alla ricezione. I messaggi di posta elettronica per i client di Regione Marche possono contenere informazioni confidenziali e con privilegi legali. Se non si � il destinatario specificato, non leggere, copiare, inoltrare o archiviare questo messaggio. Se si � ricevuto questo messaggio per errore, inoltrarlo al mittente ed eliminarlo completamente dal sistema del proprio computer. Ai sensi dell�art. 6 della DGR n. 1394/2008 si segnala che, in caso di necessit� ed urgenza, la risposta al presente messaggio di posta elettronica pu� essere visionata da persone estranee al destinatario.
IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of Regione Marche may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system.

        [[alternative HTML version deleted]]


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Re: How to produce rainfall maps

Sarah Goslee
Hi,

You might get more help from the R-sig-geo list, which is devoted to
spatial topics.

However.

The *.asc file is an ArcGIS raster export format. You should use
whatever the appropriate import commands are for your own gridded
rainfall data. If you have a different format, you might or might not
be able to import it directly with raster.

?raster will tell you more about the kinds of formats that function
can handle importing.

I'm not sure what the intent of converting a raster to point data
actually is; if you have point data, then import it as point data. If
you have gridded data, then map it as gridded data. But if it makes
sense to you, then go for it.

The comments in your code sample explain what the CSV file should be:
coordinates of the points to be mapped.

I'm not even certain from your question what your objective is.

What kind of rainfall data are you starting with?
What kind of maps do you want to produce?

Sarah



On Fri, Nov 17, 2017 at 3:40 AM, Stefano Sofia
<[hidden email]> wrote:

> Dear R users,
> I need to produce rainfall maps using R.
> I know that this is possible, I looked though the web, I found the example below reported (the author is Andrew Tredennick).
> I would ask you if this is the most performing way to make rainfall maps; if yes would someone be able to give me an example of how file.asc and pointfile.csv should be? If no would somebody please show me another way providing a small example?
>
> Thank you for your help
> Stefano
>
>
> library(raster)
> library(ggplot2)
>
> #open ASCII file using ‘raster’ command, which converts the ASCII to a raster object
> map <- raster(“/your/path/to/file.asc”)
>
> #convert the raster to points for plotting
> map.p <- rasterToPoints(map)
>
> #Make the points a dataframe for ggplot
> df <- data.frame(map.p)
> #Make appropriate column headings
> colnames(df) <- c(“Longitude”, “Latitude”, “MAP”)
>
> #Call in point data, in this case a fake transect (csv file with lat and lon coordinates)
> sites <- data.frame(read.csv(“/your/path/to/pointfile.csv”))
>
> #Now make the map
> ggplot(data=df, aes(y=Latitude, x=Longitude)) +
> geom_raster(aes(fill=MAP)) +
> geom_point(data=sites, aes(x=x, y=y), color=”white”, size=3, shape=4) +
> theme_bw() +
> coord_equal() +
> scale_fill_gradient(“MAP (mm/yr)”, limits=c(0,2500)) +
> theme(axis.title.x = element_text(size=16),
> axis.title.y = element_text(size=16, angle=90),
> axis.text.x = element_text(size=14),
> axis.text.y = element_text(size=14),
> panel.grid.major = element_blank(),
> panel.grid.minor = element_blank(),
> legend.position = “right”,
> legend.key = element_blank()
> )
>
>
>
>          (oo)
> --oOO--( )--OOo----------------
> Stefano Sofia PhD
> Area Meteorologica e  Area nivologica - Centro Funzionale
> Servizio Protezione Civile - Regione Marche
> Via del Colle Ameno 5
> 60126 Torrette di Ancona, Ancona
> Uff: 071 806 7743
> E-mail: [hidden email]
> ---Oo---------oO----------------
>


--
Sarah Goslee
http://www.functionaldiversity.org

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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Re: How to produce rainfall maps

Michael Sumner-2
Fwiw the engine behind geom_raster needs explicit observation-per-row form
for input (with no structural normalization), so conversion to points is
perfectly proper here,  albeit confusing in context. (It's closer to what
graphics devices actually use ultimately, but the expansion is laid out
very early in ggplot2 because there's no standard for intermediate forms.)

Cheers, Mike

On Wed, 22 Nov 2017, 07:12 Sarah Goslee, <[hidden email]> wrote:

> Hi,
>
> You might get more help from the R-sig-geo list, which is devoted to
> spatial topics.
>
> However.
>
> The *.asc file is an ArcGIS raster export format. You should use
> whatever the appropriate import commands are for your own gridded
> rainfall data. If you have a different format, you might or might not
> be able to import it directly with raster.
>
> ?raster will tell you more about the kinds of formats that function
> can handle importing.
>
> I'm not sure what the intent of converting a raster to point data
> actually is; if you have point data, then import it as point data. If
> you have gridded data, then map it as gridded data. But if it makes
> sense to you, then go for it.
>
> The comments in your code sample explain what the CSV file should be:
> coordinates of the points to be mapped.
>
> I'm not even certain from your question what your objective is.
>
> What kind of rainfall data are you starting with?
> What kind of maps do you want to produce?
>
> Sarah
>
>
>
> On Fri, Nov 17, 2017 at 3:40 AM, Stefano Sofia
> <[hidden email]> wrote:
> > Dear R users,
> > I need to produce rainfall maps using R.
> > I know that this is possible, I looked though the web, I found the
> example below reported (the author is Andrew Tredennick).
> > I would ask you if this is the most performing way to make rainfall
> maps; if yes would someone be able to give me an example of how file.asc
> and pointfile.csv should be? If no would somebody please show me another
> way providing a small example?
> >
> > Thank you for your help
> > Stefano
> >
> >
> > library(raster)
> > library(ggplot2)
> >
> > #open ASCII file using ‘raster’ command, which converts the ASCII to a
> raster object
> > map <- raster(“/your/path/to/file.asc”)
> >
> > #convert the raster to points for plotting
> > map.p <- rasterToPoints(map)
> >
> > #Make the points a dataframe for ggplot
> > df <- data.frame(map.p)
> > #Make appropriate column headings
> > colnames(df) <- c(“Longitude”, “Latitude”, “MAP”)
> >
> > #Call in point data, in this case a fake transect (csv file with lat and
> lon coordinates)
> > sites <- data.frame(read.csv(“/your/path/to/pointfile.csv”))
> >
> > #Now make the map
> > ggplot(data=df, aes(y=Latitude, x=Longitude)) +
> > geom_raster(aes(fill=MAP)) +
> > geom_point(data=sites, aes(x=x, y=y), color=”white”, size=3, shape=4) +
> > theme_bw() +
> > coord_equal() +
> > scale_fill_gradient(“MAP (mm/yr)”, limits=c(0,2500)) +
> > theme(axis.title.x = element_text(size=16),
> > axis.title.y = element_text(size=16, angle=90),
> > axis.text.x = element_text(size=14),
> > axis.text.y = element_text(size=14),
> > panel.grid.major = element_blank(),
> > panel.grid.minor = element_blank(),
> > legend.position = “right”,
> > legend.key = element_blank()
> > )
> >
> >
> >
> >          (oo)
> > --oOO--( )--OOo----------------
> > Stefano Sofia PhD
> > Area Meteorologica e  Area nivologica - Centro Funzionale
> > Servizio Protezione Civile - Regione Marche
> > Via del Colle Ameno 5
> > 60126 Torrette di Ancona, Ancona
> > Uff: 071 806 7743
> > E-mail: [hidden email]
> > ---Oo---------oO----------------
> >
>
>
> --
> Sarah Goslee
> http://www.functionaldiversity.org
>
> ______________________________________________
> [hidden email] mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

--
Dr. Michael Sumner
Software and Database Engineer
Australian Antarctic Division
203 Channel Highway
Kingston Tasmania 7050 Australia

        [[alternative HTML version deleted]]

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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Re: How to produce rainfall maps

Stefano Sofia
Thank you Sarah and Mike for your explanations.
My final objective is to produce maps (png image or any kind of extension I can import in LaTeX) where rainfall data are interpolated, using the Inverse Distance method or Kriging.
My input file (pointfile.csv in the reported example) reports the station code, lat and long of the meteorological station and the rainfall value (which might be the cumulate of a week or ten days or the period I need to investigate). Here a small example:

Station_Code, Init_Year, Init_Month, Init_Day, Init_Hour, Init_Minute, Fin_Year, Fin_Month, Fin_Day, Fin_Hour, Fin_Minute, Rainfall_Cumulate, Long, Lat
1056,  2017 , 11 , 1 , 0 , 0 ,  2017 , 11 , 11 , 0 , 0 ,  28.40, 12.786904,  43.851849
1064,  2017 , 11 , 1 , 0 , 0 ,  2017 , 11 , 11 , 0 , 0 ,  27.20, 12.967556,  43.762669
1072,  2017 , 11 , 1 , 0 , 0 ,  2017 , 11 , 11 , 0 , 0 ,  21.80, 12.897710,  43.907555

As far as I can understand (as you can see, I am not an expert on GIS or any spatial topic)
- my input file pointfile.csv is in "observation-per-row form";
- I need a grid (file.asc) where I can interpolate my rainfall data (I can get it, a resolution of 1km will be enough for me)
- ggplot should produce the map I need; but where are the options for the interpolation method?

Again, any help will be appreciated.
Stefano

         (oo)
--oOO--( )--OOo----------------
Stefano Sofia PhD
Area Meteorologica e  Area Nivologica - Centro Funzionale
Servizio Protezione Civile - Regione Marche
Via del Colle Ameno 5
60126 Torrette di Ancona, Ancona
Uff: 071 806 7743
E-mail: [hidden email]
---Oo---------oO----------------
________________________________
Da: Michael Sumner [[hidden email]]
Inviato: mercoled� 22 novembre 2017 10.48
A: Sarah Goslee
Cc: Stefano Sofia; [hidden email]
Oggetto: Re: [R] How to produce rainfall maps


Fwiw the engine behind geom_raster needs explicit observation-per-row form for input (with no structural normalization), so conversion to points is perfectly proper here,  albeit confusing in context. (It's closer to what graphics devices actually use ultimately, but the expansion is laid out very early in ggplot2 because there's no standard for intermediate forms.)

Cheers, Mike

On Wed, 22 Nov 2017, 07:12 Sarah Goslee, <[hidden email]<mailto:[hidden email]>> wrote:
Hi,

You might get more help from the R-sig-geo list, which is devoted to
spatial topics.

However.

The *.asc file is an ArcGIS raster export format. You should use
whatever the appropriate import commands are for your own gridded
rainfall data. If you have a different format, you might or might not
be able to import it directly with raster.

?raster will tell you more about the kinds of formats that function
can handle importing.

I'm not sure what the intent of converting a raster to point data
actually is; if you have point data, then import it as point data. If
you have gridded data, then map it as gridded data. But if it makes
sense to you, then go for it.

The comments in your code sample explain what the CSV file should be:
coordinates of the points to be mapped.

I'm not even certain from your question what your objective is.

What kind of rainfall data are you starting with?
What kind of maps do you want to produce?

Sarah



On Fri, Nov 17, 2017 at 3:40 AM, Stefano Sofia
<[hidden email]<mailto:[hidden email]>> wrote:

> Dear R users,
> I need to produce rainfall maps using R.
> I know that this is possible, I looked though the web, I found the example below reported (the author is Andrew Tredennick).
> I would ask you if this is the most performing way to make rainfall maps; if yes would someone be able to give me an example of how file.asc and pointfile.csv should be? If no would somebody please show me another way providing a small example?
>
> Thank you for your help
> Stefano
>
>
> library(raster)
> library(ggplot2)
>
> #open ASCII file using �raster� command, which converts the ASCII to a raster object
> map <- raster(�/your/path/to/file.asc�)
>
> #convert the raster to points for plotting
> map.p <- rasterToPoints(map)
>
> #Make the points a dataframe for ggplot
> df <- data.frame(map.p)
> #Make appropriate column headings
> colnames(df) <- c(�Longitude�, �Latitude�, �MAP�)
>
> #Call in point data, in this case a fake transect (csv file with lat and lon coordinates)
> sites <- data.frame(read.csv(�/your/path/to/pointfile.csv�))
>
> #Now make the map
> ggplot(data=df, aes(y=Latitude, x=Longitude)) +
> geom_raster(aes(fill=MAP)) +
> geom_point(data=sites, aes(x=x, y=y), color=�white�, size=3, shape=4) +
> theme_bw() +
> coord_equal() +
> scale_fill_gradient(�MAP (mm/yr)�, limits=c(0,2500)) +
> theme(axis.title.x = element_text(size=16),
> axis.title.y = element_text(size=16, angle=90),
> axis.text.x = element_text(size=14),
> axis.text.y = element_text(size=14),
> panel.grid.major = element_blank(),
> panel.grid.minor = element_blank(),
> legend.position = �right�,
> legend.key = element_blank()
> )
>
>
>
>          (oo)
> --oOO--( )--OOo----------------
> Stefano Sofia PhD
> Area Meteorologica e  Area nivologica - Centro Funzionale
> Servizio Protezione Civile - Regione Marche
> Via del Colle Ameno 5
> 60126 Torrette di Ancona, Ancona
> Uff: 071 806 7743
> E-mail: [hidden email]<mailto:[hidden email]>
> ---Oo---------oO----------------
>

--
Sarah Goslee
http://www.functionaldiversity.org

______________________________________________
[hidden email]<mailto:[hidden email]> mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Dr. Michael Sumner
Software and Database Engineer
Australian Antarctic Division
203 Channel Highway
Kingston Tasmania 7050 Australia


________________________________

AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu� contenere informazioni confidenziali, pertanto � destinato solo a persone autorizzate alla ricezione. I messaggi di posta elettronica per i client di Regione Marche possono contenere informazioni confidenziali e con privilegi legali. Se non si � il destinatario specificato, non leggere, copiare, inoltrare o archiviare questo messaggio. Se si � ricevuto questo messaggio per errore, inoltrarlo al mittente ed eliminarlo completamente dal sistema del proprio computer. Ai sensi dell�art. 6 della DGR n. 1394/2008 si segnala che, in caso di necessit� ed urgenza, la risposta al presente messaggio di posta elettronica pu� essere visionata da persone estranee al destinatario.
IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of Regione Marche may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system.

        [[alternative HTML version deleted]]


______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
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Re: How to produce rainfall maps

Micha Silver-2
Hi

On 11/23/2017 10:04 AM, Stefano Sofia wrote:

> Thank you Sarah and Mike for your explanations. My final objective is
> to produce maps (png image or any kind of extension I can import in
> LaTeX) where rainfall data are interpolated, using the Inverse
> Distance method or Kriging. My input file (pointfile.csv in the
> reported example) reports the station code, lat and long of the
> meteorological station and the rainfall value (which might be the
> cumulate of a week or ten days or the period I need to investigate).
> Here a small example: Station_Code, Init_Year, Init_Month, Init_Day,
> Init_Hour, Init_Minute, Fin_Year, Fin_Month, Fin_Day, Fin_Hour,
> Fin_Minute, Rainfall_Cumulate, Long, Lat 1056, 2017 , 11 , 1 , 0 , 0 ,
> 2017 , 11 , 11 , 0 , 0 , 28.40, 12.786904, 43.851849 1064, 2017 , 11 ,
> 1 , 0 , 0 , 2017 , 11 , 11 , 0 , 0 , 27.20, 12.967556, 43.762669 1072,
> 2017 , 11 , 1 , 0 , 0 , 2017 , 11 , 11 , 0 , 0 , 21.80, 12.897710,
> 43.907555 As far as I can understand (as you can see, I am not an
> expert on GIS or any spatial topic) - my input file pointfile.csv is
> in "observation-per-row form"; - I need a grid (file.asc) where I can
> interpolate my rainfall data (I can get it, a resolution of 1km will
> be enough for me)
If I understand, in order to interpolate point data to a grid, the steps
you need to do in R are:

 1. import the CSV of rain data and convert to a SpatialPointsDataFrame
 2. Convert that SPDF to a projected coordinate system, such as UTM, for
    kriging
 3. create an empty grid as the target for kriging, probably based on
    the extent of the rain data
 4. Run kriging using the point rain data and target grid

Here's a basic workflow for the above

#-----------------------------------

# Required libraries

library(gstat)
library(automap)
library(rgdal)

# Read in CSV file and convert to SPDF
rain_data <- read.csv("pointfile.csv")
str(rain_data)

# Check what you have so far

point_coords <- rain_data[c("Long","Lat")]
coordinates(rain_data) <- point_coords
p4str <- CRS("+init=epsg:4326")  # Since the coordinates are in
Long/Lat, first declare this CRS
proj4string(rain_data) <- p4str


# Now Convert to UTM

p4str_UTM <- CRS("+init=epsg:32633")
rain_data_UTM <- spTransform(rain_data, p4str_UTM)

str(rain_data_UTM)    # Check that this is a SPDF in the UTM coordinate
system


# Create Grid for kriging output, using the extent of the rain data SPDF
minx <-  rain_data_UTM@bbox[1,1]
maxx <- rain_data_UTM@bbox[1,2]
miny <- rain_data_UTM@bbox[2,1]
maxy <- rain_data_UTM@bbox[2,2]
pixel <- 1000        # Each pixel will be 1000 meters
grd <- expand.grid(x=seq(minx, maxx, by=pixel), y=seq(miny, maxy, by=pixel))
coordinates(grd) <- ~x+y
gridded(grd) <- TRUE
proj4string(grd) <- p4str_UTM

# Kriging, using autoKrige which creates a best guess variogram

# The formula for ordinary kriging is "<data_column> ~ 1"

OK_rain <- autoKrige(Rainfall_Cumulate ~ 1, rain_data_UTM, grd)

#-----------------------------------


The kriging result contains a component "prediction" which you can
either plot directly, convert to an R raster object for plotting with
ggplot2, or export to a Geotiff.


HTH,

Micha

> Dear R users,
>> I need to produce rainfall maps using R. I know that this is
>> possible, I looked though the web, I found the example below reported
>> (the author is Andrew Tredennick). I would ask you if this is the
>> most performing way to make rainfall maps; if yes would someone be
>> able to give me an example of how file.asc and pointfile.csv should
>> be? If no would somebody please show me another way providing a small
>> example? Thank you for your help Stefano

-- Micha Silver Ben Gurion Univ. Sde Boker, Remote Sensing Lab cell:
+972-523-665918

______________________________________________
[hidden email] mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.