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2019-automated factsheets for sediment (& phosphorus input) into waterbodies

(based on a 20 year long soil erosion database in the region of Frienisberg, Switzerland)

If you are interested in the scientific setting of this coding project as well as some first interpretation of the results, then have a look at "project_automated_factsheets_David_Remund.pdf".

Author: David Remund 13-104-591, University of Berne, Seminar Geodata analysis and modelling (Springsemester 2019)

aim of the scripts:

The aim of the scripts is to make PDF overview sheets that show for so called region-period objects (e.g. Frienisberg 1997-2007) important information about sediment & phosphorus input.

methodical realization:

The aim is reached with 4 scripts. The first script makes a treelike output folder structure for the input data (which was already calculated beforehand in this case). The second script copies initial the sediment (phosphorus) input rasters to the right destination folder in the created treelike output folder structure. Some rasters are had to be summed up prior to the copying process. The third script checks if some "strange rasters" have been created during the copying process (probably these strange rasters are temporary storage files). If a strange raster should be detected, then this script deletes them. The fourth and last script calculates afterwards the total sum [t] and the mean annual input [t/ha*a] and makes boxplots as well as timeseries. All the calculated elements are drawn together on a PDF sheet. One script is called "build_df_from_arcpy_181119.py": This is a helping script that makes a pandas dataframe out of a GIS attribute table. A collegue gave these few lines of code to me and I want to highlight that they weren't developped by me (I'm unaware of the initial developper's identity...).

used software:

The programming was done with Python 3.6 in the IDE PyCharm 2018.2.5 Community Edition.

workflow

The workflow of this project consists of four scripts and is the same for sediment & phosphorus input. Therefore the workflow is only explained for the sediment input. The resulting PDF's are available for both sediment and phosphorus input. (remark for the lecturer: Only the sediment input scripts are commented comprehensibly. Therefore, only these scripts were loaded up on Github)

The first script is called make_db_structure_SE.py, the second copy_management_SE.py, the third check_strange_rasters.py and the fourth and last one create_pdf_spreadsheet_SE.py. (for phosphorus input check the corresponding _PE.py scripts).

script 1: make_db_structure_SE.py

This script creates for each region-period object like Frienisberg 1997-2007 a treelike folder structure, where the sediment input can be copied to afterwards (the treelike folder structure is shown at the begining of script 1). It needs several input paths (line 51-66): path where the treelike folder structure starts (the subfolders "Frienisberg", "Lobsigen", "Seedorf", "Schwanden" and "Suberg" already existed!!!), path where the vector files are stored, path were the raster files are stored, path of a helping script (that aids to extract information out of attribute tables).

Once the input paths are specified, you can run the script without further editing anything if you have the same vector and raster data as I used. If you want to adjust this script to other data, it's important to note that the naming convention of the input vectors and rasters is crucial. E.g. the FEKRE01_M1_037_SE.shp vector file has a corresponding sediment input raster called FEKRE01_M1_037_SE.tif. Also the naming of the vector attribute table, in my case e.g. "Datum" or "Parzelle", is crucial as well as it's format. E.g. the date in the attribute table column "Datum" was sometimes recorded as string and sometimes as timestamp.

Special attention sould be paid to the following: In the folder where the treefolder structure starts, you have to first manually create subfolders with the name of the region , e.g. the subfolder "Seedorf" (-> do this for each region)!!! At the end of the script, one additional "strange folder" was created (probably a temporary storage file...) which is deleted at the very end of the script. In line 59 poped up an exclamation make (import of the aiding script) - igonre this exclamation mark! At the end of script one, compare the folders you created with the raster data you want to copy: In my case e.g. Seedorf 2007-2017 had no "flaechenhaft Erosion", therefore I deleted the folder Seedorf_2007_2017/Erosionsform/flaechenhaft. (this deleting is implemented in script 2 on line 712, 713...if you delete the folders manually after script 1, then uncomment the lines 712,713 in script 2).

script 2: copy_management_SE.py

This script copies each sediment input raster to the right branch in the threelike folder structure. Sometimes rasters also had to be summed up prior to copying (which is done within this script). The script needs several input paths (line 47-67): path where the treelike folder structure starts, path where the vector files are stored, path were the raster files are stored, path of the helping script, path where the mean annual sediment input is stored (because this was calculated in advance…).

Once the input paths are specified, you can run the script without further editing anything if you have the same vector and raster data as I used. If you want to adjust the script, also note that the naming convention of the vector and raster data is important as well as the naming of the attribute table columns as well as their formats. The summing up of the rasters in my case was relatively easy, since all rasters e.g. in Frienisberg 1997-2007 had the same X-Y-extent! The X-Y extent of all summed up rasters has to be the same, otherwise my programmed approach in this script won't work for you.

It's important to note that some lines (e.g. 115) with "des.split(os.sep)[6]" extract e.g. the part "Seedorf_2007_2017" out of the path "E:\David_Remund_Masterarbeit\alle_GE_MA\Gewässereintrag\Sedimenteintrag\Seedorf\Seedorf_2007_2017\Periode\Einzel". But if the data is stored on a different place on your device, the part "Seedorf_2007_2017" might not be "des.split(os.sep)[6]" but for example "des.split(os.sep)[8]". So you might have to adjust this number: Use for this ctr + F (search "os.sep") in the script and if you have to e.g. replace [6] with [8] at one place, the increase +2 stays the same for all other "os.sep"-regions. Another important thing is that you store the vector and rater input data on the same folder level and with the same subfolder hirarchie as my inital data was stored (otherwise you have to adjust some script parts where list of folder-paths are created).

Special attention sould be paid to the following: Like in script 1, ignore the exclamation mark that is due to the import of the helping script! Convert the rasters to numpy arrays and then sum up the rasters! In this way, the execution of the script is much quicker. At the end, don't forget to convert the numpy array back to a raster and set the output coordinate system. In the developing stage of this script, it did not always work properly. To note such errors during the copying process, control numbers are very crucial (otherwise you drift more and more apart from reality). After I copied some files to a new branch in the treelike folder structure, I always checked if the sum of all rasters in e.g. Frienisberg 1997-2007 is still the same as before (e.g. for Frienisberg_97_07 the sum had to be 200.90 tons before and after the copying process). The control scripts were not uploaded on Github but can be easily deduced out of script 2. Some strange additional rasters were also procuced (very rarely) during the copying process (probably temporary storage files...). With this problem is dealt in script 3.

script 3: check_strange_rasters.py

This script checks if some strange raster (they always begin with "numpyarraytorater...") were produced during the copying process. If so, it deletes them and prints the name of the raster that has been deleted. This script only needs one input path: the path where the treelike folder structure starts. Special attention: Not every region-period object might have rasters in each folder branch, e.g. in Seedorf_2007_2017 there's no areal (flaechenhaft) erosion. Therefore the "check_strange_rasters.py" might have to be adjusted. In this case the paths .../Seedorf_2007_2017/Erosionsform/flaechenhaft/Einzel and .../Seedorf_2007_2017/Erosionsform/flaechenhaft/Summe must be deleted out of the date_einzel_list (in approximately lines 320 and 380).

script 4: create_pdf_spreadsheet_SE.py

For a certain region-period object like Frienisberg 1997-2007, this script calculates the total sum [t], the mean annual input [t/ha*a] and makes boxplots as well as timeseries. All the calculated elements are then drawn together on a PDF sheet. The script needs two input paths: a path were the treelike folder structure starts (line 53) and a path that specifies the folder, where all the boxplots, timeseries and spreadsheets are saved (line 226). The pdf-sheet creating was done with the reportlab package.

If you want to adjust this script, it's important to note that the boxplots and timeseries input are lists. The x-axis labeling of the timeseries was typed in manually (format: timestamp), since otherwise minor shifts would have occured in leap years. This process could certainly be improved. But the labeling of the y-axis sould be dynamic for boxplots and timeseries. Still, check the labeling if you adjust this script. Another thing you might have to change is line 57: I had to change the part "SE_path = os.path.join(Gebiete,Sedimenteintrag)" to only "SE_path = Gebiete" when I moved the data and scripts to another location.

results

See: sediment_input_overview.pdf, phosphorus_input_overview.pdf

thanks

This project wouldn't have been possible for me without the support of many commited researchers/instructors: My thanks goes to Dr. Andreas Zischg (University of Bern), Dr. Jorge Ramirez (University of Bern) and Dr. Pascal Horton (University of Bern) for supervising me during the geodata analysis & modelling seminar. I also thank the supervisors of my master thesis Dr. Volker Prasuhn, Dr. Andreas Heinimann and Dr. Hanspeter Liniger. A special thank goes to my collegue Jan Liechti who's input was always very enlightening :)

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