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- | ='''An accumulated rainfall image improved with altitude'''= | + | ='''An improved accumulated rainfall image (using SEDI with altitude)'''= |
- | The image in the previous paragraoh can be improved | + | The image in the previous paragraoh can be improved with tye application of a DTM. The DTM (altitude) constitutes a background factor that helps the interpolation. The assumption is that the higher the altitude, the higher the rainfall. |
{|"class=prettytable" cellpadding="15" border="1" style="border-collapse:collapse" | {|"class=prettytable" cellpadding="15" border="1" style="border-collapse:collapse" | ||
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- | |width="300"|In Excel the totals file has to be reformatted to a CSV file. This CSV file should have the column order ''(1)longitude (2)latitude (3)value (4)station name''||[[Image:graph49.jpg|400px|]] | + | |width="300"|In Excel the totals file has to be reformatted to a CSV file. This CSV file should have the column order ''(1)longitude (2)latitude (3)value (4)station name''||[[Image:graph52.jpg|400px|]] |
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- | |width="300"| Using the ''Interpolate-Inverse Distance'' function, the CSV file can be interpolated to an image. ||[[Image:graph50.jpg|400px|]] | + | |width="300"| Using the ''Interpolate-Inverse Distance'' function, the CSV file can be interpolated to an image. ||[[Image:graph53.jpg|400px|]] |
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- | |width="300"| The result is an image. This gives a much more visual picture of the cumulative rainfall.||[[Image:graph51.jpg|400px|]] | + | |width="300"| The result is an image. This gives a much more visual picture of the cumulative rainfall.||[[Image:graph54.jpg|400px|]] |
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Revision as of 14:19, 18 August 2006
Contents
Preparation of ten-daily rainfall and ET0 maps for crop forecasting
Crop forecasting based on water balance calculations is usually done in a ten-day timestep. A ten day period is called a “dekad”. However, should daily weather data of good spatial and temporal extend be available, the water balance can be run in AgrometShell on a daily basis.
In order to do crop forecasting the following weather data have to be gathered:
- Actual decadal rainfall data for the running season.
- Actual decadal ET0 data for the running season
- Normal rainfall data
- Normal ET0 data
These data form indicators in itself, even without using them directly in a water balance calculation. Some examples are given below:
A simple rainfall map for the current dekad
Accumulated rainfall from the beginning of the season
Excel is needed to do the accumulation.
An accumulated rainfall image
By applying interpolation to the total rainfall amounts calculated in the previous step, an image is created.
An improved accumulated rainfall image (using SEDI with altitude)
The image in the previous paragraoh can be improved with tye application of a DTM. The DTM (altitude) constitutes a background factor that helps the interpolation. The assumption is that the higher the altitude, the higher the rainfall.