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| ==3.1. Entering and importing normal and actual weather data. == | ==3.1. Entering and importing normal and actual weather data. == | ||
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| After a network has been created, crop data can be entered by hand. In principle this is possible for grid-based networks and station networks alike. However as grid-based networks do not coincide with a ground network, it will usually not make sense to enter data manually. | After a network has been created, crop data can be entered by hand. In principle this is possible for grid-based networks and station networks alike. However as grid-based networks do not coincide with a ground network, it will usually not make sense to enter data manually. | ||
Revision as of 14:25, 27 September 2006
3.1. Entering and importing normal and actual weather data.
Peter Hoefsloot After a network has been created, crop data can be entered by hand. In principle this is possible for grid-based networks and station networks alike. However as grid-based networks do not coincide with a ground network, it will usually not make sense to enter data manually.
Entering weather data manually
As the FAO water balance model is usually run with a 10-day (dekadal) time step, this example will show how to enter dekadal data.
Activate the Database - Manage Weather Data - Dekad function. In this example data for Bangladesh will be entered. 
New rainfall data will be entered for 2006. The filter at the top part of the screen is applied to reflect this. 
A new record of data (36 dekadal values for a year) can be entered after pressing the + sign in the toolbar at the top of the screen. In the next window, the station name can be entered. 
Data are entered directly into the window. Flags could be specified as well, although one is not obliged to do so. 
All weather data for all time periods (daily, decadal and monthly data) can be entered in the same way.
Entering weather data from images
Weather data derived from satellite imagery are getting better every year. The satellite imagery record that has been built up from the nineteen seventies now enables the calculation of normals as well. Although satellite derived data cannot be a substitute for ground data, these data are often the only possibility to run a water balance model, due to lack of ground data.
These satellite-derived data can be used in AgrometShell after importing them. This can be done in the following way:
Activate the Database - Import – from image function. In this example data for Niger will be imported from a Sahelwide image. 
The new data will be extracted from the image. To check whether the data have been imported, use the Data – Inventory function. 
The same function can also be used to import altitude data from a Digital Terrain Model (DTM).
Importing tabular weather data from ASCII files
In many circumstances data come in a digitized form. It is a long and error-prone procedure to type those data manually into Agrometshell. Therefore an import module exist that is described here.
