Variables codes

Rules for variables names

In this page all the information needed to correctly report variables to the database are provided. To submit the data it is fundamental to use the correct variables names and units as reported in the table at the bottom of the page. However, in addition ot the variable name it is requested to use a 3 figures code which identifies univocally the location within the site where measurements are taken. The importance of this code is related to the possibility to associate to each variable a set of metadata like the method or instrument used, the measurement depth/height, the last calibration of the sensor etc.

Generally, the name of the variable has to be indicated as:

VAR_x₁_x₂_x₃

VAR= variable name (refer to the list of input variables)

The first figure stands for the position of the sensors on a 2D space. For instance, if soil temperature is measured at 3 different locations, these can be numbered as 1, 2, 3.

The second figure represents the vertical level (height above the ground/depth of the soil) of the sensors. Supposing to measure soil temperature at 3 different depths along a vertical profile at each location, then each variable can be identified as follows:

Numeration increases moving downwards along a vertical profile but same number at two different locations can indicate different height/depth, that is specified in the metadata. So for example the deeper soil temperature measurement point in two different profiles of 4 sensors each will be indicated as TS_1_4_1 and TS_2_4_1 even if the first is at 80cm and the second 120cm below ground.

The third figure identifies the presence of replicated measurements in the same location. For instance, given 2 replicates of soil temperature measurements at position 1 and depth 1 (i.e. for sensors comparison), these would be indicated as:

Another example where the third figure should be used is for measurements at tree level like sap flow sensors. In this case the first figure indicate the tree (again specified in the metadata), the second the measurement height if you have for example sap flow measurements on the same tree at different heights and the third can be used to identify different sensors at the same height, commonly used in sap flow measurements.

Remember: All variables to be submitted must be characterized by the 3 figure code and in case of a variable being measured with a single sensor in a given point in space, the three figures of the code clearly equals 1.

New variables

We tried to consider all the common variables collected in the network also on the basis of what has been collected in previous projects. However new measurements are continuously added and it is possible that a variable to be submitted is not present in the “Variables codes”. In this case please contact the Databse Staff at the address [email protected] and we will think together to the best solution. In any case do not send variables with names not consistent with those listed because these would be rejected by the system.

IMPORTANT: Additional information regarding the variables (height, depth) must be included in the metadata and not in the data file neither in the variable name. All additional information included in the data file are lost during the upload process.

Variables Codes List