Calculating Sensitivity to Desertification (MEDALUS)

Land degradation and desertification (LDD) analysis is done using the MEDALUS–(Mediterranean Desertification and Land Use Model, a series of international cooperation research projects funded by the European Union) is used worldwide to identify ‘sensitive areas’ that are potentially threatened by land degradation and desertification (LDD). The distinctive outcome of the approach is a multidimensional index (the ESAI) composed of partial indicators of climate, soil, vegetation, and management quality that are derived from the elaboration of 14 elementary variables.

All the varialbes are grouped into four Quality Indicators (Soil quality, SQI; vegetation quality, VQI; climate quality, CQI; and management quality, MQI), which were estimated as the geometric mean of the respective scores of the elementary variables.

Calculating Individual Quality Indicators

The current implementation of the MEDALUS model in MISLAND overcomes the problem of no data by computing the geometric mean of Individual Quality Indicators by using the variables with available information for any of the elementary variables.

Note

To upscale the model for regional analysis, the following cosiderations were made for the selection of variables to be used in the computation of individual Quality indices: (a) Consistancy with the original MEDALUS Approach; (b) Time-series data availability and regularity for multi-temporal analysis; and (c) data source quality and reliability for future updates.

To compute the individual quality indicators(Soil quality, SQI; vegetation quality, VQI; climate quality, CQI; and management quality, MQI), Follow the following simple steps:

  1. On the service menu-bar select the MEDALUS option as shown below:

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Selecting the MEDALUS option from the service Menu

  1. On the layer settings options select the Quality index to compute from the dropdown list and the year you wish to compute:

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Selecting the Quality index to compute form the dropdown list

The resultant layer and statistics will be computed and visualized as shown

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Results for SQI computation

Calculate the Environmental Sensitivity Areas Index(ESAI)

To coumpute the Environmental Sensitivity Index select MEDALUS option from the service menu. On the layers selection option dropdown, selsect the ESAI option as shown below

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Selecting the ESAI option from the layer selection dropdown