*3.2.2. Data preparation*

Yucatan peninsula, Mexico. Landsat imagery was used as the main source to estimate indica‐ tors such as canopy cover (CC) and net primary productivity (NPP). Use of Landsat imagery enables to see changes over time [68] within a pixel 30 m resolution over 28 years (1986–2014). The methods enabled selection of priority areas and spatial patterns. The MENDA‐1 water‐ shed [73] in the Yucatan Peninsula, Mexico, was selected as experimental area (**Figure 1**).

10 Land Degradation and Desertification - a Global Crisis

**Figure 1.** Study area.

The integration of the methodology is described as follows:

Selection of the indicators to monitor and assess degradation was the first step. Each one of the indicators selected was estimated using remote sensing as the primary source of data input. Because of the characteristics and free availability of Landsat archive [13], Landsat imagery is suggested as the major contribution. The indicators were estimated for the period of time required according to particular needs. Although in many tropical regions cloud cover is a significant issue, the probability of acquiring at least one cloud‐free or reasonably cloud‐free Landsat image per season is relatively high [74]. At least one Landsat image per season ensures continuity in historical estimations of the forest landscape dynamics based on Landsat archive.

Very high‐resolution satellite imagery or LiDAR data is recommended as auxiliary data to validate calculations. Another data set crucial for the implementation of this framework was forest inventory databases. Many developing countries (e.g. Mexico) carried out periodical
