Use of the temperature–vegetation dryness index for remote sensing grassland moisture conditions in the vicinity of a lignite open-cast mine

Anthropogenic activities, especially resulting in changes in the water conditions, usually disturb biological and agricultural functions of grasslands, leading to their degradation, often on large areas. Remote sensing observations of such changes in grassland ecosystems evoke a great interest, but they are still a difficult task, especially when performed on industrial and mining areas. This paper presents a new effective method of remote sensing of grassland moisture conditions based on temperature–vegetation dryness index (TVDI) calculated from free Landsat imagery, and employing the TVDI spatial variability estimated from a semivariance analysis. The practical applicability of the method is demonstrated on the example of monitoring of the extensive neighborhood of lignite open-cast mine within a period of a few years. Besides, the developed method was validated at the studied area, using in situ information. Thus, we demonstrated that TVDI may serve as an effective indicator of grassland moisture conditions, even in problematic areas.