Recent spatio-temporal changes of land sensitivity to degradation in Romania due to climate change and human activities: An approach based on multiple environmental quality indicators

The analysis of land degradation based on sensitivity models has become a widely used scientific method for understanding the spatial pattern of this complex environmental process that is affecting numerous countries globally, including Romania. However, most specialized studies have been dealing with a static analysis of land sensitivity to degradation, and studies focusing on the process from a dynamic perspective are extremely rare or even lacking altogether in certain states, such as Romania. Given this knowledge gap, the study performs the first dynamic analysis of land sensitivity to degradation across Romania, in the key-period 1990-2018, marked by considerable changes in climate and anthropic driving forces of land degradation. This approach is based on the analysis of spatio-temporal trends of land susceptibility to degradation over the past three decades, based on the Land Degradation Sensitivity Index (LDSI) geospatial tool, computed for the years 1990 and 2018, and analyzed in detail in terms of the cartographic and statistical differences between the two analyzed years. Our investigations showed an expansion of similar to 1300 km(2) (< 1% of Romania's territory) of the LDSI classes critically sensitive to degradation, the national spatial footprint of which was estimated in 1990 at similar to 67,300 km(2) (28.4%), and at similar to 68,600 km(2) (29%) in 2018. Although this recent net expansion does not seem to be exceedingly high, our results are in fact alarming considering the very high territorial differences in the intensification of land degradative conditions throughout the country. The most apparent such territorial discrepancies were detected in Romania's extra-Carpathian regions, which, post-1990, seem to have become the most susceptible to degradation nationally, amid intense climate change (intensification of aridity) and anthropogenic changes (various changes in land use/cover classes and other unsustainable anthropogenic activities). These findings are alarming, considering, first and foremost, the large-scale presence of arable systems in these regions of the country, the agricultural productivity of which can be seriously eroded due to the intensification of land degradation. Our results can be useful for a more effective implementation of measures against land degradation, which can be applied throughout the country as a priority based on the recent accelerating national trends of land degradation.