## 5 Discussion
In some cases, this can lead to erroneous interpretations, as in cases in which the evidence of a change in the rock glacier's degree of activity, for example, surface degradation or weathering, appears after some time has passed. In the specific case of rock glaciers, the classification requires previous discrimination between rock glaciers and other landforms, and then a classification as a function of their state of activity (active, inactive, or relict rock glaciers). Geomorphological analysis does not always give a straightforward view of this aspect. For example, the discrimination between an active/inactive rock glacier or an inactive/relict rockglacier is very difficult, especially in transition areas. In addition, it is possible that some rock glaciers show no signs of permafrost degradation yet, although these processes are occurring. In this context, [PERSON] et al. [74] proposed the use of two independent experts to carry out the classification and only including in the inventory those landforms detected by both. The work concludes that this approach significantly reduces the uncertainties in the inventory and classification of landforms. Other works propose solving the ambiguity between active and inactive rock glaciers by considering only two different categories: intact rock glaciers [68], including both active and inactive in the same category; and the relict rock glaciers [1; 3; 74]. However, this approach avoids the discrimination between active and inactive rock glaciers, which is key given that the climatic, paleoclimatic, geomorphologic, and hydrologic significance is different for each case [24]. On one hand, an active rock glacier is in thermal equilibrium with the environment. It conserves its ice and its active layer acts as a water regulator, keeping the water in a solid state in winter and releasing it in summer. On the other hand, an inactive rock glacier is not in thermal equilibrium with the environment and slowly loses its internal ice as it melts, introducing new water to the active part of hydrologic cycle. Furthermore, both [PERSON] and [PERSON] [9] and [PERSON] [10] have shown that the geomorphological, geomorphometric, and environmental or ecological parameters are more useful to discriminate between active or relict rock glaciers than between active or inactive glaciers. Moreover, some of the parameters used are in situ measurements, an important constraint for regional applications. In this context, the measurement of the surface movement of rock glaciers becomes very important for their classification. However, field techniques are difficult for regional studies because of the high economic cost, time constraints, and inaccessibility to many places. In this sense, the use of active remote sensors is fundamental for regional geocryological studies. Another option used is the cross-correlation technique based on optical satellite images. However, this presents difficulties at lower scales for regional studies, since it requires satellite images of a high spatial resolution that are subjected to very thorough orthorectification and corregistered processing. Likewise, it must cover sufficiently significant periods, again requiring greater economic and human efforts [5; 75]. Several surveys have tried to identify the topo-climatic variables and their degree of influence on the development of rock glaciers [30; 70; 76]. But, as this work does not aim to identify these parameters or their relative importance, only elevation has been considered as a topographical variable to elucidate the influence on true active rock glacier distribution. Elevation or altitude can be considered as an indirect indicator (proxy) of an influencing factor. This means that the distribution of rock glaciers depends on another factor that is highly correlated with the obvious one. The dependence of rock glacier distribution on elevation results mainly from its dependence on air temperature [77].