Rapid mass movements (RMM) pose a substantial risk to people and infrastructure. Reliable and cost-efficient measures have to be taken to reduce this risk. One of these measures includes establishing and advancing the state of practice in the application of early warning systems (EWSs). EWSs have been developed during the past decades and are rapidly increasing. In this paper, we focus on the technical part of EWSs, i.e., the prediction and timely recognition of imminent hazards, as well as on monitoring slopes at risk and released mass movements. Recent innovations in assessing spatial precipitation, monitoring and precursors of the triggering and deformation of RMM offer new opportunities for next-generation EWSs. However, technical advancement can only be transferred into more reliable, operational EWSs with an adequate well-instructed dedicated staff. To this end, an intense dialog between scientists, engineers and those in charge of warning, as well as further experience with new comprehensive prototype systems jointly operated by scientists and practitioners, will be essential.

Modeling of surface energy balance and the separation of evapotranspiration to its component fluxes require quantification of evaporation from land surfaces. The nonlinear relationship between surface heat fluxes and the hydration state of soil surfaces present a challenge to remote estimation of surface evaporation rates. We study the often‐overlooked role of soil properties in determining surface evaporation resistance. We present a framework for quantifying how the ratio of actual to potential evaporation rates varies with changes in surface water content for different soil textures. The model uses the evaporative characteristic length (a soil‐dependent active depth of evaporation) and soil resistance to capillary flow across that region. Predictions were in good agreement with flux tower measurements of bare‐soil evaporation from 10 soil textural classes. The study offers a simple and physically based method for incorporating surface evaporation resistance into land‐surface models considering soil type and surface water content.

High and nearly constant evaporation rates from initially saturated porous media are sustained by capillary-driven flow from receding drying front below the evaporating surface. The spatial extent of continuous liquid pathways in homogeneous porous medium is defined by its hydraulically connected pore size distribution. We consider here evaporative losses from porous media consisting of two hydraulically coupled dissimilar domains each with own pore and particle size distributions separated by sharp vertical textural contrast. Evaporation experiments from texturally dissimilar media were monitored using neutron transmission and dye pattern imaging to quantify water distribution and drying front dynamics. Drying front invades exclusively coarse-textured domain while fine-textured domain remains saturated and its surface continuously coupled with the atmosphere. Results show that evaporation from fine-textured surface was supplied by liquid flow from adjacent coarse domain driven by capillary pressure differences between the porous media. A first characteristic length defining limiting drying front depth during which fine sand region remains saturated is deduced from difference in air-entry pressures of the two porous media. A second characteristic length defining the end of high evaporation rate includes the extent of continuous liquid films pinned in the crevices of the pore space and between particle contacts in the fine medium. We established numerically the lateral extent of evaporation-induced hydraulic coupling that is limited by viscous losses and gravity. For certain combinations of soil types the lateral extent of hydraulic coupling may exceed distances of 10 m. Results suggest that evaporative water losses from heterogeneous and coupled system are larger compared with uncoupled or homogenized equivalent systems.