Water may be present in soil, groundwater or surface storage yet remain inaccessible because it is hydraulically disconnected, too saline, too tightly retained, or stored on timescales mismatched with biological or human demand. We define water accessibility as the capacity of stored water to enter ecologically or societally relevant fluxes, with that capacity varying with hydrological state, connectivity, salinity, biological demand and human intervention.
This session asks when, where, for whom and for how long stored water becomes accessible in human-modified critical zones. We welcome studies of mobile and less-mobile domains, preferential flow, soil hydraulic structure, root access, groundwater depth, salinity, wetting-drying transitions, irrigation, drainage, pumping, land-use change, restoration, hydrological memory, water age and transit times.
Contributions may use field or laboratory experiments, stable isotopes and other tracers, geophysics, remote sensing, water-age and transit-time analyses, and a broad range of modelling approaches. We encourage studies addressing accessibility and functional outcomes for transpiration, recharge, runoff, ecological resilience, crop production, water security and other major ecohydrological or societal fluxes.
We particularly encourage work from agricultural systems, wetlands, deltas, drylands, forests, restored landscapes and other human-modified critical zones. Comparative and negative-result studies are welcome, including cases where connectivity or tracer contrasts strengthen, collapse or shift with hydrological state. The aim is to identify measurable indicators, thresholds, trade-offs and management timing while avoiding the assumption that more stored water necessarily means more accessible water.