Abstract. In the present paper we describe some methods for verifying and evaluating probabilistic forecasts of hydrological variables. We propose an extension to continuous-valued variables of a verification method originated in the meteorological literature for the analysis of binary variables, and based on the use of a suitable cost-loss function to evaluate the quality of the forecasts. We find that this procedure is useful and reliable when it is complemented with other verification tools, borrowed from the economic literature, which are addressed to verify the statistical correctness of the probabilistic forecast. We illustrate our findings with a detailed application to the evaluation of probabilistic and deterministic forecasts of hourly discharge values.

In the present paper we describe some methods for verifying and evaluating probabilistic forecasts of hydrological variables. We propose an extension to continuous-valued variables of a verification method originated in the meteorological literature for the analysis of binary variables, and based on the use of a suitable cost-loss function to evaluate the quality of the forecasts. We find that this procedure is useful and reliable when it is complemented with other verification tools, borrowed from the economic literature, which are addressed to verify the statistical correctness of the prob-abilistic forecast. We illustrate our findings with a detailed application to the evaluation of probabilistic and determinis-tic forecasts of hourly discharge values.

Soil water content is a key determinant of the health of terrestrial ecosystems. It plays a fundamental role in the feedbacks between the Earth and the atmosphere, as well as in all aspects of vegetation growth and composition. The dynamics of soil water in humid areas, and especially in wetlands, presents particularly challenging features for its quantitative description, since it needs to be linked to the intertwined stochastic fluctuations of the water table and the soil moisture of the unsaturated zone. These fluctuations are themselves dependent on the climate, soil, and vegetation of the region. The paper describes some of the most important problems that need to be considered in attempting to develop a quantitative framework for the ecohydrology of humid areas. The avenues of research suggested here will play a keystone role in the understanding of the complex dynamics of humid lands as well as in their scientifically based management in the face of a changing climate.

[1] Areas with a relatively shallow water table are environments where the groundwater plays a key role on the ecosystem function, and important interactions exist between hydrology and ecosystem processes. We propose here an analytical model to study the interactions between rainfall, water table, and vegetation in groundwater-dependent ecosystems. The water table dynamics are studied as a random process stochastically driven by a marked Poisson noise representing rainfall events. Infiltration, root water uptake, water flow to/from an external water body, and capillary rise are accounted for in a probabilistic description of water table fluctuations. We obtain analytical expressions for the steady state probability distribution of water table depth, which allows us to investigate the long-term behavior of water table dynamics, and their sensitivity to changes in climate, vegetation cover, and water management.