Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: <i>Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic</i> and <i>Edaphic</i>. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as <i>Permanent, Temporary-pools, Temporary-dry</i> and <i>Episodic</i>. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that determine the presence of different biotic assemblages. This novel concept links hydrological and ecological conditions in a unique way. All these methods were implemented with data from eight temporary streams around the Mediterranean within the MIRAGE project. Their application was a precondition to assessing the ecological quality of these streams

The assessment of the ecological status of water bodies, as requires by the European Water Framework Directive, can raise a number of problems when applied to temporary streams. These problems are because of the particular physical, chemical and biological conditions resulting from the recurrent cessation of flow or even the complete drying of the stream beds. In such non‐permanent water bodies, the reference quality standards developed for permanent streams may only be applicable under certain circumstances or may not be applicable at all. Work conducted within the collaborative EU‐funded project Mediterranean Intermittent River ManAGEment (MIRAGE) has addressed most of these difficulties and has used diverse approaches to solve them. These approaches have been brought together in the so‐called MIRAGE Toolbox. This toolbox consists of a series of methodologies that are designed to be used in a sequential manner to allow the establishment of the ecological and chemical status of temporary streams and to relate these findings to the hydrological status of the streams. The toolbox is intended to serve the following purposes: (i) the determination of the hydrological regime of the stream; (ii) the design of adequate schedules for biological and chemical sampling according to the aquatic state of the stream; (iii) the fulfillment of criteria for designing reference condition stations; (iv) the analysis of hydrological modifications of the stream regime (with the definition of the hydrological status); and (v) the development of new methods to measure the ecological status (including structural and functional methods) and chemical status when the stream's hydrological conditions are far from those in permanent streams. Copyright © 2014 John Wiley & Sons, Ltd.

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Hydrological modellers have recently been challenged to improve watershed models by better integrating soil information into model applications. Reliable soil hydraulic information is thus necessary for better describing the water balance components at the catchment scale. Frequently, that information does not exist. This study presents a set of class-pedotransfer functions (PTFs) for estimating the water retention properties of Portuguese soils. The class-PTFs were established from a dataset containing 697 soil horizons/layers, by averaging values of total porosity and volumetric water contents at –0.25, –1, –3.2, –6.3, –10, –33, –100, –250, and –1500 kPa matric potentials after grouping data by soil texture class, soil horizon, and bulk density. Fitted retention curves using the van Genuchten model were also obtained for every class-PTF. The root mean square error varied between 0.039 and 0.057 cm3/cm3, with smaller values found when using the 12 texture classes of the International Soil Science Society (ISSS) system rather than the five texture classes of FAO, and when bulk density was also considered. The class-PTFs were then integrated into Portuguese soil maps and its usage was demonstrated by deriving maps of available water capacity to be used for modelling the water balance in a small catchment area with the SWAT model. The model successfully simulated the reservoir inflow when using the derived maps, but the results did not vary much whether using coarser or finer description of the catchment soils. Nonetheless, the class-PTFs contributed to a better soil characterisation than when using coarse-scaled information. The approach followed here was simple, inexpensive, and feasible for modellers with few resources but interested in considering the spatial variability of soil retention properties at large scales and in advancing hydrologic modelling in Portugal.