Model-Based Evaluation of the Effects of River Discharge Modulations on Physical Fish Habitat Quality

Hydraulic habitat simulation models were designed for the quantitative determination of environmental flows that consider the needs of aquatic fauna in rivers and streams. In the past 50 years, the modeling techniques were significantly developed, but expectations associated with model utility also increased. Nowadays, the tools are expected to be applicable across a range of spatial and temporal scales and to protect entire aquatic communities, while being inexpensive as well as easy to use in administrative and legal environments. Addressing these challenges is the focus of this volume. We invited papers that present recent developments in habitat modeling, supported by real life case studies. The submitted papers well represent the wide applicability of habitat simulation models, allowing us to address both ends of river management requirements: the ability to address very detailed site specific issues as well as the ability to address the coarse scale applications necessary in regional management.

Section: Site Specificitymentioning

confidence: 99%

Environmental Flows Determination and Monitoring with Hydraulic Habitat Models—Pushing the Boundaries of Habitat Models Application

Parasiewicz

Prus

Theodoropoulos

et al. 2019

“…The maintenance of the sediment regime is critical for the riverine/riparian environment and any changes to flow/sediment can affect habitats and organisms [31,32]. To validate the proposed EF release, we also carried out a simplified sediment analysis at Mabine Station, where both sediment and flow data were available at daily intervals.…”

Section: Impacts On Sediment Rate Regime At Mabine Stationmentioning

confidence: 99%

Assessment of Environmental Flows from Complexity to Parsimony—Lessons from Lesotho

Tegos

Schlüter²,

Gibbons³

et al. 2018

Over the last decade, Environmental Flow Assessment (EFA) has focused scientific attention around heavily-modified hydrosystems, such as flow regulated releases downstream of dams. In this light, numerous approaches of varying complexity have been developed, the most holistic of which incorporate hydrological, hydraulic, biological and water quality inputs, as well as socioeconomic issues. Finding the optimal flow releases, informing policy and determining an operational framework are often the main focus. This work exhibits a simplification of the DRIFT framework, and is regarded as the first holistic EFA approach, consisting of three modules, namely hydrological, hydraulic and fish quality. A novel conceptual classification for fish quality is proposed, associating fish fauna requirements with hydraulic characteristics, exported by fish survey analyses. The new methodology was applied and validated successfully at three stream sites in Lesotho, where DRIFT was formerly employed.

“…This influences the availability and allocation of water resources for the different consumptive and non-consumptive uses as well as to the environmental flows required to sustain the aquatic ecosystems and the human well-being that depend on them [2]. Therefore, adaptive and integrative flow regulation management and strategic water resource management plans are required to allow for economic and social development without putting ecosystems at risk [3,4].…”

Section: Introductionmentioning

confidence: 99%

Drought and Ecological Flows in the Lower Guadiana River Basin (Southwest Iberian Peninsula)

Pulido‐Calvo

Gutiérrez‐Estrada

Sanz‐Fernández

2020

Drought temporal characterization is a fundamental instrument in water resource management and planning of basins with dry-summer Mediterranean climate and with a significant seasonal and interannual variability of precipitation regime. This is the case for the Lower Guadiana Basin, where the river is the border between Spain and Portugal (Algarve-Baixo Alentejo-Andalucía Euroregion). For this transboundary basin, a description and evaluation of hydrological drought events was made using the Standardized Precipitation Index (SPI) with monthly precipitation time series of Spanish and Portuguese climatic stations in the study area. The results showed the occurrence of global cycles of about 25–30 years with predominance of moderate and severe drought events. It was observed that the current requirements of ecological flows in strategic water bodies were not satisfied in some months of October to April of years characterized by severe drought events occurring in the period from 1946 to 2015. Therefore, the characterization of the ecological status of the temporary streams that were predominant in this basin should be a priority in the next hydrologic plans in order to identify the relationships between actual flow regimes and habitat attributes, thereby improving environmental flows assessments, which will enable integrated water resource management.