Improving Indicators of Hydrological Alteration in Regulated and Complex Water Resources Systems: A Case Study in the Duero River Basin

Abstract

Assessing the health of hydrological systems is vital for the conservation of river ecosystems. The indicators of hydrologic alteration are among the most widely used parameters. They have been traditionally assessed at the scale of river reaches. However, the use of such indicators at the basin scale is relevant for water resource management since there is an urgent need to meet environmental objectives to mitigate the effects of present and future climatic conditions. This work proposes a methodology to estimate the indicators of hydrological alteration at the basin scale in regulated systems based on simulations with a water allocation model. The methodology is illustrated through a case study in the Iberian Peninsula (the Duero River basin), where different minimum flow scenarios were defined, assessing their effects on both the hydrological alteration and the demand guarantees. The results indicate that it is possible to improve the hydrological status of some subsystems of the basin without affecting the water demand supplies. Thus, the methodology presented in this work will help decision makers to optimize water management while improving the hydrological status of the river basins.

Potential Climate Impacts of Hydrological Alterations and Discharge Variabilities of the Mura, Drava, and Danube Rivers on the Natural Resources of the MDD UNESCO Biosphere Reserve

“…In the analysis of the IHA, separating human impacts from climate impacts on the river regime is very difficult. The IHA method was primarily developed for analyzing hydraulic structures, such as river regulation structures and reservoirs [17][18][19][20][21].…”

Application of watershed-scale habitat modeling and decision-support tools for reservoir reoperations in coastal northern California

“…Popular flow-based aquatic habitat evaluation methods include Indicators of Hydrologic Alteration [8], the functional flows approach [9], and Hydroecological Integrity Assessment Process [10]. These methods evaluate aquatic habitat by comparing the streamflow regime between altered and natural conditions, and have been used to conduct habitat evaluations at a watershed scale [7,[11][12][13]. However, such approaches lack the capacity to fully represent the hydraulic, geomorphic, and ecologic interactions of physical habitat [13][14][15][16].…”

“…The operations of Valley Water's water utility system in the Three Creeks watershed under the water management scenarios described above were simulated in a daily water allocation model using the SEI's WEAP [27] platform as part of the overall AHA modeling toolkit shown in Fig 1 . Several model platforms, including AQUATOOL, MODSIM, RIBASIM, WARGI-SIM, are common in water resources planning [12] and could potentially be applied in place of WEAP. In this case, WEAP was chosen based on its ability to simulate water allocations during each…”

“…daily time step based on user-defined priority [27] rather than using pre-defined allocation of other models such as WARGI-SIM or RIBASIM [12] as well as the ability to build off the utility's existing monthly WEAP model. The hydrologic portion of the model was populated from 1990-2010 using historical observed inflows above the reservoirs, local climate, and modeled rainfall-runoff inflows beneath the reservoirs.…”

Habitat alteration assessment for the management of environmental flows in regulated basins

“…Over the past twenty-five years, several methods have been proposed and applied to assess hydrological alteration in regulated basins (e.g., Richter et al, 1996;Richter et al, 1997;Pyron and Neumann, 2008;Martínez Santa-María and Fernández Yuste, 2010;Lu et al, 2018;do Vasco et al, 2019;Pardo-Loaiza et al, 2021;Monico et al, 2022, among others). Two representative examples of these methods are the Indicators of Hydrologic Alteration (Richter et al, 1996) and the Indicators of Hydrologic Alteration in Rivers (Martínez Santa-María and Fernández Yuste, 2010), which are based on the comparison of hydrological variables under regulated and natural conditions.…”