Baseflow recession and recharge as nonlinear storage processes

Publikation: Beiträge in ZeitschriftenKonferenzaufsätze in FachzeitschriftenForschungbegutachtet

Authors

Discharge in many rivers is often fed by outflow from a shallow groundwater reservoir. It is becoming clear that the outflow from this aquifer is not linearly proportional to storage as is commonly assumed in many algorithms. Numerical analysis of flow recession curves from about 100 river gauging stations instead reveals a nonlinear relationship between baseflow, Q, and storage, S, for which the equation S = aQb was adopted. Values of the exponent b are found by calibration to be between 0 and 1 but with a high concentration around 0.5, which is in accordance with the findings of other studies and theoretical approaches yielding b = 0.5 for unconfined aquifers and relating the coefficient a to catchment properties, primarily area and shape of basin, pore volume and transmissivity. This non-linear reservoir function is proposed as a more realistic alternative to the linear reservoir function. The relatively fast response of groundwater flow to rainfall is mainly a result of the increase of hydraulic head of the groundwater reservoir accelerating the exfiltration of 'old', pre-event water into the river bed. As fissure and pore volumes communicate hydraulically, it appears physically reasonable to model the system by one non-linear reservoir for catchments, or parts of them, instead of applying independent parallel linear reservoirs. The non-linear reservoir algorithms are supported by an analytical derivation. They are extended for the automatic separation of baseflow from a time-series of daily discharge in rivers and the computation of storage and effective recharge of groundwater in river basins by inverse nonlinear reservoir routing. The time-series obtained allow the identification and quantification of long-term changes to the water balance. Relationships between computed groundwater storage and observed groundwater level can also be established.

OriginalspracheEnglisch
ZeitschriftHydrological Processes
Jahrgang13
Ausgabenummer5
Seiten (von - bis)715-726
Anzahl der Seiten12
ISSN0885-6087
DOIs
PublikationsstatusErschienen - 15.04.1999
VeranstaltungInternational Congress on Modelling and Simulation- MODSIM-97 - Hobart, Tas., Australien
Dauer: 08.12.199711.12.1997
https://www.mssanz.org.au/MODSIM97/MODSIM97.htm

Zuletzt angesehen

Publikationen

  1. Contextualizing certification and auditing
  2. Ten essentials for action-oriented and second order energy transitions, transformations and climate change research
  3. Effect of consumable stud microstructure on friction surfacing
  4. Embedding Evidence on Conservation Interventions Within a Context of Multilevel Governance
  5. Who can nudge for sustainable development? How nudge source renders dynamic norms (in-)effective in eliciting sustainable behavior
  6. HyperKult
  7. Inquiry-based learning as an approach to realize inclusive science education
  8. Evaluation of mechanical property predictions of refill Friction Stir Spot Welding joints via machine learning regression analyses on DoE data
  9. Open-flow mixing and transfer operators
  10. Introduction
  11. Variational pragmatics in the foreign language classroom
  12. Stressing the Relevance of Differentiating between Systematic and Random Measurement Errors in Ultrasound Muscle Thickness Diagnostics
  13. E-privacy concerns
  14. Changing the decision context to enable social learning for climate adaptation
  15. Ensuring tests of conservation interventions build on existing literature
  16. Making mutual learning tangible
  17. Does an individualized learning design improve university student online learning? A randomized field experiment
  18. Process characteristics of constrained friction processing of AM50 magnesium alloy
  19. Sensemaking and abductive reasoning for transformative biodiversity conservation
  20. Robot Makes Free
  21. Structure and dynamics of secondary and mature rainforests
  22. Why context matters: Understanding transdisciplinary research through the lens of nine context factors
  23. Development of a Mobile Application for People with Panic Disorder as augmentation for an Internet-based Intervention
  24. EDUCATION FUNDING AS A DETERMINANT OF THE EDUCATIONAL SYSTEM'S EFFECTIVENESS AND SOCIETAL PERFORMANCE
  25. Do we fail to exert self-control because we lack resources or motivation? Competing theories to explain a debated phenomenon