Infiltration During Infiltration During WadiWadi RunoffRunoffA Modeling Tool for Improving Indirect A Modeling Tool for Improving Indirect Groundwater Recharge AssessmentGroundwater Recharge Assessment

Faculty of Environmental Sciences, Institute of Hydrology and Meteorology, Chair of Hydrology

ICWRER 2013, Koblenz, Germany, June 6, 2013

Andy Philipp and Jens GrundmannTechnische Universität Dresden, Chair of Hydrology

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 2

01 Ephemeral River Flow and Transmission Losses

02 Concept of an Integrated Modeling System

03 Applications for Oman

04 Outlook

Photo courtesy of David O. Rankin

Contents

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 3

01 Ephemeral River Flow and Transmission Losses

• Groundwater is often the only source of freshwater in arid areas

• The quantification of groundwater recharge is of paramount interest for water resources management

• Ephemeral river flow often features significant in-stream infiltration, referred to as transmission losses or indirect groundwater recharge

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

Effects of transmission losses on flood flow in a semi-arid catchment (Walnut Gulch, Arizona). Data from Renard and

Keppel (1966).

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 4

02 Concept of an Integrated Modeling System

Groundwater recharge processes in an ephemeral channel under the influence of a recharge dam (e.g., as in Oman‘s Al Batinah coastal plain region).

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 5

02 Concept of an Integrated Modeling System

• An envisaged model therefore should

– Regard the governing, highly variable hydrodynamics

– Include transmission losses ( coupling!)

– Include dam operation and dam evaporation

– Circumvent numerical issues and singularity problems when modeling advancing free-boundary flow over an initially dry channel bed under weakening process dynamics

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 6

Components of the proposed wadi flow and dam simulation model.

02 Concept of an Integrated Modeling System

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 7

02 Concept of an Integrated Modeling System

• Special focus: free-boundary problem of potentially weakly advancing flow

• (semi-)analytical zero-inertia model of Philipp et al. (2010)

• Assumptions

– (Nonprismatic) channel geometry approximated by power functions

– Only valid for non-zero (but weak) advance conditions

Iterative solution procedure for theZI model.

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 8

03 Applications for Oman

The study area in Northern Oman, Al Batinah Region.

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 9

Model calibration (roughness coefficient and infiltration parameters) for the neighboring catchment of Bani Kharus (with a series of gauges).

03 Applications for Oman

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 10

03 Applications for Oman

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

Modeling results for WadiMa’awil (06/06/07 event, caused by cyclone Gonu).Only stage recorder data available for validation.

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 11

Spatiotemporal information on transmission losses below the recharge dam as potential upper boundary condition for groundwater modeling; Gonuevent.

03 Applications for Oman

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 12

03 Applications for Oman

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

Total event-related volumetric water balance (MCM); Gonu event.

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 13

Advance and recession trajectories below Ma’awil Dam; Gonu event.

03 Applications for Oman

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 14

04 Outlook

• Robust and accurate process-oriented modeling tool

• Performs well under weak-advance conditions and for initially dry channels beds (free lower boundary numerically stable)

• Further needs

– Better data (event-related for a series of gauges, channel morphology, observations of maximum extents of flow domain)

– Including (spatially and temporally) uncertain process parameters

– Inclusion of changing wadi morphology

– Sediment–flow interactions

– Assessment of surface processes not addressed (i.e., re-evaporation)

INTRODUCTION | CONCEPTS | APPLICATION | OUTLOOK

A. Philipp and J. Grundmann: Infiltration During Wadi Runoff Slide 15

Thanks For Your Attention!

References

Haimerl, G. & Strobl, T. (Ed.)Groundwater Recharge in Wadi Channels Downstream of DamsTechnische Universität München, Institute of Hydraulic Engineering and Water Resources, TechnischeUniversität München, Institut für Wasserwesen, 2004

Lerner, D. N.; Issar, A. S. & Simmers, I.Groundwater Recharge: A Guide to Understanding and Estimating Natural RechargeA. A. Balkema Publishers, Rotterdam, 1990

Philipp, A.; Schmitz, G. H. & Liedl, R.Analytical Model of Surge Flow in Nonprismatic Permeable Channels and Its Application in Arid RegionsJournal of Hydraulic Engineering, 2010, 136, 290-298

Philipp, A. & Grundmann, J.An Integrated Modeling System for Flash Flood Routing in Ephemeral Rivers Under the Influence of Groundwater Recharge Dams (accepted)Journal of Hydraulic Engineering, 2013

Renard, K. G. & Keppel, R. V.Hydrographs of ephemeral streams in the SouthwestJournal of the Hydraulics Division of the ASCE, 1966, 92, 33-52

de Vries, J. J. & Simmers, I.Groundwater recharge: an overview of processes and challengesHydrogeology Journal, 2002, 10, 5-17