MIKE-SHE integrated groundwater and surface water model used to simulate scenario hydrology for input to DRIFT-ARID: the Mokolo River case study

Authors

  • Bob Prucha Integrated Hydro Systems, LLC, PO Box 830, Golden, CO, USA
  • Douglas Graham DHI, Agern Allé 5, DK-2970 Hørsholm, Denmark
  • Marie Watson Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Marinda Avenant Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Surina Esterhuyse Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Alison Joubert Southern Waters, PO Box 12414, Cape Town, South Africa
  • Marthie Kemp Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Jackie King Water Matters, PO Box 209, Constantia, South Africa
  • Pieter le Roux Soil, Crop and Climate Sciences Department, University of the Free State, PO Box 339, Bloemfontein, South Africa
  • Nola Redelinghuys Social Sciences Department, University of the Free State, PO Box 339, Bloemfontein, South Africa
  • Linda Rossouw Environmental and Water Quality Consultant, PO Box 16018, Panorama, 7506, South Africa
  • Kate Rowntree Geography Department, Rhodes University, PO Box 94, Grahamstown, South Africa
  • Maitland Seaman Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Frank Sokolic Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa
  • Leon van Rensburg Soil, Crop and Climate Sciences Department, University of the Free State, PO Box 339, Bloemfontein, South Africa
  • Bennie van der Waal Geography Department, Rhodes University, PO Box 94, Grahamstown, South Africa
  • Johan van Tol University of Fort Hare, Private Bag X1314, Alice, South Africa
  • Tascha Vos Centre for Environmental Management, University of the Free State, P.O. Box 339, Bloemfontein, South Africa

DOI:

https://doi.org/10.4314/wsa.v42i3.03

Keywords:

hydrology, non-perennial, MIKE SHE, integrated surface and groundwater modelling

Abstract

A fully integrated, physically-based MIKE SHE/MIKE11 model was developed for the Mokolo River basin flow system to simulate key hydraulic and hydrologic indicator inputs to the Downstream Response to Imposed Flow Transformation for Arid Rivers (DRIFT-ARID) decision support system (DSS). The DRIFT-ARID tool is used in this study to define environmental water requirements (EWR) for non-perennial river flow systems in South Africa to facilitate ecosystem-based management of water resources as required by the National Water Act (Act No. 36 of 1998). Fifty years of distributed daily climate data (1950 to 2000) were used to calibrate the model against decades of daily discharge data at various gauges, measurements of Mokolo Dam stage levels, and one-time groundwater level measurements at hundreds of wells throughout the basin. Though the calibrated model captures much of the seasonal and post-event stream discharge response characteristics, lack of sub-daily climate and stream discharge data limits the ability to calibrate the model to event-level system response (i.e. peak flows). In addition, lack of basic subsurface hydrogeologic characterisation and transient groundwater level data limits the ability to calibrate the groundwater flow model, and therefore baseflow response, to a high level. Despite these limitations, the calibrated model was used to simulate changes in hydrologic and hydraulic indicators at five study sites within the basin for five 50-year land-use change scenarios, including a present-day (with dam), natural conditions (no development/irrigation), and conversion of present-day irrigation to game farm, mine/city expansion, and a combination of the last two. Challenges and recommendations for simulating the range of non-perennial systems are presented.

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Published

2016-07-29

Issue

Section

Research paper

How to Cite

Bob Prucha (2016) “MIKE-SHE integrated groundwater and surface water model used to simulate scenario hydrology for input to DRIFT-ARID: the Mokolo River case study”, Water SA, 42(3 July). doi:10.4314/wsa.v42i3.03.