Hydrology Professional Development Series (PDS) 2 : Develop, Implement and Maintain Models and Tools

PCU 1: Calibrate a model

Producers:

Description of Job Competency to be Achieved :
NWS hydrologic forecasting requires simulations that are representative of the systems they seek to emulate so that projections of hydrologic conditions in the future can be made with accuracy and confidence.

Description of Need :
Hydrologic forecasters, whether at an RFC or WFO, need to understand how the parameters embedded within the structure of existing, vetted hydrologic models affect simulation outcome and calibration. To conduct simulation calibration, hydrologists will need to describe drainage basin topology, assemble quality-controlled historical forcing datasets, characterize the hydraulic routing behavior through usage of unit hydrographs and routing schemes, and configure system simulation architecture and data retrieval. Hydrologists will also need to make the choice of whether to pursue manual or automated means of parameter estimation. Automated methods introduce a new set of control parameters that govern the selection of a non-dominated set of parameter values for the hydrologic model being calibrated.

Training resources may initially be available at: http://www.nws.noaa.gov/oh/hrl/modelcalibration/outline.html

Abilities/Performance Elements:

Ability 1. Model Calibration Background (manual "tuning" guidelines) Explore the effect of various parameters on model outcome, across the spectrum of available models in usage by NWS, and choose a calibration strategy to employ. Skill 1.1. Sacramento Soil Moisture Accounting Model (SAC-SMA) Recognize and define the effect of model parameters in SAC-SMA on hydrologic budget, hydrograph, and flow routing. Specific training module needed - will be made available when developed. References: Anderson, Eric. 2002. Calibration of Conceptual Hydrologic Models for Use in River Forecasting. http://www.nws.noaa.gov/oh/hrl/hsmb/hydrology/calibration/training_Aug2002.html Koren, K. et al. 2007. Physically-Based Modifications to the Sacramento Soil Moisture Accounting Model: Modeling the Effects of Frozen Ground on the Rainfall-Runoff Process. NOAA Technical Report NWS 52. http://www.nws.noaa.gov/oh/hrl/hsmb/docs/hydrology/PBE_SAC-SMA/NOAA_Technical_Report_NWS_52.pdf Moser, C. et al. 2013. Comparison of the SAC-SMA and API-CONT Hydrologic Models at Several Susquehanna River Headwater Basins. Eastern Region Technical Attachment No. 2013-01 https://repository.library.noaa.gov/view/noaa/6634 Sacramento Soil Moisture Accounting (SAC-SMA) Model http://www.nws.noaa.gov/oh/hrl/general/chps/Models/Sacramento_Soil_Moisture_Accounting.pdf Related training materials: IC Title: National Weather Service River Forecast System Model Calibration Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: An overview of the calibration process. Specific addresses estimation of parameter values which will minimize differences between observed and simulated streamflows. Vetted: No Skill 1.2. Recognize and define the effect of model parameters in API on hydrologic budget, hydrograph, and flow routing. Specific training module needed - will be made available when developed. References: Moser, C. et al. 2013. Comparison of the SAC-SMA and API-CONT Hydrologic Models at Several Susquehanna River Headwater Basins. Eastern Region Technical Attachment No. 2013-01 https://repository.library.noaa.gov/view/noaa/6634 Continuous Incremental API (API-CONT) Model http://www.nws.noaa.gov/oh/hrl/general/chps/Models/Continuous_Incremental_API.pdf Skill 1.3. SNOW-17 parameter selection and use Recognize and define the effect of model parameters in SNOW-17 on hydrologic budget, hydrograph, and flow routing. Specific training module needed - will be made available when developed. References: Anderson, Eric. 2002. Calibration of Conceptual Hydrologic Models for Use in River Forecasting. http://www.nws.noaa.gov/oh/hrl/hsmb/hydrology/calibration/training_Aug2002.html Snow 17 model documentation http://www.nws.noaa.gov/oh/hrl/general/chps/models/SNOW-17.pdf Gridded SNOW-17 Model http://www.nws.noaa.gov/oh/hrl/general/chps/Models/Gridded_Snow-17.pdf Related training materials: IC Title: Snowpack and Its Assessment Present Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This module explores the science of snowpack and snowpack assessment. It begins by describing the factors involved in snowpack development and then focuses on snowpack evolution. Using two scenarios (one set in mountainous terrain, the other in a relatively flat area), the module explores how basic processes, such as conduction and radiation, and various precipitation events impact snowpack. Vetted: Yes IC Title: Snowmelt Processes Present Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This module helps the student develop an understanding of the contribution of snowmelt in the hydrologic forecasting process. The module first explains the influences of wind, sun, terrain, and vegetation on snow water distribution and then discusses the evolution of snowpack characteristics. From there, the student will learn about energy exchanges between the snow and the atmosphere and how that affects how quickly and how completely snow will melt. Finally, an explanation is presented of water flow through snow and the fate of that water when it reaches the ground surface. The lesson will be highlighted with brief examples of actual snowmelt cases. Vetted: Yes Skill 1.4. Research Distributed Hydrologic Model (RDHM) components and use Recognize and define the effect of model parameters in RDHM on hydrologic response and where a distributed approach may be more advantageous. Specific training module needed - will be made available when developed. Related training materials: IC Title: Distributed Hydrologic Models for Flow Forecasts - Part 1 Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: Distributed Hydrologic Models for Flow Forecasts – Part 1 provides a basic description of distributed hydrologic models and how they work. This module is the first in a two-part series focused on the science of distributed models and their applicability in different situations. Presented by Dr. Dennis Johnson, the module begins with a review of hydrologic models, and then examines the differences between lumped and distributed models. Other topics covered include the advantages of physically-based versus conceptual approaches and some strengths and challenges associated with distributed modeling. Vetted: Yes IC Title: Distributed Hydrologic Models for Flow Forecasts - Part 2 Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: Distributed Hydrologic Models for Flow Forecasts Part 2 is the second release in a two-part series focused on the science of distributed models and their applicability to different flow forecasting situations. Presented by Dr. Dennis Johnson, the module provides a more detailed look at the processes and mechanisms involved in distributed hydrologic models. It examines the rainfall/runoff component, snowmelt, overland flow routing, and channel response in a basin as represented in a distributed model. Calibration issues and situations in which distributed hydrologic models might be most appropriate are also addressed. Vetted: Yes Skill 1.5. HEC-RAS model parameter selection Recognize and define the effect of model parameters in HEC-RAS on hydraulic flow routing. Specific training module needed - will be made available when developed. References: Koehler, R. 1988. An Analysis of a Numerical Tidal Model Applied to the Columbia River. Master’s Thesis. U.S. Naval Postgraduate School. Monterey, CA. https://archive.org/details/analysisofnumeri00koeh Related training materials: IC Title: Dams and Dam Failure - Module 1: Terminology and Open Channel Hydraulics Present Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This is the first module of a two-part series offering an introduction to the science explaining catastrophic dam failure and flood-wave prediction methods associated with these events. This module explains key terminology and concepts including dam types and purposes, failure statistics, the general dam failure process, open channel hydraulics, critical flow, Manning's equation, and conveyance. The information covered in this two module series will provide a scientific foundation for advanced course work needed to run dam break simulations and to conduct hydraulic modeling as a part of dynamic wave forecasting. IC Title: Dams and Dam Failure - Module 2: St. Venant Equations, Modeling, and Case Study Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This second module in the two-part series expands on the science explaining catastrophic dam failure and flood-wave prediction methods associated with these events. This module introduces the St. Venant equations for dynamic wave flow, and flood wave characteristics. It also explains the general dam failure modeling process along with advantages and limitations of dam failure models including model stability, accuracy, and sensitivity issues. Finally, it also provides an overview of the Teton River dam failure, one of the most famous hydrologic events in U.S. history. The two modules that comprise this series are designed to be taken consecutively and together provide a fundamental understanding of this complex hydrologic and hydraulic topic. Skill 1.6. Automated versus manual calibration Describe the difference between manual and automated simulation calibration, and understand the generic principles of optimization. Specific training module needed - will be made available when developed. References: Models: http://www.nws.noaa.gov/oh/hrl/general/indexdoc.htm Calibration: http://www.nws.noaa.gov/oh/hrl/modelcalibration/outline.html

Ability 2. Building Input Datasets for Calibration Skill 2.1. Create basin topology Define basin topology with subdivided basin boundary outlets that are based on available flow data, watershed drainage characteristics and service requirements (ie; new forecast point request). Specific Integrated Hydrologic Automated Basin Boundary System (IHABBS) training module needed - will be made available when developed. References: NOHRSC Technology > NOHRSC GIS Applications > IHABBS Integrated Hydrologic Automated Basin Boundary System (IHABBS), An Overview http://www.nohrsc.noaa.gov/technology/gis/ihabbs_overview.html Characterize sub-basin hydrology through creation of unit hydrographs (manual and synthetic). Both manual methods and synthetic methods IHABBS training modules needed, although existing Unit Hydrograph Theory training modules may suffice. References: NOHRSC Technology > NOHRSC GIS Applications > IHABBS Integrated Hydrologic Automated Basin Boundary System (IHABBS), An Overview http://www.nohrsc.noaa.gov/technology/gis/ihabbs_overview.html Related training materials: IC Title: Unit Hydrograph Theory Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This module offers a thorough introduction to the use of unit hydrographs and the application of unit hydrograph theory in flood prediction. The lesson outlines the steps in creation of a unit hydrograph, examines the issues surrounding application of unit hydrograph theory, and discusses important considerations for forecasters. Vetted: Yes Skill 2.2. Acquire historical data for calibration activities and create historical forcings Locate, acquire, and examine historical station data (precip, temp, evap, snowpack and flow). This includes NCDC precipitation and temperature data access, PRISM data access, USGS WATSTORE access, and datacard formatting for input into calibration system. Specific training module needed - will be made available when developed. Define forcings by developing MAP (Mean Areal Precipitation) and MAT (Mean Areal Temperature) time series. Specific training module needed - will be made available when developed. (IDMA and refs available). Skill 2.3. Configure system settings for simulation calibration with CHPS Build CHPS calibration configuration to utilize manufactured inputs. Specific training module needed - will be made available when developed. References: He. K. et al., 2012. Guidance on Conducting Streamflow Hindcasting in CHPS. Unassigned release number. https://www.nws.noaa.gov/oh/hrl/general/HEFS_doc/HEFS-0.3.2_HindcastingGuide.pdf Skill 2.4. Estimate initial parameters (SAC-SMA, SNOW-17, etc) Estimate reasonable and justifiable initial parameter values through usage of the Calibration Assistance Program (CAP), automated procedures, values for nearby calibrated basins, or through interaction with senior, experienced forecaster. Specific training module needed. See Skill 1.1 through 1.3 listed above. Skill 2.5. Select routing methods for non-headwater basins (basins with multiple upstream data or forecast points) Select an appropriate and justifiable routing method to employ when modeling non-headwater basins and create appropriate format for inclusion in calibration configuration. Specific training module needed - will be made available when developed. References: IC Title: Streamflow Routing Present Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This module offers a thorough introduction to streamflow routing methods and applications in the river forecasting process. This module explains key routing concepts, flow characteristics, and tools with a primary focus on hydrologic routing methods. Vetted: Yes Skill 2.6. Prepare inputs specific to HEC-RAS Create/obtain river and floodplain geometric data (cross-sections, estimates of manning’s n values, conveyance parameters, etc.) and observed stage/flow data for input into HEC-RAS. Specific training module needed on inputs specific to HEC-RAS calibration- will be made available when developed. References: Koehler, R. 1988. An Analysis of a Numerical Tidal Model Applied to the Columbia River. Master’s Thesis. U.S. Naval Postgraduate School. Monterey, CA. https://archive.org/details/analysisofnumeri00koeh Related training materials: IC Title: Dams and Dam Failure - Module 1: Terminology and Open Channel Hydraulics Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This is the first module of a two-part series offering an introduction to the science explaining catastrophic dam failure and flood-wave prediction methods associated with these events. This module explains key terminology and concepts including dam types and purposes, failure statistics, the general dam failure process, open channel hydraulics, critical flow, Manning's equation, and conveyance. The information covered in this two module series will provide a scientific foundation for advanced course work needed to run dam break simulations and to conduct hydraulic modeling. IC Title: Dams and Dam Failure - Module 2: St. Venant Equations, Modeling, and Case Study Type: Formal Training (in LMS) URL/location: https://doc.csod.com Description: This second module in the two-part series expands on the science explaining catastrophic dam failure and flood-wave prediction methods associated with these events. This module introduces the St. Venant equations for dynamic wave flow, and flood wave characteristics. It also explains the general dam failure modeling process along with advantages and limitations of dam failure models including model stability, accuracy, and sensitivity issues. Finally, it also provides an overview of the Teton River dam failure, one of the most famous hydrologic events in U.S. history. The two modules that comprise this series are designed to be taken consecutively and together provide a fundamental understanding of this complex hydrologic and hydraulic topic.

Ability 3. Conduct Calibration Calibrate a forecast point or other hydrologic condition that is simulated, either through manual or automated optimization techniques. Skill 3.1. Optimization control for automated procedures Optimize the controls embedded within automated calibration routines and tools (parameters in Shuffled Complex Evolution, SLS, etc.). Specific training module needed - will be made available when developed. Skill 3.2. Test hydrologic calibration outcome and assess future performance Assess performance (based on relevant statistics, other criteria, etc.) of hydrologic simulation using new model inputs. Compare simulated to observed, where historical data are available. Adjust model parameters to improve simulation until desired results are achieved. Specific training module needed - will be made available when developed. Skill 3.3. Calibrate and run HEC-RAS Calibrate (based on relevant statistics, other criteria, etc.) hydraulic simulation by comparing simulated to observed data, where historical data are available. Adjust model parameters to improve simulation until desired results are achieved. Employ HEC-RAS simulation results or other quantified hydraulic conveyance to test, corroborate, and/or calibrate the performance of hydrologic forecast simulation. Specific training module needed - will be made available when developed. References and related training materials: The US Army's Hydrologic Engineering Center (HEC), Davis, CA has a wealth of training material and classes already prepared dealing with HEC-RAS. https://www.hec.usace.army.mil/training/list.aspx It may be cost effective for NWS to partner with HEC to provide this training to NWS hydrologic staff. Courses include: Advanced 1D/2D Modeling with HEC-RAS Advanced Applications of HEC-HMS Advanced Steady Flow Analysis with HEC-RAS Consequence Estimation with HEC-FIA CWMS Modeling for Real-Time Water Management Flood Frequency Analysis H&H for Dam Safety Studies Hydrologic Analysis For Ecosystem Restoration Hydrologic Engineering Applications for GIS Hydrologic Modeling with HEC-HMS Reservoir System Analysis with HEC-ResSim Risk Analysis For Flood Risk Management Sediment Transport Analysis With HEC-RAS Statistical Methods in Hydrology Steady Flow with HEC-RAS Unsteady Flow Analysis with HEC-RAS Water Data Management with HEC-DSSVue Water and the Watershed Water Quality Modeling with HEC-RAS Water Resource Analysis Using HEC-WAT