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South Dakota Department of Transportation
Project Synopsis
SD2013-05


Title: Climate and Groundwater Data to Support Mechanistic-Empirical Pavement Design in South Dakota
Project Researcher: Bora Cetin, SDSM&T
Project Manager:
Research Period: 11/14/2013 - 11/30/2014
Status:
Cost: $120,000.00

Problem Statement:The AASHTOWare® Pavement ME Design™ software requires location-specific traffic, materials, and climatic data to reliably predict performance of pavement design alternatives. The South Dakota Department of Transportation has begun work to characterize materials and acquire needed traffic data, but has not yet addressed climatic data needs. ME Design uses a complex model known as the Enhanced Integrated Climate Model (EICM) to predict temperature and moisture profiles throughout the pavement structure over its entire design life. EICM requires historical records of five weather-related parameters reported on an hourly basis: ? Air temperature ? Precipitation ? Wind speed ? Percentage sunshine ? Relative humidity For any project location, the user selects an individual weather station or creates a virtual station by selecting multiple stations nearby. The software then interpolates between the selected stations to estimate climatic data for the project location. Embedded within the software are weather observations that comprise 5 to 9 years of data from 11 AWOS or ASOS equipped weather stations scattered across South Dakota. Other agencies such as South Dakota State University, the US Department of Interior, and the Bureau of Reclamation may also have historical data that can be used to enhance the ME Design database. Much of the state, especially the northwest corner, is underrepresented. The user guide for ME Design recommends dividing states that span a wide range of climatic conditions into appropriate climatic zones. Since South Dakota has climatic zones spanning wet freeze, dry freeze, and the higher elevation areas in the Black Hills, appropriate climatic zones must be defined for specific regions. SDDOT also needs to know whether the number and location of weather stations and the historical data record adequately cover the state highway network or need to be enhanced by adding more stations and years of data. ME Design also requires an estimate of depth to water table to predict pavement performance. Although the United States Geological Survey and the SD Department of Environment and Natural Resources operate numerous groundwater monitoring wells throughout the state, the ME Design software does not include historical observations of water table.

Findings:

Research Objectives:
1  Assess the availability and quality of climate and groundwater data within ME Design and from other existing data sources.
2  Develop procedures enabling SDDOT to acquire, maintain, and use climate and water table data in ME Design.
3  Identify enhancements needed to supply and maintain climate and water table data adequate for ME Design.

Research Tasks:
1  Meet with the project’s technical panel to review the project scope and work plan.
2  Review and summarize literature pertinent to climate and groundwater data inputs to the ME Design software.
3  Perform a sensitivity analysis to evaluate the climate and groundwater data needed to support ME Design in South Dakota.
4  Assess the adequacy of climate and groundwater data currently embodied in the ME Design software.
5  Identify other existing sources of climate and groundwater data and evaluate the availability and quality of data for use in ME Design.
6  Identify remaining gaps in climate and groundwater data needed to support ME Design in South Dakota.
7  Submit to the project’s technical panel a technical memorandum summarizing the results of tasks 1-6 and recommending the number of climatic stations, climatic record length, and water table data that should be used in the ME Design Guide.
8  Update ME Design climatic files for appropriate weather stations based on panel recommendations.
9  Develop a procedure and map and software or other appropriate tools for dividing the state into climate zones and selecting one or more weather stations for interpolation to a specific location.
10  Provide a methodology and automated means to annually update climatic files in the format required by ME Design.
11  Provide a map and software or other appropriate tools to assist with the selection of water table depth at a specific location.
12  Prepare a final report summarizing the research methodology, findings, conclusions, and recommendations.
13  Make an executive presentation to the SDDOT Research Review Board at the conclusion of the project.

Documents Available:
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