Introduction

Numerical modeling of the hydrologic system is an important tool used by scientists and engineers to increase their understanding of how man interacts with natural water systems. The USGS/WRD uses many different types of numerical models, including chemical transport, groundwater flow, surface-water flow and watershed models. The USGS is a leader in the development and application of ground-water models. The USGS flomod groundwater model is the standard tool used for groundwater modeling by private and governmental organizations in the United States. Additionally, the USGS has developed a watershed modeling framework,the Modular Modeling System, that allows nonprogramming hydrologic modelers to develop site specific models from a tool kit of routines. And until recently, the USGS also had surface-water hydraulic models such as WSPRO and FESWMS that were used extensively in the United States.

However, the availability of commercial software that has model pre and post processing capabilities has led to a decline in the use of some USGS models and to a lack of recognition by the public of the USGS contributions to the models that they are using. Funding earmarked specifically for model development has also declined. Most widely used USGS models were funded either by outside agencies (FESWMS and WSPRO were funded by FHWA, and HSPF by EPA) or by a large national program such as RASA (ModFlow). Funding has not been available from these sources and the current major national program, NAWQA, does not have any emphasis on modeling transport and flow mechanisms. This has resulted in the stagnation of model development in some areas.

Problem Statement

Most of the USGS models lack computer programs for pre and post processing of model inputs and results. This is hampering the use of USGS models because other models of similar capability have these tools available. In some cases, lack of user guides and documentation for research community models has also limited their application by persons outside the research community of the WRD. Other research models need additional development to allow users to apply the model at new locations without having to alter the source code of the model. Additionally, the utility of many existing models could be improved by enhancements or by the addition of new features. In some modeling areas new numerical schemes need to be investigated for suitability in solving difficult flow problems.

Proposed Solution

It is proposed that special funding be earmarked for model development. This funding will provide model developers with the means to assemble model-development teams. Model development teams will be composed of a team leader-model developer, interface programmers and model programmers. Development teams will focus on either improving the simulation capabilities of a model or building pre and post processors for a class of models. Funds will be awarded competitively, based on proposals submitted by model developers. Funding will be for a two year period with renewal possible at the end of two years. Proposal selection would be based on how well proposals address existing and especially future modeling needs of programs in the WRD. The selection committee would be drawn primarily from the technical offices of the WRD.

Funding requirements

Funding needs for model development are dependent on the priorities of the WRD. It is outside of the scope of this proposal to prioritize specific modeling issues and therefore estimate the total funding needed for WRD model development. However, the funding requirements for a small modeling team is presented to illustrate the amount of funding needed for one model development team.

A modeling team for developing a pre and post processor will typically have at least a model developer/programmer as the lead and an interface programmer as support. Using this as a base, the estimated costs for funding a modeling team is:

Project leader GS 13      @70K/year
Programmer GS 11/12      @45K/year
Overhead est 20%      @23K/year
Equipment      @3K/year

Total      141K/year = 282K/team/funding cycle

Summary

This proposal outlines a funding method to help refresh and invigorate use and development of USGS/WRD models. It proposes competitive funding for model development teams and estimates the cost of a development team to be 141K/year. A committee drawn from the technical offices would solicit and select which proposals to fund.