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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Publications at this Location » Publication #337470
Title: Incorporating the Hooghoudt and Kirkham tile drain equation into the Agricultural Policy Environmental eXtender (APEX) model

Author
item FENG, QINGYU - Purdue University
item ENGEL, BERNARD - Purdue University
item Huang, Chi Hua
item Flanagan, Dennis

Submitted to: ASABE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2017
Publication Date: 7/16/2017
Citation: Feng, Q., Engel, B., Huang, C., Flanagan, D.C. 2017. Incorporating the Hooghoudt and Kirkham tile drain equation into the Agricultural Policy Environmental eXtender (APEX) model [abstract]. ASABE Annual International Meeting. CD.

Interpretive Summary:

Technical Abstract: Nitrogen and phosphorus loss from subsurface (tile) drainage systems are reported to play important roles in eutrophication problems happening in various places, especially around the Midwest US. The evaluation of nutrient losses generally take advantage of hydrologic and water quality models that are capable of simulating flow from subsurface drainage systems. The Agricultural Policy Environmental eXtender (APEX) model is one of the models capable of simulating flow from drainage systems and has been intensively used in the Conservation Effects Assessment Projects (CEAP) and many other projects. In the current APEX model, flow from subsurface drainage is simulated by assuming all subsurface flow becomes quick return flow in the drainage soil layer (old routine). This way of representing the drainage system restricts the application of the model for drainage design and planning purposes, which generally considers factors such as drainage spacing, pipe efficiency, etc. This study incorporated the algorithms used in the DRAINMOD model, the Hooghoudt and Kirkham equation, to simulate flow and nutrient loss from the subsurface drainage systems. The results for tile flow, nitrogen and phosphorus loss by the old and new routines were compared to each other and both against observed flow at the field scale. The modification of the model increased the capability of the APEX model for field planning and evaluation regarding subsurface drainage system design and nutrient loss.