Development of DRAINMOD-based VBA model for evaluating drainage system response

Subsurface drainage, optimal tile depth, climate change, DRAINMOD

Adhikari, Nidhi ; Cooke ; Richard A.

关键词: Subsurface drainage, optimal tile depth, climate change, DRAINMOD;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/102441/ADHIKARI-THESIS-2018.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This study presents the development of a VBA (Visual Basic for Applications) model that incorporates climatological data, crop drainage requirements and drainage theory into a viable design procedure. The design of subsurface drainage systems is affected by climatic variables such as temperature and precipitation. Climatic conditions are likely to change in the coming decades due to an increase in the atmospheric concentration of greenhouse gases, with global impacts on agriculture. This study assesses the potential impacts of climate change on subsurface drainage design in Illinois. Climate model projections from two general circulation models (GCMs), namely CCSM4 (Community Climate System Model) and MIROC5 (Model for Interdisciplinary Research on Climate), were used to create the climatological database for the VBA model. Case studies were developed with the model for six counties in Illinois for their predominant soil type. Hydrologic simulations from the model were used to determine the optimal depth and spacing of tile drains that maximize crop yield for corn and soybean during the mid and late 21st century. Results show a steady decline in crop yield due to extreme heat stress. For the counties analyzed, a shallow tile depth corresponded with a higher yield for both corn and soybean, while results were inconclusive for an optimal spacing due to variation based on location.