Search

The Lower Scioto Cataloguing Unit (LSCU) (OH) is experiencing an increase in irrigated land area. Information on potential impacts of irrigation groundwater withdrawals expansion is needed to assist in the management of a sustainable irrigated land area expansion. It is essential that the evaluation accounts for potential changes in crop irrigation water requirements due to anticipated climate change to insure that the results of the study reflect the aspects of crop irrigation in the short and long term.The study used the Scippo Creek-Scioto River Watershed (SCSRW) (OH) as a case study, and focused on the two most important crops grown in the area of study, which were corn and soybeans. In a preliminary study, a hybrid model that coupled the multimodel ensemble method (Kharin and Zwiers, 2002, Christensen and Lettenmaier, 2007) to a Monte-Carlo simulation was developed to predict future seasonal gross irrigation water requirements. The hybrid model was tested for the years 1969 to 1999 and used to predict seasonal irrigation water requirements for corn for the year 2015 to 2099.A groundwater flow model was developed for the study area using MODFLOW and used to investigate the potential groundwater level decline and streamflow depletion. Mean drawdowns in the order of 0.05 m to 6.26 m occurred between 2015 and 2099 in response to the simulation of various withdrawal scenarios. A depletion model developed using the simulation results indicated that mean drawdowns in the aquifer system could reach 6 m within 73 years in the worst case scenario.