Natural Resources, School of

 

Date of this Version

Spring 2-9-2012

Comments

A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Natural Resource Sciences, Under the Supervision of Professors James W. Merchant and Xun-Hong Chen. Lincoln, Nebraska: February, 2012

Copyright (c) 2012 Ruopu Li

Abstract

Modeling groundwater vulnerability to pollution is critical for implementing programs to protect groundwater quality. Traditionally, groundwater vulnerability was modeled based on current hydrogeology and land use conditions. However, groundwater vulnerability is strongly dependent on factors such as depth-to-water, recharge and land use conditions that may change in response to future changes in climate and/or socio-economic conditions. For example, global warming may lead to northward shifts in cropping patterns and changes in crop mixes (and use of farm chemicals). Meanwhile, growing demands for biofuels are resulting in expanding corn acreage, and may lead to pressures to remove land from the Conservation Reserve Program (CRP) or otherwise open lands that are currently not cropped to cultivation. Such changes may have significant implications for groundwater quality. In this research, a modeling framework, which employs four sub-models linked within a GIS environment, was presented to evaluate the groundwater pollution risks under future climate and land use changes in North Dakota. The major sub-models include a groundwater vulnerability model and a biofuels-related land use change model, which were illustrated in two separate studies. The results showed that areas with high vulnerability will expand northward and/or northwestward in Eastern North Dakota under different scenarios. GIS-based models that account for future changes in climate and land use can help decision-makers identify potential future threats to groundwater quality and take early steps to protect this critical resource.

Advisers: James W. Merchant and Xun-Hong Chen