Professor Maggi Kelly
Department of Environmental Science, Policy and Management
“Creating a Spatial Groundwater Database from Historical Records: Adventures in Interpolation”
Groundwater is an invaluable resource that is extremely important to the vitality of California. Over 30 million people, including large industries and agriculture use this natural resource and may have the potential to contaminate or deplete California’s groundwater resources. Groundwater is difficult to monitor from the surface and historical data on groundwater conditions and use is scarce and difficult to locate for the public and regulatory organizations. This study uses advanced Geographical Information System (GIS) tools to compile and digitize California’s groundwater data in a pilot study located in central California. Historic 1950s groundwater data from the United States Geological Survey (USGS) from wells near Fresno, CA were digitized from paper and put into a spatial database. Spatial interpolations of the 1950s digitized data were created to compare the data to current groundwater data. Interpolations use information from known data points to create a continuous surface of information where data points do not exist. Using three methods of interpolation: Kriging, Spline, IDW visual trends can be seen throughout the data for various attributes of groundwater such as sodium or pH concentration. Research proved kriging to be the most accurate method providing the least error in prediction rates throughout the interpolated surface. Through interpolation it is possible to visually identify which wells are contaminated and which wells are not. The data allows us to see pollution, contaminates, and concentrates in the historic study area for comparison with the current data to see changes over time. This project is important because it helps us understand what the historic trends in our groundwater resources are, in order to address the potential problems we might face today.
Sinead is student at Merritt College. She plans on transferring to UC Berkeley and majoring in Conservation and Resource Studies. Her ultimate goal is to teach science to urban kids in underprivileged communities. She has been tutoring at Merritt College since fall 2008. She has worked as a part-time Supplemental Instructor for the Maximum Achievement Project, whose goal is to increase graduation rates of African-American males and other low-income students, tutoring math. After completing her undergraduate degree she intends to continue on with a graduate degree to pursue a career in Conservation Research. While perusing her PhD Sinead wants to focus her research on behavioral ecology of large carnivores.
