Water Resources Research Act Program

Details for Project ID 2006TX222B

Determining Effects of Brush Clearing on Deep Drainage Using Soil Chloride; a Feasibility Study for South Texas Rangelands

Institute: Texas
Year Established: 2006 Start Date: 2006-03-01 End Date: 2007-02-28
Total Federal Funds: $4,974 Total Non-Federal Funds: $18,312

Principal Investigators: David Barre, Georgianne Moore

Abstract: There is a need to understand the possibility of using land management as a tool to increase groundwater recharge. Quantifying deep drainage can be used to better inform soil water balance comparisons due to likely impacts of changing land use on groundwater recharge and quality. Using chloride mass-balance methods is a useful tool to measure deep drainage because it quantifies cumulative drainage over long time periods. The objectives for this study are to obtain preliminary estimates of soil chloride levels and electrical conductivity in order to provide necessary information to plan a future extensive study. The study area is located approximately 3 miles (KM) east of Cotulla, TX in La Salle County on Private land Northcut Ranch. Brush clearing is a common treatment by ranchers to reduce brush cover and increase forage production. There are 3 sites within the study area, each with 4 treatments; a control (not cleared), 3 months, 5 years and 15 years since vegetation removal. For this preliminary study, 4 profiles will be sampled at each of 2 treatments (the control and the 15 years treatment) for 2 of the sites (total of 16 profiles). We expect to be able to determine rates of deep drainage, using the chloride mass balance data, to see if clearing of vegetation over a period of 15 years will increase groundwater recharge.