DETECTION OF BURIED AGRICULTURAL DRAINAGE PIPE WITH GEOPHYSICAL METHODS

Abstract

One of the more frustrating problems confronting farmers and land improvement contractors in the Midwest United States involves locating buried agricultural drainage pipes. Enhancing the efficiency of soil water removal on land already containing a subsurface drainage system typically involves installing new drain lines between the old ones. However, before this approach can be attempted, the older drain lines need to be located. Conventional geophysical methods have the potential to provide a solution to this problem. Therefore, in order to determine a better way to detect buried drainage pipe, the abilities of four near-surface geophysical methods were investigated, including geomagnetic surveying, electromagnetic induction, resistivity, and ground penetrating radar (GPR). Of these four, only GPR proved capable of finding agricultural drainage pipe. Furthermore, GPR grid surveys were conducted in southwest, central, and northwest Ohio at 11 test plots containing subsurface drainage systems, and in regard to locating the total amount of pipe present at each site, this technology was shown to have an average effectiveness of 81% (100% of the pipe was found at six sites, 90% at one site, 75% at two sites, 50% at one site, and 0% at one site.) GPR proved, on the whole, to be successful in finding clay tile and corrugatedplastic tubing drainage pipe down to depths of approximately 1 m (3 ft) within a variety of different soil materials. Consequently, although more research is certainly warranted, ground penetrating radar methods appear to have excellent potential with respect to agricultural drainage pipe detection.