DEVELOPMENT OF A DEEP BOREHOLE PERMEAMETER TO DETERMINE UNSATURATED HYDRAULIC PROPERTIES DEVELOPMENT OF A DEEP BOREHOLE PERMEAMETER TO DETERMINE UNSATURATED HYDRAULIC PROPERTIES

PREDICTING THE RATE OF SOIL WATER MOVEMENT AND THE IMPACT OFAGRI-CHEMICALS ON WATER RESOURCES IS VITALLY IMPORTANT TO MANAGING AGRICULTURE, FOR OPTIMIZING PRODUCTIVITY AND MINIMIZING ENVIRONMENTAL IMPACT. SOPHISTICATED MODELS FOR MAKING SUCH PREDICTIONS ARE AVAILABLE, BUT DATA ON SOIL HYDRAULIC PROPERTIES ARE DIFFICULT AND OFTEN EXPENSIVE TO OBTAIN. IN FACT, AT DEPTHS BELOW THE ROOT ZONE THERE IS NO FIELD METHOD AVAILABLE TO DETERMINE WHAT IS OFTEN THE SINGLEMOST IMPORTANT SOIL PROPERTY, UNSATURATED HYDRAULIC ] CONDUCTIVITY. THE PROPOSED RESEARCH IS DIRECTED TOWARD DEVELOPING A PRACTICAL FIELD TOOL TO DETERMINE UNSATURATED HYDRAULIC CONDUCTIVITY IN SITU IN DISCRETE INTERVALS OVER ANY DEPTH. IN PHASE I OUR FIRST TASK IS TO COMPILE EXISTINGANALYTICAL SOLUTIONS THAT MAY BE RELEVANT TO DEVELOPING OUR UNSATURATED SOIL PERMEAMETER. THE SECOND TASK WILL BE TO EVALUATE THE SUITABILITY OF THE EXISTING SOLUTIONS USING MATHEMATICAL ANALYSES, AS WELL AS NUMERICAL SIMULATIONS. WEWILL ALSO EXPLORE THE FEASIBILITY OF DEVELOPING NEW ANALYTICAL AND NUMERICALLY-BASED REGRESSION SOLUTIONS. THE THIRD TASK IS TO ASSESS THE FEASIBILITY OF DEVELOPING FIELD EQUIPMENT NECESSARY TO SATISFY THE BOUNDARY CONDITIONS AND DATA REQUIREMENTS SPECIFIED BY THE MATHEMATICAL MODEL. IN PHASE II WE WOULD PROPOSE TO CONSTRUCT AND TEST THE FIELD EQUIPMENT, AND IN PHASE III THE APPARATUS WOULD BE COMMERCIALLY DEVELOPED AND MARKETED. THE APPLICATION OF OUR NEW METHODOLOGY WOULD PROVIDE A TIMELY RESPONSE TO A VERY SIGNIFICANT DATA REQUIREMENT FACED NOT ONLY BY MANY SOIL SCIENTISTS, BUT ALSO GEOTECHNICAL ENGINEERS AND HYDROLOGISTS CONCERNED ABOUT SEEPAGE FROM IMPOUNDMENTS AND LAND FILLS, HAZARDOUS WASTE MOVEMENT IN SOIL, REMEDIAL ACTION PROGRAMS, AND HIGH LEVEL RADIOACTIVE WASTE STORAGE IN THE UNSATURATED ZONE. MODELERSAND REGULATORS WILL HAVE SIGNIFCANTLY GREATER CONFIDENCE IN PREDICTIONS OF UNSATURATED FLOW AND TRANSPORT IF A RELIABLE TOOL IS USED TO OBATAIN DATA AT ALL DEPTHS IN THE FIELD AT THE SCALE OF INTEREST.