Frozen soil impact on ground water-surface water interaction

Ground water and surface water interaction in the prairie pothole region of the United States and Canada is seasonally dominated by the presence of th ick, frozen soil layers that affect infiltration. During a spring thaw, the subsoil may remain frozen, preventing infiltration. The impact of the froz en soil layer on the timing of infiltration of depressional-focused recharg e to the ground water is not clearly understood. The objective of this pape r is to relate changes in the water table during spring to changes in frost depth and soil water content. A depression and adjacent upland study site were instrumented with CRREL-type frost tubes, neutron probe access tubes, and ground water monitoring wells. Increases in water table levels in a dep ression occurred before the frost layer decomposed and infiltrating water q uickly formed a recharge mound. Water table responses at the upland site to ok place as two events. The first event was a gradual rise, probably caused by the lateral dissemination of the recharge mound. The second rise was a rapid rise coinciding with the decomposition of the soil frost layer. Becau se of the accumulation of surface water in depressions, agricultural practi ces that remove water from a field can affect water resources management by limiting the addition of water recharge to unconfined ground water.