D-horizon, dam, damping, dar gecit, Darcian velocity; seepage velocity, Darcy unit, Darcy's law, Darcy-Weisbach equation, dark adaptation, dark zone, dating of cave sediments, datum plane, daylight hole, dead cave, dead end, dead water, debris, debris karren, decalcification, Deckenkarren, declination, declogging, decomposers, decoration, deep percolation, deflocculation, deformation, degradation, degree of cementation, degree of karstification, degree of saturation, delay, delta, demand, demineralization, dendritic, dendritic drainage pattern, density, density current, denudation, denuded karst, depletion, deposition factor, depression, depression spring, depth gage, depth of penetration, desalinization, desander, descender, desert, desiccation, desiccation crack, desorption, detritus, developed section, development, deviation, dew-point, diagenesis, diatomaceous earth, differential water capacity, diffuse circulation; diffuse flow, diffusion, diffusion coefficient, diffusion, convective, diffusivity, hydraulic, diffusivity, soil water, dig, dike, Dinaric Karst, dip, diphenyl brilliant flavine 7GFF, direct yellow 96, dipmeter survey, discharge, discharge area, discharge hydrograph, discharge pipe, discharge pressure, discharge velocity, discharge, evaporation, discharge, hydraulic, discharge, maximum, discharge, natural, disconformity, discontinuity, discontinuity surface, dispersion, dispersion coefficient, dispersion zone, dispersion, longitudinal, dispersion, mechanical, dispersion, transverse, dispersivity, displacement, disposal well, dissociation, dissolution, dissolution of limestone, dissolution zone, distortion, distribution coefficient, distribution, frequency, disturbance, disturbed sample, divide, DNAPL, dog-tooth crystal; dog-tooth spar, doline karst, doline lake, doline; sinkhole, dolomite, dolomitic flour (sand), dolomitic limestone, dolomitization, domain, dome, dome pit, donga, double brake bars, downwarping, drag, drain tile; french drain, drainage area, drainage basin, drainage density, drainage ditch, drainage divide, drainage network, drainage pattern, drainage ratio, drainage system, drainage well, drapery, draw, drawdown, drawdown curve, driphole, dripline, dripstone, drought, drowned karst, drowned spring, dry cave, dry hole, dry valley, duck; duck-under, dug well, dune limestone, Dupuit's assumption, duration curve, Durchgangshohle, dye gaging, dye test, dynamic phreas, dynamic similarity, dynamometer,