topography dividetopography maptoposequencetoppingtopset bed slopetopsoil = surface soiltornadotorpedo sinkertorrenttorrential bed loadtorrential erosiontorrential raintorridtorrid zonetortuous flowtortusitytotal dischargetotal dissolved solidtotal dissolved solidstotal headtotal loadtotal ozonetotal porositytotal pressuretotal radiationtotal runofftotal solidstotal storagetotal stresstotalizertower spillwaytrace elements = micronutrientstrace gasetrace of raintraceingtracerstracetiontracetive forcetracingtracing methodtrackingtractive forcetrade windtrade wind belttrade wind cumulustrade wind fronttrade wind inversiontrade windstraining walltrajcetory basin