The urbanisation influences strongly the development of Bulgarian villages - on the first place by attracting rural population to urban centers. Main sources of migration flows are the grain-producing regions, the areas nearby the cities, remote
and less-industrialised peripheries as well as some ports with less favourable natural conditions. Between 1946-83, the rural population decreased from 5,3 to 3,1 millions. A special attention is paid to the rapid expansion of labour commuting from villages