Seim River [Сейм; Sejm]. (Map: Seim River.) The largest tributary (left-bank) of the Desna River. After originating in the uplands of Belgorod oblast the river flows for 748 km through Kursk oblast, Sumy oblast, and Chernihiv oblast. It has a width of approx 80–100 m, a valley of 9–12 km, and a basin area of 27,500 sq km. It ices over from early December to late March. Its waters are used for industrial and water-supply purposes as well as for pisciculture and agriculture. Navigation is possible on its lower reaches. Some of the major centers on the river are Kursk, Lgov, Rylsk, Putyvel, and Baturyn.
[This article originally appeared in the Encyclopedia of Ukraine, vol. 4 (1993).]