TheDaugava (/ˈdaʊɡəvə/DOW-gə-və),[a] also known as theWestern Dvina[b] or theVäina River,[c] is a large river rising in theValdai Hills ofRussia that flows throughBelarus andLatvia into theGulf of Riga of theBaltic Sea. The Daugava rises close to the source of theVolga. It is 1,020 km (630 mi) in length,[1] of which 352 km (219 mi) are in Latvia[3] and 325 km (202 mi) in Russia. It is a westward-flowing river, tracing out a great south-bending curve as it passes through northern Belarus.
Latvia's capital,Riga, bridges the river'sestuary four times. Built on both riverbanks, the city centre is 15 kilometres (9.3 mi) from the river's mouth and is a significant port.
According toMax Vasmer'sEtymological Dictionary, thetoponym Dvina cannot stem from aUralic language; instead, it possibly comes from anIndo-European word which used to mean 'river' or 'stream'.[4] The nameDvina strongly resemblesDanuvius which is itself derived from the Proto-Indo-European*dānu, meaning 'large river'.
The Swedish army bombarding the fortress ofDünamünde at the Daugava's estuary inLatvia
Humans have settled at the mouth of the Daugava and along the shores of the Gulf of Riga for millennia, initially participating in a hunter-gatherer economy and utilizing the waters of the Daugava estuary for fishing and gathering. Beginning around the sixth century CE,Viking explorers crossed the Baltic Sea and entered the Daugava River, navigating upriver into the Baltic interior.[5]
In medieval times, the Daugava was part of thetrade route from the Varangians to the Greeks, an important route for the transport of furs from the north and ofByzantine silver from the south. The Riga area, inhabited by theFinnic-speakingLivs, became a key location of settlement and defence of the mouth of the Daugava at least as early as the Middle Ages, as evidenced by the now destroyed fort atTorņakalns on the west bank of the Daugava in present-day Riga.
The river began experiencing environmental deterioration in the Soviet era due to collective agriculture (producing considerable adverse water pollution runoff) and hydroelectric power projects.[6] This is the river that theVula river flows into.
Upstream of the Latvian town ofJekabpils, the river'spH has a characteristic value of about 7.8 (slightalkaline). In this area, the concentration of ionic calcium is around 43 milligrams per liter,nitrate is about 0.82 milligrams per liter, ionicphosphate is 0.038 milligrams per liter, and oxygen saturation is 80%. The high nitrate and phosphate load of the Daugava has contributed to the extensive buildup of phytoplankton biomass in the Baltic Sea; theOder andVistula rivers also contribute to the high nutrient loading of the Baltic.[citation needed]
In Belarus, water pollution of the Daugava is considered moderately severe, with the chief sources being treated wastewater, fish-farming, and agricultural chemical runoff (such as herbicides, pesticides, nitrates, and phosphates).[7][8]
