Rivers Lakes Bogs Ground waters Protection of fresh waters
Geological structure, topography, climate, and regional history conditioned the diversity of fresh waters in Primorye.
About 600 rivers over 10 km long are found in Primorye. Their general length makes 180 000 km, however, the length of only 91 rivers exceeds 50 km. Mountainous relief, abundant atmospheric fallout, and rather scarce evaporation have conditioned the significant density of a river net in Primorye. Each square meter of land surface houses 0.73 km of rivers, that exceeds the average density of a river net in Russia, that is 0.22 km\km2. Characteristic of the regional rivers is their relatively small extension. The main watershed is the Sikhote-Alin Ridge. From its eastern steeper slope the rivers flow into the Japan Sea, from the western one into the River Ussuri. Another watershed (less extended) is the East Manchurian Mountain System, its rivers flow into Peter the Great Bay.
The area of the western Sikhote-Alin slope includes the upper part of the River Ussuri (basins of rivers Arsenyevka, Bolshya Ussurka, mid part of Malinovka, etc.) The average coefficient of a river net density there makes 0.6-0.8 km/Km2. The area of the eastern slope including the rivers of the Japan Sea basin to the north-east of the River Zerkalnaya mouth is characterized by a well -developed river net mostly peculiar of its southern part (0.8-1.0 km/km2).
South-western Primorye houses the rivers of the Japan Sea basin, the area south off the River Zerkalnaya, the ones flowing into Peter the Great Bay, some rivers of Lake Khanka basin, and the upper and mid parts of the River Komissarovka. It is the area with the densest river net. Its density coefficient (1.2-1.8 km/km2) is the greatest in Primorye. The major rivers are: Partizanskaya, Razdolnaya, Kievka, Artemovka.
The valley around Lake Khanka is drained by the rivers Melgunovka, Ilistaya, Spassovskaya, Belaya, etc. Only the Sungach flows out of the lake and runs into the Ussuri. The rivers of the valley are the shallowest many of them freeze through in winter and dry up in summer.
With distance from a source a river stream changes. In its upper part the steep mountainous slopes come close to riverbeds, wild streams run through rapids and roll over stones, a slope gradient makes 3-5m per 2 km. In mid and low parts the slope gradient increases, the stream becomes quieter, splits into branches, and meanders.
The territory of Primorye is characterized by a monsoon climate therefore the rivers there are predominantly rain-fed. Snow covers formed in winter are not thick ground waters are not abundant.
Non-uniform distribution of atmospheric fallout in time and over territory conditions water regime of local rivers. Characteristic of the rivers in Primorye are floods in warm season, and uneven and unstable water transport in cold season. In warm season rapidly intensifying floods may cause an inundation. Often floods follow one another. At this time the average value of maximal water transport is 10-25 times as high as minimal summer values. Rain floods are common up to September, however in some individual years they occur in October and even in early November. In winter season (December-March) water transport is not intensive, it makes 4-5% of annual volume. Nevertheless the rivers in Primorye abound in water: the average modulus of annual transport makes 10-20 l/sec per a square kilometer, of minimal winter transport it is 0.4-1.0 l/sec per a square kilometer.
Characteristic of water regime of the rivers in Primorye is spring high water added with rain floods. Spring high water occurs in April-May, at this time about 20-30% of annual water volume are transported. Floods of each second/third year cause an inundation. The total square area impacted by catastrophic inundations makes 30% of plains. Inundations impact crop fields and meadows, industrial and residential areas, the damage they produce is tremendous. Thus, in the basin of the River Razdolnaya the flooded are 29 villages, over 60 000 hectares of crop fields and meadows, the city of Ussuriysk and all administrative settlements. Most often catastrophic inundations occur in the basin of the River Ussuri. It is over 60% of all registered major and catastrophic inundations with 34% of them occurring in the area of rivers Bolshaya Usurka and Malinovka. Major floods were registered in other areas too. The most damaged by floods are the cities of Ussuriysk, Lesozavodsk, and Dalnerechensk. During major inundations the period these cities stay flooded makes 8-11 days.
Over one half of all inundations in Primorye occur in August-September. Sometimes major inundations occur on the same river twice. The greatest rise of water level 5.8m\day was registered in the River Razdolnaya near Ussuriysk on August 31 in 1945, on July 24 in 1950 it was 3.6 m/day. Intensive rise of water level was registered in the River Partizanskaya and others in September 1994. Great daily rises of water levels (2.5-3.0 m) were also registered in the rivers Artemovka, Arsenyevka, Ussuri, Belaya, Ilistaya and others. Nowadays the flood protection program has being realized in Primorye.
Rivers in Primorye are the principle source of fresh water for regional industry and residents, as well as for rice fields, vegetable gardens and pasture irrigation. Major and medium rivers are navigable they are used for cargo shipments within Primorye. Much valuable fish, salmon inclusive, come there for spawning. Their energy potential is great but practically not used.
Lakes in Primorye are located mostly in lowlands. Many lakes are found in the basins of rivers Rrazdolnay and Ussuri. Within the Razdolnaya basin the lakes are located in the upper part of the river. They have been formed in course of river wondering over a valley or are the flooded lowest lands. The major lakes are Sazanye and Utinoye. The Ussuri basin accommodates Lake Khanka and 2 800 small lakes whose total square area is 120 km2 .The major in Primorye Lake Khanka occupies the center of Pprikhankaiskaya Plain (its northern part is in China). This pear-shaped lake widens in its northern part. Its water surface is not constant, at high level it is 5 010 km2, at medium 4 070 km2, at low 3 940 km2. Its length at the average multiyear level is 90 km, the greatest width is 67 km. Despite 24 rivers flowing into and only one (Sungach) out of it, the Khanka is shallow. Its average depth is 4.5 m, the maximal depth near the north-western steep coast does not exceed 6.5m. Due to often winds the water in the lake is muddy. Fluctuations in water level depend on climate conditions, however, the recent economic activities, and water-hungry rice farming above all, contribute to the lake ecology. The Khanka is also famous with well-developed fish farming facilities.
Many brackish and saline lakes are concentrated along the Japan Sea shoreline, narrow sand spits isolate them from the sea (some lakes are not completely isolated). These near-shore lakes or lagoons are usually small in size. Several lakes with fresh water are located in the southern Primorye.
Bogs occupy 4% of Primorye territory. Unlike other parts of the Russian Far East the bogs in Primorye are not landscape important. There are many temporary over-dump meadows scattered over plains, however they are not classified as bogs.
Most bogs are concentrated in the Prikhankaiskaya Plain, in the area to the east and west of Lake Khanka, around the Sungach source, and in the Ussuri valley. In the Prikhankaiskaya Plain bogs are the product of Lake Khanka shrinking in size. Most common are bush-and-moss bogs. Between mountains on plateau-like heights there are sphagnum bogs with peat thickness up to 3.5m. Local authorities promote the policy of bog draining and use the drained lands for agricultural purposes.
Besides rivers, lakes, and bogs the fresh waters of Primorye include ground waters, both fracture and middle. Fracture waters are found in hard rock areas occupying the most part of the territory. This type of ground waters accumulated in multiple fractures penetrating mountain rocks is the most abundant in Primorye.
Middle waters are found in sand deposits of river valleys. Primorye is rich of about 60 mineral springs. The water from springs "Lastochka" (the valley of Chernaya the tributary of the Ussuri) and "Shmakovka" is bottled and used for different medical and other purposes.
Protection of fresh waters
Protection of waters is an important part of the environmental protection policy executed in Primorye. It includes the quality control of wastes discharged by local industries and business. The basins of rivers providing tap water for cities and villages are qualified as protected territories restricted for construction activity, logging, pasturing, wild herbs and plants harvesting. All rivers in Primorye are restricted for timber floating. Municipal and administrative centers with intensive economic activity contributing much industrial, agricultural and domestic wastes are required to have waste-water purifying facilities.
Water is a precious gift of nature, to keep it clean is our duty!!!
P. BAKLANOV et al. Geography of
Primorye. Publishing House "USSURI". Vladivostok, 1997. Pacific
Institute of Geography, Far Eastern Branch, Russian Academy of Sciences