Reciprocal influence of large reservoirs and adjacent territories in different natural conditions of the USSR

✍ Scribed by Prof. S. L. Vendrov

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 307 KB
• Volume: 58
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.19730580205

✦ Synopsis

Reciprocal influence of large reservoirs and adjacent territories in different natural conditions of the USSR The surface area of large reservoirs in the USSR (impounded rivers and lakes) reached 120,000 kmz by 1971 including 70,000-75,000 km2 of flooded land. Most, reservoirs are located in plain areas and floods inundate a n additional 20,000-40,000 kmz of land surface. The available storagc is 450 km3; the total annual river discharge of the country is about 4,350 kma; guaranteed natural discharge (dormant season streamflow plus minimal flood flow) is 1600-1800 km3/year. We may say that a considerable transformation of the drainage network has been made, including that on thc Volga and the Kama, the Dniepr, the Nizhny Don, many rivers of the Caucasus and Transcaucasus, Kola Peninsula, the Volkhov, the Svir, the Zapadny Dvena, the Neman, the Dnestr, the Verkhnaya ob, the Enisey, the Angara, the Zeya, the Sirdarya and the Amudarya and their tributaries, the Irtysh, the Ili, the Ural and others.

The construction of reservoirs has resulted in changes of natural and economic coridit.ions on vaste territories. Therefore, the optimal utilization of water and other natural resources (soil, forest, climate, oil and gas, minerals, fuel, building materials, ctc.) becomes pressing for the national economy in general.

For these reasons, the problems of reciprocal influence of new large reservoirs and thc adjacent. lands (river valleys and adjacent territories) acquire a n increasing importance. It is necessary to study not only the influence of the drainage basin upon the rcservoir (this dcterrnines the quantity, quality and regime of the incoming water and the chemistry and biology of rescrvoir), but also tJhe effect of reservoirs on t.he land. This influence differs from that of lakes diie to thc different amplitude of water level fluctuations. The annual amplitude of water levels of large natural lakes of t,he country existing a t different latitudeson plains and in the mountainsis 0.2-1.2 ni. The following annual fluctuations of water levels are characteristic for large reservoirs: 2-8 m on the plains, 50-80 m in the mountains, 10-20 I n on the intermediate territories. These fluctuations produce changes in the surface area (on the plains nearly 2 times). They change the depth, water movements, t.he charactcr of abrasion, tho income of suspended solids and t,heir accretion, and cause seasorial changes of the dynamics of groundwaters in the shore slopes. Reservoirs, in contrast t o lakes, in different seasons of t,he year are somewhat different water bodies. Their influences on the adjacent land are different.

All types of influencc of a reservoir on the adjacent land are long-term. They can be divided into 3 groups: ( 1 ) the immediate influences-sharply changing the economic conditions of the territory, for example, transformation of the shores by a newly constructed reservoir; ( 2 ) influences which also are immediate, but where the transformations changing the economic conditions occur a t a very slow rate-for example, the consequences of changes in the local climate and groundwater level in the adjacent areas, or radical changes of the river valley topography, especially