Types of water supply
Types of food ponds. The type of water supply is one of the main indicators characterizing the features of the design and functioning of the reservoir. Four main types of water supply are common: surface runoff, groundwater, forced filling of reservoirs-digging from a guaranteed source of water supply and a combined diet.
Surface runoff is the main type of water supply of all dam reservoirs. The difference lies only in the ratio of the volumes of the basin of the reservoir and the volumes of the flow. With a significant excess of flow volumes, it is possible to create a cascade of reservoirs located on the same watercourse.
Ground water, as a rule, provides the best sanitary condition of the reservoir due to lower pollution of groundwater and lower temperature, which hinders the formation of duckweed and the development of other algae. Especially favorable is the nutrition of groundwater-pressure water, providing more significant flow and flowage of the reservoir. The number of reservoirs on a purely underground feed is less than on surface runoff. Such reservoirs, as a rule, are located in the floodplains of medium and large rivers, distinguished by wide floodplains. In narrower floodplains, the placement of reservoirs, the organization of water supply and protection from spring and summer-autumn inundation are difficult.
Forced filling of reservoirs-digging from a guaranteed source of water supply is made if there are no good natural sources of water supply. Small reservoirs filled with water from a watering or ordinary water supply. Large reservoirs are often filled with water from specially drilled wells or general wells. There are also such sources as water supply by pumps from rivers, reservoirs or larger and more well-supplied water bodies.
The combined nutrition has to some extent almost every body of water, since liquid and solid precipitations fall on its surface and surface run-off water comes in part.
Regulation of flow. Flow control is typical of dam reservoirs located on permanent or temporary streams. There are three main types of flow control: perennial, seasonal and daily.
The long-term flow regulation is mainly characteristic of large reservoirs (reservoirs) that are of significant economic importance. Landscape works on the shores of such a reservoir should take into account the range of long-term fluctuations in the water level, as a result of which (both natural and forced) seasonally part of the slopes of the reservoir basin is freed from water. It is possible, in the event of a lack of runoff for seasonal regulation, to create a full-fledged reservoir of long-term regulation, provided that the development of economic water use is enhanced or very fluctuationsweak through water withdrawal.
Seasonal flow regulation is based on the fact that runoff is delayed in water bodies during the high-water period (in spring) and consumed in the low-water period (in summer). Every year the process of filling and partial emptying of the reservoir is repeated. This is due to the fact that the main volume of water in the reservoir (with the exception of “dead” volume) is spent on economic needs, such as irrigation of fields, gardens, urban plantings, etc. Such reservoirs are not very attractive in the landscape due to significant seasonal fluctuations in the water level and exposure of the slopes, and partly the bottom of the reservoirs.
Daily flow control is used when operating pumped storage power plants.