From Big Medical Encyclopedia

GARDENING — creation in the inhabited places of zones of green plantings. Lakes carry out for improvement of the air basin, formation of an optimum microclimate, improvement of the noise mode, creation of conditions for rest, and also with the decorative and planning purposes (individualization of an appearance of the city, revival of its landscape, elimination of monotony of building and creation of the favorable habitat for the person). Results of studying a heat - and the gas-detaining role of wood and shrubby landings demonstrate that dust content of air among green plantings is 2 — 3 times lower, than on open sites.

Fig. 1. The recommended scheme of landing of protective strips from trees and bushes: a profile (a) and the plan (b) of a design of one forest shelter belt consisting of four rows of a bush (1, 2), trees of auxiliary breeds (3) and the main breeds (4). General bandwidth of 21 m. A profile (v) of gardening from three forest shelter belts. Distance between strips of 40 m.

The greatest pylezaderzhivayushchy ability breeds of trees and bushes with the rough, covered with fibers leaves (an elm, a linden, a maple, a lilac) have. The gas-protective role of green plantings is caused by ability of plants to catch the gases which are contained in free air and firmness in relation to them. The poplar, the Canadian maple, an acacia white, a privet, a honeysuckle can be carried to the most gas resistant. Influence of green plantings on dust content of air and decrease in concentration of gases depends on the nature of landings: their density, configuration, structure (fig. 1). In improvement of air of the inhabited places ability of plants to absorb carbon dioxide gas and to emit oxygen is of great importance. On average 1 hectare of green plantings for an hour absorbs 8 l of carbonic acid. Intensity of this process depends on features of photosynthesis of various breeds of trees and bushes.

Green plantings play an essential role in formation of a favorable microclimate of the inhabited places, changing radiatsionnoteplovy conditions, the wind mode and air humidity. It is noted that heatfeelings of the person who is in a zone of a green array are more favorable, than in other zones, even in hot weather since green plantings depending on the frequency of landings and transparency of kroner pass from 1/20 to 1/100 parts of a range of sunlight. On the shaded sites temperature of the soil and hard coatings of roads decreases, tension of the direct and reflected heat of solar energy decreases. Improvement of a microclimate is promoted a takyacha by increase in air humidity as a result of evaporation of moisture leaves at an elevated temperature. It is known what for a year of 1 hectare of the wood evaporates 1 — 3,5 million kg of moisture in the atmosphere. Even small green arrays increase air humidity in the adjacent territory for 20 — 30%. Wind-shelter action of green plantings is of great importance. Dependence of reduction of speed of wind on height of a strip of green plantings is presented in the table.

Fig. 2. The scheme of convection air exchange between the insoliruyemy and shaded platforms in a residential zone: 1) asphalt (insoliruyemy site); 2) the planted trees and shrubs site (shadow); 3) the direction of convective currents (it is shown by shooters).

Plantings influence the local air flows promoting vertical airing of the territory (fig. 2). Alternation of the planted trees and shrubs and open sites allows to strengthen airing of the territory and to create a favorable microclimate in the city that is especially important for the cities located in climatic zones of the South.

Green plantings influence decrease in noise level. Well developed wood and shrubby landings at the correct organization of a noise-protective strip (dense landing of vysokokronny trees and a bush) can lower noise levels in the territory, adjacent to the highway, by 8 — 12 dB.

O.'s inclusion in planning structure of the city favorably influences the environment and living conditions of the population. City green plantings refer to three main categories: public (city, regional recreation parks, gardens of inhabited districts and residential districts, squares, boulevards, forest parks); limited use (the planted trees and shrubs sites of schools and other educational institutions, nurseries, treatment and prevention facilities, sports constructions, etc.); special purpose (gardening of streets, sanitary protection zones, nurseries, botanic gardens, etc.).

The total area of green plantings in the territory of the residential district shall make not less than 10 m 2 on the person.

Control over the implementation of accepted standards and recommendations about O. is carried out at all stages a dignity. supervision of a design of the inhabited places (see. Town planning , the Design of the inhabited places ). Bodies dignity. - epid, services and services of gardening of the cities control performance of norms of gardening, correctness of the organization of system of green plantings taking into account their main functions, equitability of green plantings in the territory of the settlement, O.'s carrying out of residential districts, sanitary protection zones, streets, sites of nurseries and treatment and prevention facilities.

Table. Reduction of speed of wind depending on height of a strip of green plantings

Bibliography: Lunts L. B. City dried construction, M., 1974; Masha of N with to and y V. JI. and For l about of ii-ii and. Design of gardening of residential areas, M., 1978; M and it and N - with to and y JI. O. Gorod and nature (City green plantings), M., 1973; Improvement of the environment of the cities, under the editorship of S. B. Chistyakova, century 3, page 82, M., 1978.

G. I. Muravyeva.