RU2518447C1 - Method of determining affection of mountain valley with avalanche stream - Google Patents

Abstract

FIELD: ecology.

SUBSTANCE: method comprises phytoindication on age of woody vegetation. Determination of the upper limit of affection of a mountain valley with avalanche stream, at which avalanching no vegetation is left on the slopes of the valley, is carried out by measuring the difference in height between the bottom of the valley and the lower limit of the phytometer - autochthonous birch forests, which grow over the affected slope; assessment of date of affection is determined by measuring the amount of annual rings on wood cores drilled by the age-related borer, or on transverse saw cuts at the base of trunks at the level of root collar of the largest trees in the newly formed growing stocks, renewable in the affected area lower the autochthonous birch forests.

EFFECT: method enables to improve efficiency of detection of signs of hazardous natural phenomena.

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Description

The invention relates to methods for identifying signs of natural disasters and may find application in assessing the risk of damage to territories.

A known method for predicting a landslide, which uses the method of phytoindication for old-aged diseased trees (application No. 99107239, IPC A01G 7/00, publ. 01/20/2001).

However, in the known method there are not enough indicators to determine the damage to the mountain valley by an avalanche-like flow only in old-aged diseased trees, which reduces the effectiveness of the method.

The closest technical solution is a method for detecting changes in landscapes in areas affected by mudflows, determining the nature and speed of succession in mudflow deposits, which can be used as one of the indicators of mudflow activity (Petrushina M.N., Suslova E.G. Indication of mudflow activity in landscapes of the North Caucasus // Modern problems of geology, geophysics and geoecology of the North Caucasus. - Grozny: AN CR, 2012. - P.634-640. - Source No. 1, attached).

The objects of study were landscapes of the basins of the Baksan, Chegem and Cherek Rivers Besengi (Central Caucasus) and r. Teberda (Western Caucasus). A complex of methods was used - large-scale landscape mapping and profiling, phytoindication and lichenindication, analysis of remote sensing data. The main attention was paid to the study of mudflow cones as part of the functional-dynamic geosystems formed by mudflows.

It is concluded that at the first succession stages, the species composition of the grass stand, the projective cover of the grass stand, the age and height of the stand are more informative indicators of the age of mudflow deposits, and the role of soils and the diameter of lichens Rhizocarpon geographicum increase in later stages.

The disadvantage of the prototype method is that although it allows you to identify the age of mudflow deposits, the scope of this method remains the option of the absence of deposits on the sides of the valley, as well as the assessment of the scale of the defeat of the mountain valley in an avalanche-like flow, which reduces the effectiveness of the method.

The technical result is an increase in the efficiency of the method for identifying signs of dangerous natural phenomena.

The technical solution of the claimed object lies in the fact that, in contrast to the prototype method, a method for determining the upper boundary of a mountain valley damage by an avalanche-like flow, during which there is no vegetation on the valley slopes, by measuring the height difference between the valley bottom and the lower boundary of the phyto-indicator (indigenous birch trees ) growing over the affected slope, and an estimate of the date of the lesion is established by measuring the number of tree rings on the core samples drilled by an age drill, and whether on transverse saw cuts at the base of the trunks (at the level of the root neck) of the largest trees in the newly formed stands, renewing in the lesion zone below the root birch forests.

The method is as follows.

Mountain birch forests (birch forests) are widespread in the upper part of the forest belt. These indigenous communities, firmly holding their positions in the vegetation cover, are characterized by resistance to the effects of the natural environment and human economic activity.

The lower boundary of the native birch forests growing above the affected slope is visually determined. Next, measurements are made using the altimeter of the height above sea level of the bottom of the valley and the lower border of the indigenous birch forests. The difference in these values gives us the upper limit of the defeat of the mountain valley by an avalanche-like flow (power of an avalanche-like flow). An estimate of the date of a previous catastrophe is established by measuring the number of tree rings on wood cores drilled by an age drill, or on transverse saw cuts at the base of trunks (at the level of the root neck) of the largest trees in newly formed stands, renewing in the affected area below the root birch forests.

Example. In the valley of the river. Ginaldon (Appendix, Fig. 1) after the avalanche-like flow disappeared, the altitude of the lower boundary of the native birch forests (point 1, elevation 1560 m above sea level) and the bottom of the valley (point 2, elevation 1435 m above sea level) were measured using an altimeter. It follows that the upper limit of the defeat of the mountain valley with an avalanche-like stream above the level of the bottom of the valley is 1560-1435 = 125 m.

In autumn 2012, in the newly formed stands (below point 1), 15 of the largest trees were cut down at the base of the trunk (at the level of the root neck). The number of annual rings on cuts ranged from 8 to 10.

Thus, the maximum age of the trees of the newly formed stand is 10 years, whence it follows that the defeat of the valley by an avalanche-like flow dates from the autumn of 2002.

The proposed method of phytoindication improves the efficiency of the method of assessing natural hazards when monitoring sites for construction, the formation of agroecosystems, and recreation.

Claims (1)

A method for determining damage by an avalanche-like flow of a mountain valley, including phytoindication by age of woody vegetation, characterized in that the determination of the upper boundary of the defeat of a mountain valley by an avalanche-like flow, during which no vegetation remains on the slopes of the valley, is carried out by measuring the height difference between the bottom of the valley and the lower boundary of the phyto-indicator - indigenous birch forests growing over the affected slope; Estimation of the date of damage is established by measuring the number of annual rings on wood cores drilled by an age drill, or on transverse saw cuts at the base of trunks, at the level of the root neck of the largest trees in newly formed stands, renewing in the affected area below the root birch forests.

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