Anti-wind architecture of ridges

Anti-wind architecture of ridges

Protecting the mountain ecosystem while taking into account abnormal winds

Windbreak architecture on mountain ridges is more than just planting a single row of trees. At the summits, wind interacts with the terrain, vegetation, snow, rain, roads, rocky outcrops, and soil moisture. An improperly constructed windbreak may not reduce wind but rather increase turbulence, snow drifts, and the risk of windthrow.

The system must be designed simultaneously for:

normal prevailing winds;

seasonal storms;

rare hurricane gusts;

thunderstorm squalls;

downward flows;

winds changing direction;

slanting rain;

dust and sand storms;

snowstorms;

winds after the fire;

combination of wind and saturated soil.

The main principle:

Wind cannot be completely stopped. It must be gradually picked up, dispersed, weakened at the surface, and safely channeled across the area.

1. The role of wind-resistant architecture

The system must solve several problems simultaneously:

reduce wind speed near the surface;

prevent soil from blowing away;

reduce evaporation;

protect young plants;

retain snow without forming dangerous drifts;

collect fog and horizontal precipitation;

reduce mechanical damage to plants;

reduce the transfer of sand and dust;

do not block flood drainage;

do not create a continuous fire line;

preserve ecological corridors.

Wind protection is considered successful not when there is no wind behind it at all, but when the flow becomes less destructive and more uniform.

2. Why a solid wall is dangerous

A dense wall of trees, shrubs or artificial panels creates a sharp pressure drop.

Wind:

hits an obstacle;

partially rises upwards;

accelerates over the top edge;

forms vortices;

drops sharply behind an obstacle;

damages soil and plants in the downwind zone.

As a result, a zone of strong turbulence can arise directly behind the dense strip.

Additional risks:

massive windfall;

formation of deep snow drifts;

accumulation of dry organic matter;

rapid spread of fire;

the fall of the entire strip in one direction;

blocking roads and riverbeds.

Therefore, protective strips must besemipermeable, multi-tiered and divided into functional sections.

3. Main types of winds on ridges

3.1. Prevailing background wind

This is the most common wind direction.

It is used to determine:

main orientation of protective strips;

arrangement of low and high tiers;

leeward landing zones;

snow retention;

directions of soil transfer.

But it is impossible to design a system only for the prevailing wind.

3.2. Seasonal storm winds

They may have a different direction and a much higher speed.

For example, a normal wind might come from the west, while the most destructive winter storm might come from the northwest.

Therefore, the map must contain:

frequent direction;

the strongest direction;

direction of cold winds;

direction of dry winds;

wind direction with rain;

wind direction with fire hazard.

3.3. Thunderstorm squalls

Before a thunderstorm, wind direction can change quickly.

Shkval is capable of:

break branches;

pull out trees;

carry heavy objects;

direct slanting rain at an unusual angle;

form short-term local flows.

Long straight strips of identical trees are especially dangerous for squalls.

3.4 Downward Flows

During a thunderstorm, cold air can drop sharply and spread across the surface.

This flow does not act like a normal horizontal wind.

He can:

strike from above;

fan out;

change direction in seconds;

damage plants from several sides;

create strong pressure on the crowns.

Protection must be spatial, not just one-directional.

3.5. Mountain accelerated flows

The wind is picking up:

in saddles;

narrow passages;

between rock walls;

over sharp ridges;

along the gorges;

near artificial excavations;

between buildings and forest belts.

Such places become natural "wind nozzles".

They cannot be covered with tall, dense vegetation without modeling.

3.6 Leeward rotors

Rotating air currents can form behind the ridge.

They cause:

sharp gusts from opposite directions;

unstable snow distribution;

increased load on trees;

local drying;

damage to roofs and structures.

The leeward side is not always a calm and safe area.

3.7. Foehn and dry hot winds

Warm, dry winds quickly reduce the moisture content of plants and soil.

They:

enhance evaporation;

dry out young plantings;

increase the fire risk;

accelerate snow loss;

damage leaves;

increase the need for water.

Here, protection must combine wind speed reduction, soil shading and moisture retention.

3.8. Dust and sand storms

Dust and sand act as an abrasive.

They:

damage leaves and bark;

young plants fall asleep;

pollute water bodies;

cover the sensors;

impair visibility;

carry seeds of invasive plants.

It is necessary not only to stop the particles, but also to provide places for their safe deposition and subsequent removal.

4. Wind relief map

Before designing, a map is created showing:

average wind speed;

maximum recorded gusts;

dominant directions;

seasonal destinations;

acceleration zones;

turbulence zones;

leeward pockets;

areas of snow drifts;

snow blowing zones;

wind erosion sites;

sand transport routes;

existing windfalls;

direction of tree fall;

areas of slanting rain.

Used:

weather stations;

anemometers;

weather vanes;

temporary measuring masts;

drones;

digital elevation model;

snow observations;

crown condition;

direction of inclination of bushes;

historical information;

computer simulation of air flow.

One weather station per valley isn't enough. On the ridge, the wind can be significantly stronger and in a different direction.

5. Calculated wind scenarios

Several scenarios are generated for each territory.

The system must maintain its basic function even when some vegetation or structures are damaged.

6. Multi-stage wind protection system

The most stable is not a single strip, but a cascade of several zones.

Zone 1. Front rough surface

On the wind inflow side the following are preserved or created:

stone placers;

low grasses;

mosses;

lichens;

creeping shrubs;

slight unevenness of the terrain.

This zone begins to weaken the wind just at the surface.

It also bears the first brunt of sand, ice and slanting rain.

Zone 2. Low semi-permeable zone

Consists of:

dense grasses;

low shrubs;

flexible stems;

sparse rock-plant lines.

Its purpose is to reduce the speed of the lower part of the flow without creating a sharp barrier.

Zone 3. Middle shrub layer

It is not necessarily located in one straight line, but in groups and islands.

Used:

multi-stemmed shrubs;

flexible types;

plants of different heights;

species with different crown densities.

This zone lifts part of the air flow and disperses it.

Zone 4. High tier

Tall shrubs and trees are placed:

below the ridge line itself;

in protected areas;

in groups;

with a gradual increase in height;

with intervals;

taking into account fire breaks.

The high tier should not start abruptly.

Zone 5. Leeward Passage

Behind the main strip are located:

tall grasses;

individual bushes;

young trees;

natural restoration areas;

snow retention fields;

humid microzones.

The transition must be gradual so that the air does not collapse onto the surface immediately after the obstacle.

7. Spatial shape of protective strips

Straight stripes

Acceptable on relatively flat terrain with a stable wind direction.

On ridges their use is limited, as the wind often changes direction.

Curved stripes

They follow the contours of the terrain and distribute the load better.

They should not turn into a bowl that collects wind or snow in one point.

Chessboard arrangement

Shrub and tree groups are located with an offset.

Advantages:

the flow is dispersed many times;

there is no single line of destruction;

passages for water and animals are preserved;

fire risk is reduced;

If one group drops out, the system continues to work.

Island system

Most suitable for open mountain ridges.

Separate stable islands are created:

herbs;

shrubs;

trees;

stone-plant structures.

Controlled air and water corridors remain between them.

Honeycomb structure

The territory is divided into small protected cells.

Cell boundaries are formed:

low bushes;

herbs;

stone lines;

local earth forms.

The honeycomb system protects the soil well, but should not impede the emergency passage of water.

8. Orientation relative to the wind

Protective strips are usually located approximately across the dangerous wind direction.

However, in the mountains it is necessary to take into account:

ridge bend;

lateral gusts;

ascending currents;

downward flows;

winter and summer directions;

winds with rain;

fire winds.

Therefore, often not just one orientation is used, but a combination:

main strip;

side wings;

diagonal sections;

islets;

transverse microbands.

It is impossible to create a closed vegetation pocket in which snow, dry matter or water accumulates without an outlet.

9. Permeability of the protective strip

The strip must allow some air to pass through.

A strip that is too open has little effect on the wind.

Too dense creates:

strong rise in flow;

acceleration above the upper limit;

vortices;

a sharp drop in air behind the strip;

damage to the downwind area.

The optimal structure is achieved by combining:

gaps between the trunks;

different sizes of leaves;

of unequal height;

flexible branches;

several tiers;

gaps between groups.

Permeability must be maintained even in winter, when deciduous species lose their leaves.

10. Height and protection zone

The higher the protective band, the further its influence can extend.

But increasing the height also increases:

sail area;

load on roots;

probability of windfall;

amount of wood when falling;

fire load;

cost of service.

On open ridges, several low and medium bands are often more effective than one high one.

11. Selecting plants

Plants are selected not only for frost resistance or drought tolerance.

It is necessary to evaluate:

trunk flexibility;

the ability to recover from a breakdown;

crown shape;

sail area;

depth and width of roots;

resistance to saturated soil;

icing resistance;

snow holding capacity;

fire hazard;

ability to produce root shoots;

compatibility with the local ecosystem.

Preferred:

local species;

multi-stemmed forms;

low and medium shrubs;

trees with a moderately sparse crown;

plants that form groups;

species with different types of roots.

12. Root resistance

In case of abnormal wind, not only the strength of the trunk is important, but also the condition of the soil.

Windfall is especially likely when:

the soil is completely saturated;

the root system is superficial;

the tree stands on the edge of the embankment;

there is a sliding layer under the roots;

some of the roots are cut by the road;

the soil is loosened;

there is a drainage ditch nearby;

The tree is tilted by the previous winds.

Tall trees should not be placed:

on the unstable edge of the ridge;

above the road;

over the emergency channel;

near important sensors;

near communication lines;

on the landslide body without inspection.

13. Protection from slanting rain

Strong wind changes the trajectory of drops.

Slanting rain can:

destroy windward slopes;

get under the plant litter;

wash away road embankments from the side;

saturate the soil unevenly;

bypass conventional protective canopies;

carry water across a watershed.

The wind-blocking architecture should reduce droplet velocity but not concentrate water at the base of the strip.

For this purpose the following are used:

low front tiers;

stone mulch;

dense turf;

distributed shrubs;

safe overflow routes.

14. Wind and snow

Protective vegetation changes the distribution of snow.

She can:

hold back snow;

reduce blowing;

create stable snow pockets;

increase spring moisture.

But an incorrect strip can form:

deep skid on the road;

dangerous cornice;

avalanche-prone accumulation;

prolonged over-watering of roots;

ice crust;

damage to branches.

Therefore, before landing, the following is simulated:

winter wind direction;

expected snowfall zone;

maximum drift depth;

melting rate;

direction of melt water;

stability of the lower slope.

15. Wind, fog and horizontal precipitation

On cloud ridges, protective strips can act as natural fog catchers.

Drops settle on leaves, needles and branches, which then flow into the soil.

The following are useful for this:

small foliage;

pine;

pubescent surfaces;

multi-tiered crowns;

rough bark;

dense small branching.

However, an overly dense system can:

constantly retain moisture;

promote fungal diseases;

increase the weight of icing;

overload the branches.

It is necessary to combine fog capture with good ventilation.

16. Wind and Fire

On ridges, fires often spread especially quickly.

Wind:

carries sparks;

accelerates the fire front;

directs fire along the strips;

dries out vegetation;

creates fiery whirlwinds;

spreads fire across roads.

The protective strip should not become a continuous fuel corridor.

Required:

mosaic structure;

breaks;

low-flammability types;

removal of excess dry matter;

dividing dense shrub groups;

access for fire services;

water points;

remote monitoring.

A continuous line of conifers along a ridge can be both a windbreak and an extremely dangerous path for fire spread.

17. Artificial windbreaks

Until vegetation is restored or in particularly difficult areas, the following can be used:

semi-permeable meshes;

wooden gratings;

stone walls with openings;

wicker barriers;

low earthen forms;

snow-retaining screens;

temporary protective panels.

They must:

let some air through;

have a solid foundation;

withstand gusty loads;

do not turn into a dangerous piece of debris;

do not block water;

do not harm birds;

be repairable;

gradually be replaced by a living system.

Solid metal sheets and dense fencing on the tops usually create too much stress and turbulence.

18. Wind protection of roads

On ridge roads the wind can:

overturn vehicles;

cover the canvas with snow;

impair visibility;

carry stones and branches;

cause icing;

destroy road slopes.

Protective elements are not placed too close to the road if they cause skidding directly onto the road surface.

It is necessary to take into account:

place of snowfall;

tree fall range;

emergency detour;

review;

fire safety;

water drainage;

Possibility of cleaning.

Near critical areas, low shrubs and artificial semi-permeable screens are preferable to tall trees.

19. Protection of settlements and infrastructure

Several circuits are created near buildings, monitoring stations, reservoirs and energy facilities.

External contour

Diffuses the main flow.

Middle contour

Reduces wind speed and traps particles.

Inner contour

Protects a specific object without creating dangerous turbulence near walls and roofs.

Inside you need to save:

fire distances;

access for repairs;

evacuation routes;

safe tree fall;

water drainage.

20. Wind + saturated soil scenario

This is one of the most dangerous scenarios.

The sequence may be as follows:

several rains saturate the soil;

root resistance decreases;

the storm begins;

trees are falling;

the roots tear out layers of soil;

depressions and open areas are formed;

tree trunks block riverbeds and roads;

A new downpour creates a breakthrough flow.

To reduce the risk the following are used:

limiting the height of plantings;

mixing of ages;

multi-stemmed shrubs;

removal of hazardous trees;

protection of riverbeds from tree jams;

tilt monitoring;

reserve water routes;

emergency access routes.

21. Scenario "wind after a fire"

After a fire, the soil remains open, and the roots of damaged plants gradually lose strength.

A strong wind can:

blow out ash and fine soil;

break down burnt trees;

create dangerous blockages;

carry contaminated dust;

destroy temporary anti-erosion coatings.

After a fire, you must quickly:

assess the stability of trees;

remove only truly dangerous trunks;

to consolidate the soil;

install low temporary screens;

restore turf grasses;

protect waterways;

control the movement of people and equipment.

Complete clearing of all burned trees can increase wind and water erosion.

22. Cascading failure

The design must take into account that during an extreme storm the following may occur simultaneously:

trees fall;

the grid will collapse;

block the roads;

the sensors may be damaged;

connection disappears;

a fire will start;

a landslide will form;

the direction of flow will change.

Therefore, the system should not depend on a single line of defense.

Required:

several independent tiers;

breaks;

backup sensors;

autonomous power supply;

alternative routes;

safe fall zones;

manual inspection methods;

simple repair elements.

23. Monitoring abnormal winds

The observation network includes:

anemometers at several heights;

direction sensors;

gust meters;

cameras;

tree tilt sensors;

vibration sensors;

soil moisture sensors;

precipitation stations;

snow gauges;

acoustic destruction sensors;

drones;

satellite images.

Not only the wind speed is observed, but also the consequences:

the appearance of exposed soil;

tilt of plants;

breakage of branches;

change in snow drifts;

formation of vortex zones;

sand accumulation;

damage to protective strips.

24. Wind danger levels

Green level

Normal wind. The system operates without restrictions.

Yellow level

Strong gusts are expected. High-altitude work and the movement of light equipment are restricted.

Orange level

Falling branches and snow drifts are possible. Some routes will be closed.

Red level

There is a high risk of windfall, destruction of structures and blocking of roads.

Black level

Actual widespread damage, lack of communication, or a combination of a storm with a fire, flood, or landslide.

25. System maintenance

Wind-resistant architecture requires regular inspection.

The following are carried out:

removal of dry and dangerous branches;

tree tilt control;

restoration of ruptures;

thinning out overly dense areas;

replacement of damaged nets;

sediment removal;

invasive species control;

maintenance of fire passages;

post-storm survey;

digital model adjustment.

Thinning should be done gradually. Abruptly removing the front tier can expose plants that weren't previously exposed to the full wind load.

26. Performance indicators

The system is assessed according to the following parameters:

decrease in wind speed at the surface;

reduction of the area of ​​wind erosion;

preservation of vegetation cover;

reduction in the number of breakdowns;

reduction of snow loss;

absence of dangerous drifts;

reduction of evaporation;

increasing the humidity of protected areas;

post-storm resilience;

absence of massive windfall;

preservation of waterways;

lack of a continuous fire corridor.

The number of trees planted alone is not an indicator of effectiveness.

27. What not to do

On the ridges it is forbidden to:

create one continuous high wall;

plant a single-aged monoculture;

design protection only for the average wind;

ignore squalls and changes in direction;

place tall trees above the road;

block wind passages without modeling;

create dense strips in fire directions;

block natural water passages;

install solid panels without gaps;

create snow drifts over infrastructure;

plant trees on saturated unstable soils;

consider the leeward side to be completely safe.

28. Design sequence

Stage 1. Wind mapping

The main and extreme directions, acceleration and turbulence zones are determined.

Stage 2. Soil assessment

The stability of roots in dry and saturated soil conditions is studied.

Step 3. Defining functions

It is decided what exactly needs to be protected: soil, plants, a road, a settlement, snow or a body of water.

Step 4: Creating a Low Tier

Grasses, mosses, lichens and creeping shrubs are restored.

Stage 5. Formation of the middle tier

Shrub groups and islands are created.

Stage 6. Careful introduction of trees

Trees are placed only in stable and protected places.

Step 7: Testing extreme scenarios

Squalls, snow, rain, fire and saturated soil are simulated.

Stage 8. Monitoring and adaptation

After real storms, the system is adjusted.

The final principle

The anti-wind architecture of the ridge should be:

multi-tiered;

semipermeable;

mosaic;

resistant to change of direction;

safe in case of partial destruction;

compatible with water runoff;

fire resistant;

adapted to snow and slanting rain;

based primarily on local vegetation.

The main goal is not to create a stationary wall, but to form a living system that gradually receives, lifts, disperses and weakens the air flow.

Strong winds cannot be defeated by a single barrier. They can be made less destructive only through properly managed terrain, vegetation, space, and a sequence of protective layers.