Landscape Features and Techniques For

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LANDSCAPE FEATURES AND TECHNIQUES FOR- HOT AND DRY CLIMATE- HOT AND HUMID CLIMATE

SILVINUS CLISSON PRAGASH


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HOT AND DRY CLIMATE GENERAL CHARACTERISTICS

Hot and dry climatic regions are characterised by very highradiation levels, ambient temperatures and relatively lowhumidity , this region comprises of the arid and semi arid regions

of India.

A long stretch of land situated to the south of Tropic ofCancer and east of the western ghats and the CardamomHills experiences this climate. It includes Karnataka, interior andwestern Tamil Nadu, western Andhra Pradesh and central

Maharashtra. This area receives minimal rainfall due to beingsituated in the rain shadow area. This region is a famine pronezone with very unreliable rainfall which varies between 40 to75 cm annually.

The coldest month is December but even in this month thetemperature remains between 20C and 24C. The months of

March to May are hot and dry with mean monthly temperatures ofaround 32C.

The vegetation mostly comprises grasses with a few scatteredtrees due to the rainfall. Hence this area is not very well suited forpermanent agriculture.

Most of western Rajasthan experiences an arid climatic


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HOT AND DRY CLIMATE GENERAL CHARACTERISTICS


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HOT AND DRY CLIMATE Landscape Design Considerations

Site planning and orientation which is ambient for the prevalentclimatic conditions .Regions in this zone are generally flat andheat up uniformly.

In case of an undulating site, constructing on the leeward side ofthe slope is preferred. This protects the building from directimpact of hot winds which can be quite uncomfortable.

An east-west orientation is preferred in hot and dry climaticregions.

Locating the built form in a depression with proper ventilation is

advantageous due to the concept of hot air rising up.


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Waterbodies like ponds and lakes act as heat sinks and can alsobe used for evaporative cooling. They humidify the air and makeit comfortable inside. Fountains and water cascades in the vicinity

of a building also aid in cooling.

Streets must be narrow so that they cause mutually shade thebuildings. Streets need to be oriented in the north-south directionto block solar radiation.


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Courtyards are means of ventilation they also act as heat sinksduring the day and radiate the heat back at night.

Grass can be used as ground cover to absorb solar radiation andaid evaporative cooling.

Earth berming can help lower the temperature and also deflecthot summer winds.


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An earth berm is a landscaping feature that creates a barrier,adds interest to a flat landscape, improves drainage and canseparate areas of land. A mounding process that adds earth to a

flat or low-lying area until it is built up is all that is needed tocreate a berm.

Earth berm construction requires dry soils of low conductivity. Wetsoils should be avoided or with proper mitigation may beacceptable. Earth bermed building should be vented with anappropriate air exchange and slab should be sealed and ventedfor random gas mitigation.


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A roof garden is any garden on the roof of a building.Besides the decorative benefit, roof plantings may provide food,temperature control, hydrological benefits, architectural

enhancement, habitats or corridors for wildlife, and recreationalopportunities.


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Arid climates place special demands on landscape ornamentals.Low humidity and rainfall and high summer temperatures dictatethe use of tolerant plants as well as management techniques that

cope with the high potential for water loss. Ground-cover plantings in dry-climate region scan be done in two

basic ways. The first involves using conventional ornamentals thatare tolerant of heat, dry air and periodic moisture stress.

The second approach calls for native species and other regionally

adapted plants that can survive with less soil improvement andthat require relatively little supplemental irrigation.

Native and regionally adapted species often provide specialchallenges. Plants from arid regions rarely grow as continuous,carpet-like ground covers. Further, many of these species have

distinct periods of growth, flowering and dormancy that relate toseasonal moisture availability. Few of them tolerate shade, andeven fewer withstand poor drainage or excessive irrigation. Sochoose species must be in line with the context.


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When working with native species, it is best to avoid large,continuous plantings of a single ground-cover species. Instead,develop a more natural-looking design by combining several plant

species in natural-looking drifts or groupings This design strategy is useful for large perimeter and foreground

areas. It also is a flexible approach; if a specific plant dies, it willnot compromise the design or appearance of the ground-coverplanting. This type of landscape also lends diversity of characterand seasonal variation to its aesthetic value and, by design, willlook different throughout the year.

Grade the site with topographic relief for added visual character,and then locate plants to take advantage of small microclimateswithin the contoured landscape. Contouring also can be helpful forcapturing rainfall.

Entries, courtyards and raised planters often are places wherecolor and refreshing foliage are the most welcome. By studyingthese areas and identifying other microclimates in the landscape,it is possible to incorporate a wide variety of ground covers intodry-climate landscapes.

Roof gardens are also a means of reducing heat gain in such


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Drip irrigation provides a distinct advantage over sprinklers bysupplying moisture from below the plants. This avoids wettingfoliage and surface organic matter, something that can promote

disease in xeric landscapes. Plus, because of lower applicationrates, drip irrigation can run for longer periods without runoff.

Thus, water penetrates the soil more deeply, which encouragesdeeper rooting and, ultimately, greater drought resistance. Dripsystems also enable us to use the same line to apply differentamounts of water to various trees, shrubs and ground covers. By

using emitters with varying discharge rates and by adding orsubtracting emitters as needed, you can tailor irrigation to meetthe needs of individual landscape plants.


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Mulches are a sustainable landscape feature in hot and dry regions

Mulches are opaque organic or inert materials applied in layers ontop of bare soil and around trees and shrubs.

The purpose of mulches is to reduce water evaporation, preventweeds by stopping photosynthesis, buffer soil temperatures,protect irrigation systems from harmful solar rays, and give thegarden a finished look.

Mulch should be porous to air and water. The coarser the material,the thicker the mulch layer needs to be.

Organic mulch, such as shredded cedar bark or compost, will alsoamend the soil as it decomposes.

Mulch is reported to reduce watering demand by 40 to 70 percent.


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Xeriscaping areas with dry climates is a landscaping techniquethat requires various techniques including proper plant selection,soil types, composts, mulch and plant placement. Here are some

tips you can keep in mind when trying out a xeriscape project ofyour own.

Because water conservation is your first issue, you might want tochoose and grow plants that do not require more water than whatyour climate can naturally provide. The best way is to use nativeplants that do not require extra watering and soil amendmentsand can survive with what your environment can provide.

Soil type is another important factor to consider when planning toxeriscape. Use soil that can retain more water so that you donthave to water very often. You might have to put extra work on thisbecause you need to replace the soil you have on your yard

because areas with hot climate usually have dry soil that absorb tomuch water.

Composting is a very useful technique when xeriscaping. This canimprove the quality of the soil with minimal cost on expensive soilamendments. The natural bacteria and fungi in compost helps soil

both conserve water and give nutrients to the plants. Aeration isimproved when soil is composted and this allows for better water


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HOT AND DRY CLIMATE

CII Sohrabji Godrej Green Business Centre in Hyderabad is goodexample of landscape done in hot and dry region


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HOT AND HUMID CLIMATE

In hot and humid climatic regions, high temperatures areaccompanied by very high humidity levels leading to immensediscomfort. Cross ventilation is hence very essential here.

Adequate shading measures are also necessary to protect thebuilding from direct solar radiation.

The goal of landscaping in this area is to channel the breezetoward the home and maximize shade in the summer whileallowing the sun to penetrate during the winter. An importantelement of this region is plant placement. Since the area ishumid, it is very important not to place plants that requirewatering near the home. If this is done, the humidity immediatelyaround the home will be increased.

For flat sites, design considerations for the landform is immaterial.Incase of slopes and depressions, the building should be located

on the windward side or crest to take advantage of cool breezes.

Buildings should be spread out with large open spaces in betweenfor unrestricted air movement.


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Water bodies are not essential as they would tend to furtherincrease the humidity.

Major streets should be oriented parallel to or within 30 deg of theprevailing wind direction during summer months to encourageventilation in warm and humid regions.

A north-south direction is ideal from the point of view of blockingsolar radiation.

The width of the streets should be such that the intense solarradiation during late morning and early afternoon is avoidedduring the summers.

Landscape techniques.

When shaded, ground temperatures were found to drop an

average of 3 - 6F in only five minutes. Studies have also shownthat temperatures on a forest floor can be as much as 25F coolerthan those recorded at the tree tops.

Home comfort levels and energy costs can be also dramaticallyaffected by shade. Creative landscape planning with trees, shrubs

and vines will help alter the climate outside your home and modifyindoor temperatures.


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Trees

Determine the best places to plant shade trees by observing whichof the windows receive the most sun. top priority should beproviding shade for east and west windows and walls, since thesesurfaces receive about fifty percent more sunshine during thewarmer months than those facing north and south.

When planning your design, keep in mind that trees are moreeffective at shading when planted close to the home. A tree

planted ten feet from the west wall will shade an area four timeslonger than a tree planted twenty feet.

. A tree's shape also influences the duration of the shade.Spreading, round, and vase-shaped tree canopies will provideshade for the longest time.

Shrubs

Shrubs are also useful for shading your home. When planted a fewfeet away from the house, they can provide extra shade andcontrol humidity without obstructing air currents. Trellised vinescan be used to shade windows where space is limited, since they

can grow in more confined spaces than trees or shrubs. Evergreenvines are a good choice for providing shade along the east and


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Trees

Determine the best places to plant shade trees by observing whichof your windows receive the most sun. Your top priority should beproviding shade for east and west windows and walls, since thesesurfaces receive about fifty percent more sunshine during thewarmer months than those facing north and south.

When planning your design, keep in mind that trees are moreeffective at shading when planted close to the home. A tree

planted ten feet from the west wall will shade an area four timeslonger than a tree planted twenty feet.

. A tree's shape also influences the duration of the shade.Spreading, round, and vase-shaped tree canopies will provideshade for the longest time.

Shrubs

Shrubs are also useful for shading . When planted a few feet awayfrom the house, they can provide extra shade and control humiditywithout obstructing air currents. Trellised vines can be used toshade windows where space is limited, since they can grow in

more confined spaces than trees or shrubs. Evergreen vines are agood choice for providing shade along the east and west sides of


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Using landscaping to manage breezes is a very effective means ofcontrolling indoor home temperatures during both winter andsummer. By using trees, shrubs, vines, and other vegetation, you

can alter the direction of wind. Paved surfaces absorb the sun's heat and radiate it back into the

immediate environment. Research has shown that temperaturesmay be 15F to 25F hotter over asphalt or concrete. Paved areasalso store heat, radiating warmth long after sundown.

Planting groundcovers around paved areas can help reduce thesetemperatures.

Groundcovers are low-growing plants that can be used to cover anarea in the landscape.

Evidence indicates that taller groundcovers--with their larger leafsurface--can provide even more cooling than shorter groundcoverssuch as mowed grass.

All plants are capable of modifying their environment through aprocess called evaporative cooling. Plants release water throughpores in their leaves. When warm winds pass over the leaf surface,

surface water absorbs the heat. The warmed water thenevaporates into the atmosphere, leaving behind a cooler


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Plant barriers

The usefulness of vegetation, along with its various aestheticbenefits in the urban landscape, is that trees and other plantsrepresent a natural protective element against solar radiation aswell as wind control.

In the case of warm and humid microclimates, where the greaterpart of the year requires protection from excessive solar radiationand at the same time the passage of air, vegetation may be used

like a parasol; as in the case of

palm trees, whose perennial leaves are able to block solarradiation, but whose tall trunks will easily allow unimpededventilation.

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Landscape Features and Techniques For