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The Metropolitan Jerusalem Master Plan

The Metropolitan Jerusalem Master Plan


Of course, in order for this effect to take

place, the groups of trees need to be more

or less of similar volume as the burst of

hot air arriving.

Even now, the Jerusalem forest helps

break heat waves coming towards the

city from the west, and metropolitan

Jerusalem has a high potential for creating

a forest belt to protect the city from heat

wave conditions coming in from the

southeast. But a desert lies to the east

of Jerusalem – so how can we increase

the numbers of trees in such areas

where precipitation is never enough?

In such areas, the determining factor in

Sustainability in Jerusalem

Urban Heat Islands

Urban heat islands are a climate phenomenon that occurs when a

city affects the climate, causing substantial differences between

the city’s climate and the climate of the surrounding area.

Building a city causes changes, including tearing up

plants, creating stone and asphalt pockets, limiting

exposed topsoil, and putting up topographic

obstacles. Human activity in the city adds to this,

causing greater output of greenhouse gasses.

These changes create climate conditions different

to those in open areas around the city. The

phenomenon is usually expressed by a rise in city

temperatures and the creation of a hot layer above

it. The layer where this phenomenon can be sensed

most is the urban space – the layer of air trapped

between the ground level and building roof levels.

The urban heat island phenomenon can

cause temperature differences of up to 10-12

degrees between a big city and nearby rural

areas. Therefore, data on global warming reflect

microclimate changes in big cities more than

climate change worldwide.

The trend towards the creation of urban heat

islands exists in Jerusalem as well. Temperature

differences in the city center and further

neighborhoods can reach up to three degrees,

whereas twenty years ago it was two. Since the

change in policies regarding building height in

Jerusalem took place, the urban heat island trend

has taken on greater velocity. In light of the fact

that already today some half of all electricity

manufactured in Israel is used for air conditioning,

heating, and ventilating homes, this phenomenon

will definitely bring about an increase in energy

consumption, harm the environment, and lower

quality of life. This difference of just a few

degrees on a hot day can mean uncomfortable

temperatures for city residents, disruption of

tourists’ plans, dehydration and heat stroke.

Among the factors causing the formation of

urban heat islands are a lack of urban parks, the

construction of tall buildings, sealing off topsoil

with asphalt or concrete, and construction which

doesn’t incorporate full-grown trees close to

buildings. In order to minimize this phenomenon,

buildings higher than eight floors should not be

built, stretches of parks and forests should be

established equally and uniformly throughout

the metropolis, and full-grown trees should be

planted on every street.

whether flora is to develop is topography.

A concentration of runoff water increases

the amount of water seeping into the

soil much more than the amount of

precipitation coming in. Ancient Nabatean

agricultural methods in the Negev were

based on this concept. Runoff water must

be channeled so that it reaches the location

for forestation.

Further, there are types of trees which

are suited for planting in the desert and

can still give enough humidity to break dry

heat waves: tamarix aphylla, acacia raddiana,

Christ’s Thorn Jujube, eucalyptus and pine


Kanfei Nesharim

Street today, and

simulated imagery of

its appearance after

making it usable for


Sustainability in Jerusalem