Jerusalem 5800 English

The Metropolitan Jerusalem Master Plan

there is an average annual rainfall of only

450mm. The impression that there is a lack

of water in Jerusalem stems from the fact

that the rainy days are not scattered evenly

throughout the year. The same amount

of water that European cities get in small

doses throughout the year can come down

in Jerusalem in only a few days – and only

in autumn or winter.

The geological structure of the land

in Jerusalem and its surroundings, which

includes many underground caves, has

caused the creation of many large, natural

underground reservoirs. As of today,

there is no comprehensive information

regarding all of the underground

reservoirs or the amount of water therein.

Occasionally new ones are discovered,

such as HaUma Cave, discovered 75

meters under Jerusalem in 2011 – the

largest flowing underground channel

discovered in Israel to date.

Jerusalem has especially good

conditions for the development of flora.

As a rule, plants cannot blossom during

months with average temperatures

of less than 7.5 degrees – the average

temperature of Jerusalem’s coldest month,

January. Therefore, throughout the entire

year, there is blossoming in the city –

mostly that of wild flowers. Moderate

temperatures, together with an abundance

of sunlight and reasonable precipitation,

created good conditions for agriculture

in the region even back in ancient times,

and there are archeological findings

which prove that there was agriculture in

Jerusalem thousands of years ago.

Jerusalem’s location on a mountaintop

between the Mediterranean Sea and the

Dead Sea enable effective ventilation. Also,

the relatively little heavy industry has made

Jerusalem a leader among Israel’s cities in

terms of its excellent air quality.

The natural region

surrounding Jerusalem

allows comfortable

conditions for existence.

The rural forested area

around the Beit Zayit

Dam, which is a part of

metropolitan Jerusalem.

In the background:

Jerusalem’s western

corridors

Sustainability in Jerusalem

oday, the city of Jerusalem is a

cultural, spiritual, ethical center for

religions and nations. This is a focal

point attracting hundreds of thousands

of tourists. It is a city that is known by

virtually every human on earth. Its status

as the capital of Israel has been in the

making for at least 5,000 years. Some of

the main reasons for this are the unique

natural conditions of this place.

Nature has certainly favored man

in Jerusalem. The Jerusalem climate is

moderate Mediterranean, with comfortable

temperatures year-round, ample water,

diverse flora blossoming year-round,

and clean mountain air. These excellent

conditions created a platform for the

development of human life, as well as

material and spiritual culture in ancient

times, in this place above all others.

Metropolitan Jerusalem has an

extraordinarily diverse climate. To the

east, there is the hot, arid desert region

surrounding the Dead Sea and the Judean

desert. The mountainous Binyamin and

Gush Etzion regions are rich in natural

springs receiving large amounts of water

from melting snow each year. The west

Judean Hills and Shfela lowlands have

forested slopes and deep rivers which flow

to the Nahal Soreq and Nahal Ayalon

basins.

The human body is strong, but still,

it cannot survive in climate conditions

outside a very specific temperature range.

Only a few hours spent in a very hot

environment can cause dehydration or

heatstroke, while remaining out in the cold

can cause hypothermia, freezing, or even

endanger human life. The temperature

range in which the human body is

comfortable – referred to as “thermal

comfort” in research literature – is quite

narrow, from 18 to 29 degrees in the

shade, and 6 to 18 in the sun.

The average annual temperature in

Jerusalem is 16 degrees. From season to

season, average temperatures can go from

a low of 6.4 degrees to a high of 29.4

degrees. This means that nature itself

provides thermal comfort for people on

most days of the year in Jerusalem.

Another factor influencing comfort in

any given place is the relative humidity.

Unrelated to temperature, thermal

comfort can only exist between 22-80%

relative humidity. Optimal humidity is

between 40 and 70 percent. On most

days of the year, humidity in Jerusalem is

between 46 and 58% - which is optimal.

In winter the average relative humidity is

75%, which is within the range of optimal

humidity, but when over 73%, humidity

encourages the growth of mold and fungi

– which harms the quality of life and

health.

A small degree of deviation from the

maximum recommended relative humidity

(73%) doesn’t take place during the day,

rather, mainly at night, and only on a

handful of days during winter. During

the warm season, from April through

September, relative humidity goes below

40%.

The amount of precipitation in

Jerusalem is high relative to that of other

central cities in Europe. In Jerusalem,

there is an average rainfall of about 600

mm of rain per year, like in Berlin – and

a bit more than in Stockholm or Prague

– and much more than in Madrid, where

The amount of

precipitation in

Jerusalem is high

in comparison to

that of other central

cities in Europe, but

the rainy days aren’t

scattered evenly

throughout the year.

Sustainability in Jerusalem