This study analyses the physical factors of the Palestinian bioclimate, the mean monthly and annual temperature, mean monthly maximum temperature, and mean monthly minimum temperature using data from six weather stations from the Palestine Meteorological Department, recorded in two periods: The first period from 1969 to 1981, the second period from 1975 to 1995 (more than 32 years). Statistical tests included a bioclimatic analysis of Palestinian meteorological stations for the periods from 1969-1981 and 1975-1995 by using bioclimatic classification of the Earth of Rivas Martinez Salvador, with regard to thermicity index, compensated thermicity index, annual ombrothermic index, and simple continentality index. The bioclimate of Palestineis affected by various factors, such as the Jordanian-Syrian desert, and its natural geography and topography, among others as well as biodiversity. Annual ombrothermic index value ranging between 0.6 to 3.4 and simple continentality index was from 12.4 to 18.1. It is concluded that the occupied Palestinian territories belong to the arid, semiarid, dry, sub-humid and humid ombrotype, and the Inframediterranean, Thermomediterranean and Mesomediterranean bioclimatic belt.
Palestine is the conventional name used to describe the geographic region between the Mediterranean Sea and the Jordan River and various adjoining lands, the Holy Land and the Southern Levant. Palestine has historically been known by other names including Canaan, Syria Palestine, Southern Syria, Jund Filastin and Outremer [
The mountainous area of the West Bank serves as the main rainfall collection and replenishment zone for the underground water aquifers. The current climate conditions reveal the cascading effect of bioclimate change. The start and duration of the seasons have changed, and this has exposed Gaza to more fragility [
The main aims of the present study are to contribute to the knowledge of the mean temperature occurring in Palestine over the past few decades at the monthly, seasonal and annual resolution, and to analyze the physical factors of the bioclimate according to data from the Palestinian meteorological stations for several years.
Palestine is located between longitudes 34˚15' and 35˚40' east and between latitudes 29˚30' and 33˚15' north. The geographic location of Palestine plays a major role in affecting the features of its climate and the climate diversity between the southern and northern parts.
Topography of Palestine
The thermal regime varies significantly with altitude and continentally, especially in winter: from west to east it undergoes a transition from a typical Mediterranean to a continental climate. The winter rain regime has been extensively studied [
Mean temperature data from six stations with records from 1969 to 1981 and from 1975 to 1995 have been analyzed in this study. A bioclimatic analysis has been made of the data from the Palestinian meteorological sta- tions of the same years ago, so we are dependent in the bioclimatic analysis about used temperature and rain full amount of data for Palestinian Meteorological Stations, elaboration the diagram bioclimatic according the pro- fessor Rivas Martinez Salvador in 1996 [
Tm: mean monthly temperatures, (It) thermicity index, (Itc) compensated thermicity index, (Io) annual om- brothermic index, (Ic) simple continentality index, (Twm) mean temperature of the warmest monthly, (Tcm) mean temperature of the coldest monthly, (Ios1) monthly estival ombrothermic index, (Ios2, Iso3) bimonthly, three monthly estival ombrothermic index, (Tm. M. Max) mean monthly maximum temperatures, (Tm. M. Min) mean monthly minimum temperatures.
Nevertheless, in the first period, we can observe that the precipitation amounts differ from one station to another, with the highest proportion in Hebron and Al-Arroub (located in Hebron) 596 mm and 633 mm respectively, and the lowest at the Jericho station. The mean temperature of the warmest month in Jericho is about 22˚C; Al-Fará (in Nablus) is about 19.5˚C, while the lowest mean monthly temperature is in Hebron with 4.0˚C. The monthly, biomonthly, three monthly estival ombrothermic indexes were equal to zero for most stations except Hebron and
. Coordinates of meteorological stations Palestinian
Station | Latitude (North) | Longitude (East) | Elevation m |
---|---|---|---|
Jenin | 32.28 N | 35.18 E | 178 |
Gaza | 31.30 N | 34.27 E | 13 |
Tulkarem | 32.19 N | 35.01 E | 83 |
Nablus | 32.13 N | 35.15 E | 570 |
Al-Arroub | 31.50 N | 35.09 E | 887 |
Ramallah | 31.89 N | 35.21 E | 856 |
Jericho | 31.51 N | 35.27 E | −260 |
Hebron | 31.32 E | 35.06 E | 1005 |
. Bioclimatic analysis of Palestinian meteorological stations in the periods 1969-1981 and 1975 to 1995 (32 years)
Station | Tm | P. mm | Io | Ic | It/Itc | Twm. | Tcm. | Tm. M. Max. | Tm. M. Min. | Iso3 | |
---|---|---|---|---|---|---|---|---|---|---|---|
1969-1981 | |||||||||||
Jericho | 22.4 | 166 | 0.6 | 13.0 | 528/528 | 22.0 | 7.4 | 34.8 | 15.3 | 0.0 | |
Hebron | 15.5 | 596 | 3.2 | 15.0 | 297/297 | 10.2 | 4.0 | 19.9 | 11.1 | 0.01 | |
BeitGad | 21.3 | 414 | 1.6 | 15.0 | 466/466 | 18.2 | 7.1 | 26.7 | 13.5 | 0.0 | |
Al- Fara | 23.6 | 225 | 0.8 | 17.0 | 524/524 | 19.5 | 9.3 | 30.2 | 17.0 | 0.0 | |
Gaza | 19.8 | 446 | 1.9 | 12.4 | 467/467 | 17.5 | 9.4 | 23.6 | 16.1 | 0.0 | |
Al-Arroub | 17.1 | 633 | 3.1 | 16.7 | 428/428 | 21.3 | 4.4 | 22.9 | 10.4 | 0.0 | |
1975-1995 | |||||||||||
Ramallah | 17.2 | 636 | 3.4 | 14.9 | 306/306 | 10.5 | 4.4 | 21.1 | 31.1 | 0.01 | |
Jericho | 22.7 | 168 | 0.6 | 13.0 | 496/496 | 19.1 | 7.8 | 29.6 | 15.7 | 0.0 | |
Hebron | 15.5 | 628 | 3.4 | 15.3 | 294/294 | 10.0 | 4.0 | 19.6 | 11.2 | 0.1 | |
Gaza | 19.9 | 441.3 | 1.85 | 13.6 | 457/457 | 18.0 | 7.8 | 25.8 | 13.9 | 0.0 | |
Nablus | 17.2 | 664 | 3.1 | 13.4 | 378/378 | 13.0 | 7.2 | 21.6 | 13.6 | 0.0 | |
Tulkarem | 20.1 | 652 | 2.7 | 12.8 | 468/468 | 18.8 | 7.9 | 25.7 | 13.9 | 0.0 | |
. Bioclimatic belts and ombrotype in Palestine.Simple continentality index (Ic), ombrothermic index (Io) and com- pensated thermicity index (It/Itc)
Provinces | Termotype | Omprotype | Ic | Io | It/Itc |
---|---|---|---|---|---|
Ramallah | Lower mesomediterranean | Upper dry | 16.4 | 3.1 - 3.4 | 306/306 |
Nablus | Upper thermomediterranean | Upper dry | 18.1 | 3.0 - 3.1 | 378/378 |
Jericho | Lower inframediterranean | Upper arid | 13 | 0.6 - 1.0 | 528/528 |
Hebron | Lower mesomediterranean | Upper dry | 17.6 | 3.1 - 3.4 | 297/297 |
Tulkarem | Lower inframediterranean | Lower dry | 16.0 | 2.2 - 2.7 | 468/468 |
Beit gad | Upper inframediterranean | Upper semiarid | 15.0 | 1.6 | 466/466 |
Al-Arroub | Lower thermomediterranean | Upper dry | 16.7 | 3.1 | 428/428 |
Al-Fara | Lower inframediterranean | Upper arid | 17 | 0.8 | 524/524 |
Gaza | Upper Inframediterranean | Upper semiarid | 12.4 | 1.9 | 467/467 |
Jenin, which have a very low three monthly estival ombrothermic index of about 0.01. This factor appears similar to another recent study [
The series indicate that the mean monthly temperatures over the period 1975-1995 is between 15.5˚C in Hebron station, and 22.7˚C in Jericho station, while in 1968-1981 the mean monthly temperature is between 15.5˚C in Hebron station and 22.4˚C in Jericho station. The annual mean rainfall was between 160 mm at Jericho station, and 664 mm at Nablus station. The rainfall year 1991-1992 has the highest quantity rainfall throughout the past thirty years, the quantity of rainfall ranges between 352 mm in Jericho station with an increase of 192 mm over the normal average, and 1388 mm in Nablus station with an increase of 720 mm over the normal average, the mean monthly maximum temperature is between 19.9˚C in Hebron station, and 34.8 in Jericho station, while it is 23.6 in
Ombrotype of Palestine
Gaza station (1969-1981). In general, the lowest mean monthly temperature was recorded in the Hebron station and the highest in Jericho. Time series data indicated that the mean monthly minimum temperature over the period 1975-1995 was between 11.2˚C in Hebron and 15.7˚C in Jericho. There is a difference in temperature between the previous stages in the regions and by Israeli research demonstrating that the average temperatures in the eastern Mediterranean have increased steadily over the last 100 years [
However, there are some studies suggested that precipitation levels may decrease for Israeli-Palestinian region [
The Occupied Palestinian Territory (OPT), with a total area of 6023 km2, is located in South-West Asia in the heart of the Middle East. It consists of two physically separated land masses: the West Bank and the Gaza Strip with a total area of 5661 km2 and 362 km2 respectively [
According to (
Moreover, the climate of Palestine is traditionally described as “Mediterranean”, characterized by winter rain and summer drought. However, there is a great diversity in this climate, which is modified locally by latitude and altitude. This is especially apparent in the West Bank. Climate zones range from extremely arid to humid ac- cording to the De Martonne aridity index classification for arid area. The total area of extremely arid, hyper arid and arid climates is 2461 km2 which comprises about 44% of the land area of the West Bank; the area of the semi-arid part is 1682 km2 (about 30%); the sub humid area is 1435 km2 (25%) and the humid area is 67 km2 (1%) [
Thermotypes of Palestine
The bioclimate of Palestine can be classified as Mediterranean pluviseasonal-oceanic, Mediterranean xericocea- nic, Mediterranean desertic-oceanic, while the latitudinal belt is subtropical, within the territorial of a tropical character. Continentally it is oceanic-low semi-continental, oceanic-low euoceanic, oceanic-low semi-hyper oceanic and oceanic-low sub-continental. In addition, the thermotype ranges from inframediterranean to meso- mediterranean (inframediterranean, thermomediterranean, mesomediterranean).
The physical factors of the Palestinian bioclimate are affected by several factors: 1) The Mountain range ex- tending from north to south and running parallel to the coast; b) The Sinai and the North African desert; c) The Jordanian-Syrian desert; d) The terrain and the extent of the rise or fall in sea level; e) Natural geography and topography. Palestine is located within a radius of 500 kilometers from the island of Cyprus, and as we move further from the center of this circle, the low air deflects or moves towards the north, and thus the low air moving away from Palestine leads to a decrease in the proportion of rain-fed on Palestine. This also plays an important role in influencing the physical factors of bioclimate and climate and then bioclimate influence on plant communities and biological resources.