Chapter 3- Study area PDF

Preview

Summary

Download Chapter 3- Study area PDF

Description

Description of the Study Area 3.1 Location and Demography

The Gaza Strip is a semi-arid region located in the Mediterranean basin between Egypt and Israel; The Gaza Strip is located between longitudes 34° 2” and 34° 25” east, and latitudes 31° 16” and 31° 45” north of Palestine, it covers a long and narrow rectangular coastal area with length of 40 km and a width varies between 6 km in the north to 12 km in the south, comprising a total area of 365 km2 as shown in Figure. 3.1. The Gaza strip consists of five Governorates, named as North, Gaza, Middle, Khan Younis, and Rafah, respectively. An estimated 1.9 million inhabitants are living there by the end of 2018, the Gaza strip is one of the most densely populated areas in the world, with an average population density of 5,205 person/km2, which is bound to increase tremendously in the future, as the annual natural population growth rate continues to be around 3.0-3.4% (UNRWA, 2018). The Palestinian Central Bureau of Statistics (PCBS) forecasts the population in the Gaza strip will doubled by the year 2050. Table 3.1 shows the estimation of the population projection in Gaza Strip according to the Palestinian Central Bureau of Statistics (PCBS) in 2018. As a result of the continuous population growth, the total water demand and lack of environmental awareness and sustainability in the Gaza Strip is strongly increasing. Nowadays, there is both a serious shortage and pollution of natural resources, coupled with long-term environmental degradation (UNDP, 2012). This caused rapid deterioration in all aspects of the life and the need of water is not satisfied by the available resources leading to a huge deficit between water demand and supply and the aquifer quality situation is so critical and this problem is still a long way from being solved. (Qahman and Larabi, 2006; El Baba et al., 2020).

3.2. Climate The climate of Gaza Strip is located in the transitional zone between a temperate Mediterranean climate in the west and north, and an arid desert climate of the Sinai Peninsula in the east and south. The Gaza Strip has got a semi-arid Mediterranean climate with a long hot and dry summer subject to drought from April to October, and short cool and rainy winter from November till March. (PWA----)

Figure 3.1: Location map of the Gaza Strip

Population 4500000 4000000 3500000 3000000 2500000 2000000 1500000 1000000 500000 0 00 03 06 09 12 15 18 21 24 27 30 33 36 39 42 45 48 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20

Figure 3.2: Population projection in Gaza Strip between 2020-2050

3.2.1 Temperature The Temperature in Gaza Strip gradually changes throughout the year with a daily mean average temperature ranges from 25 °C in summer and 14 °C in winter. The annual mean of air temperature, annual mean of maximum air temperature, Temperature gradually changes throughout the year, and reaches in Summer its maximum in August and in winter its minimum in January; average of the monthly maximum temperature ranges from about 17.6 ºC for January to 31.7 C° for August, while the average of the monthly minimum temperature for January is about 10 ºC and 24.4 ºC for August. Table (3.1) Mean monthly minimum, maximum and average temperature [°C] for the Gaza Strip.

Jan

Tmea n

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

10

11.3

12.7

15.6

18.4

20.9

23

24.4

21.3

18.8

14.7

12.3

17.6

18.8

20.4

22.8

24.7

27.3

30.2

31.7

28.5

26.8

23.8

19.7

Tmin Tmax

Feb

13.8 15.1 16.6 19.2 21.6 24.1 26.6 28.1 24.9 22.8 19.3 16.0

(Source: meteorological station of Gaza 2016)

35

Tmin

Tmax

Tmean

30 25 20 15 10 5 0 Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Figure 3.3: Gaza monthly mean maximum, minimum and average temperature (0C).

3.2.2 Wind

Wind speed reaches its maximum value at noon period and decrease during night. According to Shaat 2006 and D'Haeyer 2000 most of the wind blow from the Southwest and the average wind speed is 3.4 m/s at 10 meter measurement and 2,5 m/s at 2 meter. In summer, winds blow regularly at certain hours, and the daily average wind speed is 2.4 and 1.8 m/s as shown in Table 3.2 and figure 3.4 (D'Haeyer, 2000) and come from the Northwest direction. According to EMCC 2012 Storms have been observed in winter with maximum hourly wind speed of 18 m/s (EMCC,2012). Table (3.2) Mean monthly wind speed at 10m (U10) and at 2m (U2) in [m s-1], Gaza Strip.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

u10

3.1

3.6

3.8

3.3

2.8

2.6

2.4

1.9

2.2

2.6

3.0

3.3

u2

2.3

2.7

2.8

2.5

2.1

1.9

1.8

1.4

1.6

1.9

2.2

2.5

Aug

Sep

(Source: Shaat, A., 1999, D'Haeyer, 2000)

u10

u2

3. 3 2.5 2 1.5 1 0.5 0 Jan

Feb

Mar

Apr

May

Jun

Jul

Oct

Nov

Dec

Figure 3.4: Mean monthly wind speed at 10m (u10) and at 2m (u2) in [m s-1] in Gaza Strip Adabted from D'Haeyer, 2000

3.2.3 Rainfall Rainfall is the main important component for the natural groundwater recharge in the area. It is affected by climatic variables such as temperature, speed and direction of winds, insolation, evaporation and evaportranspiration. Gaza Has two defined seasons: the wet season, starting in

October and extending into end March and the dry season, extending from April to September. Actually, the rainy season extends from about mid- October to the end of March, with essentially no rain falling in the remaining months. The rainfall in the Gaza Strip gradually decreases from the north to the south. There is a striking difference between the annual amount off rain falling in Beit Lahia in the north (440 mm/year) and the annual precipitation in Rafah near the Egypt border in the south (238 mm/year). The rainfall data set of the Gaza Strip is based on the data collected from 9 rain stations supervised by Ministry of Agriculture. Data at these stations are collected daily by the Ministry of Agriculture (MoA). Table 3.3 presents the locations of these rainfall stations, while Fig 3.5 shows the average annual rainfall rates of all Gaza rain stations for the time period 1995-2016. Most of the urban areas of the Gaza Governorates do not have a natural drainage outlet because of their low lying topography. Heavy rainfall causes storm water to collect in low areas and flood streets and walkways. Rapid growth has decreased the open areas available for percolation of rainwater and has greatly increased the runoff to low lying areas. (UNEP, 2009)

Table 3.3: Average annual precipitation in nine different locations in the Gaza Strip.

Station name

Average annual precipitation

Range of observations

(mm year-1) Beit Lahia

460

1995 – 2016

Beit Hanoun

448

1995 – 2016

Shati

411

1995 – 2016

Gaza

395

1995 – 2016

Nusseirat

346

1995 – 2016

Deir Al Ballah

312

1995 – 2016

Khan Younis

284

1995 – 2016

Rafah

238

1995 - 2016

Figure 3.5: Annual Rainfall average with stations location in the Gaza Strip

3.2.4 Humidity and Solar Radiation The maximum Monthly relative humidity varies from 81 % to 86 %, the highest values are reached during summer. The minimum relative humidity varies from 53 % to 66%, with again the highest values during summer as shown in Table3.4. D'Haeyer 2000 obtained the Humidity data means of a dry and a wet bulb thermometer also installed in the standard shelter, at about two meters above the grass. Values available for calculation of the reference evapotranspiration are monthly average daily maximum relative humidity [RHmax] and minimum relative humidity [RHmin]. Figure 3.6 presents the relative humidity is given in percentage. The solar radiation is that part of the radiation emitted by the sun that reaches the surface. Solar radiation is characterized by short wavelengths. It varies with the degree of cloudiness. Solar radiation can be measured, however this in not being done in Gaza. According to Ministry of Environmental Affairs the mean annual solar radiation in Gaza is 2200 J/cm2/day (MEnA, 2000).

Table 3.4: Mean monthly maximum relative humidity [%] and mean monthly minimum relative humidity [%]

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

RHmin

54

53

55

54

60

64

66

65

62

58

52

54

RHmax

83

84

84

83

86

86

86

85

82

82

82

83

Nov

Dec

(Source: meteorological station of Gaza strip)

90

RHmin

RHmax

70 60 50 40 30 Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Figure 3.6: Mean monthly maximum relative humidity [%] and mean monthly minimum relative humidity [%]

3.2.5 Evaporation The mean monthly evaporation in Gaza Governorates varies significantly throughout the year. Evaporation measurements had clearly shown that the long term average open water evaporation for the Gaza Strip is in the order of 1300mm/year. Maximum values in the order of 140mm/month are quoted for summer, while relatively low panevaporation values of around 70mm/month were measured during the months of December and January (CLICO, 2010) 3.3 Topography Gaza topography is characterized by elongated ridges and depressions, dry streambeds and shifting sand dunes. The ridges and depressions generally

extend in a NE–SW direction, parallel to the coastline. Land surface elevations gradually slopes downwards from east to west, ranging from the eastern highest at 105 meters above the mean sea level, to the mean sea level in the west. The sand dunes are 30-60 m above mean sea level and cover a total area of 70 km2, the surface elevations of individual ridges range between 20 m and 90 m above mean sea level. More specifically, there are four ridges: the coastal ridge (20 m MSL), the Gaza ridge (up to 50 m MSL), the El Muntar ridge (80 m MSL), and the Beit Hanoun ridge (90 m MSL). These ridges are separated by deep depressions (20-40 m MSL) with alluvial deposits (Figure 3.7). The terrain is flat or rolling, with dunes pushing in from the coast towards east, particularly in the southern part of the Gaza Strip. The Gaza topography (Figure 4.4) is characterized by elongated ridges and depression parallel to the coastline, dry streambeds and sand dunes. The parallel Kurkar ridges have been dissected by Wadi Gaza, the largest surface water feature in Gaza which rarely flows due to water diversion at the east of Gaza borders by Israelis.

Figure 3.7: Elevation topographical map of the Gaza Strip

3.4 Soil Soil in the Gaza Strip can be distinguished in six different types as shown in Figure 3.8: Sandy Regosols represent 31.6% of the total area of the Gaza Strip, Loessal-Sandy Soil with total of 22.8%, Sandy Loess Soil, Loess Soil, Sandy Loess soil over Loess, Clay Loam (alluvial soils) represent 13.7% as shown in table 3.5 (MOPIC, 1997, El Baba, et.al 2015). Goris and Samain, 2001 described the soil types as follow:

SOIL SANDY REGOSOLS

SQ KM 115.31

% 31.59

LOESSAL SANDY SOIL SANDY LOESS SOIL LOESS SOIL SANDY LOESS SOIL OVER LOESS CLAY LOAM (alluvial soils) TOTAL

83.30 32.89 24.21 59.07 50.22 365

22.82 9.01 6.63 16.18 13.76

Table 3.5: Soil classification and percentage distribution in the Gaza Strip. 3.4.1 sandy soils

Sandy soils on dune accumulations are regosols, soils without a marked profile. Textures in the top meters are usually uniform and consist of medium to coarse quartz sand with a very low water-holding capacity. The soils are moderately calcareous, very low in organic matter and chemically poor but physically suitable for intensive horticulture in greenhouses. In the deeper subsurface occasionally loam or clay loam layers of alluvial origin can be found. Often, farmers mix the top layer of these kind of soils with clay in order to increase the waterholding capacity of the soils. The clayey material is found in deeper layers of the soil or was transported from other locations. The mixed layer usually is some 50 cm deep. This kind of soil preparation is very intensive and has an enormous effect on the properties of the soil but it makes soil classification and soil mapping much more difficult since it is not implemented on every field to the same extent. On the sandy soils, traditional farmers often use an agricultural system called “el Mawasy”. The sandy top layer of the soils is removed and crops are planted in the fine textured material underneath on which crops can grow without irrigation because of its high moisture content. This system used to be widespread in the south areas around Khan Younis and Rafah. 3.4.2 loessial sandy soils Loessial sandy soils can be found some 5 km inland in the central and southern part of the Strip, in a zone along Khan Younis towards Rafah, parallel to the coast. This belt forms a transitional zone between the sandy soils and the loess soils, usually with a calcareous loamy sandy texture and a deep uniform pale brown soil profile.

3.4.3 loess soils Typical loess soils are found in the area between the city of Gaza and the Wadi Gaza. They are brownish yellow-coloured, silty to sandy clay loams, often with an accumulation of clay and lime concretions. These soils could be of great importance for agriculture but because they are situated near Gaza City, they are often used for small-scale industrial purposes. sandy loess soils A sandy loess soil is a transitional soil, characterised by a rather uniform, lighter texture. These soils can be found near Deir el Balah. Apparently, windblown sands have been mixed with loessial deposits. Deposition of these two kinds of materials have occurred more or less simultaneously. 3.4.5 sandy soil over loess This is another kind of transitional soil. It is loess or loessial soils which have been covered by a 20 to 50 cm thick layer of dune sand. These soils can be found east of Rafah and Khan Younis. 3.4.6 Clay Loam (alluvial soils) Alluvial soils, dominated by loamy clay textures, are found on the slopes of the northern depressions between Erez and Wadi Gaza. Usually they are dark brown to reddish brown in colour, with a well-developed structure. At some depth, lime concretions can be found. The calcium carbonate content can be around 15-20 %.

Figure 3.8 The Gaza strip soil types map.

3.5 Land use Land is one of the scarcest natural resources in the Gaza Strip. The major part of the Gaza district land is owned by private sector. The distribution and characteristics of the land use across Gaza are shown in Fig (3.9) and listed in Table (3.6). It is obvious that the agricultural and urban development areas makes up the highest portion, covering occupies about 158 km about 44% of the total area. 2

Which shows also the importance of the agricultural sector for the national economy. These agricultural lands are located in the eastern parts of Gaza where the population density is low. Further important land uses are natural resources areas cover about 27.6% followed by urban built up areas with 13.8 % table (--) show the percentage of land use for the 15-land use type. Future expansion is expected for the domestic use only, producing an increase of total amount of

rainwater losses due to urbanization as surface run-off and resulting in an increasing pressure on underground water resources

Table 3.6: classification percentage the Gaza Figure 3.8: map of the 3.6

LANDUSE BUILTUP AREA CULTIVATED AREA NATURAL RESOURCES NATURAL RESERVES URBAN DEVELOPMENT TOURISM DEVELOPMENT RECREATIONAL AREA EXISITING INDUSTRIAL AREA PROPOSED INDUSTRIAL AREA FREE TRADE ZONE AIRPORT HARBOUR FISHERIES SITE SOLID WASTE DISPOSAL SITE WASTE WATER TREATMENT SITE TOTAL

SQ KM 50.19 87.38 100.82 27.49 71.00 2.63 6.52 1.56 5.00 2.89 8.02 0.17 0.24 0.18 0.90 365

% 13.75 23.94 27.62 7.53 19.45 0.72 1.79 0.43 1.37 0.79 2.20 0.05 0.07 0.05 0.25 100

Land use and distribution in Strip Land use Gaza strip.

Hydrogeology The Gaza Strip is a shore plain consists of a series of Mesozoic to the Quaternary geological formations sloping gradually from east towards the west. It is a Pleistoceneage granular aquifer (Kurkar Group), formed by marine and eolian calcareous sandstone ("kurkar"), reddish silty sandstone ("hamra"), silts, unconsolidated sands and conglomerates with intercalation of clay of marine origin and loam. Some of them are lenses which are randomly distributed in the area, causing local perched water conditions (Shomar et al., 2010); others begin at the coast, extending 2-5 km inland, and separate the aquifer into various subaquifers, indicated as A, B, B1 and C (Figure 3.10). Subaquifer A is phreatic, whereas B and C become confined toward the sea. The aquifer overlies marine clay of Neocene age, known as Saqiya Clay aquiclude, which is the bottom of the aquifer (Greitzer, 1967; PWA 2003). The average thickness of the aquifer body is about 150 m, reaching its maximum of about 200 m near Gaza city and its minimum of about 20 m in the eastern part (landward boundaries) and in the south, near the city of Rafah. The aquifer system can be described more specifically as follows:

Figure 3.10: Schematic geological cross-section through the study area; this cross-section could be located anywhere in the GCA, although the existence and position of the subaquifers, clay lenses and aquitards vary from north to south; arrow within the section indicates the direction of undisturbed groundwater flow driven by slope of the water table.

Upper sub-aquifer A The uppermost aquifer which is classified as sub-aquifer A and extends from the shoreline to the east up to 2 km. This aquifer is bounded from the top by the water table and at the bottom partly bounded by the first aquitard of silty clay. The thickness of this aquifer varies between 10 to 30 meters.

Middle sub-aquifers B1 and B2

These two sub-aquifers, classified as B1 and B2, consist mainly from Kurkar and microconglom...