Gaza Water Status Report 2017

Transcription

1 Gaza Water Status Report 2017 Water Resources Directorate June 2018

2 Gaza Water Status Report 2017 DomesticWaterSupply GazaStriphadapopulationof1.899millionpeopleliving 2 on365kmarea(pcbs2018). ThetotalwatersupplyfordomesticuseintheGazaStripis about96,308in2017asfollows: from273municipalwaterwells.(fig.1) fromnineunrwawells. frommekorot. fromdesalinationplants (BrackishandSeawater). Figureno.2showsthecategoriespercentageofthetotal watersupply. Totaldomesticwaterconsumptionwas61.508/y. Dailyaveragepercapitawaterconsumptionwas88.7l/c/d, Dailyaveragepercapitafromthetotalwaterproductionis 133.3l/c/d. The network distribution efficiency of 62.3% as a mean value. Distributionsystemefficiencyvariesfromgovernorateto another,wherethehighestwasinkhanyounisgovernorate is71%. Based on that, the per capita consumption in the Gaza governorates was ranging between 103 l/c/d in the Northerngovernorateand80l/c/dinRafahgovernorate. Themaximumpercapitawaterproductionwasrecordedin thenortherngovernorateof171l/c/dandthelowestwas 106l/c/dinRafahgovernorate. Fig.1:MunicipalWellsLocationMap Fig.2:WaterSuppliedCategories 02

3 ﺳﻠﻄﮥ اﻟﻤﯿﺎه اﻟﻔﻠﺴﻄﯿﻨﯿﮥ Figure no. 3 shows the relationship between total water production and water consumption with variations of system efficiency, as well as daily per capita consumption and production in each governorate with the minimum WHO limit (100 l/c/d). Fig.3: Pattern Water Supply System in the Gaza Strip Governorates Table no. 1 shows more specific for system efficiency and total water consumption as an individual municipality area, as well as per capita consumption. 03

4 سلطە المیاه الفلسطینیە GroundwaterLevel Based on the water level records during the year 2017thewaterlevelcontourmaphasbeendrawn andprepared(fig.4).groundwaterlevelsvariesfrom 12.7m above sea level in the southeastern side of Gaza Strip to about-18.3 m below sea level in the southpartofgazastrip(rafaharea).inthenorthern, areaofgazastripthemaximumwaterleveldeclineis -5.8mbelowsealevel. GroundwaterLevelTrend The water level records for 2017 showed the stability or slightly recovering comparing with records for Figure 5 shows some of the selected wells that characterized by continued trenddeclineofgroundwaterlevels,particularly, whichareclosetotheconeofdepressionsinthe north and south of the Gaza Strip areas. The behavior of that decline varies from well to another controlled by the hydrogeological conditionofthewaterbearinglayer,aswellasthe abstraction rates in terms of quantity and duration, where those wells are located in the areas that have municipal wells, which pump continuouslywithhighpumpingrates.thesignificantwaterleveldeclineoccurredinthewellsthat arelocatedinthecentralpartofthenorthernareawithmaximumdeclineof5.8mbelowmslaswell asinthewesternpartoftherafaharea(southernarea)withmaximumdeclineof18.3mbelowmsl. 04

5 ﺳﻠﻄﮥ اﻟﻤﯿﺎه اﻟﻔﻠﺴﻄﯿﻨﯿﮥ Chloride Content Fig.6: Chloride Concentration Trends Nitrate Content There is no certain trend for nitrate (NO3) concentration with time as represented in (fig.7) since, it is on spot effect as a result of wastewater leaching through the unsaturated zone mainly from the sewerage system in the residential area. Generally, NO3 concentration is mainly controlled by the well location, surface wastewater leached, agricultural activities, thickness of the unsaturated zone and its transmissivity. Fig.7: Nitrate Concentration Trends 05

6 ﺳﻠﻄﮥ اﻟﻤﯿﺎه اﻟﻔﻠﺴﻄﯿﻨﯿﮥ Pumped Water Quality The chloride concentration map for 2017 (fig.8) shows the areas that affected by seawater intrusion which were in the north-west, south-west and towards from west to east of Gaza City, south-west of Rafah and west Deir El-Balah. That expansion is due to the continuation of the intensive pumping from the surrounding domestic wells. Nitrate (NO3) concentration map for year 2017 (fig.9), shows that most of the Gaza Strip has NO3 of more than the WHO limit (50 mg/l). Where it is in range of mg/l and is mainly located beneath the residential areas reflecting the percolation of the wastewater from the sewerage system. Fig.8: Chloride Contour Map 2017 Fig.9: NO3 Contour Map 2017 Regarding the domestic water acceptability for drinking use and based on the pumped water quality the followings can be illustrated (fig.10): 06 Fig.10. Cl and NO3 acceptable Percentage based on WHO limit

7 سلطە المیاه الفلسطینیە 21%(58wellsoutof282wells)ofthepumpedwateriswithCllessthanWHOlimit(250mg/l). 79%(224outof282wells)ofthepumpedwateriswithClmorethan250mg/l. 12%(34outof282wells)ofthepumpedwaterhasNO lessthan50mg/l(wholimit). 3 88%(248outof282wells)iswithNO morethan50mg/lexceedsthewholimit. 3 TakinginconsiderationboththeClandNO concentrationitisclearthat96.1%ofthe 3 groundwaterpumpedexceedingthewhoacceptablelimitandonly3.9%ismatchingwith thewholimit. Conclusion Based on the above assessment, the followingscanbeconcluded: 18.41% of the water supplied from the different sources (3.25% groundwater, 10.97% Mekorot and 4.19% desalinated water) is matching with WHO drinking limit Only3.9%(11of282wells)ofthe domestic groundwater supply in 2017 wasmatchingwithwhodrinkinglimitin termsofclandno3 ( fig.11.) Fig. 11: Chloride & Nitrate Values in Domestic wells Mostofthecoastalareaandwithadistanceofabout3kminlandwasaffectedbytheseawater intrusionphenomenawithdifferentdegree. The yearly Cl increase rate in some wells increasing in chloride reached to more than 2,500 mg/l/year. 07