THE EXPLORATION AND EVALUATION OF WATER RESOURCES IN HARRAT KHYBAR SAUDI GEOLOGICAL SURVEY DEPARTMENT OF APPLIED GEOLOGY HYDROGEOLOGY SECTION JEDDAH

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1 THE EXPLORATION AND EVALUATION OF WATER RESOURCES IN HARRAT KHYBAR SAUDI GEOLOGICAL SURVEY DEPARTMENT OF APPLIED GEOLOGY HYDROGEOLOGY SECTION JEDDAH

2 Water Resources under stress

3 Kingdom of Saudi Arabia belongs to the extended arid belt of the lower latitudes of the Northern Hemisphere.

4 Population growth Construction activity Agricultural activity Industrial activity

5 Water Stress by Country

6 GRACE Technology Use GRACE technology to estimate temporal changes in Terrestrial Water Storage (TWS) in Saudi Arabia High Mass Low Mass

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8 Looking for water resources in all environments!!

9 Exploration of water resources in Volcanic Area

10 Alkali basalt (Harrat) covering an area of square km 2 in Saudi Arabia.

11 Harrat Al Harrah km 2

12 Harrat 'Uwayrid 3600 km 2 Harrat ar Rahah 3600 km 2

13 Harrat Hutaymah 800 km 2

14 Harrat Khaybar km 2 Harrat Ithnayn 3700 km 2 Harrat Kura 3200 km 2

15 Harrat Al-Shaqah 3700 km 2

16 Harrat Rahat km 2

17 Harrat Kishb 6000 km 2

18 Harrat Haden 2300 km 2

19 Harrat Elbuqom km 2

20 Harrat Al Birk 2300 km 2

21 Harrat Al Sarah 700 km 2

22 Study Area %76 %24 Volcanic Area

23 Study Area 15% 17% 68% Harrat Khaybar km 2 Harrat Ithnayn 3700 km 2 Harrat Kura 3200 km 2

24 Geological Setting Study Area is one of 3 coalesced basaltic lava fields, Harrats Khaybar, Ithnayn, and Kura, which constitute the largest contiguous area of Cenozoic basalt in Saudi Arabia, similar in extent (20,564 km2). The field contains: scoria cones - 46 basaltic shield volcanoes - 20 domes - 5 tuff cones - one basaltic stratovolcano.

25 Hydrlogical Setting The study area is located between tow major basins - Rumah Basin - Hamdh Baisn

26 Hydrlogical Setting Rain Gauges Stations Station Long Lat H H H H M M M M

27 Seasonal rainfall variations over the study area. ( ) Winter rainfall variations over the study area. ( ) Station H108 H210 H111 H203 M214 M116 M112 M102 Winter (mm) Winter Rainfall (mm) H 210H 111H 203H 214M 116M 112M 102M Station

28 Seasonal rainfall variations over the study area. ( ) Spring rainfall variations over the study area. ( ) Station H108 H210 H111 H203 M214 M116 M112 M102 Spring (mm) Spring Rainfall (mm) H 210H 111H 203H 214M 116M 112M 102M Station

29 Seasonal rainfall variations over the study area. ( ) Summer rainfall variations over the study area. ( ) Station H108 H210 H111 H203 M214 M116 M112 M102 Summer (mm) Summer Rainfall (mm) H 210H 111H 203H 214M 116M 112M 102M Station

30 Seasonal rainfall variations over the study area. ( ) Autumn rainfall variations over the study area. ( ) Station H108 H210 H111 H203 M214 M116 M112 M102 Autumn (mm) Autmn Rainfall (mm) H 210H 111H 203H 214M 116M 112M 102M Station

31 Seasonal rainfall variations over the study area. ( ) Seasonal rainfall variations over the study area. ( ) Annual Rainfall (mm) H 210H 111H 203H 214M 116M 112M 102M Station

32 Well Inventory and data recording Study area has divided into three sectors, namely: Sector (A) represent the northern area. Sector (B), represents the western area. Sector (C), represents the eastern part of Harrat Khyber. Well Inventory: wells data recording Samples Water table and total depths for wells in the study area

33 Hydrochemical Characteristics of the Groundwater chemical analyses results of the major ions of the groundwater samples obtained from the three sectors (A, B, and C). The ph of the groundwater tends to be slightly alkaline. However, the great majority is between 7.0 and 7.7. The EC measurements generally show that the groundwater salinity varies from low to moderate. High saline waters were also found but less common

34 Classification of Groundwater The groundwater character in the study area is shown graphically on the Piper diagrams. NaCl and Na 2 SO 4 NaCl, Ca(HCO 3 ) 2 and Ca-Na (SO4) NaCl and Na HCO3

35 Groundwater Quality TDS (ppm) Number of Sample Percentage % > > Total < % < % %28

36 Aquifer Description The most important aquifer system of the Harrat Khyber area is formed by the basalt flows and the old subbasaltic alluvial deposits.

37 Aquifer Description A B C

38 Geophysical Setting Electrical resistivity sections were carried out in 2 stages in an eastwest direction across the centre of Harrat Khaybar in order to determine whether there are any significant aquifers underlying the near-surface basalts.

39 Geophysical Results N Line 7 Line (b) Second stage 9 profiles over the western side of the harrat Khybar (a) First stage 9 profiles across the eastern part of the harrat Khybar Line 14 Line 15

40 Concluding - There is no residential or agricultural activity within the Harrat area. - Availability of water is concentrated on the outskirts of the study area. - Most of the exploitation of water is for irrigation. - Characterized by the area between the western part of Harrat Khaybar and Harrat Kura abundance of good quality and quantity. - According to the geophysical studies, there are four areas intercourse and promising for the presence of water. Agriculture Activity

41 We must all work hard to develop and save our resources for the next generations.

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