Ranges, South Australia Presenter Ian Clark for Alaa Ahmed - - PowerPoint PPT Presentation

Hydrogeological characterisation of lineaments in the Central Flinders Ranges, South Australia

Presenter Ian Clark for Alaa Ahmed

Acknowledgements

• PhD Scholarship from Government of Egypt
• Top-up scholarship from Goyder Institute
• Support from SA Arid Areas NRM Board
• Post-Doc research SA Water

Introduction

Groundwater in Australia makes up about 33% of the estimated total water use (ABS 2012) Increased by 60% in the period from 1983- 1997 (Harrington and Cook 2014) 10% of total groundwater usage is from fractured rocks (Harrington and Cook 2014) The sustainable management

• f

water resources in such environment becomes an urgent issue to many communities and ecosystems within Australia

Study Area

Location



In Central Flinders Ranges

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79 km. southwest of Leigh Creek and 210 km north east

• f Port Augusta

Climate



Semi-arid to arid climate.

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Highest daily (159 mm. to 35.5 mm

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Highest monthly (262.8 mm. to 82.8 mm

Catchment

Study Area….Geology and Hydrogeology

Geology

• The main lithologic units that outcrop in the study area are the

Umberatana and Wilpena groups (Preiss 2000) Hydrogeology

• The main water bearing formations are:

➢ Etina Formation ➢ Brachina Formation ➢ Bunyeroo Formation

Problem Statement

Limited data Scaling Fractured or porous

• The geology has been studied in some detail, little or nothing

is known about the groundwater regime.

• Groundwater is considered as the main source of water and

played a significant role in human occupation and settlement (DWLBC 2009)

• The scaling problem is considered the biggest challenge

(Cook 2003; Krásny & Sharp 2007)

• Most of the studies focused on local-scale problems such as

mining, nuclear waste or contamination (Neuman 2005)

• Groundwater occurred in fractured bedrocks which has been

described as a complex, hydrogeological environment (Krásny & Sharp 2007)

Fractured aquifers – have potential to supply larger quantities than other aquifers.

 Geolineament:

a surface expression

• f

fracturing (geologic structure) in the form of:

 Alignments of topography and drainages  Linear

trends in vegetation and soil-moisture anomalies

 Truncation of rock outcrops  Lineaments are indicative of secondary porosity

• Potential to supply large and reliable quantities of

water

• Relationship exists between lineaments and greater

well productivity

 Lineaments can be identified using remotely sensed

imagery (Tone, color, texture, pattern)

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Fault Breccia Cleavage and Joints

Objectives

General Objective Determine whether it is feasible to use the available data to develop a reasonable model on which a sustainability plan for groundwater management can be developed Specific objectives were:

• Identify and extract Geolineaments and other discontinuities from remote

sensing data, geologic maps and field work

• Evaluate hydrogeological characteristics by correlating water information

and extracted lineaments

Materials and Methods

Geolineamets Fractures Hydrogeology Geologic Map Satellite Image Composite Bands Mosiac+Clipping Enhancement Clipping Tracing Drainage Lines Lineament Layer Faults Layer Office Work Field Work SRTM Filling Voids Flow Direction Flow Accumulation Stream Networks Watershed Delineation Scanline Survey Evaluation Field Survey Analysis Data Processing Extraction Evaluation

Results……………….Delineation

Delineation of the watershed

Results….Faults

N=85 N=3 N= 31 N= 9 All faults (b1) (b2) (b3) (b4)

(b) (c) (d) (e) (a)

Orientation and Length Density Map

All lineaments N= 254 N= 39 N=68 N= 32 (a) (a1) (a2) (a3) (a4)

(a): (a) (b) (b) (c) (d) (e)

Lineaments

Orientation and Length Density Map

Fractures

Station: Blinman Hut Well Station: Witches Well Station: Glass Gorge Well Station: Fourth Spring Station: Third Spring Station: Third Spring N=22 N=49 N=26 N=65 N=30 N=40 N=22

20 40 60 80 Blinman Hut Well Witches Well Salt Bore Glass Gorge Well Third Spring First Spring Fourth Spring

Frequency Station: Salt Bore

Zone Formation Trends of lineaments Frequency

• f

lineaments Trends of fractures Frequency of fractures Correlation Northern Bunyeroo NNW–SSE NW–SE NE–SW Low NNW–SSE, NW–SE, NE–SW Low (< 7/m) Fracture correlated Eastern and western Etina and Brachina NW–SE NE–SW NE–SW Low to moderate NNE–SSW, NW–SE NE–SW Low to moderate (< 7/m) Fracture correlated Southern Tapley Hill NNW–SSE NW–SE E–W Moderate to high NWW–SEE NE–SW Moderate to high (> 7/m) Fracture correlated

• A

notable similarity between the prominent trend of the different linear features.

• There

may be a local variation in lineament

• rientations,

length and density which is probably attributable to the heterogeneity of the bedrock, and or structural and stress variations. Comparative analysis

Springs and Lineaments

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Spring Proximity to lineaments Class (<600 limit) Clock Spring 520 Lineaments Hannigan Spring 1000 Non-lineaments Bald Hill Spring 2000 Non-lineaments Willigen Spring 420 Lineaments Six Mile Spring 500 Non-lineaments Witches Spring 490 Non-lineaments Warra Warra Spring 83 Lineaments Second Spring 190 Lineaments Third Spring 150 Lineaments Fourth Spring 800 Non-lineaments

Wells and Lineaments

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Water Well Proximity to lineaments (m) Class (<300m limit) TDS (meq/l) Yeild (L/s) Blinman Well 510 Non-lineaments 46.20 0.5 Pendulum Well 120 Lineaments 62.90 0.5 Bore 170 650 Non-lineaments 37.72 0.5 Witches Well 275 Lineaments 99.41 1.5 Home Well 900 Non-lineaments 97.58 0.5 Salt Bore 1200 Non-lineaments 210.12 <0.5 Glass Gorge 95 Lineaments 38.40 >1.5 Breakneck Well 150 Lineaments 39.20 >1.5 Oratunga Bore 240 Lineaments 28.40 1.5 Warra Warra Well 90 Lineaments 30.40 1

Proximity to lineaments

50 100 150 200 250 200 400 600 800 1000 1200 1400

TDS (meq/L) Proximity to lineaments (m)

Blinman Well Pendulum Well Bore 170 Witches Well Home Well Salt Bore Glass Gorge Breakneck Well Warra Warra Well Oratunga Bore

The correlation between the water composition and location of springs and lineaments, indicates the occurrence of fracture zones of greater porosity and conductivity.

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Hawker

Quorn

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21

Water yield (L/s) EC (μS/cm)

Conclusion

• 1. In areas with limited previous investigations and hydrogeological data, remote

sensing and GIS methods provide support in water studies

• 2. Lineament maps, plotted from satellite data are very useful for groundwater

studies, while, field studies help to detect the nature of structures and correlate lineament interpretation with geological structures

• 3. All the interpretations supports the hydrogeological significance of lineaments,

a correlation of the different parameters with the proximity to lineaments interpreted from satellite images confirms that high yielding wells, low saline and springs are related to lineaments.

• 4. This knowledge could be used to build hydrogeological models of areas for

which there is only limited data