and water resources assesment in semi arid terrain. using ... · and water resources assesment in...

INTERNATIONAL JOURNAL OF GEOMATICS AND GEOSCIENCES Volume 1, No 2, 2010

© Copyright 2010 All rights reserved Integrated Publishing services Research Article ISSN 0976 – 4380

119

Impacts of Climate, Topograpy and Weathearing profile on Hydrogeology and Water Resources Assesment in SemiArid Terrain. Using Earth

Observation 1 ALI, ASTERDEM and GIS techniques

G. Balamurugan 1 , Dr. S. Rajendran 2 , V.Tirukumaran 3 1Centre fore Remote Sensing and Geoinformatics, Sathyabama University, Chennai600 119.

2Department of Earth Science, Annamalai University, Chidambaram. 3Department of Applied Geology, Govt.Arts, College, Salem636 007

[email protected]

ABSTRACT

The demands of growing populations in semiarid regions feed a continual need to locate new groundwater resources and to explore other unconventional water supply options. Locating groundwater is especially critical as such regions are normally characterized by low and highly variable rainfall, high temperatures, low humidity, high rates of potential evapotranspiration and the near absence of permanent surface water. The purpose of this study is to the use of space technology and Geographic Information System GIS, which are applied to identify the hard rock aquifer characteristics in Semiarid terrain. The study area is highly fractured and undulating crystalline terrain. Hence, satellite images of Landsat 7 ETM+ and EOALI were processed using ERDAS Imagine software, among which the major elements controlling groundwater accumulation and flow were determined. Various digital enhancements and hyperspectral techniques are applied to extract the LithoStructures, weathering profiles, soil types and land cover types. A combination of Spectral information from Landsat ETM+ data plus spatial information from ASTERDEM data is used to address the topographical variations in the study area. All these elements were manipulated in GIS system, and each of them was given a certain rate of effectiveness. Final maps are describing. The research results could provide effective tools for the hydrology research, and support the sustainable water resources development and management in arid regions.

Keywords: Climate, Topography, Hyper spectral, AridEnvironment, Water Resources.

1. Introduction Water supply shortage has become a serious environmental problem in many regions of

the world. Thus, demand for water has increased with the increase in the population size and the change in climatic conditions. This is well pronounced in arid and semiarid regions. Climate change is expected to have an impact on hydrological systems because of changes in precipitation, temperature, and reference evapotranspiration, which are the primary input variables for the terrestrial part (Topography, weathering thickness) of the hydrological cycle. Normally, in determining groundwater potential zones as well as in delineating the flow regime of groundwater, geologists rely on several lithologic and structural elements. However, Topography and fracture systems are considered as a major indicative element in groundwater storage/or flow. This has been given concern in several studies, notably those which utilized the space tools, such obtained by ElBaz and Himida (1995); Teeuw (1995) and Per Sandra, et al.



120

(1996). Recently, the reliable procedures to delineate Topography, fracture systems, weathering profile are successfully achieved when using space tools, notably the processing of satellite images.

2. Objectives The objective of this study is to introduce two major concepts. First is the procedure how

to identify groundwater controlling parameters like Geology, Structures, Topography, Soil, Land use from space data, and second is to utilize these systems and integrate with metrological information to assess groundwater regime.

2.1. Study area The study area is located in Vellore district, Northern Tamilnadu, between latitudes,

13 o 12’32” N and longitudes, 78° 24′ 16”E in the west of Vellore city Figure 1. Study area covers an area of 825 sq kmwith a variety of geological formations, climatic conditions and vegetation types (i.e., forests, scrublands, grasslands and agricultural lands).

2.2 . Physiography and climate Physiographicaly the study area is undulated terrain with local elevation and lowlying

areas Figure 2. The study area is of an elevation varying from 250 to 830m above MSL in the mountain areas. Diversity in land forms of study area has resulted in a variety of forest and agricultural systems in the region. Vellor river is the main lifeline of the district with most of the settlements located alongside the river. Generally subtropical climate prevails over the district. The temperature rises slowly to maximum in summer months up to May after which it drops slowly. The mean maximum temperature ranges from 28.2 o C to 36.5 o C and the mean minimum temperature from 17.3 o C to 27.4 o C.

The normal mean maximum and minimum temperature for Vellore and Tiruppathur stations are recorded Table 1. The normal average rainfall of this district is 953.4 mm Table 2.

Table 1: Normal Mean Temperature (Celcius) Table 2: Normal average annual rainfall

St at io n

J F M A M J J A S O N D

VELLORE

Ma x

28 .3

29 .7

31 .7

33 .3

35 .6

36. 5

34 .4

33 .9

33 .5

31 .5

29 .2

28 .2

Min

20 .8

20 .8

22 .9

25 .8

27 .4

27. 2

25 .8

25 .4

25 .4

24 .4

22 .7

21 .4

THIRUPPATHUR

Ma x

29.5

32.5

35.4

36.5

36.5

34.9

32.9

33.4

32.9

30.6

28.9

28.4

Min

17.3

17.5

19.6

23.1

24.1

23.7

23.0

22.9

22.3

21.5

19.4

17.6

Sl.N o. Season Period Rainfall in

mm

Perc enta ge

1. Winter January to February 23.2 2.4

2. Hot Weather Period

March to May 102.1 10.7

3. South West Monsoon

June to September 448.8 47.1

4. North East Monsoon

October to December 379.3 39.8

Total 953.4 100. 0



121

2.3 . Geology and soil Geologically the study area consists of mainly Charnockite, Fissile hornblendebiotite

gneiss and sand and silt Figure 3A. Mountains with dense and scattered vegetations, weathered and solid rocks, complex slopes with exposures, south and north looking faces, and various soil types (alluvial, colluvial and/or residuals) with varying depth normally show a great variability Figure 3B.

3. Data used Landsat TM and ETM + were used in this study. The Landsat ETM+ image (Path143,

Row 51) 24022001 was downloaded from GLCF (Global Land Cover Facility) (http://www.landcover.org/data/). The Advanced Land Imager (ALI) satellite sensor was designed in part to provide future data continuity with the Landsat record (http://eo1.usgs.gov/ali.php). Although the EO1 ALI swath width (37 km) is more restricted than that of Landsat (185 km), and ALI acquisitions must be scheduled in advance, the ALI sensor is pintable. The spectral range and spatial resolution of bands for each sensor are given in Table 3. The ALI measures solar irradiance in 9 multispectral bands between 0.433 and 2.35 μm, providing 3 more multispectral bands than Landsat TM or ETM+. The spatial resolution of the panchromatic (PAN) band is 10 m, compared to the 15 m resolution of the ETM+ panchromatic band. Furthermore, ALI data are 16bit rather than 8bit, offering greater dynamic range. ALI data was downloaded from USGS earth explorer http://edcsns17.cr.usgs.gov/EarthExplorer/. Topographical data ASTERDEM (30m) was downloaded from http://www.gdem.aster.ersdac.or.jp/login.jsp.

Table 3: Band Characteristics for Landsat ETM+ and EO1 ALI sensors. n/a = “Not applicable”

4. Methodology Data processing and interpretation for this work were performed at the Center for Remote

Sensing and Geoinformatics at Sathyabama University Chennai, Tamilnadu. ERDAS IMAGINE 9.1 and ENVI 4.7 were the main software packages used for the image processing. For preparation of thematic layers like Geology, Structures, Drainage Soil, Geomorphology and

EO1 ALI Landsat ETM+

Band Wave Length (µm)

Ground Resoluti on (m)

Wave Length (µm)

Ground Resoluti on (m)

1p 0.433 0.453 30 n/a n/a

1 0.450.515 30 0.450.515 30

2 0.525 0.605 30 0.525

0.605 30

3 0.6330.69 30 0.630.69 30

4 0.775 0.805 30 0.780.90 30

4p 0.8450.89 30 n/a n/a 5p 1.21.3 30 n/a n/a 5 1.551.75 30 1.551.75 30 7 2.082.35 30 2.092.35 30 Pan 0.480.69 10 0.520.90 15

(A)

Legend Deep moderately well drained, calcareous, clayey soils on gently sloping lowlands, slightly erodrd.

Moderately deep, moderately we ll dra ined g ravelly loam soils on gently slop ing hills moderately eroded.

Moderately deep, somewhat excessively drained, gravelly clay soils on moderately sloping high hills, severely eroded

Moderately deep, wel l drained,gravelly clay soils on gently sloping lands, moderately eroded.

Rock out crops: a ssociated wit h moderately deep, wel l drained, clayey soils on moderately sloping h ills, severely eroded.

Rock out crops: a ssociated wit h, shal low, well drained, lo amy soils on und ulating lands, moderat ely erode d

Very dee p, well drained, clayey soils on gen tly slop ing lands,slightly eroded, asso ciated with very deep, w ell drained, loamy soils.

Legend Aplite

Charnockite

Dark/Grey biotite gneiss

Epidote–hornblende gneiss

Fiss ile hornblende biotite gneiss

Sand and silt



122

Land use ArcGIS 9.2 software used. The overall methodology for this study is presented in Figure 4.

Figure 4. A flow chart depicting the methodology adopted for preparation of Thematic Information through remote sensing and GIS techniques for this study.

5. Image Analysis and Interpretation

5.1. Resolution Merge For each sub scene, 30m resolution Landsat 7 ETM+ Multispectral bands 1 to 5 and 7

were fused with the 15 m resolution panchromatic band. For 30m resolution EO1 ALI multispectral bands 2 to 9 were fused with 10m resolution panchromatic band. The resulting fused bands were spatially enhanced while keeping the spectral characteristics close to the original Multispectral bands. Some qualitative and quantitative analyses were implemented to assess the spatial and spectral quality of the fused images. The results show that it was possible to carry out the fusion of a narrowband Hyperspectral image and a high spatial resolution panchromatic image.

5.2. Digital data enhancement Image enhancement in this study utilized the procedures that made the georeferenced

images clearer and more interpretable for hydrogeological analysis. To extract the Lithological, Structural and Geomorphological features and from satellite images that cannot be clearly detected in a single band, the spectral information of the lithological and structural features recorded in multiple bands are utilized. The geological structures, especially the fractures that are considered to be one of the high rating groundwater controlling parameters, have been clearly brought out during the digital image enhancement techniques. The selection procedure using the

Multitemporal Landsat ETM and EO1 ALI SRTMDEM Climatic data, Soil

map

Atmospheric correction

Optimum band selection

PCA

Hydrogeology

Shaded Relief Image

Field data

Rainfall and temperature

Thematic Layers

Groundwater

Topography Profile



123

statistical techniques was applied in ALI and ETM+ data that covers the most prominent rock types in study area. Principal component analysis (PCA) was performed with the six reflective bands of ETM+ and a number of different threeband PC color composite combinations were created and analyzed for their content.

After transformation the data were subjected to histogram equalization to enhance spectral differences in the terrestrial materials. Several color combinations of PC images were assessed. The most informative PC color composite for study area is that of PC 1, 2 and 3 in RGB. The moisture bearing fractures could be easily demarcated by PCA FCC 432 (Figure 3. A), due to the association of vegetation all along the fractures. The Decorrelation stretch (DS) conducted on ALI bands 5, 4 and 3 is shown in Figures 3.B; better lithological contrast and Weathered Soil surface was obtained when compared, for instance, with the standard band combination of PCA images. Moreover most of the lithological units in the study area are discernible in the image.

5.3. ASTERDEM Data Analysis DEMs can help in identifying lineaments that may represent the surface manifestation of

geological structures that might have morphological expression. ASTERDEM (30 M) data are used for Topographical analysis. The primary method used for the interpretation of the ASTER DEMs was to extract fractures& lineaments through the creation of hillshading DEMs. Hill shading DEMs with different azimuth direction and sun angle are used in this study Figure 6. The shaded relief images are created from the multiplied raster data sets using 45 o and 75 o of sun angles and 315 o for sun azimuth. They show that the texture and pattern of certain areas are enhanced. This technique is effective in creating images that enhance the topographical and geomorphical features.

A B



124

Figure 5. Enhanced Landsat ETM+ and ALI Images. A. ETM+PCA bands 7–4–2 & B. Decorrelation Stretched S bands 452) showing the main Hydrogeological Features of the study area.

Figure 6. Examples of shaded relief image with varying sun azimuth and angle that can enhance features in the study area. A. Shaded Relief image (Solar Azimuth 345 o , Solar Elevation 45 o ). B. Painted Relief Image (Solar Azimuth 315 o , Solar Elevation 45 o ).

Profile extraction is semiautomatic because the data are in raster, grid format with northing, easting, and elevation values for each sampled point. In our study, the Spatial and Surface profiles have been selected along the mountains and adjacent undulated terrain. A frequent use of a DEM image is that longitudinal profiles of mountain ranges can be extracted to display how topography varies Figure 7. Microbasins as identified from space were studied with respect to form and geometry, to their geologic and geomorphologic association, as well as for an assessment to explain their origin. For this reason ALI & ETM+ image perspective views of the

A B

Surface

Spatial



125

Average Rainfall (19912005)

0 50 100 150 200 250 300 350 400 450 500

January to February

March to May June to September

October to Decemeber

Winter Hot Weather Period

South West Monsoon

North East Monsoon

season

Rainfal in

mm

Rainfall in mm

Percentage

Figure 7. ASTERDEM (30M) and profiles of the study area. study area were generated using digital elevation models (DEM) Figure 8. However the relief displacements were not considered and therefore not compensated. But still, this type of simulation contributes significantly to the understanding of surface characteristics, since structural and geomorphologic features, landforms and macrorelief appear well enhanced. The results of the interpretation are judged to be meaningful and enlightening in a variety of hydrogeological situations.

Figure 8. 3D Perspective View of the study area

5. Rainfall data analysis The general prevailing climate in the Study area is Semiarid condition. The maximum

rainfall receives from southwest monsoon Figure 9. There are two rainfall stations which could provide the depth of precipitation in overall study area, include Ambur and Gudiyatham. Rainfall data were collected from the Meteorological Department, Chennai for 28 years. Average annual rainfall for all three stations for the last 8 years (2001 – 2008) is 803mm. The rainfall for the Study area mainly received from four distance monsoon periods such as, southwest, northeast, summer and winter. The month of September and October receives maximum rainfall in the area. The analysis of precipitation for the last 28 years indicated that the frequency of failure of monsoon (less precipitation) is higher in the study area for the last 8 years particularly in the year 2002 and 2006; severe drought conditions prevailed in the block and thus lead to extensive water management practices in the district. The trend of rainfall in the district has indicate that the increase of precipitation from south to north direction. Rainfall is the direct recharge source and irrigation return flow is the indirect recharge source of groundwater in the study area. Development of groundwater is through open dug wells and bore wells. Groundwater occurs in the weathered zone under unconfined conditions as well as in the fractured zone under semi confined conditions.



126

Figure 9. Average rainfall in Gudiyatham and Ambur stations from 1991 – 2007.

6. Results and Discussion

The obvious diversity in the existing physical conditions in any area results different hydrogeological characteristics, weather in terms of surface water or groundwater behavior. This is well pronounced in arid regions where rainfall is rare, while rugged topography and fractured rocks, which is the case in the western part of the Tamilnadu. For this purpose, the study aimed to tackle a major hydrogeological topic concerning groundwater storage in this area where water resources are rare.

6.1. Topographical Setting and Groundwater System

Groundwater is found in a wide range of rock types, from ancient crystalline basement rocks that store minor quantities of water in shallow weathered and jointed layers, to alluvial plain sediments that may extend to depths of several hundred meters and contain enormous volumes of groundwater. Crystalline rocks and metamorphic rocks even though the primary bedding is obscured. It occurs because weathering processes enlarge fractures and introduce interstices near to the ground surface in rocks of otherwise very low permeability. Such rocks may also be overlain by a thin superficial layer of much more recent alluvial deposits which, if permeable, can provide a temporary storage medium for rainfall recharge, thereby increasing the productivity and apparent storage of the underlying hard rock formation. It results in much more localized flow systems because the aquifer is limited in vertical or lateral extent (Figure 10) as in the case of relatively recent alluvial (C) sediments, or because the bedrock is highly consolidated and usable water only occurs either in certain fracture systems or in a thin weathered zone near the ground surface (B). Groundwater becomes one of the most critical and sensitive factors that affect the ecological environment, because of the dry climate in this region. Groundwater, relatively rich in alluvial and floodplain, is recharged by rivers in upper desert plain areas and discharged by springs and envptranspiration in lower plain areas. In lower plain, formed by fine sand, silt and clay, the aquifer system can be schematically subdivided into two layers, i.e. the shallow water, the upper layer with depth of 1015m, and the deep groundwater, the lower layer with depth of 1625m.

6.2. Groundwater Resources

For relative evaluation of groundwater resources is proposed and computed by integrating all factors such as geology, structures, drainage, Soil, Land use, lineaments, weathered and fractured rocks and related to occurrence and movement of groundwater resources. The synthesizing of information in a GIS is an excellent methodology, albeit timeconsuming and fraught with many deceiving problems such as spatial incompleteness, spatial uncertainty and coordinate inaccuracies. In this study, the given weights were adopted, in addition to the field observation, from a miscellany of previous studies (Edet et al., 1998; Robinson, et al., 1999;



127

Das, 2000 and Shaban, 2003). Therefore, the integrated factors in this study were given the following weights Figure 11.

Figure 10. Topographical setting and Localized groundwater flow systems of the Study area. A. 3D perspective view of the study area B. Structurally controlled hard rock aquifer C. Narrow alluvial aquifer.

By integrating both metrological and hydrogeological details derived through the visual onscreen interpretation of different enhanced products, a groundwater prospective zone map of the study area was prepared Figure 12. In the study area Homogeneous charnockites and gneisses, composed mainly of quartz and feldspars, often develop open fractures or joints. These create some water potential, which is increased by selective weathering along joints to develop highly porous regolith.

Weathered Zone

Bedroc k



128

Figure 11. GIS Integration method of Metrological and Hydrogeological data for Groundwater resource mapping.

Figure 12. Groundwater Potential Zone map of the study area

Jointcontrolled zones of saturation combine with the high potential of colluvial aprons around granite or gneiss outcrops to give surprisingly large supplies of high quality water. Of greatest interest are zones of tectonic faulting in quartzrich crystalline rocks. They can create



129

wide zones of high porosity and excellent permeability, extending downwards for several hundred meters. In low relief areas, alluvial groundwater infiltrates into the zones. Where such fractures outcrop in highland areas, they are generally followed by drainages that serve to recharge the vertical zones of high porosity. If vertical fracture zones cross from high to low elevations, they can act as means of regional transfer of groundwater from wet upland areas to dry plains.

7. Conclusion In general, the hard rock formations do not have good groundwater potential, still

integrated studies help to ascertain presence of hidden water bearing formations. Advanced Remote Sensing and GIS proves to be an effective tool to locate the productive zones, when interpreted in conjunction with hydrogeological and metrological data. The occurrence of groundwater in study area is controlled by rock type, structures, Topography and landforms as revealed from GIS analyses and field investigations. Due to rugged landforms, groundwater occurs mainly in drainage channels with valley fill deposits. Fractures along drainage channels together with valley fill deposits form an integrated aquifer system and have high groundwater potential. In granitic rocks groundwater availability is largely controlled by bedrock fractures. Alluvial materials and weathered bedrock in hydraulic connection with bedrock fractures constitute promising sites for groundwater exploration. Dense lineaments on alluvial flood plains have high groundwater prospects. High yields are often related to thick alluvial cover and thick weathered horizons.

8. References

1. Krishnamurty J, Venkatesa Kumar N, Jayaraman V, Manivel M (1996) an approach to demarcate groundwater potential zonesthrough remote sensing and a geographical information system. Int J Remote Sensing 7:1867–1884

2. Lieke van Roosmalen,* Britt S. B. Christensen, and Torben O. Sonnenborg. Regional Differences in Climate Change Impacts on Groundwater and Stream Discharge in Denmark.

3. YuShih Lin a, YiWen Lin b, Yu Wang a, YueGau Chen a, , MeiLing Hsu b, ShouHao Chiang b, ZuengSang Chen. Relationships between topography and spatial variations in groundwater and soil morphology within the Taoyuan–Hukou Tableland, Northwestern Taiwan. Geomorphology 90 (2007) 36–54

4. Thomas J. Crawford¹ and Randy L. Kath. Ground Water Exploration and Development in Igneous and Metamorphic Rocks of the Southern Piedmont/Blue Ridge.

5. J. Asfahani and y. Radwan Tectonic Evolution and Hydrogeological Characteristics of the Khanaser Valley, Northern Syria, Derived from the Interpretation of Vertical Electrical Soundings. Pure appl. geophys. 164 (2007) 2291–2311

6. John L. Wilson and Huade Guan. MountainBlock Hydrology and MountainFront Recharge



130

7. Miriam riossanchez. Identification of geologic lineaments and groundwater flow systems, using digital elevation models, satellite imagery, and spring data in quito, ecuador

8. Adel Elfouly. Faults and Fractures Intersections Delineation as a Tool for Groundwater Detection Using Remote Sensing and Ground Penetrating Radar Techniques at Saint Catherine area, Southern Sinai, Egypt.

9. Jill N. Bruning. A Digital Processing and Data Compilation Approach for Using Remotely Sensed Imagery to Identify Geological Lineaments in HardRock Terrains: An Application for Groundwater Exploration in Nicaragua

10. Drury, S.A., Peart, R.J., Deller, M.E.A. 2001. Hydrogeological potential of major fractures in Eritrea. Journal of African Earth Sciences, 32, 2, pp. 163177.

and water resources assesment in semi arid terrain. using ... · and water resources assesment in...

Documents