A GIS based Hydrogeomorphological Mapping of Basaltic Terrain Implications for Water Resource Evaluation and Management
Bhopal, the capital city of Madhya Pradesh having highest population density and situated over Malwa plateau. The area in and around Bhopal city faces acute water scarcity and chronically drought prone region. The present study was under taken to evaluate various hydrogeomorphological units of the area through the use of high resolution satellite data and field survey. The evaluated hydrogeomorphological units along with geological setup and topographic condition are integrated in GIS environment on the basis of contribution of particular factor in groundwater occurrence and movement. Digital image processing techniques were also applied for better understanding of the features which are helpful for identification of boundaries of various landforms and geology. The deeply and moderately weathered pediplains with shallow alluvial plains are the most potential zones for groundwater exploration and site for water management plan. Keywards: Hydrogeomorphological mapping, Basaltic terrain, remote sensing GIS, Bhopal, India. About the Author: Dr. Prafull Singh Ph. D.Hydrogeology Remote Sensing GIS Dr.Prafull Singh, working as Assistant Professor, Amity Institute of Geo informatics and Remote Sensing, Amity University, Noida. His current research interests are in geosciences and hydrogeology especially in the assessment of groundwater resources and its pollution modeling from Earth observing remote sensing and GIS techniques for sustainable natural resource management. He has research papers in the leading research journals in the field of Water resources and Environmental geology. E mail ID: singhgeoscience@rediffmail.con psinghamity17@amity.edu Contact No: +91 09958196406 13 Esri India User Conference 2012 Page 2 of 8 Introduction Groundwater is a dynamic and replenishable natural resource for the survival of human beings and the development of society. Therefore accurate and reliable information was required for water resources assessment and management. One of the most concerning issues currently being faced by the society, is the growth of population and its impact on the water resources. A groundwater resource plays a fundamental role in the sustainability of livelihood and regional economies throughout the world. It is the primary safeguard against drought and plays a central role in food security at local, national as well as global levels. Space borne remote sensing information with its unique capabilities of spatial, spectral resolutions and temporal availability covering large and inaccessible areas within short time has become a very versatile tool in natural resource mapping. Geographical Information System (GIS) is a powerful tool for collection; storing, retrieving, transforming and displaying spatial data from the real world (Brunner et al. 2007; Leblanc et al. 2007).Remotely sensed data provides is a rapid and cost effective tool in generating valuable data on geology, geomorphology, land/ use, lineaments/structures and slope, etc. that helps in demarcating groundwater prospect zones over a conventional techniques of hydrological analysis (Singh et al. 2011) A systematic integration of these data with field information provides rapid and cost effective tool for identification of groundwater prospect zones and management of water resources in hard rock areas (Singh, 2012, Imran et al. 2011) The groundwater occurrence and movements in hard rock areas are depending on the underlying rock formation, thickness of weathered material, topography, secondary porosity (fold, fault, fractures and lineaments) and climatic conditions. It is well known that hard rocks are having very less prospect for groundwater storage due to hard in nature, diversify physiographic conditions and climate change resulting is a severe crisis of availability of portable drinking water.The available water resources are inadequate to meet all the water requirements as well as high cost of exploration make the serious concern to find out the groundwater prospect zones with cost effective techniques especially in hard rock terrain.In this direction mapping and monitoring of existing groundwater resources and predicting the future scenarios are the major issues in hard rock areas such as basaltic terrains in India. The incorporation of various field information collected from several sources are the key input data for groundwater prospecting of hard rock area with sustainable manner (Jasmin et al. 2011; Singh et al. 2011; Jha et al. 2007) The present study has been taken for the Bhopal area using remote sensing and GIS techniques for understanding the terrain for groundwater assessment and management. STUDY AREA: Bhopal is the capital city of the state of Madhya Pradesh situated in the central part of India and widely known as a City of Lakes. The study area comes under latitudes 23 0 10' 23 0 20' N and longitudes 77 0 20' 77 0 30'E of Bhopal city (Fig.1) The average annual rainfall of city is 1270 mm. The southern part of the city receives more rainfall than northern part of the city. The maximum rainfall takes place during the month of July.The city form a part of Malwa plateau with undulating topography. The major part of the city is covered by Vindhyan hills and by Deccan trap basalt. There is no major river flowing through the Bhopal city except number of large and small lakes. The area is drained by small drains which are lastly contributed to the river Betwa in the downstream. 13 Esri India User Conference 2012 Page 3 of 8 Bhopal has been sprawling a fast rate of urban development and industrialization, over the last decade population growth of the city has been change drastically and the rate of high urbanization have an severe impact on the available water resource. The Deccan Traps cover almost one third of the area followed by Vindhyan sandstone. In Deccan Trap basalts, aquifer is encountered at shallow depth and in vindhyan sandstone depth ranges more than 150 m bgl. The water supply to Bhopal city is mainly comes from surface water bodies and small amount by groundwater. Nowadays number of bore holes tube wells area drilled in the area without consideration of hydrological status of the aquifer formation to meet the water requirement this unaware drilling has also lead to the declining trend of water level and also failure of well in successive years. Fig. 1: Location map of the study area. Geological and Hydrological status: The Deccan Traps sequence consists of multiple layers of solidified lava flows. It is more than 2000 m thick on its western margin and decreases in thickness eastward and occupies 500,000 sq. km area spread over parts of Madhya Pradesh, Maharashtra, Gujarat, Andhra Pradesh and Karnataka. The Deccan Trap covers around 65% of the area of the city and Vindhyan sandstones inhabit 35% of the area. In Deccan Trap basalts, aquifers are encountered at shallow depth and in vindhyan sandstone aquifer zones are deep seated. The basaltic lava flows vary in color from dark grey to purple and pink. Each lava flow consists of an upper vesicular unit and a lower massive unit which may or may not be fractured/jointed. Two lava flows at some places are separated by intertrappean sedimentary beds. Therefore, unlike other hard rocks, the Deccan Traps behave as a multi aquifer system, somewhat similar to a sedimentary rock sequence. Bhopal is occupied by the rocks of Vindhyan Deccan trap Basalt and alluvial formations. Geologically area is divided in three major type's alluvium, Deccan trap and Vindhyan sandstones with small patches of shale which makes the major aquifers of the city. In the study area, Deccan traps are sporadically 13 Esri India User Conference 2012 Page 4 of 8 distributed mainly in the form of linear patches. On the satellite image, this rock type is seen with distinct grey color with rough texture. The derivatives of Deccan trap rock are the black soils, which are seen on the satellite image as dark grey tone with smooth texture. Hydrologically major groundwater yielding aquifer zones are confined in shallow depths the groundwater .The shallow aquifer occurs in Alluvium, Weathered jointed and fractured Deccan traps and Weathered and jointed Vindhyan sandstone. Alluvium is deposited in patches along the major drainage channels and the yield is very limited due to very low thickness. The Deccan trap basalt forms good shallow aquifers zones due to high thickness of weathered deposits. Weathered basalts make the major water bearing horizon. Sometimes a layer of jointed basalt located at suitable geographic locations show very high permeability and supports high pumping through dug wells. In low lying areas the depth of weathering is greater and often a thick clay layer is also developed which confined the ground water at deeper levels. In general Deccan traps yield between 100 and 400 cum/day. (CGWB, 2011) Vindhyan sandstones being general orthoquartzitic in nature are resistant to weathering and do not favour development of thick weathered profile unless the area is predominantly shale. In sandstones groundwater occurs mainly in fractures and along bedding joints. The Vindhyan sandstones in the area occupy mainly higher ground where weathered profile is insignificant or. It acts as recharge for the low lying areas. Data Used and Methodology Assessment and management of groundwater from the remote sensing, field data and other published maps required a systematic methodology in which entire dataset support for the integration and analysis in GIS environment. For the groundwater resource evaluation of an area, a multiparametric data set comprising remote sensing data (IRS ID, ASTER) Survey of India toposheets and published geological map of GSI along with other published maps of the district. The IRS ID LISS III and PAN data were geometrically rectified and registered with SOI topographical maps using ENVI image processing software through map to image registration techniques. The digit