कᴂ द्रीय भूमि जल बो셍ड जल संसाधन, नदी विकास और गंगा संरक्षण विभाग, जल शक्ति िंत्रालय भारि सरकार Central Ground Water Board Department of Water Resources, River Development and Ganga Rejuvenation, Ministry of Jal Shakti Government of India AQUIFER MAPPING AND MANAGEMENT OF GROUND WATER RESOURCES KOTTAYAM DISTRICT, KERALA केरल क्षेत्र, ति셁िनंिपुरि Kerala Region, Thiruvananthapuram GOVERNMENT OF INDIA MINISTRY OF JAL SHAKTI DEPARTMENT OF WATER RESOURCES, RIVER DEVELOPMENT AND GANGA REJUVENATION CENTRAL GROUNDWATER BOARD AQUIFER MAPPING AND GROUND WATER MANAGEMENT PLAN FOR HARD ROCK TERRAINS IN KOTTAYAM DISTRICT, KERALA (AAP2018-19) Vijesh V.K. Scientist – B (Jr. Hydrogeologist) KERALA REGION Trivandrum January 2020 TABLE OF CONTENTS 1. INTRODUCTION ................................................................................................................. 1 1. 1 Approach and Methodology ........................................................................................... 1 1.2 Study area............................................................................................................................. 2 1.3 Climate ................................................................................................................................. 4 1.4 Soil ....................................................................................................................................... 4 1.5 Physiography and Geomorphology...................................................................................... 6 1.6 Agriculture & Land use ....................................................................................................... 9 1.7 Drainage and Drainage Characteristics .............................................................................. 14 1. 8 Geology ............................................................................................................................. 16 1.9 Previous Work ................................................................................................................... 18 2 DATA COLLECTION, GENERATION AND INTERPRETATION ................................. 19 2.1 Data collection and Data Gap Analysis ............................................................................. 19 2.1.1 Water Level Monitoring ................................................................................................. 19 2.1.2GroundwaterExploration.................................................................................................. 20 2.1.3 Vertical Electric Soundings (VES) ................................................................................. 20 2.1.4 Water Quality Monitoring............................................................................................... 20 2.1.5 Rainfall ............................................................................................................................ 21 2.1.6 Soil Infiltration Tests ...................................................................................................... 23 2.1.7 Determination of storage parameter of phreatic aquifer ................................................. 23 2.2 Data Generation and Integration ........................................................................................ 23 3. AQUIFER MAPPING ......................................................................................................... 29 3.1 Phreatic aquifer system (Aquifer I).................................................................................... 29 3.1.1 Thickness of weathered zone .......................................................................................... 29 3.1.2. Water levels ................................................................................................................... 29 3.1.3. Water level trend ............................................................................................................ 36 3.2 The fracture aquifer system (Aquifer II) ............................................................................ 40 3.2.1 Geophysical investigations ............................................................................................. 43 3.2.2 Groundwater and its relation to Geological Structures ................................................... 43 3.2.3 Aquifer characteristics .................................................................................................... 45 3.2.4 Chemical quality of groundwater .................................................................................... 47 3.2.4(a). Groundwater quality in phreatic aquifer system ....................................................... 47 3.2.4(b). Groundwater quality in deeper aquifer system ......................................................... 50 3.3. Groundwater Resource Estimation ................................................................................... 51 3.4 Groundwater related problems ........................................................................................... 55 Table3.10: Block wise number of sources contaminated in Kottayam district. .............. 55 3.5 Aquifer map ....................................................................................................................... 56 4.MANAGEMENT STRATEGIES & AQUIFER MANAGEMENT PLAN ......................... 59 4.1 Sustainable Plan ................................................................................................................. 59 4.2 Augmentation Plan............................................................................................................. 59 4.3 Aquifer Management Plan ................................................................................................. 59 4.3.1 Short-Term Local Solutions for Groundwater Management .......................................... 59 4.3.2 Long-Term Local Solutions for Groundwater Management .......................................... 60 List of figures Fig.1.1: Location map of the study area .................................................................................................. 3 Fig.1.2: Soil map ..................................................................................................................................... 5 Fig.1.3: Digital Elevation Model of the study area (Source: SRTM data, USGS) ................................. 7 Fig.1.4: Geomorphology map ................................................................................................................. 8 Fig.1.5: Land use pattern in the study area ........................................................................................... 13 Fig.1.6: Drainage pattern in the study area ........................................................................................... 15 Fig.1.7: Geology of the area ................................................................................................................. 17 Fig.2.1: Graph showing average annual rainfall versus year ................................................................ 21 Fig.2.2: Rainfall isohyets in the area ..................................................................................................... 22 Fig.2.3: Graphical Representation of Mean Monthly Rainfall in Kottayam district ............................. 23 Fig.2.4: Location of water level monitoring wells (GWMWs and new KOWs established) in the study area ........................................................................................................................................................ 25 Fig.2.5: Location of vertical electric soundings (existing and new) in the study area .......................... 26 Fig.2.6: Location of exploratory wells (existing and newly constructed) in the study area ................. 27 Fig.2.7: Location of water quality monitoring stations (existing and newly established) in the study area ........................................................................................................................................................ 28 Fig 3.1: Spatial variation of weathered zone thickness in the area ....................................................... 31 Fig.3.2: Pre-monsoon Water level map of Phreatic aquifer .................................................................. 32 Fig.3.3: Post-monsoon Water level map of Phreatic aquifer ................................................................ 33 Fig.3.4: Water level Fluctuation map of Phreatic aquifer ..................................................................... 34 Fig.3.5 Water table elevation contour map of Phreatic aquifer. ........................................................... 35 Fig.3.6: Hydrographs of some of the wells in the study area ................................................................ 39 Fig.3.7: Cross section along AA’ and B-B’ .......................................................................................... 41 Fig.3.8: Fence and conceptual 3D aquifer disposition of the study area .............................................. 42 Fig 3.9: Representation of different field curves in Kottayam district.................................................. 44 Fig.3.10: Rose diagram of lineaments .................................................................................................. 44 Figure 3.11: Curves of infiltration and cumulative depth of infiltration at Chengalam ........................ 46 Figure 3.12: Curves of infiltration and cumulative depth