GROUND WATER LEVEL SCENARIO in RAJASTHAN - 2014 Pre and Post Monsoon Survey - 2014
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Government of Rajasthan Ground Water Department GROUND WATER LEVEL SCENARIO IN RAJASTHAN - 2014 Pre and Post Monsoon survey - 2014 DATA STORAGE AND PROCESSING CELL (DSPC) APRIL, 2015 CONTENTS Page. No. 1.0 Overview 1 – 3 1.1 Climate 1 1.2 Rainfall 1 1.3 Physiography 1 1.4 Drainage 2 1.5 Hydrogeology 2 2.0 Abstract 4 3.0 Scenario Of Groundwater Level In Rajasthan – Year 2014 5 – 9 3.1 Depth to water level Pre Monsoon – 2014 5 3.2 Depth to water level Post Monsoon – 2014 6 – 7 Change In Water Level (Fluctuation) Pre Monsoon - 2014 To 3.3 8 – 9 Pre Monsoon – 2014 4.0 Rainfall condition – 2014 10 FIGURES 1 Aquifer Distribution Map of Rajasthan as per ROLTA Study. 11 PLATES District Wise Average Depth To Water Level Of Pre Monsoon 1.1 to 1.3 12 – 14 2014 And Post Monsoon – 2014 2 Change in water level pre monsoon & post monsoon – 2014 15 3.1 to 3.2 Rainfall condition of all the districts during 2013 & 2014 16 – 17 TABLES District Wise Average Depth To Water Level During Pre 1 18 Monsoon and Post Monsoon 2014 Block Wise Average Depth To Water Level And Fluctuation 2 19 – 25 During Pre Monsoon 2014 And Post Monsoon 2014 Depth To Water Level Data Of Key Wells During Pre 3 26 – 148 Monsoon and Post Monsoon – 2014 Normal Monsoon, Non monsoon, Annual Rainfall & Rainfall 4 149 Condition 2014 1.0 OVERVIEW Rajasthan, the largest state of India with geographical area of 342230 Sq.km. and situated in the north-western part of the country. It extends between 23 0 30’ and 30 0 11’ N latitudes and 69 0 29’ & 78 0 17’ E longitudes. According to 2011 census population of the State is 68548437. The state has been divided into 33 districts and further in 248 developments blocks. 1.1 Climate The Aravalli range divides the state into two different climatic zones. The region west of Aravallis is desert to semi-desert and east of Aravallis is semi arid to sub-humid and characterized by large extremes of temperature long periods of drought, high wind velocity and high potential evapotranspiration. Based on the weather conditions, three distinct seasons are in the state – (i) Hot-weather season (March to end of June) (ii) Monsoon season (end of June to September) (iii) Cold-weather season (October to February) 1.2 Rainfall The long term rainfall in the state ranges from 158 mm to 895.3 mm. The state receives 90% rainfall from south-east monsoon during June- September. The winter rainfall is meager. The rainfall on the eastern side of the Aravallis is much higher than that on the western side and southern part of the state receives more rainfall than, the northern part. The annual (on average basis) rainfall of the state during the year 2013 was 691.23 mm. 1.3 Physiography The state has a fairly motive topography developed during the long period of denudation and erosion. The present physiography and landforms are greatly determined by the underlying geological formations and structures and are the product of the fluvial cycle of erosion in the past and the recent and continuing desert cycle of erosion. The state can be divided into four physiographic units – (i) Aravalli Hill ranges. (ii) Eastern plains (iii) Western sandy plain with sand dunes (iv) Vindhyan scarpland and Deccan Lava Plateau 1.4 Drainage 1 Aravalli Hills ranges form the main water divide in the state. Luni river is the only river in the west Aravallis and rest 60% area of western Rajasthan has internal drainage and the streams are lost in the desert sands after flowing for a short distance from the point of origin. The Chambal catchment occupies 21% (72032 sq.km) of total geographical area of the State. The other important catchments are Yamuna-Ganga in the north-east and Mahi and Sabarmati in south-west part. In desert area, a few salt lakes and depressions exist, prominent among them are the Sambhar lake, Didwana lake, Bap, Pachpadra and Rann of Jaisalmer and Pokran. 1.5 Hydrogeology The principal source of recharge to ground water in state is rainfall. In canal irrigated areas, a part of canal water through seepage. The geological formations are divided in two groups broadly on the basis of their degree of consolidation and related parameters. (I) Porous Formations (a) Unconsolidated Formations – The Quaternary sediments comprising of younger and older alluvium composed of clay, silt, sand, gravel and form potential aquifers. The yield of exploratory tube wells in alluvium formation is medium to high ranging from 36 to 360 m 3/hrs. (b) Semi Consolidated Formations – These formations composed of siltstone, claystone, sandstone, shale conglomerates and limestone of Paleozoic, Mesozoic and Cainozoic age. The sandstone and limestone forms good aquifer in various district of state. Ground water occurs under semi-confined to confined conditions. (II) Fissured formation Fissured formations as hydrogeological unit occupy 32% area of the state and divided into four units- (a) Consolidated sedimentary rocks (b) Igneous and metamorphic rocks (c) Volcanic rocks (d) Carbonated rocks The development of ground water resources in Rajasthan has passed through various phases starting with meager irrigation of pre plan era, the 2 ground water is now providing irrigation to more than 55% area and catering the drinking water needs of about 80% water supply schemes. The demand of industrial need is increased many fold in last 2-3 decades. The rapid and haphazard exploitation of ground water has resulted in declining water levels, gradual exhaustion of ground water reservoirs and deterioration of ground water quality. This is evident from the fact in the year 1984 irrigation draft was 4926 mcm with stage of development 35.75% only where as in 2011 the irrigation draft is estimated 13133.1818 mcm and stage of development 137.07%. Looking to present status of ground water resources in the state it has been realized that ground water management and its judicious use with public participation should be taken up on priority. 3 2.0 ABSTRACT The pre monsoon and post monsoon hydrogeological survey, 2014 of the State of Rajasthan has been carried out during the months of May – June and Oct – Nov 2014. A monitoring network comprising dug wells and piezometers located in all districts of the State was monitored during the survey. There are 7790 water level monitoring stations (District Key wells) which includes 2575 piezometers spread all over the state. Water level is available for 5320 key wells only during post monsoon survey 2014. 2470 key wells are either dried up or water level has gone deep in the boring or could not be measured due to one or other reason. The average depth to water level of blocks and districts of pre monsoon, 2014 and post monsoon, 2014 has been analysed to know the depletion or rise of water levels during the year 2014. (Table-1 to 2). The change in water level between pre monsoon 2014 and post monsoon, 2014 referred as annual (seasonal) water level fluctuation. While computing pre monsoon 2014 depth to water level data it is observed that depth to water level ranges between 0.10 mtrs, i. e. just on ground level, Charna Bhundwai in Ghatol block of Banswara district to 145.05 mtrs below ground level in Medusar (Khaniyani) village in Sheo block of Barmer district. Average depth to water level of the state is computed as 21.81 meters below ground level considering all wells giving water level. While computing post monsoon 2014 depth to water level data it is observed that depth to water level ranges between 0.05 mtrs, i. e. just on ground level, at Bhawana in Mandal block of Bhilwara district, Diwandi in Rohat block of Pali district to 147.10 mtrs below ground level in Nagari village of Nagaur district. Average depth to water level of the state is computed as 18.58 meters below ground level. Looking to the above figures it is observed that an overall rise of 2.64 metres has been observed in the state from pre monsoon to post monsoon 2014. 4 3.0 SCENARIO OF GROUND WATER LEVEL IN RAJASTHAN - YEAR - 2014 The pre monsoon and post monsoon hydrogeological survey, 2014 of all the 33 districts of the State of Rajasthan has been carried out during the months of May and June, 2014 and October and November, 2014 respectively. However post monsoon survey of Churu district was not conducted due to administrative constraiits. In all 7666 monitoring stations comprising dug wells and piezometers have been monitored during pre monsoon and 7590 (ecluding Churu) during post monsoon, 2014. The average of depth to water level of blocks and districts of pre-monsoon and post-monsoon along with change in water levels has been computed and results are shown in Tables 1 and 2. These water level data are used to know trend of water levels during pre monsoon and post monsoon period. The average depth to water level (Plate 1.1 to 1.3) and change in water levels (Plate – 2) in all the 33 districts of the State during pre monsoon and post monsoon 2014 are displayed through bar diagrams. Analysis of water level data for the year 2014 have been done and results are shown in tabular form as well as in bar diagram form. 3.1 Depth To Water Level Pre Monsoon – 2014 During pre Monsoon 2014 survey a total network of 7666 key wells including 2466 piezometers were monitored in the months of May and June, 2014.