Saline Water Intrusion in Appikatla and Gudipudi Villages in Guntur District of Andhra Pradesh
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International Journal of Civil Engineering and Technology (IJCIET) Volume 9, Issue 4, April 2018, pp. 1495–1500, Article ID: IJCIET_09_04_165 Available online at http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=4 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed SALINE WATER INTRUSION IN APPIKATLA AND GUDIPUDI VILLAGES IN GUNTUR DISTRICT OF ANDHRA PRADESH R. V. Ramana Department of Civil Engineering, VFSTR University, Guntur, Andhra Pradesh, India ABSTRACT The intrusion of saline water in the groundwater table of an area affects crop yield and production of crops as well as the development and health aspects of living beings in that area. Hence a detailed study has been carried out to assess the ground water quality in Appikatla (Latitude: 15.97290 N; Longitude: 80.50910 E) and Gudipudi (Latitude: 16.42000 N; Longitude: 80.21610 E) villages of Bapatla mandal in Guntur district in Andhra Pradesh state of India. The formations in the study area belong to recent alluvium. Groundwater occurs under unconfined conditions. The groundwater is analyzed for various physico-chemical parameters. Values of most of these parameters like PH etc., fall beyond the standard limits for drinking water. The chloride-bicarbonate ratio greater than 6 as per Revel’s classification suggested that the groundwater is injuriously contaminated with saline water. The present attempt is made to ascertain the saline water intrusion into the groundwater in the study area. Suitable precautionary measures are suggested for sustainable development of ground water quality to maintain the environmental balance in the study area. The present study can be extended in similar saline water intrusion areas throughout the world. Keywords: Andhra Pradesh, Appikatla, Groundwater quality, Gudipudi, Saline water intrusion Cite this Article: R. V. Ramana, Saline Water Intrusion in Appikatla and Gudipudi Villages in Guntur District of Andhra Pradesh, International Journal of Civil Engineering and Technology, 9(4), 2018, pp. 1495–1500. http://iaeme.com/Home/issue/IJCIET?Volume=9&Issue=4 1. INTRODUCTION The management and maintenance of groundwater quality becomes more important as the dependency on groundwater for drinking, irrigation and industrial purposes is increasing day by day even in rural areas of Andhra Pradesh, India. Saline water intrusion in coastal areas affects not only the groundwater quality but also environmental aspects and agricultural production in that area. Transgression and incursion of saline water deteriorates the quality of groundwater in coastal regions and many river basins in the country [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]. Earlier studies carried out in the area are on geochemistry of groundwater [12, 13], http://iaeme.com/Home/journal/IJCIET 1495 [email protected] R. V. Ramana prospecting and management of groundwater resources [14] and seasonal variation of groundwater quality [15]. Literature suggests that little work on this aspect has so far been done in India [16, 17, 18, 19, 20, 21, 22]. By knowing various geochemical processes responsible for deterioration of groundwater quality, the managers can plan and to be maintain and monitor the groundwater quality in that area. Hence an attempt is made in this paper to examine the associated hydro geochemical processes. 2. STUDY AREA 2.1. Location The area is located North of Bapatla town in Bapatla mandal of Guntur district in Andhra Pradesh and lies in between East longitudes 80.21610 and 80.50910 and North latitudes 15.97290 and 16.42000 and shown in map enclosed (Fig.1). The Appikatla and Gudipudi villages are situated west side of the Tungabhadra drain which drains north to southwards into the Bay of Bengal. The study area has gentle slope and scattered drainage pattern. Figure 1 location map of appikatla and gudipudi villages in guntur district, andhra Pradesh,india 2.2. Physiography The area is plain and has gentle dip towards the Bay of Bengal. In general the drainage is not well defined and scattered drainage pattern have developed as irrigation channels and drains. 2.3. Hydrogeology The area contains alluvium of recent age. The alluvium consists of both sands and clays in this area [23]. The alluvium comprises of coarse permeable to medium sands and all along the Tungabhadra drain and also in and around the villages of Appikatla and Gudipudi. The permeable sandy deposits occur down to a depth range of 10 to 19 meters, underlained by thick clay in which the quality of ground water is saline. Fresh Ground water occurs in sandy aquifer. Rainfall and canal water are the direct recharge sources of the groundwater. Ground water is extracted by means of shallow filter points for irrigation purpose. The depth to water level varies from 3.1 to 4.8 meters below ground level. The thickness of alluvium sands range from 9 to 28 meters. http://iaeme.com/Home/journal/IJCIET 1496 [email protected] Saline Water Intrusion in Appikatla and Gudipudi Villages in Guntur District of Andhra Pradesh 3. QUALITY STUDIES During the hydro geological reconnaissance investigations carried out in Appikatla and Gudipudi areas, it is observed that in the recent past, quality of groundwater has deteriorated significantly. This feature is predominant in the areas nearer to Tungabhadra drain. Keeping in view of this quality problem in this area, 6 samples of groundwater from each village during Pre monsoon and post monsoon of 2017 were collected to examine the associated hydro geochemical processes leading to salinity by a number of anthropogenic activities within the flow path [24, 25]. Physical parameters of water samples such as PH and spot electrical conductivity (EC) were measured in the field, immediately after the sampling, using portable EC meter. All standard precautions, necessary for reliable estimation were observed during field measurement. The accuracy of measurement was ± 0.1 units. The groundwater samples after collection were subjected to determination of hydrochemical parameters such as calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), carbonate (CO3), bicarbonate (HCO3), chloride (Cl), sulphate (SO4) ions. The sampling, preservation and analytical techniques used are as per the reputed laboratories for analysis of groundwater samples and American Public Health Association (APHA) manual of ‘Standard Methods for Examination of Water and Wastewater. The accuracy of chemical data for major ions is estimated from the electro neutrality condition. Spot/ field EC is selected for assessment of groundwater quality as it represents total ionic content in water. It indicates the extent of mineralization in groundwater and generally increases with contamination, flow, and residence time of water in the aquifers. It is one of the important parameters that reflect even minor changes in the quality of groundwater from shallow aquifers. Average chemical analysis data of groundwater samples for the year 1975 [26], Pre monsoon and post monsoon of 2017 is considered and compared. The data is presented in the TABLE 1. Table 1 Showing the chemical analysis of groundwater samples in Appikatla and Gudipudi villages in Guntur district, A.P. (in meq/l) A – Appikatla Village B – Gudiudi village Chemical Post Pre Post Pre Parameter 1975 monsoon monsoon 1975 monsoon monsoon 2017 2017 2017 2017 PH 7.66 9.03 9.18 7.61 8.96 9.32 EC (µs/cm) 1.75 2.94 3.08 1.59 2.88 3.23 2 CO3 (meq/l) 0.38 3.48 3.75 0.27 3.59 3.71 - ,, HCO3 5.77 2.36 2.45 3.06 2.23 2.59 Cl- ,, 8.37 18.55 17.89 5.24 18.88 18.76 2- ,, SO4 0.46 3.97 5.06 3.34 7.09 7.35 Ca2+ ,, 2.26 1.28 1.53 1.08 1.24 1.45 Mg2+ ,, 2.14 1.59 1.76 0.93 1.34 1.78 Na+ ,, 3.88 38.38 37.24 1.76 36.58 36.27 K+ ,, 0.19 0.34 0.55 0.12 0.25 0.66 Ratio(Cl- - 1.45 7.86 7.30 1.71 8.47 7.24 /HCO3 ) http://iaeme.com/Home/journal/IJCIET 1497 [email protected] R. V. Ramana Table 2 Chloride/Bicarbonate ratio as per Revel’s classification Range Ratio of S. NO Name of Category Chlorite/Bicarbonate 1 Non-contaminated (fresh water) <1 2 Slightly contaminated 1-2 3 Moderately contaminated 2-6 4 Injuriously contaminated 6-15 5 Highly contaminated 15-25 6 Very highly contaminated sea water >25 - - 3.1. Chloride / Bicarbonate ratio (Cl /HCO3 ): - - It is observed from Table 1 that the chloride / bicarbonate (Cl /HCO3 ) ratio of groundwater in Appikatla area is 1.45 in 1975 ranges from 7.30 to 7.86 during Pre monsoon and post monsoon - - of 2017. The chloride bicarbonate (Cl /HCO 3 ) ratio is 1.71 in Gudipudi area in 1975 and ranges from 7.24 to 8.47 during Pre monsoon and post monsoon of 2017 respectively. Chloride is dominant anion of ocean water, and normally occurs in only small amounts in fresh groundwater. On the other hand bicarbonate is usually most abundant anion in ground water and occurs in only minor amounts in sea water. The chloride-bicarbonate ratio, more than 6 indicates the injuriously contaminated groundwater with sea water as per TABLE 2. Accordingly the ratio is 1.45 in Appikatla and 1.71 in Gudipudi during the year 1975 indicates that there is no contamination of ground water during that period. The ratio ranges from 7.24 to 8.47 in the Pre monsoon and post monsoon of 2017 years indicating the injuriously contamination of ground water with sea water. The quality deterioration of ground water in the area may be due to increasing in ground water development through filter points and subsequently ingress of back waters from Tungabhadra drain.