416 JOUR.GEOL.SOC.INDIA, VOL.94, OCT. 2019 JOURNAL GEOLOGICAL SOCIETY OF INDIA Vol.94, October 2019, pp.416-418 Past Two Decadal Groundwater Level Study in Tikamgarh District of Bundelkhand Deepak Patle* and M. K. Awasthi Department of Soil and Water Engineering, College of Agricultural Engineering, JNKVV, Jabalpur - 482 004, India E-mail: deepak.patle12@gmail.com*; mka6@rediffmail.com ABSTRACT Groundwater level fluctuations and trends can be used to estimate changes in aquifer storage resulting from the effects of groundwater withdrawal and recharge. These data can be used to address water management needs and to evaluate the effects of management and conservation programs. The study was divided in two periods; 1997 to 2006 – the Phase 1 and 2007 to 2016 – the Phase 2. Though the significant decline in average water levels, both in pre-monsoon and post-monsoon, were observed from Phase 1 to Phase 2 but the rate of decline in water level was not only checked from 0.102 m/yr (Phase 1) to rise at 0.056 m/yr (Phase 2) in pre monsoon season. In post monsoon season this became more prominent as decline rate of 0.308 m/yr in Phase 1 changes to rise in water level at 0.101 m/yr during Phase 2. This trend may be attributed to the construction of water conservation structures. INTRODUCTION In Tikamgarh district, Central Ground Water Board has been carrying out water level monitoring of permanent observation wells (POWs), since more than last two decades. To study ground water regime of the area, pre-monsoon and post-monsoon depth to water levels are important. In order to bring out the spatial and temporal changes in the ground water regime, the study was conducted in different blocks of Tikamgarh district, Madhya Pradesh, which is one of the districts where number of water conservation structures have been constructed under Bundelkhand special package. A major part of this district is dependent on rains. Though underground water is used for irrigation purposes but due to deeper water table submersible pumps are required. Due to inadequate number of water harvesting structures in the district the water table is getting less recharged. Periodic monitoring of the ground water regime is an essential prerequisite for effective planning, management and sustenance of quantity as well quality of this precious resource. STUDY AREA Tikamgarh district is situated in the northern part of Madhya Pradesh. It is situated on the Bundelkhand plateau between Jamuni, (a tributary of Betwa) and Dhasan river. It extends between the 24°26' and 25°34' N latitudes and 78°26' and 79°21' E longitudes. The district is divided into six blocks viz., Tikamgarh, Baldeogarh, Jatara, Palera, Pirthvipur and Niwari. The maximum length of the district is about 119 km from north to south and width is about 80 km. The major part of the study area is comprised of granite rocks and soils which are classified as black humus granitic and yellowish grey colour with kankar soils. The entire district comes under Betwa sub-basin of Ganga basin. DATA AVAILABILITY The groundwater level data of 100 permanent observation wells (POWs) tapping unconfined aquifer were collected for 20 years (1997- 2016) from the State Water Data Centre, MPWRD, Bhopal and Central Ground Water Board (CGWB) Bhopal, Madhya Pradesh. Conservation structures constructed under Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA) Tikamgarh, Integrated Watershed Management Programme (IWMP), various Joint Forest Management Committees in Bundelkhand special package, Tikamgarh. Locations of POWs sites are shown in Fig.1. METHODOLGY Using sub-sheets of toposheet 54K, 54L, 54O and 54P, the block boundaries are digitized in GIS platform with Arc map 10.3 and on shape file of thus prepared district map the location of POWs are marked using their lat-long coordinates. Water level data of respective wells were averaged separately for Phase 1 (1997-2006) and for Phase 2 (2007-2016). F - Test In agricultural experiments the performance of a treatment is assessed not only by its mean but also by its variability. Hence, it is of interest to us to compare the variability of two populations. In testing of hypothesis the equality of variances, the greater variance is always placed in the numerator and smaller variance is placed in the denominator. F-test is used to test the equality of two population variances, equality of several regression coefficients, ANOVA. F- test was discovered by G.W. Snedecor. The range of F: 0 to ∞ Let x 1 , x 2 ,........., xn 1 and y 1 , y 2 ,.......yn 2 be the two independent random samples of sizes n 1 and n 2 drawn from two normal populations N(μ 1 , σ 1 2 ) and N(μ 2 , σ 2 2 ) respectively. S 1 2 and S 2 2 are the sample variances of the two samples. Null hypothesis H 0 : σ 1 2 = σ 2 2 Under H 0 , the test statistics becomes Which follows F- distribution with (n 1 -1, n 2 -1) d.f. F =  1 2  2 2 where, S 1 2 > S 2 2 Where  1 2 = 1  1 −1 ∑  2 − ∑  2  1   2 2 = 1  2 −1 ∑  2 − ∑   2  2  or F =  2 2  1 2 where, S 2 2 > S 1 2 Which follows F- distribution with (n 2 -1, n 1 -1) d.f. If calculated value of F < table value of F with (n 2 -1, n 1 -1) d.f at specified level of significance, then the null hypothesis is accepted and hence it is concluded that the variances of the populations are homogeneous otherwise heterogeneous. DOI: 10.1007/s12594-019-1330-6 | 0016-7622/2019-94-4-416/$ 1.00 © GEOL. SOC. INDIA