Declining Trends of Irrigation Tank Capacities in Srikakulam District, Andhra Pradesh - a Study Using Rs & Gis Applications
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International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development (IJCSEIERD) ISSN(P): 2249-6866; ISSN(E): 2249-7978 Vol. 4, Issue 1, Feb 2014, 95-100 © TJPRC Pvt. Ltd. DECLINING TRENDS OF IRRIGATION TANK CAPACITIES IN SRIKAKULAM DISTRICT, ANDHRA PRADESH - A STUDY USING RS & GIS APPLICATIONS YERRAMSETTY ABBULU1 & G. V. R. SRINIVASA RAO2 1Associate Professor, Department of Civil Engineering, AUEC (A), Andhra University, Visakhapatnam, Andhra Pradesh, India 2Professor, Department of Civil Engineering, AUEC (A), Andhra University, Visakhapatnam, Andhra Pradesh, India ABSTRACT The space technology is useful in generating information on natural resources which is a pre-requisite for their optimum utilization and effective management. Remote Sensing is one such space technology which can aptly be utilized for the study of Land use/Land cover (LU/LC) patterns and various other factors related to irrigation studies. Hence, an attempt is made in the present work to study the minor irrigation under tanks in Srikakulam district of Andhra Pradesh using Remote Sensing and GIS applications. The Topo Sheets, IRS-P6 LISS-III satellite data of the study area during Khariff, Rabi and Zaid seasons are used to develop LU/LC maps and for the determination of tank capacities. A comparative study of the present capacities of the tanks obtained from the imageries with that of original tank capacities is conducted. It is observed that the capacities of tanks in most of the mandals of the district are reduced to 2/3rd of their original capacities. KEYWORDS: Land Use/Land Cover Patterns, Toposheets, Khariff, Rabi and Zaid Seasons INTRODUCTION Tanks have been an important source of minor irrigation in Andhra Pradesh historically and also at present. The net irrigated areas under minor irrigation, though, increased over a period of time, the component of minor irrigation under tanks received a setback during the recent past. This necessitated the researchers to conduct studies on minor irrigation under tanks in various districts of Andhra Pradesh. The present work focuses on various aspects related to minor irrigation under tanks, taking Srikakulam district, Andhra Pradesh as study area. In Srikakulam district, where tank irrigation accounts for 54.23 percent of the total irrigated area, declined to 28.14 percent during 1960 and 1986 (Partha Saradhi4 1993). There was a continuous neglect of tank infrastructure in north coastal Andhra Pradesh affecting the sustainability of tank irrigation in Srikakulam and other districts (Chinna Rao2 et al. 2009). Advanced technologies like Remote Sensing and GIS can be used effectively to conduct studies on irrigation systems. The application of Remote Sensing and GIS can be used to address various issues relevant to sustainable management of irrigation systems in India (S.M Chintapalli7 et al. 2000). The emergence of remote sensing as a tool for providing a base-line information w.r.t. crop inventory, land cover, soils, source-wise distribution of irrigated areas and irrigation tank inventory, not only in a spatial dimension but also to monitor them through time, is cost and time effective (V. V. Rao and A. K. Chakraborti8 2000). Remote sensing technology, with its high-resolution sensors, can provide the information on the agricultural, hydrological and structural conditions of the tank irrigation systems necessary for prioritization (Abdul Hakeem k1 et al. 2009).The art of application of satellite remote sensing data supports management of irrigation systems effectively (S.K. Ambast6 et al. 2002). The Remote Sensing derived statistics of irrigated areas can be compared with census derived irrigation statistics to conduct further studies on water use assessments and food scarcity 96 Yerramsetty Abbulu & G. V. R. Srinivasa Rao studies (Prasad S. Thenkabail5 et al. 2009). Also, the prediction of water availability in the tanks is important for the purpose of improving productive use of water resources in a tank cascade system, where, the RS and GIS can be used as effective tool (Krishnaveni3 et al. 2011). Hence, in line with these observations an attempt is made in the present work to study the minor irrigation under tanks in Srikakulam district of North coastal Andhra Pradesh using Remote Sensing and GIS applications. METHODOLOGY Study Area Srikakulam, a north coastal district of Andhra Pradesh, consisting of 7,721 tanks with 7,472 Panchayat Raj tanks and 249 PWD administered tanks is taken as study area. Even after the large scale decrease in the irrigated area under tanks, still tanks account for more than 50% of the net area irrigated in the district. Specific reference of Rajam mandal of Srikakulam district is incorporated in the present work, as tanks account for more than 95% of the total irrigation in that mandal. Data The data with reference to utilization of land for various activities in the study area is obtained from The Directorate of Economics and Statistics, Government of Andhra Pradesh, Hyderabad, for a period of 55 years duration i.e., from 1955-56 to 2004-05. IRS-P6 LISS-III satellite data for the study area during Khariff, Rabi and Zaid seasons is obtained for the year 2005-06 from Andhra Pradesh State Remote Sensing Applications Centre (Planning Department, Government of Andhra Pradesh), Hyderabad. The Topo Sheets 1974 (scale: 1:50,000) of the study area are obtained from the O/o Assistant Director, Survey of India, Hyderabad. Land Use and Land Cover Maps In the present study, satellite imageries pertaining to three seasons viz., Kharif, Rabi and Zaid are used for LU/ LC mapping of the Srikakulam district. NRSC classification scheme (NRSA, 1989) is adopted and ERDAS 9.1 software is used for the generation of LU/ LC maps. In supervised classification, spectral signatures are developed from specified locations in the image. The land use categories of interest in this study are agriculture, current fallow land, water bodies, plantation, wasteland and forest. Final land use map was prepared by incorporating the field observations through cartographic work with an appropriate legend. Studies w.r.t Tank Capacities Using toposheets (20 nos.) covering various mandals of the district, the mosaic topo sheet of Srikakulam district and grid map are prepared. Further several maps are prepared showing the details of administrative boundaries of various mandals, villages, rivers, watersheds, micro-watersheds, tanks and streams etc. of the study area. The water spread areas and the capacities of all the tanks existing in the 38 mandals of Srikakulam district are determined using the toposheets. The capacities of these tanks are determined by multiplying the water spread areas with average depths given by O/o Executive Engineer, I&CAD, Irrigation Division, Srikakulam. These original capacities of tanks are compared with that of the present capacities of tanks obtained from the imageries. Declining Trends of Irrigation Tank Capacities in Srikakulam District, 97 Andhra Pradesh - A Study Using RS & GIS Applications RESULTS The details of Land Use and Land Cover patterns are presented in the table 1. From the table, it can be seen that the percentage of cropland varied as 16.63, 15.4 and 12.8 against Khariff, Rabi and Zaid seasons respectively. However, the cropland and current fallow put together remained same in all the three seasons i.e. 23.8 percent on an average. In total, 7,721 tanks comprising of 7,472 PR tanks and 249 PWD tanks are considered for the study. A comparative study of tank capacities in the district are presented in table 2. From the table, it is observed that the capacities of tanks in 30 out of 38 mandals are decreased by varying degrees. The maximum reductions of the capacities of the tanks are reported in Etcherla mandal with 68.91 percent reduction. The total capacities of tanks in 30 out of the 38 mandals are reduced by 28.69% of their original capacities. The total tank capacities in 8 mandals are, however, increased by 17.19 percent, which is be due to the tank renovation programmes taken up by the Government of Andhra Pradesh, recently. Table 3 comprises the details of the original and present capacities of all the 332 tanks grouped into village wise of Rajam mandal where 95 percent of irrigation is dependent on tanks alone. Out of all the 34 villages in Rajam mandal, the tank capacities in 25 villages are reduced by 26.10 percent of their original capacities. Only 9 villages have reported an increase in their tank capacities by 14 percent. Table 1: Land Use/Land Cover Patterns, Srikakulam District (Based on IRS P6 LISS-III Data) Khariff Season (2005) Rabi Season (2006) Zaid Season (2006) Sl.No. Classes Hectares Percentage % Hectares Percentage % Hectares Percentage % 1 Cropland 92097.5 16.6 85521.5 15.4 71113.5 12.8 2 Plantations 26340.1 4.7 26246.1 4.7 26190.1 4.7 3 Forest 157894 28.6 157869 28.6 157819 28.5 4 Wasteland 58535 10.6 58329 10.5 58209 10.5 5 Sandy area 3241.45 0.5 3172.45 0.5 3116.45 0.5 6 Water body 11065.2 2.0 10920.2 1.9 10810.2 1.9 7 Current fallow 39199.4 7.1 46564.4 8.4 61564.4 11.1 8 Others 163525 29.6 163275 29.5 163075 29.5 Total 551897 100 551897 100 551897 100 Table 2: Comparative Study of Capacities of Tanks, Srikakulam District ** Total *Capaci *Total *Capaci *Total **Total Sl PWD *WSA *WSA WSA (as ty of PR WSA ty of PR Capacity Capacity % N Mandal Tank of PR of PWD per PWD Tanks (RS&GIS Tanks of Tanks of Tanks Variation o. s Tanks Tanks TOPOSHE Tanks study) (M.Cft ) (M.Cft ) (M.Cft ) ETS) (M.Cft ) 1 Veeraghattam