Statistical studies on planning for water resource management on Vaigai reservoir catchment on Vaigai river, Tamil Nadu state, India

Abstract

Irregular and occasional rainfall poses problems for the government authorities to meet the demand of water for drinking and agricultural tenacities of the people dwelling in four important districts of Tamil Nadu <em>viz.</em> Madurai, Theni, Sivagangai and Ramanathapuram. Proper design and management of water resources is essential to address this issue. Therefore, a study on spatio-temporal variations on rainfall trend was done over the Vaigai river catchment, based on the long-term rainfall records for the period from 1959 to 2016. Trend analyses were examined at seven stations by the Kendall’s Tau (non-parametric test) to determine the trends. Sen’s slope estimator was used to estimate the slope of trend, Cumulative deviations & CUMSUM test were used to identify shift detection for yearly and seasonal rainfall seasons. The analysis displayed a reduction in rainfall in catchment area for most of the rainfall stations except Periyakulam and Veerapandi stations for the past 58-year period spatio-temporally. Also, the findings of change point detection, predicted for yearly and seasonal rainfall series by Cumulative deviations & CUMSUM tests are in agreement with the existence of shift deduction during 1988 over these two stations. The findings will help the authorities for effective planning of irrigation systems, storage and distribution of available water.