Rainfall probability analysis for conservation of water resources for sustainable irrigation planning

Attempts were made to analyze trends of 44-years (1970-2013) of long-term rainfall using probability distribution functions, seasonal distribution, onset-withdrawal of monsoon, dry and wet spell(s) in 52 standard meteorological weeks (SMW) for Ludhiana (Punjab). Results revealed monsoon season rainfall (598.5 mm) in 39 rainy days delivers about 79.4 % of annual rainfall and its effective rainfall was 434.7 mm; pre-monsoon, post-monsoon and winter season contributes 8.2, 7.9 and 4.5 % of annual rainfall. This call for alternate cropping system with low water requiring crops to match with rainfall and distribution, less reliance on irrigation would arrest rapid declining of groundwater.