Rainfall I-D-f Relationship & Trend Analysis of Parbhani & Aurangabad

Rainfall intensity-duration-frequency relationship provides valuable information for the use of design engineers or hydrologists, in designing runoff controlling structures for moderating flood control projects. Inadequacy of such information will lead to wrong assumption and unjustified use of factor resulting in heavy expenditure. Out of different rainfall characteristics, rainfall intensity is by far the most important one. The intensity of rainfall is inversely proportional to its duration of occurrence and directly proportional to the return period. With an increase in duration, there is a decrease in the maximum average intensity of the storm. In a specified return period (frequency) and for given duration of occurrence, a storm of higher intensity is less likely to occur than a storm of lower intensity. In respect with the variation in precipitation at Aurangabad and Parbhani stations over Marathwada region Trend analysis were followed. Analysis also helpful for crop plannings for both Kharif and Rabi seasons. The Mann-Kendall test applied to weekly rainfall data of Parbhani and Aurangabad.