Impact of Climatic Variability on Crop Production in Mahanadi Delta Region of Odisha

Abstract

The impact of climatic variability on crop production was studied in the Mahanadi delta area where upland, midland and lowland sites were selected covering Dhenkanal, Kendrapara, Nayagarh, Cuttack and Puri district. The monthly run-off (10⁶ m³) data of 19 gauging stations adequately representing the sub-basins of the Mahanadi River basin with a command area of 1,41,589 km² during the period 1972–2004 was analysed to investigate the run-off variability and trends of the basin. Analysis of hydroclimatic parameters using advanced statistical tools revealed that due to alteration in the hydrological cycle the severity of droughts and intensity of floods increased and the quantity of the available water resources also gets affected. The average annual result run-off during the period 1990–2004 exhibits an increased run-off, in comparison to the previous subseries 1972–1989 for all the stations. However, this increased run-off is also associated with an increase in the variability (standard deviation), suggesting that the wet period is more prone to uncertainty in comparison to the corresponding dry period. The rainfall status of the experimental sites on the Mahanadi delta showed occurrence of frequent drought and flood in the last 25 years (Table 1). Uneven distribution of rainfall affected the crop yield adversely. Increase in rainfall in May and September and severe drought in November and December affected the paddy yield. It has been observed that in spite of canal irrigation sources, water is unavailable during the critical stages of crop growth and moisture stress condition. To mitigate the vagaries caused by climate change, water harvesting structures for assured irrigation, microirrigation techniques to increase the water use efficiency, crop diversification and multiple use of water to improve water productivity are some of the technological interventions for resilience and sustainable identified production.