1Department of Agricultural Meteorology, Biswanath College of Agriculture, AAU, Biswanath, Chariali – 784 176
AICRP on Water Management, Department of Agronomy, Assam Agricultural University, Jorhat – 785 013, India
*Corresponding author's email: abhijitaau@gmail.com
Online published on 27 November, 2014.
The surface water and groundwater resources of a region play a major role in agriculture, livestock production, industrial activities, forestry and fisheries. In this work, monthly, seasonal and annual trends of rainfall balance have been studied using monthly data series of 36 years (1975–2011). The analysis revealed that except for May, rainfall balance decreased in all the months as indicated by Man-Kendall rank statistics. The results of the linear trend lines for the period of study clearly demonstrated a general tendency for a decrease in monsoon rainfall balance in the area. Mann-Kendall test also showed a decreasing monsoon rainfall balance at 6% probability level. Pre-monsoon balance showed non-significant increase (72% probability level) while post monsoon balance showsed non-significant decrease (75% probability level). Overall annual balance decreased at 27% probability level.
Annual rainfall balance trend, Mann-Kendall test, Monthly rainfall balance trend, Rain water balance, Seasonal rainfall balance trend
