Analysis of Drought Events and its Comparison with Cereal Crops Yield at Karnali Basin

Abstract

Nepal’s fragile geology and steep topography makes it one of the most disaster pronecountries in world. Floods, landslides, earthquakes, GLOFs (glacial lake outburst floods) and droughts are the most common natural hazards. In recent years, due to the climate relateddisasters like drought has resulted in higher food insecurity in the most vulnerable communities, particularly in Western Nepal.Karnali is one of the most affected drought region of Nepal and also the study of drought is limited in Nepal hence the study is made onthis topic at Karnali basin. For the study, simple and flexible tool was used named SPI on the basis of precipitation as the only input parameter around the basin. The study mainly focuses the meteorological and agricultural drought so the drought analysis was done with the time scale of 3 months (June,July and August) or SPI-3 for a period of 34 years (1980 to 2013). There were total thirteen stations made final after eliminating other stations due to data unavailability for the study atthe basin. Based on the study, all the stations were recorded by normal drought (extremely, very,moderately wet and near normal are merged as normal) event and then moderate type werefound in most of the stations for same or different years. And lastly severe and extreme were recorded after the previous two types. Similarly the result also shows that the number of drought events is highest in the month of June during the 7 years of time interval i.e. from1987-2013 with 22 droughts in total. And finally the drought events were compared with different cereal crops yield such as paddy, maize and millet from 1999 to 2011. The resultshows that all the crops yield were not in decreasing phase, it was in increasing trend rather apart from two or three years throughout the period of eleven years used for comparison. It was quite unknowing that theyields were not affected more by drought in this part of area from 1999 to 2011,the reason may be the use of more chemical fertilizers for quick production by the farmers and also the development of canals for irrigation purpose that made the crops good enough for the increment of yield.