Identification of climate change impact at Raknamo Dam, Kupang, Indonesia

Impacts of climate change have received extensive attention, especially for the semi-arid regions. Raknamo reservoir is located at Kupang Regency, a semi-arid area with significant differences in rainy duration (3–4 months) and dry seasons (8–9 months). This preliminary study aimed to identify the recent factors that caused the delays in initial filling of Raknamo reservoir, which may be affected by climate change. There are three rainfall stations observed surrounding Raknamo watershed, namely Camplong, Naibonat and Raknamo. Direct comparisons were made of rainfall data for 33 years (1986-2019) daily. The climatology station Lasiana was used for climatological data with a data length of 33 years (1986-2019). This research used a qualitative approach, runoff was analyzed using regression analysis. The results showed that factors such as temperature (T), potential evapotranspiration (ETo), and rainfall (R) affected the availability of initial filling in the Raknamo reservoir. The amount of rainfall intensity that is not achieved in one period to fill the reservoir has resulted in the Raknamo reservoir utilization not being optimized.