Open AccessTrend characteristics of rainy days and evaporation at a tropical rainforest region in East Malaysia, Borneo
Author(s) -
Ninu Krishna Mv,
Prasanna Mv,
H. Vijith
Publication year - 2020
Publication title -
earth sciences research journal/earth sciences research journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.181
H-Index - 15
eISSN - 2339-3459
pISSN - 1794-6190
DOI - 10.15446/esrj.v24n3.77670
Subject(s) - precipitation , environmental science , pan evaporation , evaporation , wet season , relative humidity , humidity , trend analysis , climatology , climate change , rainforest , statistical analysis , atmospheric sciences , hydrology (agriculture) , meteorology , geography , biology , geology , mathematics , ecology , statistics , cartography , geotechnical engineering
Impact of climate change over the hydrological system in a region can be identified through statistical characterization of hydrometerological parameters such as rainfall, temperature, humidity and evaporation. In order to understand the influence of climate change, statistical trend characteristics of rainy days, non-rainy days and evaporation rate in the Limbang River Basin (LRB) in Sarawak, Malaysia, Northern Borneo was assessed in the present research. Annual rainfall and monthly evaporation data, over a period of 46 years, (1970 - 2015) corresponding to three rain gauging stations, the Limbang DID, Ukong and Long Napir were used in the research. Linear regression model, Mann Kendall and Sen’s slope estimator techniques were applied to detect the statistical trends in rainy days and evaporation. A statistically significant increasing trend in annual rainy days was found at all the stations. Non-rainy days showed a statistically significant decreasing trend at Limbang DID and Ukong. Monthly evaporation rates showed an overall increasing trend and the greatest increasing trend in evaporation was observed in September (2.55 mm/year) for the Limbang DID and in December (2.61 mm/year) for Ukong. Evaporation measured at the Ukong station also showed a non-significant decrease during June and September. A comparison of the evaporation controlling meteorological variables such as rainfall, temperature and relative humidity indicates inter-influence at various strengths. Along with local precipitation characteristics, wind and fluctuation of atmospheric temperature over the region plays a vital role in increased rate of evaporation from the region. Overall, the analysis identified a statistically significant increasing trend in rainy days and evaporation in the LRB. The results of the present research can be used as critical planning data for micro and macro hydroelectric projects in the river basin.