Estimating the evapotranspiration rates of wetlands in Suriname, a case study of the Nani Swamp
Faculty of Sciences. Bioscience Engineering
Academic journal of Suriname
, p. 332-338
University of Antwerp
The Nani Swamp, located in the northwestern part of Suriname in district Nickerie, is the major irrigation source for about 25,000 hectares rice polders within that area. Managing the swamp sustainably has therefore always been a great challenge and is one of the highest priorities of this district. Evapotranspiration, which is an important part of the water balance, contributes the most to water removal from the Nani Swamp. Unfortunately there are few studies on the quantification of this parameter and its variability. In this context the current study was carried out based on hourly meteorological data from a single automatic weather station located in the heart of the swamp. The measurements were done in the period June-October 2009, and used as input to compute the evapotranspiration ET with the American Society of Civil Engineers Penman-Monteith ASCE PM method and various other empirical ET formulas. A total average value of 4.76 mm d-1 was found for the daily ET of the swamp in the study period. The observed hourly average ET was 0.45 mm h-1 and the average nocturnal ET was 0.015 mm h-1.The temporal variability of the ET could be explained by meteorological parameters, of which shortwave solar radiation Rs and cloudiness n/N showed the best correlation with the ET. These parameters were used to compute regression formulas in order to estimate the ET of the swamp without having to use the empirical ET methods.