Comparison of interception loss by different rainfall magnitudes within a secondary forest of Popa Mountain Park, Myanmar

Abstract

Partitioning of gross rainfall into throughfall, stemflow and interception loss are essential parameters for the water balance of the region. Measurements of gross rainfall, throughfall and stemflow were made during the growing season (from June to October) of 2019. The objectives of this study are to know the contributions of throughfall and stemflow by the secondary forest in assessing the water balance of the Popa catchment area and to investigate the interceptive loss under different rainfall magnitudes. A total gross rainfall of 753.58 mm was measured in the open area. Of this total rainfall, 442.30 mm (58.69%) and 142.44 mm (18.90%) were reached the forest floor as throughfall and stemflow. Three groups of rainfall were divided by the magnitude of individual rainfall events. The magnitude of rainfall does not appear to be a major driving factor for the interception loss under three rainfall groups: (1) Pg <10 mm (p=0.848); (2) 10< Pg <50 mm (p=0.060); and (3) Pg >50 mm (p=0.051). This study shows that secondary forest can contribute the high partitioning of throughfall and stemflow to the Popa catchment area. Silvicultural management and conservation activities of these secondary forests should be improved in order to have more hydrologic services from them.