Modeling assessment on the influences of physiographic dynamics of landscape and micro-climatic conditions at Siffu-Mallig Watershed in the Philippines

Changes in watershed characteristics influence its physical features including the overall hydrologic and climatologic processes which can be of high relevance to future sustainability. Variations such as land cover dynamics, urban sprawl, crop cover variations, weather, and climate drive many of these changes and can induce appreciable impacts on watershed processes. This study assessed the temporal variability of Land Surface Albedo (LSA), Land Surface Temperature (LST), Soil Moisture (SM), over the Siffu-Mallig Watershed (SMW). Watershed-scale information on model-based LSA, LST, SM using Landsat imagery, and CHIRPS monthly rainfall data from 2014 to 2023 was obtained using the Google Earth Engine (GEE) platform. The results of the study imply that there is no inherent statistical relationship existing among the assessed parameters particularly rainfall, SM, LSA, and LST based on multiple regression analysis. On the other hand, Land Use/Land Cover (LULC) dynamics and climate variables including rainfall influence the changes in these parameters with possible contributions from anthropogenic activities particularly in agriculture. The results conform to the existing literature and serve as a compelling reason to assess the intensity of inter-variable impacts that govern general watershed hydrologic and atmospheric processes. Consideration and analysis of other hydroclimatic parameters such as water and surface energy balance studies are highly suggested to further understand the driving factors that influence the land-vegetation-atmosphere interactions in the watershed. Hence, scientific studies that mainstream physical and climatological changes are encouraged to capture the significance of such changes to be incorporated into resource management planning and interventions.