PhD in Symbiotic Science of Environment and Natural Resources, Watershed hydrology and Ecosystem Management Laboratory, Tokyo University of Agriculture and Technology
Throughout my PhD studies focused on evaluating soil and ground cover characteristics for developing a simple distributed soil erosion model in headwater catchments, for estimating soil erosion in such spatially variable headwaters, modeling approaches with geographical information systems (GIS) is effective. For application of a model as a management tool, a simple model with GIS needs to be developed because current applicable models require complex parameters.
For developing a simple model, Revised Universal Soil Loss Equation (RUSLE) with LiDAR topographic data was applied, which consisted of six parameters for estimating soil loss (A) with a given period. This study also focuses on the seasonal differences of soil erosion for the period of 2010 to 2020. Rainfall erosivity factor (R) was estimated using kinetic energy and rainfall intensity. Soil erodibility factor (K) was used particle size and organic carbon content. Slope length factor (L) was estimated using 1m LiDAR data estimated by flow accumulation method. Slope gradient factor (S) was estimated using 1 m DEM. Ground cover condition (V) was used percentage based on direct field measurement. Management practice factor (M) was 1 because there were no conservation practices. Estimated soil erosion in catchment No.3 was ranged from 0.32 to 3.47 ton/ha/year (Mean: 1.25; SD: 0.81), while estimated soil erosion in catchment No.4 was ranged from 0.22 to 2.44 ton/ha/year (Mean: 0.85; SD: 0.56).
The model can successfully predict soil erosion in a catchment scale during moderate rainfall and long monitoring period and the effectiveness was 50%. Under estimations (31-48%) occurred during short monitoring periods with intense rainfall. The over estimation occurred during long monitoring period including winter season, which have different erosion process such as freezing-thawing. When eroded soil transported from hillslope near stream channel, estimated and observed soil erosion agreed well, while underestimation of model occurred when continuous soil erosion occurred during high and intense rainfall.
The finding of this study identified that spatial variability of ground cover conditions need to include for modeling soil erosion in catchment scale, while the soil erodibility factor can be applied mean and representative value in a catchment. Model proposed in this study can be applied for revising soil and water conservation guideline by considering spatial distribution of understories due to the combined effect of canopy structure and topography. It is expected that countries with a high soil erosion such as Ethiopia consider adopting this approach of modeling such as interaction between groundcover distribution and canopy conditions to improve the management practices for soil conservation.
During my research experience, I have developed proficiency in various areas:
GIS and Remote Sensing: I am competent in GIS and Remote Sensing principles and applications, with experience using software such as ArcGIS, QGIS, ERDAS Imagine, ILWIS, and Global Mapper. I am adept at utilizing these tools for spatial analysis, data visualization, and modeling.
Statistical Analysis: I possess basic knowledge of SPSS/SAS packages and advanced skills in R software for research analysis, enabling me to conduct robust statistical analyses and derive meaningful insights from data.
Communication Skills: My experience as a Remote Sensing (RS) and GIS expert has honed my communication skills, allowing me to effectively convey complex technical concepts to diverse audiences. I am adept at presenting research findings, collaborating with colleagues, and engaging stakeholders.
Certificate in Remote Sensing and Digital Image Processing: I obtained a certificate from the Faculty of Geo-information Science and Earth Observation at the University of Twente, Netherlands, which provided me with theoretical and practical knowledge in remote sensing and digital image processing techniques.
Certificate in GIS and RS Applications for the Water Sector: I also earned a certificate from UNESCO-IHE, Delft, Netherlands, focusing on the application of GIS and RS technologies for analyzing and solving water and environmental problems. This certification further enhanced my expertise in utilizing geospatial tools for addressing real-world challenges in water management and environmental science.
Overall, my comprehensive skill set in GIS, Remote Sensing, statistical analysis, and effective communication positions me as a capable researcher capable of tackling complex environmental problems and providing valuable insights for decision-making.