PhD Student Profile

I am focusing on enhancing the spatial and temporal resolution of soil moisture data to increase its value for agricultural and environmental applications. This involves downscaling soil moisture products to finer resolutions and analysing their dynamics using parameters such as land use and seasonal variations. In addition, I will derive root-zone soil moisture from surface measurements and probe data, assess the transferability of soil moisture models in data-scarce regions, and refine in-situ observation strategies using land surface model outputs.

PhD Title: Improve Soil Moisture Estimation Using Remote Sensing Data in Combination with Field and Model Data

PhD start date: January 2024

Supervisors: Dr Mehdi Khaki (University of Newcastle), Professor In-Young Yeo (The Ohio State University), Professor Shin-Chan Han (The Ohio State University), and Professor Peter Dahlhaus (Federation University)

What interested you about this research?
Soil moisture is a fundamental variable in agricultural systems, influencing crop growth and land management. I am from Sri Lanka, where agriculture has long been a central pillar of the national economy. With my family’s background in farming, I developed a natural interest in soil moisture research.

What do you love about soil?
Soil is a foothold for plants, it helps purify water, and it’s critical in disasters like flooding.

What do you love about your PhD?
I love the challenging nature of it, and the application side of this kind of research.

How will your PhD help to make a difference for farmers?
Surface soil moisture helps farmers make immediate decisions about irrigation, sowing, and fertiliser application. Root-zone soil moisture provides insight into the longer-term water availability for crops, helping to prevent water stress and optimise irrigation scheduling. Together, they support more efficient water use, improved crop productivity, and better resilience to drought.

What do you want to do when you finish your PhD?
After completing my PhD, I hope to pursue a career in industry where I can apply my research expertise to real-world problems.

Read Kalani’s publications

• Lakshani, P. A. K. R. & Welikanna, D. R. (2016). Disaster Resilience and Urban Composition a Comparative Analysis. In: JINADASA, D. K. B. S. N., ed. International Conference of International Institute for Infrastructure, Resilience and Reconstruction, 2016a Sri Lanka.
• Lakshani, P. A. K. R. & Welikanna, D. R. (2016). A Time Series Spectral Analysis on Urban Resilience. Asian Conference on Remote Sensing 2016b.
• Lakshani, P. A. K. R., Tang, D. L. & Wang, S. F. (2021). Detection of sea surface plastic in the northern south China sea using an end member analysis of sentinel satellite reflectance. GEOSYM 2020, 2021 Sri Lanka. Sabaragamuwa University of Sri Lanka.
• Yu J., Tang D., Wang S., He L. and Pathira Arachchilage K. R. L. (2022). Spatial Distribution and Composition of Surface Microplastics in the Southwestern South China Sea. Front. Mar. Sci., 9. Available at: https://doi.org/10.3389/fmars.2022.830318.
• Pathira Arachchilage, K.R.L., Tang, D., Yu, J. and Wang, S. (2022). ‘A Preliminary Analysis towards Detecting Floating Marine Macro Plastics Using an Index Developed for Sentinel 2 ACOLITE and Sen2Cor Images’, Journal of Geospatial Surveying, 2(2), p. 1-10. Available at: https://doi.org/10.4038/jgs.v2i2.37.
• Senanayake, I. P., Pathira Arachchilage, K. R. L., Yeo, I.-Y., Khaki, M., Han, S.-C., & Dahlhaus, P. G. (2024). Spatial Downscaling of Satellite-Based Soil Moisture Products Using Machine Learning Techniques: A Review. Remote Sensing, 16(12), 2067. Available at: https://doi.org/10.3390/rs16122067
• Pathira Arachchilage, K.R.L., Tang, D. & Wang, S. (2025). Detection of floating marine macro plastics using a new index with remote sensing data. J. Ocean. Limnol. 43, 723–734. Available at: https://doi.org/10.1007/s00343-024-3152-7
• Pathira Arachchilage, K. R. L., Yeo, I.-Y., Khaki, M., Han, S.-C., & Dahlhaus, P. G., Walker J.P. (2025). Assessing the Impact of Vegetated Land Cover on Downscaling Satellite Soil Moisture Products. 2025 IEEE International Geoscience and Remote Sensing Symposium (IGARSS2025). Brisbane, Australia.

• LinkedIn 
• Google Scholar
• ResearchGate