Koshi Yoshida
Professor, Agro-environmental studies
Keywords: Hydrology, Water quality environmental science, Irrigation and drainage
Lab webpage

Degree

PhD in Agriculture (The University of Tokyo)

Current research topics

• Agricultural Production and Climate Change Adaptation in Asia-Monsoon Region
• Assessment of water resource, water use, water quality problem in agricultural watershed
• Evaluation of water-heat-nutrient cycle in paddy and upland fields

Selected publications

• Yoshida, K. et al. Weather-induced economic damage to upland crops and the impact on farmer household income in Northeast Thailand, Paddy and Water Environment, 17(3), 2019

• Yoshida, K. et al. Quantitative Evaluation of Spatial Distribution of Nitrogen Loading in the Citarum River Basin, Indonesia, Journal of Agricultural Meteorology, 73, 2017

• Yoshida, K. et al. Thermal variations of water in the Nam Song stream/Mekong River: II. Experimental data and theoretical predictions, Sustainable Water Resources Management, 2(2), 2016.

Research

During the past century, human activities have been rapidly changing. Most importantly human population growth has led to increases in water and food demand, use of fertilizer and wastewater flows. At present, 70% of the water in river basins and aquifer systems is withdrawn for agricultural use in the world. Increasing nutrient loading from anthropogenic activity have resulted in widespread enrichment of nutrients in surface waters and associated problems of eutrophication linked to excessive accumulation of algal biomass, toxic algal blooms and dissolved oxygen depletion. In addition, the Intergovernmental Panel on Climate Change (IPCC) examined the impact of climate change on food production and predicted that in tropical regions, a rise of just 1–2 ° C in regional temperatures will lower crop productivity and increase the risk of famine. To mitigate these issues, it is desirable to develop and disseminate eco-friendly agricultural systems including impact assessment tool for drought problem by using water-soil-plant model, monitoring technology of agricultural production or ground water, and development of adaptive farming practice.

Recent thesis topics of my students

● Shallow ground water use for sugarcane farming

● Risk assessment of salt affected soil problem

● Mitigation effect of CO2 flux and fire risk in peat land area

● Evaluation of flood mitigation and water purification effect in urban lake