Climate change is expected to affect or already affecting how water moves above and below the ground and everything that moves with water. For instance, some areas are predicted to receive less rainfall, drier climate, frequent freeze-thaw cycle, while other areas are going to receive higher precipitation than historic normal (see the picture above). Consequently, these changes would affect the water balance in many regions. Because a balance of water cycle is necessary to maintain the supply of nutrients, elements, and trace elements to all life forms and help in natural dissipation and degradation of contaminants, a disruption of the water cycle during climate change is expected to affect these processes. This makes it difficult to achieving global sustainability at local and global scale.
In fact, the United Nations’ 17 goals to achieve sustainability includes the following two: (Goal 13) Take urgent action to combat climate change and its impact; (Goal 15) Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss. My previous studies on colloid transport have improved the mechanistic understanding of how changes in weather pattern during climate change may affect the transport and export of contaminants through soils to water bodies. However, far more work is yet to be done. Specific research questions that I would like to explore include:
- How do changes in weather pattern such as such as frequent freeze-thaw cycles, drought, and heavy rainfall affect the removal of emerging chemical contaminants and transport of pathogens in the subsurface environment?
- What are the magnitude and rate at which colloids, particulate organic carbon, nutrients, elements, and contaminants are released from soils subjected to different types of land use?
I plan to track changes in leaching of iron oxides and other soil minerals during variable weather conditions and correlate them with the observed change in the mobility of dissolved and particle-bound contaminants. Furthermore, I will track the mobility of geochemical tracers (e.g., Beryllium) with soil colloids (to quantify physical erosion) and changes in concentration of Fe and Mn with respect to the concentration of the relatively immobile elements (e.g., Ti, Nb, Y) during extreme events (to quantify chemical erosion). Both iron and manganese play a critical role in biogeochemical cycles of organic carbon and other elements and retention of contaminants in soil. This research would help design responses to mitigate the impacts of climate change (see below).