PAST HEADWATERS LECTURES

Human behavior and the economics of groundwater conservation

Dr. Jordan Suter
Associate Professor, Colorado State University

October 4, 2019

Groundwater resources are increasingly relied upon for drinking water and inputs to irrigation. However, in many areas, demand for groundwater exceeds natural recharge. As management organizations seek to sustain groundwater resources, it is important to understand the tradeoffs associated with various conservation options. Economics plays an important role in such policy analysis both from the perspective of predicting behavioral responses to policy and the valuation of policy benefits. This presentation discussed the importance of linking models of human behavior and physical models of groundwater systems to understand the implications of specific groundwater management strategies over time. It also described the role of economic valuation in determining the magnitude of conservation benefits derived from specific policies. Results related to conservation policy tradeoffs were discussed in the context of the Ogallala Aquifer in the High Plains region of the US. In addition to highlighting the implications for groundwater management, future research challenges and opportunities related to hydro-economic modeling were discussed.

GEWEX activities and the water for the food baskets of the world grand challenge 

Petrus (Peter) J. van Oevelen
Principal Scientist, USRA 
Director, International GEWEX Project office

October 5, 2018

The Water for the Food Baskets Grand Challenge is a GEWEX (Global Energy and Water EXchanges Project) led activity as part of the World Climate Research Programme. Within this grand challenge we address how to effectively incorporate aspects of the human dimension, e.g. irrigation and water management, crop rotation etc. in climate and weather modeling as well as how to link the latter to crop and vegetation modeling at regional and global scales. The human-related aspects are not just geophysically driven but in particular by socio-economical factors and hence require different expertise. Within this grand challenge, we seek to integrate the various knowledge communities to address these issues. An important aspect of modeling food and crop production is a realistic representation of the climate and weather at the appropriate scales. Hence, convection-permitting modeling provides a new and clear prospect in improving our global and regional climate forecasts and projections. This presentation gives an overview of the various aspects and rationale behind this grand challenge as well as offers an explanation on the implementation of this activity. It also will show how this is relevant to two major regional activities, Third Pole Environment in Asia and ANDEX in Latin America. The global context provides a fertile ground for knowledge increase and exchange as well as opportunities for capacity development much needed in both regions.

Blooms like it hot: Combating cyanobacterial blooms in a world experiencing climate change

Dr. Hans Paerl
University of North Carolina, Chapel Hill

March 30, 2018

Harmful (toxic, hypoxia-generating, food web altering) blue-green algal or cyanobacterial blooms (CyanoHABs) are proliferating worldwide in freshwater ecosystems, where they represent a serious threat to drinking water, recreational and fishing use and overall sustainability. Nutrient (both phosphorus and nitrogen) input reductions have been prescribed to control CyanoHABs. However, climatic changes, specifically warming, increased vertical stratification, salinization, and intensification of storms and droughts, favor CyanoHABs and thus play synergistic roles in promoting CyanoHAB frequency, intensity, geographic distribution, and duration. In particular, rising temperatures cause shifts in critical nutrient thresholds at which cyanobacterial blooms can develop. From a management perspective, nutrient input reductions aimed at controlling CyanoHABs may need to be more aggressively pursued in a warmer, hydrologically more extreme world. Additional control steps that have been taken include 1) altering the hydrology to enhance vertical mixing and/or flushing and 2) decreasing nutrient fluxes from organic-rich sediments by physically oxygenating or removing the sediments or capping sediments with clay. These efforts, however, have met with mixed results and can disrupt benthic and planktonic habitats. In most instances, long-term effective eutrophication and CyanoHAB control must consider adaptive nutrient control strategies within the context of altered thermal and hydrologic regimes associated with climate change.

Hans W. Paerl is the Kenan Professor of Marine and Environmental Sciences at the UNC-Chapel Hill Institute of Marine Sciences.

Big data in water: Opportunities and challenges for machine learning

Dr. Vipin Kumar
University of Minnesota

January 19, 2018

dr._kumars_presentation_slides.pdfpresentation_bigdatainwater_vipinkumar_pdf.pdf

Water resources worldwide are coming under stress due to increasing demand from a growing population, increasing pollution, and depleting or uncertain supplies due to changing climate in which drought and floods have both become more frequent. As domains associated with Water continue to experience tremendous data growth from models, sensors, and satellites, there is an unprecedented opportunity for machine learning to help address urgent water challenges facing the humanity. This talk will examine the role of big data and machine learning can play in advancing water science, challenges faced by traditional Machine learning methods in addressing the domain of water, and some early successes.