Year Established: 2012 Start Date: 2012-03-01 End Date: 2013-02-28
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,000
Principal Investigators: Chris Zou, William Andrews, Juanjun Ge
Abstract: Problem Statement: Long-term water resource planning and in-stream flow management implementation require improved understanding of how climate, land cover changes, and human activities collectively affect streamflow. A downward trend in total streamflow for several rivers in north-central and northwest Oklahoma over the last several decades has been identified despite of an overall upward trend in precipitation. This downward trend mirrored the notable declines of fisheries communities during the past 30 years, including the endangered Arkansas shiner in the Cimarron River. Streamflow trend is primarily driven by precipitation trend and the divergence between those two suggests an increasing role of land surface change, such as woody plant encroachment, land use change and alluvial aquifer withdrawal. However, the relative contribution of these components for long-term streamflow trends for many of the river basins in Oklahoma remains largely unknown. Project Objectives: The proposed project is a one-year, collaborative research effort between Oklahoma State University and the USGS Oklahoma Water Science Center. The overall objective is to quantitatively assess the effects of climate, land surface change and human activities on long-term streamflow characteristics of the upper Cimarron River. Methods: Climate and land surface change elasticity of streamflow provide a measure of the sensitivity of streamflow to changes in climate drivers such as precipitation and temperature and land surface change such as land use and cover changes (LULC) and human activity. We will use a climate elasticity model to conduct a quantitative assessment of the impact of climate variability on streamflow (Schaake 1990, Sankarasubramanian and Vogel 2003) using the areal mean climate data from the U.S. Historical Climatology Network and the daily recharge data from USGS National Water Information System for North Central Oklahoma. Then the land surface change elasticity of streamflow can be estimated. Land use types and woody cover will be quantified about every 10 years using aerial photos and satellite imagery from 1939 to 2010. Stepwise analysis will be used to quantitatively attribute the effect of climate, land use, woody encroachment and groundwater withdrawal on streamflow for the period between 1970 and 2010. Benefit of Results: Knowledge of the relative contribution of LULC and groundwater withdrawal in comparison to climate driving effect is the key for climate mitigation and long-term water planning. Results will help when making land-based mitigation decisions to sustain the water supplies and aquatic ecosystems considering the concomitant increases in both climatic variability and water demand.