How does NAWQA use modeling in addition to monitoring to assess nutrients?
This study integrates monitoring and modeling approaches for streams and groundwater. Successful management of our Nation’s water resources requires an integrated approach to environmental assessment that includes both monitoring and modeling. Monitoring provides direct observations, often over time, of water-quality properties and characteristics, whereas models are tools for interpreting these observations. Modeling results can advance understanding of the relation of water quality to human activities and natural processes that affect spatial variations in quality. Understanding can help to extrapolate or forecast conditions to unmonitored, yet comparable areas. This is a critical step for cost-effective protection of water resources, particularly in light of diminishing financial resources, which requires more information than can be measured directly in all places and at all times. Specifically, NAWQA models are used to (1) establish links between water quality and nutrient sources
