Journal of the American Water Resources Association
نویسندگان
چکیده
A survey of numerous field studies shows that nitrogen and phosphorous export coefficients are significantly different across forest, agriculture, and urban land-cover types. We used simulations to estimate the land-cover composition at which there was a significant risk of nutrient loads representative of watersheds without forest cover. The results suggest that at between 20 percent and 30 percent nonforest cover, there is a 10 percent or greater chance of N or P nutrient loads being equivalent to the median values of predominantly agricultural or urban watersheds. The methods apply to environmental management for assessing the risk to increased nonpoint nutrient pollution. Interpretation of the risk measures are discussed relative to their application for a single watershed and across a region comprised of several watersheds. (KEY TERMS: nutrient export; risk analysis; simulation.)
منابع مشابه
Modeling Streams and Hydrogeomorphic Attributes in Oregon from Digital and Field Data
Managers, regulators, and researchers of aquatic ecosystems are increasingly pressed to consider large areas. However, accurate stream maps with geo-referenced attributes are uncommon over relevant spatial extents. Field inventories provide high-quality data, particularly for habitat characteristics at fine spatial resolutions (e.g., large wood), but are costly and so cover relatively small are...
متن کاملExploring the Relationships between Spatial and Demographic Parameters and Urban Water Consumption in Esfahan Using Association Rule Mining
In recent years, Iran has faced serious water scarcity and excessive use of water resources. Therefore, exploring the pattern of urban water consumption and the relationships between geographic and demographic parameters and water usage is an important requirement for effective management of water resources. In this study, association rule mining has been used to analyze the data of municipal w...
متن کاملCritical Evaluation of How the Rosgen Classification and Associated ‘‘natural Channel Design’’ Methods Fail to Integrate and Quantify Fluvial Processes and Channel Response
Over the past 10 years the Rosgen classification system and its associated methods of ‘‘natural channel design’’ have become synonymous to some with the term ‘‘stream restoration’’ and the science of fluvial geomorphology. Since the mid 1990s, this classification approach has become widely adopted by governmental agencies, particularly those funding restoration projects. The purposes of this ar...
متن کاملAssociation between Heart Disease and Subjective Health in Ten North, Middle, and South American Countries
Introduction: This study was conducted to compare 10 American countries for the association between self-reported physician diagnosis of heart disease and subjective health above and beyond the effect of socio-economic factors. Methods: With a cross-sectional design, this study used data from Research on Early Life and Aging Trends and Effects (RELATE). T...
متن کاملChronic Kidney Disease, Anxiety and Depression among American Blacks; Does Ethnicity Matter?
Introduction: Chronic kidney disease (CKD) is known to be associated with deterioration of mental health. However, it is clear that this link is over and beyond the effects of socio-economic factors and other medical conditions. This study had two aims: 1) to compare the association between CKD and general anxiety disorder (GAD) among the two major ethnic groups of American Bla...
متن کامل