Application of the Ilwas Model to the Northern Great Lakes States

Garrison, Paul J.; Greb, Steve; Knauer, D. R.; Wentz, Dennis A.; Krohelski, J.T.; Bockheim, James G.; Gherini, Steven A.; Chen, Cari W.

doi:10.1080/07438148709354791

Cited by 13 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another reason that may be causing observed differences in TP loss among the watersheds is that ground water and surface runoff during a large precipitation event can cross topographically defined catchment boundaries, so the collection area of the runoff becomes uncertain (Garrison et al, 1987). The west and center watersheds, which have road boundaries on the west and south sides, respectively, in addition to topographic boundaries, could have experienced this additional source of surface runoff during large rainfall events.…”

Section: Resultsmentioning

confidence: 99%

Phosphorus Loss and Runoff Characteristics in Three Adjacent Agricultural Watersheds with Claypan Soils

2004

View full text Add to dashboard Cite

Effects of precipitation, runoff, and management on total phosphorus (TP) loss from three adjacent, row-cropped watersheds in the claypan region of northeastern Missouri were examined from 1991 to 1997 to understand factors affecting P loss in watersheds dominated by claypan soils. Runoff samples from each individual runoff event were analyzed for TP and sediment concentration. The annual TP loss ranged from 0.29 to 3.59 kg ha(-1) with a mean of 1.36 kg ha(-1) across all the watersheds during the study period. Significantly higher loss of TP from the watersheds was observed during the fallow period. Multiple small runoff events or several large runoff events contributed to loss of TP from the watersheds. Total P loss in 1993, a year with above-normal precipitation, accounted for 30% of the total TP loss observed over seven years. The five largest runoff events out of a total of 66 events observed over seven years accounted for 27% of the TP loss. The five largest sediment losses were responsible for 24% of the TP loss over seven years. Runoff volume and sediment loss explained 64 to 73% and 47 to 58% of the variation in TP loss on watersheds during the study. Flow duration and maximum flow accounted for 49 and 66% of TP loss, respectively. The results of this study suggest that management practices that reduce runoff volume, flow duration, maximum flow, and sediment loss, and that maintain a suitable vegetative cover throughout the year could lower P loss in claypan soils.

show abstract

Section: Resultsmentioning

confidence: 99%

Phosphorus Loss and Runoff Characteristics in Three Adjacent Agricultural Watersheds with Claypan Soils

2004

View full text Add to dashboard Cite

show abstract

“…The topographic watershed also does not reflect the influence of groundwater, since the topigraphically defined watershed boundaries generally do not accurately reflect groundwater-contributing areas (Garrison et al 1987). While scaling also fails to address groundwater dynamics, by focusing the area of the watershed under consideration it does have practical advantages.…”

Section: Discussionmentioning

confidence: 99%

Dissolved Organic Carbon as an Indicator of the Scale of Watershed Influence on Lakes and Rivers

Gergel

Turner

Kratz

1999

Ecological Applications

View full text Add to dashboard Cite

Land use and land cover can have a significant impact on water chemistry, but the spatial scales at which landscape attributes exert a detectable influence on aquatic systems are not well known. This study quantifies the extent of the landscape influence using the proportion of wetlands in the watershed measured at different distances to predict dissolved organic carbon (DOC) concentrations in Wisconsin lakes and rivers, and to determine whether the watershed influence varies with season or hydrologic type of lake. The proportion of wetlands in the total watershed often explained the most variability of DOC in lakes when stepwise regression was used. However, best-model techniques revealed that, for lakes, r 2 values often only differed 1-3% between models using the proportion of wetlands in the total watershed and models using only the proportion of wetlands in nearshore riparian areas (25-100 m). In rivers, the proportion of wetlands in the watershed always explained considerably more of the variability in DOC than did the proportion of wetlands in the nearshore riparian zone. The watershed influence also varied seasonally in rivers, as the proportion of the watershed covered by wetlands explained more of the variability in DOC in the fall than in the spring. Overall, the proportion of wetlands in the landscape explained much more of the variability of DOC concentrations in rivers than in lakes.

show abstract

“…The base cation and ANC concentrations of seepage lakes such as these depend largely on the proportion of water supplied by groundwater. A hydrologic study of four northern Wisconsin seepage lakes showed that three of the lakes with mean ANC's ranging from 21 to 118 ueq/L receive from 3to 15 percent of their water from groundwater, while the fourth lake with a mean ANC of 384 ueq/L receives 30 percent groundwater (Garrison et al 1987). The ANC of a seepage lake in Upper Michigan was observed to drop from 178 to 22 ueq/L over a 5-year period when drought conditions substantially reduced the input of ANC.rich groundwater (Webster et al 1990).…”

Section: Wisconsin: Rainbow Lake Wildernessmentioning

confidence: 99%

Screening procedure to evaluate effects of air pollution on Eastern Region wildernesses cited as Class I air quality areas.

Adams¹,

Nichols²,

Federer³

et al. 1991

View full text Add to dashboard Cite

Application of the Ilwas Model to the Northern Great Lakes States

Cited by 13 publications

References 8 publications

Phosphorus Loss and Runoff Characteristics in Three Adjacent Agricultural Watersheds with Claypan Soils

Phosphorus Loss and Runoff Characteristics in Three Adjacent Agricultural Watersheds with Claypan Soils

Dissolved Organic Carbon as an Indicator of the Scale of Watershed Influence on Lakes and Rivers

Screening procedure to evaluate effects of air pollution on Eastern Region wildernesses cited as Class I air quality areas.

Contact Info

Product

Resources

About