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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Land cover effects on water quality and biotic integrity in the upper White River Basin, Indiana

Wright, Andrew W. January 2005 (has links)
The aquatic ecology of the White River basin has been studied since 1875 with researchers having reported 158 fish species belonging to 25 families. Recently, an EPA 319 grant allowed for further research in the Upper White River basin. The two-year study (2002-2004) examined three watersheds in Delaware County for biotic integrity, habitat quality, and stream water quality parameters. Twenty-two sites were selected to gain a perspective on agricultural, urban, and wooded landscape influences in order to locate and implement Best Management Practices (BMPs). Samples exceeded established state regulations and guideline criteria as follows: E. col/ (80%), ammonia-N (71%), dissolved oxygen (55%), nitrate+nitrite-N (38%), orthophosphate (33%), and total suspended solids (18%). A general linear model indicated that the effects of watershed and location within each watershed were significant (p <0.001) for both the Qualitative Habitat Evaluation Index (QHEI) and Index of Biotic hntegrity (IBI) index scores. Digitized land cover developed using Geographic Information Systems (GIS) was created to determine the effects of agricultural and wooded land cover ratios on the IBI and QHEI indices. A significant positive linear relationship between the amount of woodland land cover in a 5-m streamside riparian buffer and QHEI (p<0.001, r2 = 0.55) and with IBI (p<0.001, r-2 = 0.49) was found. A significant negative linear relationship was found with the amount of agricultural land in the created 5-m riparian buffer and IBI (p<0.001, r' 0.41), QHEI (p<0.001, r2 _- 0.36). The 30-nm streamside riparian buffer and delineated subwatershed land cover ratios were significant for the biotic integrity and habitat quality parameters, but were less predictive than the 5-m buffers. In addition, the amount of high runoff soils in the subwatersheds had significant negative effects on the IBI (p < 0.001, r' = 0.47) and QHEI (p = <0.001,r' = 0.43). Wetness accumulation and soil erosion was modeled in each watershed with the use of GIS, soils, and terrain parameters. The maps produced detailed locations where BMPs (wetlands, grassed waterways, riparian buffer strips etc.) could be targeted to reduce non-point source pollutants. / Department of Natural Resources and Environmental Management
12

Best management practices and stream water quality : exploring the use of SWAT in northeast Indiana

Thompson, Jessica D. 09 July 2011 (has links)
The U.S. government implemented many incentive programs in the 1980s to encourage farmers to reduce agricultural runoff and erosion through the use of best management practices (BMPs). Remote sensing, GIS, and modeling, have been used to determine the effectiveness of BMPs through comparisons of before and after BMP implementation. The Salamonie watershed in Northeastern Indiana was studied for BMP effectiveness. The study addresses how agricultural practices have changed over a twenty nine year period (1975-2003), and how the implementation of BMPs will decrease the amount of sediment and nutrient load to surface waters. Methods reported on include the use of the Soil and Water Assessment Tool (SWAT) watershed model and how different weather data (precipitation and temperature) greatly affects streamflow predictions, as well as the effects of BMP implementation on sediment loads to surface water. The outcomes of this study provide a viable argument of how BMPs implementation positively affects water quality in the watershed region by effectively reducing sediment loads. / Department of Geography
13

Using Band Ratio, Semi-Empirical, Curve Fitting, and Partial Least Squares (PLS) Models to Estimate Cyanobacterial Pigment Concentration from Hyperspectral Reflectance

Robertson, Anthony Lawrence 03 September 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This thesis applies several different remote sensing techniques to data collected from 2005 to 2007 on central Indiana reservoirs to determine the best performing algorithms in estimating the cyanobacterial pigments chlorophyll a and phycocyanin. This thesis is a set of three scientific papers either in press or review at the time this thesis is published. The first paper describes using a curve fitting model as a novel approach to estimating cyanobacterial pigments from field spectra. The second paper compares the previous method with additional methods, band ratio and semi-empirical algorithms, commonly used in remote sensing. The third paper describes using a partial least squares (PLS) method as a novel approach to estimate cyanobacterial pigments from field spectra. While the three papers had different methodologies and cannot be directly compared, the results from all three studies suggest that no type of algorithm greatly outperformed another in estimating chlorophyll a on central Indiana reservoirs. However, algorithms that account for increased complexity, such as the stepwise regression band ratio (also known as 3-band tuning), curve fitting, and PLS, were able to predict phycocyanin with greater confidence.
14

Nitrogen, Phosphorus and Carbon Dynamics during Storms in a Glaciated Third-Order Watershed in the US Midwest

Johnstone, Joseph A. 22 August 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The characterization of the nutrients nitrogen, phosphorus and carbon (NPC) export to streams during storms is an integral part of understanding processes affecting water quality. Despite the fact that excessive levels of these nutrients in the Mississippi River basin adversely affects water quality in the Gulf of Mexico, little research has been conducted on NPC dynamics during storms on larger (>20 km2) agriculturally dominated Midwestern watersheds. This project examined the storm export of nitrate, ammonium, total phosphorus, and dissolved organic carbon (DOC) in the upper Eagle Creek Watershed (UECW) (274 km2) in Central Indiana, USA. Water samples were collected during five winter and spring storms in 2007 and 2008 on the rising and falling limb of the hydrograph, in order to characterize NPC dynamics during storm events. Stream discharge and precipitation was monitored continuously, and major cations were used to examine changes in source water over the duration of the storm and assist in the determination of potential flowpaths. DOC, total P, and TKN (Total Kjeldahl Nitrogen) tended to peak with discharge, while nitrate usually exhibited a slight lag and peaked on the receding limb. Total phosphorus, NH3-, TKN, and DOC appear to be delivered to the stream primarily by overland flow. NO3--N appear to be delivered by a combination of tile drain and macropore flow. Overall UECW displayed smoother nutrient export patterns than smaller previously studied watersheds in the area suggesting that scale may influence nutrient export dynamics. Further research is underway on a 3000 km2 watershed in the area to further examine the role scale may play in nutrient export patterns.

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