Upper White River Watershed Integrated Economic and Environmental Management Project

This report outlines enhanced existing local cooperative water quality efforts, sumarizes economic and physical data, and discusses how that information was used to develop analytical models.This project was partially funded by the US EPA Region 7, through the Missouri Department of Natural Resources (subgrant #G05-NPS-09), under Section 319 of the Clean Water Act

A simulation assessment of the Boone River watershed: baseline calibration/validation results and issues, and future research needs

A SWAT modeling framework has been constructed for the Boone River Watershed (BRW) in north central Iowa, to support further testing of SWAT and analyses of alternative management practice and/or cropping system scenarios. The BRW covers over 237,000 ha and is an intensively cropped region dominated by corn and soybean production. Nitrate losses are of particular concern in the BRW, especially through subsurface tiles that drain the predominantly flat landscapes that persist throughout the watershed. The modeling system features an intensive set of management, land use, and soil data developed at the Common Land Unit (CLU) level. The SWAT model was tested using two different hydrologic simulation approaches for the BRW, that were based on the standard runoff curve number (RCN) option versus a new alternative RCN option available in version 2005 of SWAT. These two different approaches were used to reflect differing assumptions regarding the relative contributions of surface runoff and baseflow to the total BRW streamflow. Strong annual and monthly R2 and Nash-Sutcliffe modeling efficiency (E) statistics were found for both the 1986-1996 calibration and 1996-2006 validation periods, which ranged from 0.74 to 0.99. The R2 and E statistics determined for the calibrated annual and monthly sediment, nitrate, organic nitrogen, and total phosphorus loads for the period of 2000-2006 were also generally strong for the SWAT simulations that were performed with the standard RCN approach, ranging from 0.50 to 0.92 with most exceeding 0.70. However, the accuracy of the predicted pollutant loads generally declined when the alternative RCN approach was used, especially for the organic nitrogen estimates. The results show that specific calibration is necessary for pollutant-related input parameters for the alternative RCN approach, in order to obtain improved results. The results also show weaknesses in the overall nitrogen balance predicted for the SWAT simulations, especially for the approach based on the standard RCN method. Comparisons with historical crop yields revealed that the model underpredicted corn yields, especially for the standard RCN approach, and that there is a need to update crop parameters in SWAT to more accurately simulate current corn and soybean yields in the region

CLIMATE CHANGE IMPACTS ON THE SOIL EROSION AND NUTRIENT LOSSES IN THE GREAT LAKES REGION

Pollutants from non-point sources (NPS) have become the primary reason for water quality degradation in the Great Lakes region after great progress has been made in reducing point source pollution through the enforcement of total maximum daily loads (TMDL). Climate change may impact NPS pollutant transportation processes through influencing runof

Removal of suspended solids using in-situ filtration in surface water

Compromised water quality impacts many surface water resources worldwide. The decline in the water quality can be attributed to various pollutants discharged into water areas such as rivers, lakes and ponds. Most of the pollutants, such as nutrients, organic compounds, bacteria, which were released into the water areas, are adsorbed onto the surface of the suspended solids (SS) and settle to the bottom. Phosphorus (P) is considered as the controlling element in the propagation of eutrophication in water bodies. Algal blooms threaten lake water quality and in order to control their growth, removal of P along with the SS is essential. The focus of this study was to improve water quality by removing SS and phosphorus through a pilot scale in-situ filtration tests. A nonwoven geotextile was used as the filter medium. The pilot-scale unit was set up at Lac Caron, located 75 km north of Montreal in Saint-Anne-des-Lacs, Quebec, Canada. Filtration tests using four different nonwoven filters were performed. A nonwoven filter with apparent opening size (AOS) of 150 om and thickness of 0.3 cm was effective in removing SS concentration by 91%. The water quality improved in terms of SS and P removal rendering in-situ filtration as an effective treatment system or remediation technology for contaminated surface water bodies such as inlets, bays, lakes, and ponds

Improving Surface Water Quality Using a Geotextile Filtration Technique

Different substances are carried from land to water areas such as lakes and ponds by natural or anthropogenic activities. Suspended solids (SS) consisting of organic and inorganic matter are examples of these substances that are discharged into water bodies. Contaminants, such as nutrients, bacteria, and heavy metal, which enter surface waters adsorb onto the surface of these particles and eventually settle on the bottom sediments which then become the largest potential source of contaminants into the overlying water. The presence of these SS in the water causes a decrease in the transparency and also excessive loads of nutrients which lead to eutrophication and rapid growth of algae in the water. Lake Johanne is a shallow mesoeutrophic lake located in the municipality of Saint-Anne-Des-Lacs, Quebec, Canada. The lake was exposed to algal blooms during the hot summer in the past and the water has been found to be turbid since 2008. The focus of this study was to evaluate the water quality variables of this mesoeutrophic lake, to improve the quality of water using a geotextile filtration technique and thus assess the reliability of the geotextile filters in removing suspended solids and adsorbed nutrients. To accomplish these, lake water quality was monitored for two years (2017-2018). Also, a series of on-site filtration experiments was conducted beside the lake using non-woven geotextiles as filter media. Different combinations of geotextiles, differing in apparent opening sizes and number of layers (5-6), were examined to find the combination showing maximum efficiency in removing SS and associated nutrients. Experiments were classified into four categories with respect to the geotextile combination used as a filter media. The results obtained from all the experiments conducted with different geotextile combinations were promising for the suspended solids, turbidity, chlorophyll-a, and phosphorus removals. However, combination 3 which included two layers of 100 microns followed by two layers of 90 microns, and two layers of 70 microns showed better results as compared to the other combinations used in this study. The filtration experiments conducted with this combination resulted in 8.3 g /m2-d total suspended solids (TSS), 11.6 mg /m2-d total phosphorus (TP), 9.8 g /m2-d chemical oxygen demand (COD), and 11.1 mg /m2-d chlorophyll-a removal. Overall, the results have indicated the potential of non-woven geotextiles for use as a filter media to improve the quality of surface water by removing SS and algae that impair the water quality. Thus, the geotextile filtration technique can be considered as an effective remediation method for contaminated surface water bodies such as lakes and ponds

Development of an ecohydrological model at the catchment scale and application in the humid tropics

Ziel der Dissertation war die Entwicklung eines prozessorientierten, ökohydrologischen Modellsystems, das nicht nur den Anforderungen in gemäßigten, sondern auch in tropischen Klimaten gerecht wird. Dieses war auf das in den sommerfeuchten Tropen in Südvietnam gelegene Thi Vai Einzugsgebiet anzuwenden, zu testen sowie für Prognosen zu verwenden. Als besondere Herausforderung für die ökohydrologische Modellierung in den sommerfeuchten Tropen sind die extremen meteorologischen Randbedingungen, die intensive Nutzung des Einzugsgebietes und die geringe Datenlage anzusehen. Hierzu wurde das bestehende hydrologische Modellsystem PANTA RHEI unter anderem um die Module terrestrischer, biogeochemischer Stoffkreislauf (CNP-Modul), Pflanzenwachstum und Wasserqualität erweitert. Das entwickelte ökohydrologische Modellsystem umfasst Wasserqualitätsroutinen, die eine Interaktion zwischen der aquatischen Biomasse, Sauerstoff, Nährstoffen, Detritus und Sediment berücksichtigen. Darüber hinaus werden differenzierte Stoffformen betrachtet und ein Rechenzeitschritt unter einem Tag ermöglicht. Das implementierte Wasserqualitätsmodell schließt Defizite, die bei gängigen ökohydrologischen Modellen auftreten. Daher kann über eine rein frachtbezogene Betrachtung hinausgegangen werden. Da zu Beginn der Studie nahezu keine Daten zur Wasserquantität und -qualität des Einzugsgebietes vorlagen, wurde ein Monitoringprogramm initialisiert. Unter anderem wurden die Wasserqualitätsparameter DO, NH4, NO2, NO3, PO4 sowie TSS erhoben. Die Ergebnisse der Modellkalibrierung zeigen, dass das entwickelte Modellsystem in der Lage ist, die Hydrologie und Wasserqualität der untersuchten Teileinzugsgebiete abzubilden. Eine Sensitivitätsanalyse hat gezeigt, dass die Wasserqualitätsprozesse von Stickstoff besonders durch die Prozesse auf der Landphase geprägt werden. Mittels des entwickelten CNP-Modules konnte die charakteristische Dynamik der Mineralisierung in den sommerfeuchten Tropen plausibel nachgebildet werden. Neben dem verwendeten Verfügbarkeits-Bedarfs-Ansatz, der die Zwischenspeicherung von Nährstoffen in der mikrobiellen Biomasse berücksichtigt, sind die verwendeten Bodenfeuchte-Funktionen von Bedeutung. Weitere Schlüsselkomponenten sind die Prozessgleichungen des Periphytons und die Berücksichtigung von Sedimentkompartimenten. Des Weiteren wurden weitere Anwendungsmöglichkeiten sowie die Prognosefähigkeit des Modellsystems mit veränderten Randbedingungen aufgezeigt.The objective of the dissertation was the development of a process-based, ecohydrological model that meets the requirements of temperate and tropic climates. The developed model was applied to the catchment of the Thi Vai Estuary, which is located in the humid tropics in South Vietnam. It was the aim to test and investigate the predictive power of the developed model. Ecohydrological modeling in the humid tropics is challenging because of extreme meteorological conditions, the high anthropogenic pressure in the investigated catchment and poor data availability. For this purpose, the existing hydrological model PANTA RHEI was, among others, extended with additional modules to simulate terrestrial biochemical cycles (CNP-Module), plant growth and management as well as water quality. The developed ecohydrological model includes water quality procedures, accounting for the interaction of aquatic biomass, dissolved oxygen, nutrients, detritus and sediment. Therefore, the implemented water quality model overcomes deficits found in common ecohydrological models. Additionally differentiated substances are considered and a sub-daily calculation time step is possible. Therefore not only loads but also concentrations can be investigated. At the beginning of the study nearly no data on water quantity and quality was available for the catchment. Hence, a monitoring program was initialized. Among others, the water quality parameters DO, NH4, NO2, NO3, PO4 and TSS, were measured. The simulation results show that the developed model is capable to simulate the hydrology and water quality of the investigated catchment. A sensitivity analysis demonstrated that the water quality of nitrogen is dominated by terrestrial transformation processes. The developed CNP-module is able to simulate the characteristic dynamics of mineralization typically observed in the humid tropics. Beside the implemented Availability and Demand Approach, which is accounting for a temporary storage of nutrients in the microbial biomass, the implemented moisture functions are of particular importance. The consideration of sediment compartments and processes related to periphyton activity were key components in the water quality modeling of the catchment. Furthermore, possible applications and the predictive power of the model under altered boundary conditions were demonstrated by the application on the Thi Vai catchment