Soil and Water Assessment Tool

This chapter is organized as follows. We first present a short description of the criteria used for selecting the data used for driving the hydrological simulations at the basin scale. Subsequently, we briefly describe Soil and Water Assessment Tool (SWAT), the hydrological model adopted for this study, and the setup thereof. Later on, we continue with a brief review of the main spatio-temporal patterns of climate,... 

Neitsch SL, Arnold JG, Kiniry JR, Williams JR (2005) Soil and water assessment tool theoretical documentation Version 2005. Grassland, Soil and Water Research Laboratory Agricultural Research Service, 808 East Blackland Road, Temple, Texas Blackland Research Center Texas Agricultural Experiment Station 720 East Blackland Road, Temple, Texas 76502, USA. Available at www.brc.tamus.edu/swat/doc.html... 

Gassman PW, Reyes MR, Green CH, Arnold JG (2007) The soil and water assessment tool historical development, applications and future research directions. Trans ASABE 50(4) 1211-1250... 

Di Luzio M, Srinivasan R, Arnold JG, Neitsch SL (2002) Soil and water assessment tool. ArcView GIS Interface Manual Version 2000, GSWRL Report 02-03, BRC Report 02-07. Texas Water Resources Institute TR-193, College Station, TX. 346p. Available at www.brc. tamus.edu/swat/downloads/doc/swatav2000.pdf... 

Parajuli, P. B., Mankin, K. R., and Barnes, P. L. (2009). Source specific fecal bacteria modeling using soil and water assessment tool model. Bioresour. Technol. 100, 953-963. 

Chaubey, L, K. W. Migliaccio, C. H. Green, J. G. Arnold, and R. Srinivasan. 2007. Phosphorus modeling in Soil and Water Assessment Tool (SWAT) model. In D. E. Radcliffe and M. L. Cabrera (eds.) Modeling Phosphorus in the Environment. CRC Press, New York. pp. 161-189. 

Scientists have developed computer models that depict the physical, chemical and biological processes within forest watersheds. Watershed acidification models can be used as research and management tools to investigate factors responsible for the historical acidification of soil and water as well as the ecosystem response to anticipated future changes in acidic deposition. In order to effectively predict the pH, ANC and aluminum concentrations in streams, all major chemicals must be accurately simulated (e.g., sulfate, nitrate, calcium, magnesium). The acidification model PnET-BGC was used for this assessment because it has been rigorously tested at Hubbard Brook and other sites in the northeastern United States, and it allows the user of the model to consider the ecosystem response to multiple chemicals simultaneously. Other frequently used acidification models include MAGIC (Cosby et al. 2001), and NuCM (Lui et al. 1992). 

Zillioux EJ, Newman JR. 2003. Bioindicators — essential tools for realistic assessment and remediation cost control. Soil, Sediment and Water 9 11. 

Data derived from comprehensive toxicity testing may be integrated in risk assessment frameworks for a more reliable estimation of the probability that the contaminated site poses environmental harm. Moreover, toxicity tests may be used as screening tools in order to identify polluted soil or water samples, and to reduce the number of samples that require full chemical and/or toxicological analysis. 

The BUSES model was developed to support the risk assessment of chemicals under various regulations. BUSES is a spreadsheet-based tool that incorporates SimpleBox, a multimedia fate model, and SimpleTreat, which simulates the distribution and elimination of chemicals in sewage freafment plants. The model estimates the concentrations of a substance in air, water, soil, and sediment at local and regional scales. It simulates the steady-state transport of chemicals between media and scales, and removal of the chemical by degradation and some "disappearance processes" (e.g., leaching to the groundwater, which is not then modeled) [106,107]. 

An especially valuable physicochemical property for chemical assessment is the octanol/water partition coefficient, usually expressed on a logarithmic scale (log Kow). This property correlates with partitioning from water to soil and sediment, as well as bioaccumulation in fish and other aquatic organisms. The ability to estimate log Kow from chemical structure provides a powerful tool to developers of new chemicals to model environmental partitioning and bioaccumulation prior to manufacture or even chemical synthesis (18). Log Kow... 

SimpleBox was created as a research tool in environmental risk assessment. Simple-Box (Brandes et al. 1996) is implemented in the regulatory European Union System for the Evaluation of Substances (EUSES) models (Vermeire et al. 1997) that are used for risk assessment of new and existing chemicals. Dedicated SimpleBox 1.0 applications have been used for integrating environmental quality criteria for air, water, and soil in The Netherlands. Spreadsheet versions of SimpleBox 2.0 are used for multi-media chemical fate modeling by scientists at universities and research institutes in various countries. SimpleBox models exposure concentrations in the environmental media. In addition to exposure concentrations, SimpleBox provides output at the level of toxic pressure on ecosystems by calculating potentially affected fractions (PAF) on the basis of species sensitivity distribution (SSD) calculus (see Chapter 4). 

The focus of the pilot was on the development of a practical framework for the application of biological test methods in a Triad approach. Consequently, the selection of tools for the assessment was based on scientific and pragmatic arguments, for instance by focusing on readily available techniques for determination of the concentration of contaminants in pore water and readily available biological tests such as simple bioassays and the monitoring of soil organisms. 

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