The Soil and Water Assessment Tool (SWAT) model is a continuation of nearly 30 years of modeling efforts conducted by the USDA Agricultural Research Service (ARS). SWAT has gained international acceptance as a robust interdisciplinary watershed modeling tool as evidenced by international SWAT conferences, hundreds of SWAT-related papers presented at numerous other scientific meetings, and dozens of articles published in peer-reviewed journals. The model has also been adopted as part of the U.S. Environmental Protection Agency (USEPA) Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) software package and is being used by many U.S. federal and state agencies, including the USDA within the Conservation Effects Assessment Project (CEAP). At present, over 250 peer-reviewed published articles have been identified that report SWAT applications, reviews of SWAT components, or other research that includes SWAT. Many of these peer-reviewed articles are summarized here according to relevant application categories such as streamflow calibration and related hydrologic analyses, climate change impacts on hydrology, pollutant load assessments, comparisons with other models, and sensitivity analyses and calibration techniques. Strengths and weaknesses of the model are presented, and recommended research needs for SWAT are also provided.

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The Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions

The Soil and Water Assessment Tool (SWAT) model is a continuation of nearly 30 years of modeling efforts conducted by the U.S. Department of Agriculture (USDA), Agricultural Research Service. SWAT has gained international acceptance as a robust interdisciplinary watershed modeling tool, as evidenced by international SWAT conferences, hundreds of SWAT-related papers presented at numerous scientific meetings, and dozens of articles published in peer-reviewed journals. The model has also been adopted as part of the U.S. Environmental Protection Agency's BASINS (Better Assessment Science Integrating Point & Nonpoint Sources) software package and is being used by many U.S. federal and state agencies, including the USDA within the Conservation Effects Assessment Project. At present, over 250 peer-reviewed, published articles have been identified that report SWAT applications, reviews of SWAT components, or other research that includes SWAT. Many of these peer-reviewed articles are summarized here according to relevant application categories such as streamflow calibration and related hydrologic analyses, climate change impacts on hydrology, pollutant load assessments, comparisons with other models, and sensitivity analyses and calibration techniques. Strengths and weaknesses of the model are presented, and recommended research needs for SWAT are provided.

Soil and Water Assessment Tool: Historical Development, Applications, and Future Research Directions, The

http://www.highstand.org/erohling/Rohling-papers/2004-Mayewski%20et%20al%20Holocene%20climate%20variability%20QR62.pdf

Holocene climate variability

Organic geochemical proxies of paleoceanographic, paleolimnologic, and paleoclimatic processes

http://projects.itn.pt/UCQR_QAA/Meyers_2003.pdf

Applications of organic geochemistry to paleolimnological reconstructions: a summary of examples from the Laurentian Great Lakes

Lacustrine varve formation through time

Increased aridity throughout the Great Plains and Rocky Mountain region during the middle Holo cene has been documented from pollen records, aeolian proxy variables in lake cores, and active sand dune migration. Varve calibration provided by a continuously varved record of the Holocene from a core from Elk Lake, northwestern Minnesota, shows that the influx of aeolian clastic material increased beginning about 8 ka and ended about 3.8 ka, with peak aeolian activity at about 6 ka. If aeolian influx to Elk Lake corresponds in time to aeolian influx in other lakes and to maximum dune activity in Minnesota dune fields, then the varve calibration in Elk Lake provides precise time calibration of periods of peak aeolian activity in Minnesota. Palaeowind studies from the Minnesota dune fields show that the dominant wind direction when the dunes were active was from the northwest, the same as the dominant wind direction in dune fields throughout the Great Plains and Rocky Mountains. If the mid-Holocene aeolian act...

Regional aridity in North America during the middle Holocene

IT is commonly thought that the climate conditions that supported lakes over a period of years in the Mojave Desert in southern California, only existed before 8,000 yr BP and that the environment has been arid since1,2. Here we look at a drill core in the Silver Lake playa at the terminus of the Mojave River and find Holocene lake deposits which indicate that shallow lakes existed for at least a few decades. These deposits were radiocarbon dated at 3620 ±70 and 390 ± 90 yr BP, corresponding to the early Neo-glacial and the 'little ice age' respectively3. To identify the conditions necessary to produce these Holocene lake events we have examined the modern climate and hydrological patterns that produce ephemeral lakes in this usually arid watershed. Available data indicate that there is a link between anomalous winter atmospheric conditions over the North Pacific and Mojave River floods that produced ephemeral lakes in the Silver Lake playa and that the Mojave River filters out small to medium floods and allows only the extreme floods to reach the terminal playa and leave a record of the anomalous conditions. We suggest that the late Holocene lakes may have resulted from persistent similar atmospheric circulation patterns and winter floods.

Atmospheric circulation during Holocene lake stands in the Mojave Desert: evidence of regional climate change

Lake sediments that accumulated in the Estancia basin, central New Mexico, provide a detailed record of submillennial latest Pleistocene climatic oscillations. Sedimentologic, biologic, and geochemical proxies for changes in salinity and lake level were used to identify episodes of wet and dry climate that occurred between 24 and 12 k.y. B.P., as dated by 14C by means of accelerator mass spectrometry from shoreline and basin-center deposits. These dates determine the timing and duration of the episodes of wet and dry climate. The lake expanded and contracted repeatedly during the last glacial maximum and fluctuated near its highest elevation several times during the interval ca. 20 to 15 k.y. B.P. A pronounced lowstand lasting ∼1 k.y. occurred between ca. 15 and 14 k.y. B.P., followed by two more highstands of the lake between ca. 14 and 12.5 k.y. B.P. Desiccation of the perennial lake after 12 k.y. B.P. was followed by a final, poorly dated highstand at ca. 10 k.y. B.P. The record of lake-level fluctuations from the Estancia basin provides a high-resolution record of changes in water budget in a basin, the comparatively simple physiography and hydrogeology of which ensured a direct response to the strong climatic fluctuations that occurred during the last glacial maximum and termination.

A continuous, high-resolution record of late Pleistocene climate variability from the Estancia basin, New Mexico

The Estancia basin in southwestern United States contains evidence for strong and rapid pulsations in the supply of moisture brought into the region during the last ice age. The pulses were recorded during episodes of stream discharge that spread plumes of fresh water laden with quartz sand over the saline lake. The largest pulses in stream discharge lasted only a few decades, were organized into cycles that were spaced approximately 200 to 250 and 2000 years apart, and were of sufficient magnitude to freshen and maintain the lake at its maximum recorded elevation.

Roger Y. Anderson

Papers

Lacustrine varve formation through time

Regional aridity in North America during the middle Holocene

Atmospheric circulation during Holocene lake stands in the Mojave Desert: evidence of regional climate change

A continuous, high-resolution record of late Pleistocene climate variability from the Estancia basin, New Mexico

Evidence from Western north america for rapid shifts in climate during the last glacial maximum