The Education Department is a core unit within the faculty, responsible for planning, organizing, and overseeing educational activities. It works closely with academic staff to design and update course curricula, coordinate class schedules, and enhance the overall quality of teaching. The department aims to provide a supportive environment for effective learning and the academic development of students. It also plays a key role in academic advising, addressing educational concerns, and organizing consultation sessions. By applying modern teaching methods and responding to current educational needs, the Education Department strives to improve the learning process and contribute to student success.
Lee s., S., Sadeghi, A., Yeo i.-y., I., Mccarty g.w., G.W., Hively w.d., W.D., Lang, M.W., Sharifi a., A.
Publication Date: 0
Climate change is expected to exacerbate water quality degradation in the Chesapeake Bay Watershed (CBW). Winter cover crops (WCCs) have been widely implemented in this region due to their high effectiveness at reducing nitrate loads. However, little is known about climate change impacts on the effectiveness of WCCs for reducing nitrate loads. The objective of this study is to assess climate change impacts on WCC nitrate uptake efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. We prepared climate change scenarios using General Circulation Models (GCMs) under three greenhouse emission scenarios (e.g., A1B, A2, and B1). Simulation results showed that WCC biomass increased by ∼ 58 % under climate change scenarios, due to climate conditions conducive to WCC growth. Prior to WCC implementation, annual nitrate loads increased by ∼ 43 % (5.3 kg N•ha-1) under climate change scenarios compared to the baseline scenario. When WCCs were planted, nitrate loads were substantially reduced and WCC nitrate reduction efficiency increased by ∼ 5 % under climate change scenarios relative to the baseline, due to increased WCC biomass. Therefore, the role of WCCs in mitigating nitrate loads should increase in the future given predicted climate change.
Sexton a.m., A.M., Sadeghi, A., Shirmohammadi a., A.
Publication Date: 0
7pp. 5291-5302
Hydrologic and water quality models are very sensitive to input parameter values, especially precipitation input data. With several different sources of precipitation data now available, it is quite difficult to determine which source is most appropriate under various circumstances. We used several sources of rainfall data in this study including single gauge rainfall data located outside the watershed boundary, and next generation radar (NEXRAD) rainfall data with different corrections, to examine the impact of such sources on Soil and Water Assessment Tool (SWAT) model streamflow predictions tor a 50 km 2 watershed located in the coastal plain of Maryland. For a watershed of that size with annual average precipitation of 43 inches, at least 3 rain gauges within the watershed would reduce the percentage error in measured average watershed rainfall amounts to less than 23% (for 0.5 inch storm events). The larger the amount of storm rainfall the less error was associated with its measurement. Model simulation results indicated that distance and location of the single rain gauge located outside the watershed boundary has a significant impact in simulating hydrologic and water quality response of the watershed in the temperate region of Maryland. In the absence of a spatially representative network of rain gauges within the watershed, NEXRAD data produced more accurate estimates of streamflow than using single gage data. This study concludes that one has to be mindful of the source and methods of interpolation of rainfall data for input into hydrologic and water quality models if simulation accuracies are desired.
Lee s., S., Yeo l.-y., , Sadeghi, A., Mccarty g.w., G.W., Lang, M.W., Hively w.d., W.D.
Publication Date: 0
pp. 40-43
Elevated C02 concentration, temperature, and change in precipitation patterns driven by climate change are expected to cause significant environmental effects in the Chesapeake Bay Watershed (CBW). Although the potential effects of climate change are widely reported, few studies have been conducted to understand implications for water quality and the response of agricultural watersheds to climate change. The objective of this study is to quantify changes in hydrological processes and nitrate cycling, as a result of climate variability, using the Soil and Water Assessment Tool (SWAT) model. Specifically we assessed the performance of winter cover crops (WCC) as a means of reducing nutrient loss in the realm of climate change and evaluate its impacts on water quality at the watershed scale. WCC planting has been emphasized as the most cost-effective means for water quality protection and widely adopted via federal and state cost-share programs. Climate change data were prepared by modifying current climate data using predicted mean temperature and precipitation change for the future periods (2070-2099) predicted by four global climate models. Current CO2 concentration, temperature, and precipitation increased by 850 ppm, 4.5 °C, and 23%, respectively. Although temperature increase reduced the water and nitrate loads, nitrate loads were found to increase by 40% under baseline land management and WCC were found to be less effective at reducing nitrate (nitrate increased by 4.6 kg/ha). Therefore agricultural conservation practices are likely to be even more important in the future, but acreage goals may need to be adjusted to maintain baseline effects.
Keisling t.c., , Gilmour j.t., , Scott h.d., , Sadeghi, A., Baser r.e.,
Publication Date: 1984
(111)
The use of tile drains for alleviating soluble salt accumulation on silt loam soil was investigated during 1984. Although the chemical analyses of the floodwater and tile drainage water were very similar suggeting that the floodwater was moving to the tile drain, the overall results so far indicate that this is not a feasible solution owing to lack of significant drainage. Application of DRAINMOD utilizing soil and weather data from Arkansas showed no significant effluent from the tile drains for our experimental site during rice production. This was attributed to the extremely slow saturated hydraulic conductivity values for this particular soil. However, more observations (concerning the operation of the tile field) are needed before it can be concluded that tile drain fields are not a viable solution to the problem.
Sadeghi, A., Hancock g.d., , Waite w.p., W.P., Scott h.d., , Rand j.a.,
Publication Date: 1984
Water Resources Research (00431397)20(7)pp. 927-934
Laboratory and field experiments were conducted to investigate the ability of microwave remote sensing systems to detect the moisture status of a silt loam soil exhibiting abrupt changes in moisture content near the surface. Laboratory soil profiles were prepared with a discontinuous moisture boundary in the subsurface. Reflectivity measurements of these profiles were made with a bistatic reflectometer operating over the frequency ranges of 1–2 and 4–8 GHz (wavelength ranges of 30–15 and 7.5–3.75 cm, respectively). These measurements exhibited a well‐developed coherent interference pattern in good agreement with a simple two‐layer reflectivity model. Field measurements of bare soil surfaces were conducted for initially saturated profiles and continued for extended periods of drying. During drying, coherent interference patterns similar to those observed in the laboratory were detected. These appear to be due to steep moisture gradients occurring between drying layers near the surface. The field results were modeled by a five‐segment linear moisture profile with one or two steep segments and a multilayer reflectivity program. Agreement between model and field response over the frequency range was used to estimate the depth of drying layers within the soil. These depths were monitored over the second and third drying cycles. Formation of the drying layers under field conditions appears to be influenced by drying time, tillage, and evaporative demand. In any case, it appears that the coherent effects caused by nonuniform moisture profiles may substantially affect the reflectivity of even rough soil surfaces. Copyright 1984 by the American Geophysical Union.
