Kyung H. Yoo

Hydrology and water supply for pond aquaculture

Preface Symbols Abbreviations Customary metric conversion factors Introduction Hydrology, morphometry and soils Physical properties of water and water cycle Rainfall Evaporation Runoff Water requirements for aquacultural ponds Water conservation Morphometric and edaphic factors affecting pond design Design of water supply and pond systems: Open-channel flows Pipe flows Water measurement Pumps and pumping Ground water and wells Pond design and construction Pond effluents.

Ground Water and Wells

Ground water is the largest and most widely available supply of high-quality freshwater for use in aquaculture. Many fish farmers rely on well water to fill and maintain ponds, and aquaculture often is most profitable in regions where shallow wells yield large volumes of water, such as along floodplains of major rivers. This chapter discusses features of groundwater, aquifers, and function and design of wells.

Assessment of reclaimed wastewater irrigation impacts on water quality, soil, and rice cultivation in paddy fields

The objective of this research was to monitor and assess the impact of reclaimed wastewater irrigation on water quality, soil, and rice cultivation by comparing the effects of various wastewater treatment levels on the growth and yield of rice. A randomized complete block design was used for the application methods of the wastewater effluents to paddy rice, with five treatments and six replications. The treatments were: control with groundwater irrigation (GW); irrigation with polluted water form a nearby stream (SW); and three treatments of reclaimed wastewater irrigation at different treatment levels. The three levels of wastewater treatments included wastewater effluents: (i) directly from the wastewater plant (WW); (ii) after passing through a sand filter (WSF); and (iii) after passing a sand filter followed by an ultraviolet treatment (WSFUV). Each plot was 4 × 4 m and was planted with rice (Oryza sativa L.) in 2002 and 2003. The results indicated that irrigation of rice with reclaimed municipal wastewater caused no adverse effects on the growth and yield of rice. The chemical compositions of the rice from all plots were within the normal ranges of brown rice quality in Korea. No adverse effects were observed on chemical concentrations including the heavy metals Cu, As, Cd, Zn, Hg, and Pb, in either the brown rice or the field. The results showed that treated municipal wastewater can be safely used as an alternative water source for the irrigation of rice, although continued monitoring will be needed to determine the long-term effects with regard to soil contamination and other potential health concerns.

Open-Channel Flows

Streams and man-made channels have a free-water surface exposed to the atmosphere, so they are known as open channels. The cross-sectional area of flow can vary at a given place in a channel, and the velocity of flow depends on several variables. Pressure is atmospheric, and the energy causing the flow is elevational energy (gravity); gravity drives water in a channel from higher to lower elevations. This chapter discusses principles of open-channel flow and hydraulics; the design of unlined, lined, and vegetated channels are presented with some examples.

Runoff curve numbers determined by three methods under conventional and conservation tillages

Event-based rainfall and the associated runoff data collected from a small watershed planted to cotton were analyzed to determine effects of two tillage systems on SCS runoff curve numbers. A tillage study was conducted for six years on a 3.8 ha watershed planted to cotton in the Limestone Valley region of northern Alabama. The tillage included three years of conventional (CvT), followed by three years of conservation tillage (CsT). Soils of the watershed are Decatur (clayey, kaolinitic, thermic Rhodic Paleudults) and Emory silt loam (fine-silty, siliceous, thermic Fluventic Umbric Dystrochrepts) which are classified in Hydrologic Soil Group B. Curve numbers (CN) were determined by the SCS method and a method developed assuming a log-normal probability distribution of potential maximum retention, S. The published CN of the average soil moisture condition or antecedent moisture condition II (AMC II) for the study site are 78 and 75 for CvT and CsT, respectively, which are recommended in many watershed/water quality computer simulation models such as CREAMS and AGNPS. The results showed that CN of AMC II (CN-II) calculated by the log-normal method were 83 and 88 for CvT and CsT, respectively. These were slightly higher than those calculated by the SCS method which were 82 for CvT and 86 for CsT. The calculated CN-II values were higher than the published CN-II values but the order of magnitude was reversed.

Nutrient Loss in Leachate and Surface Runoff from Surface-Broadcast and Subsurface-Banded Broiler Litter

Subsurface band application of poultry litter has been shown to reduce the transport of nutrients from fields in surface runoff compared with conventional surface broadcast application. Little research has been conducted to determine the effects of surface broadcast application and subsurface banding of litter on nutrients in leachate. Therefore, a field experiment was conducted to determine the effects of subsurface band application and surface broadcast application of poultry litter on nutrient losses in leachate. Zero-tension pan and passive capillary fiberglass wick lysimeters were installed in situ 50 cm beneath the soil surface of an established tall fescue ( Schreb.) pasture on a sandy loam soil. The treatments were surface broadcast and subsurface-banded poultry litter at 5 Mg ha and an unfertilized control. Results of the rainfall simulations showed that the concentrations of PO-P and total phosphorus (TP) in leachate were reduced by 96 and 37%, respectively, in subsurface-banded litter treatment compared with the surface-applied litter treatment. There was no significant difference in PO-P concentration between control and subsurface-banded litter treatment in leachate. The trend in the loading of nutrients in leachate was similar to the trend in concentration. Concentration and loading of the nutrients (TP, PO-P, NH-N, and NO-N) in runoff from the subsurface-banded treatment were significantly less than for the surface-applied treatment and were similar to those from control plots. These results show that, compared with conventional surface broadcast application of litter, subsurface band application of litter can greatly reduce loss of P in surface runoff and leachate.

Nonpoint source (NPS) model simulation of tillage effects on water quality

Abstract Three agricultural non‐point source (NPS) models, GLEAMS, EPIC, and WEPP, were used to simulate the effects of two tillage systems on runoff and losses of sediment, N, and P from a field‐sized watershed in the Tennessee valley region of Alabama. The field was cultivated with three years of conventional tillage (CvT) followed by three years of conservation tillage (CsT) of cotton. GLEAMS and EPIC underpredicted NO3‐N losses in runoff for both tillage systems. EPIC simulated tillage effects on soluble‐P losses better than GLEAMS. However, EPIC poorly predicted annual organic‐N and P losses in sediment, mainly due to overpredicted sediment losses. The GLEAMS prediction of annual organic‐N and P losses in sediment was more acceptable than that of EPIC. WEPP predicted sediment losses close to observed data for both tillage systems. However, EPIC simulation of sediment loss was not as accurate, because its limited definition of watershed profile prevented the model accounting for sediment deposition on...

Surface Transport of Nutrients from Surface-Broadcast and Subsurface-Banded Broiler Litter

Nutrient buildup, mainly phosphorus (P), and loss from fields fertilized with poultry (broiler) litter contribute to eutrophication of surface waters. In the U.S., broiler litter is typically surface-applied, but recently, to reduce surface transport of P and other nutrients, subsurface-banding of broiler litter has been promoted as a new manure application method. The objective of this study was to evaluate differences in nutrient transport between subsurface-banded and surface-applied broiler litter in a tall fescue pasture. Treatments were surface-applied and subsurface-banded broiler litter at a rate of 5.0 Mg ha-1, and no application of litter (control). Results showed that runoff concentrations and loadings of total P (TP), ortho-P (PO4-P), nitrate-nitrogen (NO3-N), and ammonium-N (NH4-N) were reduced by 83%, 88%, 74%, and 80%, respectively, for the subsurface-banded litter as compared to the surface-applied litter. Concentrations and loadings of all nutrients in surface runoff from the subsurface-banded treatment were similar to those from the control. This study showed that subsurface banding of broiler litter can substantially reduce nutrient losses in surface runoff. However, since less than 10% of the simulated rainfall contributed to surface runoff (more than 90% rainfall infiltrated), subsurface transport of nutrients from surface-applied and subsurface-banded litter needs to be studied in field research.

WEPP and gleams simulations of runoff and soil loss from grazed pasture in the southeastern united states

Abstract This study compared simulated values of surface runoff and erosion from two current erosion prediction technologies (WEPP and GLEAMS) to observed data for two grazing pressures on three pasture vegetation types (switchgrass, bermudagrass, and tall fescue) in the Tennessee Valley region of Alabama. Based on the results of statistical analysis for each forage type and grazing pressure, GLEAMS performed better than WEPP, although either model did not predict sediment loss within an acceptable level. Because it was determined that grazing pressure had no significant impact on runoff and erosion from the experiment plots, the data for each forage were pooled over the same grazing pressure and the correlation between observed and simulated data were analyzed. This analysis showed that overall, predicted runoff values for both WEPP and GLEAMS had linear relationship to observed data. When sediment loss was analyzed, GLEAMS predicted value showed significant correlation with observed data, while WEPP pre...

Planning of irrigation distribution and application systems by mixed-integer linear programming

Abstract A mixed-integer programming model was used to obtain optimum system plans for a 6900-ha irrigation project in southeastern Idaho. Three types of gravity conveyance (existing unlined canal, concrete lined canal, and gravity pipe) were considered along with five types of irrigation application systems in developing plans. The mixed-integer programming model was flexible and effective in developing minimum cost irrigation system plans that complied with the constraints specified. Quantitative effects of different constraints were easily evaluated. The model gives descriptive scenarios that can assist planners, irrigators, and other interested parties in making multiple-objective planning decisions for developing or rehabilitating an irrigation project.