This study was designed to evaluate the improved version of the Root Zone Water Quality Model (RZWQM) using 6 yr (1992-1997) of field-measured data from a field within Walnut Creek watershed located in central Iowa. Measured data included subsurface drainage flows, NO3-N concentrations and loads in subsurface drainage water, and corn (Zea mays L.) and soybean [Glycine mar (L.) Merr.] yields. Th...

This study was designed to calibrate and evaluate the subsurface drain flow component of the Root Zone Water Quality Model (RZWQM; Version 2.5) for four tillage-systems: chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT). Measured subsurface drain flow data for 1990 was used for model calibration. Main parameters calibrated were lateral saturated hydraulic conductivi...

global warming, as a consequence of greenhouse gases accumulation, has exerted significant impacts on biosphere. methane, a product of reduction processes of organic carbon in anaerobic conditions, is mainly emitted from paddy fields. the aim followed in this research is to evaluate the impact of midseason drainage on methane emission from paddy fields. the research was conducted with three tre...

The Regional Superfund Ground Water Forum is a group of ground-water scientists, representing EPA's Regional Superfund Offices, organized to exchange up-to-date information related to ground-water remediation of Superfund sites. One of the major issues of concern to the Forum is the transport and fate of contaminants in soil and ground water as related to subsurface remediation. Processes which...

The Regional Superfund Ground Water Forum is a group of ground-water scientists, representing EPA's Regional Superfund Offices, organized to exchange up-to-date information related to ground-water remediation of Superfund sites. One of the major issues of concern to the Forum is the transport and fate of contaminants in soil and ground water as related to subsurface remediation. Processes which...

The Regional Superfund Ground Water Forum is a group of ground-water scientists, representing EPA's Regional Superfund Offices, organized to exchange up-to-date information related to ground-water remediation of Superfund sites. One of the major issues of concern to the Forum is the transport and fate of contaminants in soil and ground water as related to subsurface remediation. Processes which...

Constructed wetlands have not been commonly used in Vietnam due to the lack of information in the selection of proper types of constructed wetlands, type of reeds, design parameters and performance efficiency, in tropical climates. This paper focuses on Canna generalis, which is a common reed and easy to grow both in water and wet land conditions. Two kinds of hybrid constructed wetlan...

South Africa has numerous thermal springs that represent topographically driven meteoric water migrating along major fracture zones. The temperature (40-70°C) and pH (8-9) of the thermal springs in the Limpopo Province are very similar to those of the low salinity fracture water encountered in the South African mines at depths ranging from 1.0 to 3.1 km. The major cation and anion composition o...

[1] Ground-penetrating radar (GPR) has the potential to image the Martian subsurface to give geological context to drilling targets, investigate stratigraphy, and locate subsurface water. GPR depth of penetration depends strongly on the electromagnetic (EM) properties (complex dielectric permittivity, complex magnetic permeability, and DC resistivity) of the subsurface. These EM properties in t...