l and drainage has been central to the development of North America since colonial times, with the first organized drainage efforts occurring as early as the 1600s (Evans et al. 1996). Drainage has been encouraged to improve public highways, reduce public health risks, promote increased crop yield and reduced yield variability, reduce surface runoff and erosion, and increase land value. Agricul...

Landfill covers are critical to waste containment, yet field performance of specific cover designs has not been well documented and seldom been compared in side-by-side testing. A study was conducted to assess the ability of landfill final covers to control percolation into underlying waste. Conventional covers employing resistive barriers as well as alternative covers relying on water-storage ...

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...

Preferential flow through soil macropores in tile drained soils can significantly increase the risk of pollution of surface water bodies by agricultural chemicals such as pesticides. While many field studies have shown the importance of preferential flow in tile-drained fields, few have included detailed numerical modelling of the processes involved. The objective of this study was to compare f...

By employing chemical and isotopic tracers ((15)N and (18)O in NO(3)(-)), we investigated the main processes controlling nitrate distribution in the unsaturated zone and aquifer. Soil water was extracted from two soil cores drilled in a typical agricultural cropping area of the North China Plain (NCP), where groundwater was also sampled. The results indicate that evaporation and denitrification...

The losses of water by evapotranspiration and evaporation from soil were investigated during two seasons from wheat and lupin crops sown at two times. Evapotranspiration was measured using ventilated chambers and microlysimeters were used within the chambers to measure evaporation from the soil surface. These techniques allowed the partitioning of evapotranspiration into its two components. In ...

In copper heap leaching structures, the ore is leached by an acidic solution. After dissolving the ore mineral, the heap is drained off in the acidic solution using a drainage system (consisting of a network of perforated polyethylene pipes and gravelly drainage layers) and is, then, transferred to the leaching plant for copper extraction where the copper is extracted and the remaining solution...

[1] Groundwater recharge is critical in semiarid regions where aquifers are currently being mined for intensive irrigation. Land use management related to agriculture can be used to control partitioning of water near the land surface and to potentially manage water resources. The purpose of this study was to quantify impacts of deep plowing in rainfed (nonirrigated) agriculture in a semiarid re...

[1] Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were investigated with a new ecosys...

The question of whether or not soil hydraulic parameters of dualpermeability models (DPM) can be properly identified by inverse analysis of preferential water flow data has not been resolved to date. We applied a DPM based on two coupled Richards’ equations to compare the performance of inverse and forward simulations of laboratory preferential flow data. Infiltration and drainage experiments w...