abstarct development of greenhouse gases in future periods not only causes change in average amounts of climate variables but also makes variables of this variability affected. then for sure concerning alternations followed with climate variables’ fluctuations and its average amounts in effecting on runoff would make more reliable results. in this inquiry initially fluctuations and average amou...

the discharge of total suspended sediments (tss) and dissolved nutrients from watersheds into receiving waters is a serious problem when natural vegetation is degraded by agriculture or overgrazing. this study was conducted in soolegan watershed to investigate land use change and overgrazing effects on phosphorus loss (dissolved & particulate), particle size associated loss of p and effect of t...

In this study, we propose a risk analysis simulation model for economic evaluation of hydroelectric engineering project. This model takes annual energy outputs as risk elements. It submits to Pearson-III distribution similar with the annual runoff. Take data from three typical years to estimate the distribution parameters and then yearly benefits can be simulated in given period. By discounting...

Hydrological models require accurate precipitation and air temperature inputs in order to adequately depict water fluxes and storages across Arctic regions. Biases such as gauge undercatch, as well as uncertainties in numerical weather prediction reanalysis data that propagate through water budget models, limit the ability to accurately model the terrestrial arctic water cycle. A hydrological m...

Three models were evaluated for their accuracy in simulating pesticide runoff at the edge of agricultural fields: Pesticide Root Zone Model (PRZM), Root Zone Water Quality Model (RZWQM), and OpusCZ. Modeling results on runoff volume, sediment erosion, and pesticide loss were compared with measurements taken from field studies. Models were also compared on their theoretical foundations and ease ...

[1] Motivated by the recent increasing availability of global remote sensing data for estimating precipitation and describing land surface characteristics, this note reports an approximate assessment of quasi-global runoff computed by incorporating satellite rainfall data and other remote sensing products in a relatively simple rainfall-runoff simulation approach: the Natural Resources Conserva...

Grazing and haying effects on runoff and erosion from a former Conservation Reserve Program (CRP) site near Streeter, North Dakota, were determined. Treatments included undisturbed CRP, twice-over rotational grazing, season-long grazing, haying, and burning. Runoff and erosion were measured from simulated rainfall which was applied to 3.7 x 10.7 m (12.0 X 35.1 ft) plots. Following an initial st...

Acid soil covers one third of the world arable lands. Excess Al and H in acid soil are not favorable for most plants. Calcium carbonates and gypsum (CaSO4) are used to improve chemical status of the acid soil. However, application of Ca cation may sometimes enhance dispersion and deteriorate soil physical properties. Presenting study discusses effect of non-ionic polyacrylamide (PAM) applicatio...

The Annualized Agricultural Non-Point Source (AnnAGNPS) model has been developed to quantify watershed response to agricultural management practices. The objective of this study was to identify critical areas where conservation practices could be implemented and to predict their impact on Beasley Lake water quality in the Mississippi Delta using AnnAGNPS. Model evaluation was first performed by...

Pasture runoff can contribute to elevated concentrations of nutrients, solids, and bacteria in downstream waters. The objective of this study was to determine the effects of vegetative filter strip (VFS) length on concentrations and transport of nitrogen, phosphorus, solids and fecal coliform in runoff from plots treated with cattle manure. Three plots with dimensions of 2.4 × 30.5 m were used....