Soil erosion from agricultural lands can be reduced by adoption of conservation management practices. The objectives of this study were to investigate the effectiveness and cost-benefit of conservation management practices on sediment reduction under a corn–soybean rotation. The experimental site was 6.4 ha (15.8 ac) and located within the Four Mile Creek watershed in eastern Iowa. Management p...

Two lumped parameter watershed scale hydrology and water quality models (WATGIS and QUALGIS) which describe the nitrogen loadings at the’outlet of coastal plain watersheds were examined with respect to their accuracy and uncertainty of model results. Latin Hypercube Sampling (LHS) was applied to determine the impact of uncertainty in estimating field exports and decay coefficients on the uncert...

for the successful tree establishment, an evaluation of land suitability is necessary.in this paper, we demonstrate how to implement fuzzy classification of land suitability in agis environment for afforestation with juglans regia in gharnaveh watershed of golestanprovince in iran. juglans regia is one of the most important agro-forestry species in manyrural parts of iran. relevant criteria for...

Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) plantations account for approximately 30% of the total forested area in Japan. Both are arbuscular mycorrhizal trees that leach more NO3 in response to nitrogen (N) deposition than do forests of ectomycorrhizal trees. However, little information is available about the size of N exports from these plantations. The ...

Best management practices (BMPs) are widely promoted in agricultural watersheds as a means of improving water quality and ameliorating altered hydrology. We used a paired watershed approach to evaluate whether focused outreach could increase BMP implementation rates and whether BMPs could induce watershed-scale (4000 ha) changes in nutrients, suspended sediment concentrations, or hydrology in a...

Non-point sources of pollutants originate at the field scale but water quality problems usually occur at the watershed or basin scale. This paper describes a series of models developed for poorly drained watersheds. The models use DRAINMOD to predict hydrology at the field scale and a range of methods to predict channel hydraulics and nitrogen transport. In-stream changes of N load are estimate...

prioritization of sub-watersheds is very important in the natural sources and watershed management. in this study, the morphometric parameter and landuse changes using rs and gis techniques used in order to identify erosion-prone sub-watersheds. the morphometric parameter such as basin relief, the linear parameters (drainage density, bifurcation ratio, length of overland flow, stream frequency ...

Over 500,000 hectares of grassland have been converted to managed forestland in Uruguay since} 990. This study was initiated to determine the hydrologic and water quality impacts of changing land use from grassland (pasture) to pine plantation in Uruguay. Two adjacent watersheds located on the El Cerro ranch in the Tacuarembo River basin were selected for a paired watershed study. Outflow rates...

Biotite is a common constituent of silicate bedrock. Its weathering releases plant nutrients and consumes atmospheric CO2. Because of its stoichiometric relationship with its transformational weathering product and sensitivity to botanical activity, calculating biotite weathering rates using watershed mass-balance methods has proven challenging. At Coweeta Hydrologic Laboratory the coupling of ...