The accuracy of agricultural nonpoint source pollution models depends in part on how well model input parameters describe the relevant characteristics of the watershed. The spatial extent of input parameter aggregation has previously been shown to have a substantial impact on model output. This study investigates this problem using the Soil and Water Assessment Tool (SWAT), a distributed-parame...

abstract in this study, evaluation of swap model in simulating crop yield, water and salt movement in soil were investigated in the wheat- fodder maize cultivated units. the research was conducted in the voshmgir network, golestan province. the crop yield, soil humidity and moisture data in different times of agriculture year of 2007-2008 were measured. the measured and simulated data were anal...

abstarct precise knowledge of all components of water balance is essential to optimize water use in irrigated agriculture. however, water balance components are difficult to measure in required time intervals because their measuring is time consuming and costly. unsaturated zone simulator models are useful tools for predicting the effects of agricultural management on crop water use and can be ...

hairsine and rose (1991) developed a process-based soil erosion model which described the erosion transport of multiparticle sizes in sediment for rain-impacted flow in the absence of entrainment in overland flow. in order to test this model laboratory experiments were carried out in a detachment tray using simulated rainfall. three contrasting soil types were subjected to simulated rainfall at...

This paper investigates slip-based traction control of a planetary rover that travels over natural rough terrain. Special attention is made on tire-soil traction mechanics and articulated body dynamics. Experiments are carried out with a rover test bed to understand the physical behavior of tire-soil interaction and, thereby, a traction model is investigated using the tire slip ratio as a state...

[1] A simple model is developed to describe the significant land-atmosphere interaction processes in the warm climate. It includes bulk soil hydrology, dynamic vegetation, and simple land-atmosphere interaction processes. The model can simulate the basic features of land surface control on evapotranspiration (ET) and exhibits a multiequilibrium behavior similar to that of some more complex mode...

A detailed laboratory study was conducted to examine the effects of particle size on hysteretic sediment transport under time-varying rainfall. A rainfall pattern composed of seven sequential stepwise varying rainfall intensities (30, 37.5, 45, 60, 45, 37.5, and 30 mm h), each of 20 min duration, was applied to a 5 m 3 2 m soil erosion flume. The soil in the flume was initially dried, ploughed ...