The resultant calibration parameter values and simulation accuracy of hydrologic models such as the 2005 Soil and Water Assessment Tool (SWAT2005) depend on how well spatial input parameters describe the characteristics of the study area. The objectives of this study were to (1) investigate the effect of soils dataset resolution (State Soil Geographic Database and Soil Survey Geographic Databas...

This study presents a simple and efficient scheme for Bayesian estimation of uncertainty in soil moisture simulation by a Land Surface Model (LSM). The scheme is assessed within a Monte Carlo (MC) simulation framework based on the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. A primary limitation of using the GLUE method is the prohibitive computational burden imposed by uni...

Factors that must be considered in compaction of the soil works were the type of soil material, field control, maintenance and availability of funds. Those problems then raised the idea of how to estimate the density of the soil with a proper implementation system, fast, and economical. This study aims to estimate the compaction parameter i.e. the maximum dry unit weight (γdmax) and optimum wat...

This paper presents an automated approach for deriving gridded a pri1 ori parameters for the National Weather Service (NWS) Sacramento Soil 2 Moisture Accounting (SAC-SMA) model from the Soil Survey Geographic 3 (SSURGO) Database and National Land Cover Database (NLCD). Our ap4 proach considerably extends methods previously used in the NWS and of5 fers automated and geographically invariant way...

Inverse solution techniques currently used for estimating unsaturated soil hydraulic functions from laboratory outflow experiments use cumulative outflow only in combination with initial and final soil water pressure head values. Additional soil water information is needed to improve the estimation procedure and to minimize uniqueness problems. It was the objective of this study to experimental...

A modified version of the model Opus was applied to measurements of soil water dynamics and atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) persistence in a Bruntwood silt loam soil (Haplic Andosol, FAO system) in Hamilton, New Zealand. The modified model, Opus2, is briefly described and parameter estimation for the simulations is discussed. Soil water dynamics were more ac...

[1] The focus of this study is on the role of precipitation uncertainty in the estimation of soil texture and soil hydraulic properties for application to land-atmosphere modeling systems. This work extends a recent study by Santanello et al. (2007) in which it was shown that soil texture and related physical parameters may be estimated using a combination of multitemporal microwave remote sens...