%0 Journal Article
%T Estimating Soil Hydraulic Parameters Characterizing Rainwater Infiltration and Runoff Properties of Dryland Floodplains
%A Sabelo S. W. Mavimbela
%A Leon D. van Rensburg
%J Computational Water, Energy, and Environmental Engineering
%P 11-40
%@ 2168-1570
%D 2019
%I Scientific Research Publishing
%R 10.4236/cweee.2019.81002
%X <p class=\"MsoNormal\">
	<span lang=\"EN-US\" style=\"font-family:Verdana;\">The</span><span class=\"apple-converted-space\"><span lang=\"EN-US\" style=\"font-family:Verdana, sans-serif;\"><span \"=\"\"> </span></span><span lang=\"EN-US\" style=\"font-family:Verdana, sans-serif;\"><span style=\"font-family:Verdana;\">two-layered (0 - 50 and 50 - 250 mm)
surface horizon hydraulic parameters of three dryland floodplain soil-types
under aquafer water management in Postmasburg, Northern Cape Province of South
Africa were estimated with HYDRUS-1D model. Time dependent water infiltration
measurements at 30 and 230 mm depths from simulated rainfalls on undisturbed 1
m</span><sup><span style=\"font-family:Verdana;\">2</span></sup><span class=\"apple-converted-space\"> </span><span style=\"font-family:Verdana;\">small plots with
intensities of 1.61 (high), 0.52 (medium) and 0.27 (low) mm¡¤min</span><sup><span style=\"font-family:Verdana;\">-1</span></sup><span style=\"font-family:Verdana;\">,
were minimised using a two-step inversion. Firstly</span></span></span><span lang=\"EN-US\" style=\"font-family:Verdana, sans-serif;\"><span style=\"font-family:Verdana;\">,</span><span class=\"apple-converted-space\" style=\"font-family:Verdana;\"> separate
optimisation of the van Genuchten-Mualem model parameters for the two
surface-horizon layers and secondly</span><span style=\"font-family:Verdana;\">,</span></span><span class=\"apple-converted-space\"><span lang=\"EN-US\" style=\"font-family:Verdana, sans-serif;\"><span \"=\"\"> </span></span><span lang=\"EN-US\" style=\"font-family:Verdana, sans-serif;\"><span style=\"font-family:Verdana;\">simultaneous
optimisation for the joint two-layered horizon with first step optimal
parameters entered as initial values. The model reproduced transient
water-infiltration data very well with the Nash-Sutcliffe model efficiency
coefficient (</span><i><span style=\"font-family:Verdana;\">NSE</span></i><span style=\"font-family:Verdana;\">) of 0.99 and overestimated runoff (</span><i><span style=\"font-family:Verdana;\">NSE</span></i><span style=\"font-family:Verdana;\">; 0.27 to
0.98). The upper surface horizon had highly optimised and variable parameters
especially</span><span class=\"apple-converted-space\"> </span><i><span style=\"font-family:Verdana;\">¦Ès</span><span class=\"apple-converted-space\"> </span></i><span style=\"font-family:Verdana;\">and</span><span class=\"apple-converted-space\"> </span><i><span style=\"font-family:Verdana;\">Ks</span></i><span style=\"font-family:Verdana;\">. Optimal</span><span
%K Floodplain Soil Types
%K Hydrus-1D Model
%K Inverse Parameter Optimisation
%K Objective Function
%K Parameter Sensitivity
%K Sedimentary Crust
%K Rainfall  Simulation
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=90245