Guidelines and a supporting toolbox for parameterising key soil hydraulic properties in hydrological studies and broader integrated modelling

Abstract

Information on soil hydraulic properties (e.g. soil moisture pressure relationships and hydraulic conductivity) is valuable for a wide range of disciplines including hydrology, ecology, environmental management and agriculture. However, this information is often not readily available as direct measurements are costly and time-consuming. Furthermore, as more complex representations of soils are being built into environmental models, users and developers often require sound hydraulic property information, while having limited access to specialist knowledge. Although indirect methods have been developed to obtain soil hydraulic properties from easily measurable or readily available soil properties via pedo-transfer functions (PTFs), few articles provide guidance for obtaining soil hydraulic properties over a wide range of geoclimatic and regional data availability contexts. The aim of this study is, therefore, to develop guidelines and an associated spatially referenced toolbox, NB_PTFs, to speed the process of acquiring sensible soil hydraulic properties for different geoclimatic and data-rich/sparse regions. The guide compiles available information about soil hydraulic properties, as well as a large number (151) of PTFs, not collated in any other guidance to date. NB_PTFs is an open-source ArcGIS toolbox which allows users to quickly get values, graphs and spatial distributions of soil hydraulic properties. The soil hydraulic properties, obtained using the guide and the toolbox, can be used as inputs for various models amongst other purposes. To demonstrate the use of the guidelines and the toolbox in different geoclimatic and data-availability contexts, the paper presents two case studies: the Vietnamese Mekong Delta and New Zealand Hurunui catchment. The Vietnamese Mekong Delta shows the use of these guidelines in a tropical, flat location with limited information on soil physical, chemical and hydraulic properties. The Hurunui catchment represents a case study for a semi-arid and hilly area in an area with detailed soil information.

Parameterising and Adapting Ecosystem Service Models in Data Sparse Regions: Gaps, Guidelines, and an Application in the Vietnamese Mekong Delta

“…For the purposes of our work, concerned with generating broadly applicable national and international guidelines and tools, we did not attempt this. However, we recommend any readers of this paper (Dang et al, 2022) interested specifically in modelling the Hurunui or broader Canterbury region, or in how to use partially mapped higher detail soil information to augment fully mapped less detailed information, investigate this data source and the methodologies behind its generation. The LUCI framework (now Nature Braid -next-gen LUCI)…”

“…These soil hydraulic properties are usually not readily available and costly to measure. To support LUCI users and broader hydrological applications, guidance, and an associated toolbox (LUCI_PTFs) to obtain required soil hydraulic properties in a cost-effective way were developed in Dang et al (2022). Although the LUCI framework has further relevant algorithms such as the flatwater inundation tool which accounts for overbank water flow (Ballinger et al, 2011;Benavidez, 2018), these algorithms have yet been well documented or widely applied.…”

“…Soil with higher saturated hydraulic conductivity had higher drainage. Information on soil hydraulic parameters were obtained using the guidance and an associated toolbox (LUCI_PTFs) provided by Dang et al (2022) . We developed three sets (Set…”