Ranmalee Bandara
Jeffrey P. Walker Christoph Rüdiger. Towards soil property retrieval from space: Proof of concept using in situ observations. Journal of HydrologyVolume 512 6 May 2014 Pages 27–38
Abstract
Soil moisture is a key variable that controls the exchange of water and energy fluxes between the land surface and the atmosphere. However the temporal evolution of soil moisture is neither easy to measure nor monitor at large scales because of its high spatial variability. This is mainly a result of the local variation in soil properties and vegetation cover. Thus land surface models are normally used to predict the evolution of soil moisture and yet despite their importance these models are based on low-resolution soil property information or typical values. Therefore the availability of more accurate and detailed soil parameter data than are currently available is vital if regional or global soil moisture predictions are to be made with the accuracy required for environmental applications. The proposed solution is to estimate the soil hydraulic properties via model calibration to remotely sensed soil moisture observation with in situ observations used as a proxy in this proof of concept study. Consequently the feasibility is assessed and the level of accuracy that can be expected determined for soil hydraulic property estimation of duplex soil profiles in a semi-arid environment using near-surface soil moisture observations under naturally occurring conditions. The retrieved soil hydraulic parameters were then assessed by their reliability to predict the root zone soil moisture using the Joint UK Land Environment Simulator model. When using parameters that were retrieved using soil moisture observations the root zone soil moisture was predicted to within an accuracy of 0.04 m3-m3 which is an improvement of ∼0.025 m3-m3 on predictions that used published values or pedo-transfer functions.