Soil moisture data using citizen science technology cross-validated by satellite data

Abstract

Soil moisture represents many attributes of the geo-hydrological cycle and the climate system. Citizen science through social media as an emerging tool could be utilized to collect soil moisture data. A pilot study area was selected in Shahriar, Iran. A user interface and a sampling process (use of citizen science by subscribers) were designed to analyze the subjective and gravimetric soil moisture data. Furthermore, explanatory moisture condition (EMC), a new initiative to consider land use in soil moisture information from vegetation cover, was evaluated. A statistical artificial neural network was used for quantifying subjective data, and soil moisture layouts were produced by utilizing the ordinary kriging (OK) method. For cross-validating, the land surface temperature data from the MODIS satellite were retrieved. A platform for the region with 200 m grids resolution to collect daily soil moisture at eight ungauged stations is proposed to utilize subjective data from the subscribers and cross-validated with satellite data. A virtual station at the centroid of the pervious part of the study area was selected as a reference station for data collection daily or weekly to generate soil moisture time series. The results showed a high potential of utilizing satellite and citizen science data for real-time estimation of scarce soil moisture data in developing regions. HIGHLIGHTS Design of a platform for real-time data estimation of SM in virtual station(s) using color contrast image processing with simple user interface for retrieving SM data through social media.; Cross-validation and error analysis with daily downscaled satellite SM data provides a unique opportunity for SM estimation in the developing regions with no national or regional plan to collect time series of this data.;

Keywords

• citizen science
• data-driven modeling
• image processing
• kriging method
• soil moisture