MODIS 이미지와 토양수분자료동화기법을 이용한 토양의 수분보유능력 평가

초록

In this study, we assessed the soil water-holding capacity by combining satellite-based MODIS data and a soil moisture data assimilation scheme. MODIS data were converted to soil moisture products based on the empirical model suggested by Scott et al.(2013). We derived the Effective Soil Hydraulic Properties (ESHP) from MODIS soil moisture products and simulated the soil moisture dynamics based on the derived ESHP values. In addition, the MODIS-scale Field Capacity (FC)/Permanent Wilting Point (PWP) and Available Water Content (AWC) values, based on the Effective Soil Characteristics (ESC) converted from the derived ESHP values, were estimated to assess the soil water-holding capacity. The estimated MODIS soil moisture products matched well with the TDR (time-domain reflectometry) measurements. The good agreement between the TDR/MODIS data and soil moisture estimates demonstrates the applicability of the data assimilation scheme in deriving ESHP/ESC values. The FC/WP and AWC values based on the derived ESC values showed relatively high variations (especially for forest regions) in the spatial domain, whereas those estimated by the soil characteristics available from the Rural Development Association (RDA) showed fewer differences. It is inferred that the high variations are due to the ESC values derived from the data assimilation scheme, which considers both soil physical and environmental factors. Thus, our proposed approach can be useful for assessing the soil water-holding capacity, representing regional conditions.

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