Advancing NASA’s AirMOSS P-Band Radar Root Zone Soil Moisture Retrieval Algorithm via Incorporation of Richards’ Equation

The role of soil moisture is widely accepted as a significant factor in the mass and energy balance of catchments as a controller in surface and subsurface runoff generation. The paper examines the potential of a new dataset based on advanced scatterometer satellite remote sensing of soil moisture (ASCAT) for multiple objective calibrations of a dual-layer, conceptual, semi-distributed hydrological model. The surface and root zone soil moisture indexes based on ASCAT data were implemented into calibration of the hydrological model. Improvements not only in the instrument specifications, i.e., better temporal and spatial sampling, but also in the higher radiometric accuracy and retrieval algorithm, were applied. The analysis was performed in 209 catchments situated in different physiographic and climate zones of Austria for the period 2007–2018. We validated the model for two validation periods. The results show that multiple objective calibrations have a substantial positive effect on constraining the model parameters. The combined use of soil moisture and discharges in the calibration improved the soil moisture simulation in more than 73% of the catchments, except for the catchments with higher forest cover percentages. Improvements also occurred in the runoff model efficiency, in more than 27% of the catchments, mostly in the watersheds with a lower mean elevation and a higher proportion of farming land use, as well as in the Alpine catchments where the runoff is not significantly influenced by snowmelt and glacier runoff.

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Derivation of a root zone soil moisture algorithm and its application to validate model data

Hydrology Research ◽

10.2166/nh.2005.0026 ◽

2005 ◽

Vol 36 (4-5) ◽

pp. 335-348 ◽

Cited By ~ 1

Author(s):

Ralf Lindau ◽

Clemens Simmer

Keyword(s):

Soil Moisture ◽

Soviet Union ◽

Former Soviet Union ◽

Root Zone ◽

Climate Simulation ◽

Second Step ◽

Retrieval Algorithm ◽

Calibration Data ◽

Vegetation Density ◽

Radiation Measurements

A retrieval algorithm for soil moisture within the uppermost metre of soil is presented. As calibration data, longtime soil moisture measurements from the former Soviet Union are used. The retrieval works in two steps. First, the distribution of longtime mean soil moisture is derived by using precipitation, soil texture, vegetation density and terrain slope. In a second step, the temporal variability at each location is deduced by using microwave radiation measurements available from satellite together with precipitation and air temperature data. This soil moisture algorithm is applied in Northern and Central Europe to validate a climate simulation from the regional model REMO.

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A statistical retrieval algorithm for root zone soil moisture

Theoretical and Applied Climatology ◽

10.1007/s00704-009-0227-5 ◽

2009 ◽

Vol 118 (4) ◽

pp. 675-694

Author(s):

Ralf Lindau ◽

Clemens Simmer

Keyword(s):

Soil Moisture ◽

Root Zone ◽

Retrieval Algorithm

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Advancing the AirMOSS P-Band Radar Root Zone Soil Moisture Retrieval Algorithm via Incorporation of Richards’ Equation

10.20944/preprints201608.0237.v1 ◽

2016 ◽

Author(s):

Morteza Sadeghi ◽

Alireza Tabatabaeenejad ◽

Markus Tuller ◽

Mahta Moghaddam ◽

Scott B. Jones

Keyword(s):

Soil Moisture ◽

Unsaturated Flow ◽

Root Zone ◽

Second Order ◽

Moisture Distribution ◽

Retrieval Algorithm ◽

Mathematical Function ◽

Moisture Profile ◽

Order Polynomial ◽

Free Parameters

P-band radar remote sensing applied during the Airborne Microwave Observatory of Subcanopy and Subsurface (AirMOSS) mission has shown great potential for estimation of root zone soil moisture. When retrieving the soil moisture profile (SMP) from P-band radar, a mathematical function describing the vertical moisture distribution is required. Because only a limited number of observations are available, the number of free parameters of the mathematical model must not exceed the number of observed data. For example, a second order polynomial that contains 3 free parameters was presumed based on in-situ SMP data. The polynomial is currently parameterized based on 3 backscatter observations provided by AirMOSS (i.e. one frequency at three polarizations of HH, VV and HV). In this paper, a more realistic, physically-based SMP model containing 3 free parameters is derived based on a solution to Richards’ equation for unsaturated flow in soils. Evaluation of the new SMP model based on both numerical simulations and measured data revealed that it exhibits greater flexibility for fitting measured and simulated SMPs than the currently applied polynomial. It is also demonstrated that the new SMP model can be reduced to a second order polynomial at the expense of fitting accuracy.

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ВОДНЫЙ РЕЖИМ ОРОШАЕМЫХ СОЛОНЦОВЫХ КОМПЛЕКСНЫХ ПОЧВ И ОСОБЕННОСТИ ЕГО РЕГУЛИРОВАНИЯ

Nacional`naia bezopasnost` Rossii: aktual`nye aspekty: sbornik izbrannyh statei Vserossiiskoi nauchno-prakticheskoi konferencii (Sankt-Peterburg, Mart 2020) ◽

10.37539/nb184.2020.13.43.005 ◽

2020 ◽

Author(s):

Valery Yashin

Keyword(s):

Soil Moisture ◽

Ground Water ◽

Irrigation Water ◽

Surface Runoff ◽

Root Zone ◽

Irrigation Methods ◽

Salt Flats

Представлены материалы исследований формирования режима влажности и динамики грунтовых вод орошаемых солонцовых комплексных почв при различных способах полива, проведенные в Волгоградском Заволжье. Установлена значительная неравномерность распределения влажности почвы при поливах дождеванием. Отмечается поверхностный сток по микрорельефу до 30% от поливной нормы, что приводит к недостаточности увлажнения корневой зоны на солонцах и переувлажнению почв в понижениях микрорельефа и потере оросительной воды на инфильтрационное питание грунтовых вод.The article presents the materials of research on the formation of the humidity regime and dynamics of ground water of irrigated saline complex soils under various irrigation methods, conducted in the Volgograd Zavolzhye. A significant unevenness in the distribution of soil moisture during irrigation with sprinkling has been established. There is a surface runoff on the microrelief of up to 30% of the irrigation norm, which leads to insufficient moisture of the root zone on the salt flats and waterlogging of the soil in the microrelief depressions and loss of irrigation water for infiltration feed of ground water.

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Insulative effect of plastic mulch systems and comparison between the effects of different plant types

Open Agriculture ◽

10.1515/opag-2020-0028 ◽

2020 ◽

Vol 5 (1) ◽

pp. 317-324

Author(s):

Kayla Snyder ◽

Christopher Murray ◽

Bryon Wolff

Keyword(s):

Soil Moisture ◽

Root Zone ◽

Plastic Mulch ◽

Root Zone Temperature ◽

Tomato Plants ◽

Black Film ◽

Black And White ◽

Mulch Film ◽

Mulch Films ◽

Zone Temperature

AbstractTo address agricultural needs of the future, a better understanding of plastic mulch film effects on soil temperature and moisture is required. The effects of different plant type and mulch combinations were studied over a 3.5-month period to better grasp the consequence of mulch on root zone temperature (RZT) and moisture. Measurements of (RZT) and soil moisture for tomato (Solanum lycopersicum), pepper (Capsicum annuum) and carrot (Daucus carota) grown using polyolefin mulch films (black and white-on-black) were conducted in Ontario using a plot without mulch as a control. Black mulch films used in combination with pepper and carrot plants caused similar RZTs relative to uncovered soil, but black mulch film in combination with tomato plants caused a reduction in RZT relative to soil without mulch that increased as plants grew and provided more shade. White-on-black mulch film used in combination with tomatoes, peppers or carrots led to a reduction in RZT relative to soil without mulch that became greater than the temperature of soil without mulch. This insulative capability was similarly observed for black mulch films used with tomato plants. Apart from white-on-black film used in combination with tomatoes, all mulch film and plant combinations demonstrated an ability to stabilize soil moisture relative to soil without mulch. RZT and soil moisture were generally stabilized with mulch film, but some differences were seen among different plant types.

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Anthropogenic warming and intraseasonal summer monsoon variability amplify the risk of future flash droughts in India

npj Climate and Atmospheric Science ◽

10.1038/s41612-020-00158-3 ◽

2021 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Vimal Mishra ◽

Saran Aadhar ◽

Shanti Shwarup Mahto

Keyword(s):

Soil Moisture ◽

Summer Monsoon ◽

Crop Production ◽

Monsoon Rainfall ◽

Root Zone ◽

Monsoon Season ◽

Intraseasonal Variability ◽

Positive Temperature ◽

Groundwater Abstraction ◽

Increased Risk

AbstractFlash droughts cause rapid depletion in root-zone soil moisture and severely affect crop health and irrigation water demands. However, their occurrence and impacts in the current and future climate in India remain unknown. Here we use observations and model simulations from the large ensemble of Community Earth System Model to quantify the risk of flash droughts in India. Root-zone soil moisture simulations conducted using Variable Infiltration Capacity model show that flash droughts predominantly occur during the summer monsoon season (June–September) and driven by the intraseasonal variability of monsoon rainfall. Positive temperature anomalies during the monsoon break rapidly deplete soil moisture, which is further exacerbated by the land-atmospheric feedback. The worst flash drought in the observed (1951–2016) climate occurred in 1979, affecting more than 40% of the country. The frequency of concurrent hot and dry extremes is projected to rise by about five-fold, causing approximately seven-fold increase in flash droughts like 1979 by the end of the 21st century. The increased risk of flash droughts in the future is attributed to intraseasonal variability of the summer monsoon rainfall and anthropogenic warming, which can have deleterious implications for crop production, irrigation demands, and groundwater abstraction in India.

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Enhanced Estimation of Root Zone Soil Moisture at 1 km Resolution Using SMAR Model and MODIS-Based Downscaled AMSR2 Soil Moisture Data

Sensors ◽

10.3390/s21155211 ◽

2021 ◽

Vol 21 (15) ◽

pp. 5211

Author(s):

Maedeh Farokhi ◽

Farid Faridani ◽

Rosa Lasaponara ◽

Hossein Ansari ◽

Alireza Faridhosseini

Keyword(s):

Soil Moisture ◽

Prediction Models ◽

Surface Soil ◽

Root Zone ◽

Analytical Relationship ◽

Moisture Profile ◽

Essential Variable ◽

Potential Benefits ◽

Spatio Temporal ◽

Hydrological Prediction

Root zone soil moisture (RZSM) is an essential variable for weather and hydrological prediction models. Satellite-based microwave observations have been frequently utilized for the estimation of surface soil moisture (SSM) at various spatio-temporal resolutions. Moreover, previous studies have shown that satellite-based SSM products, coupled with the soil moisture analytical relationship (SMAR) can estimate RZSM variations. However, satellite-based SSM products are of low-resolution, rendering the application of the above-mentioned approach for local and pointwise applications problematic. This study initially attempted to estimate SSM at a finer resolution (1 km) using a downscaling technique based on a linear equation between AMSR2 SM data (25 km) with three MODIS parameters (NDVI, LST, and Albedo); then used the downscaled SSM in the SMAR model to monitor the RZSM for Rafsanjan Plain (RP), Iran. The performance of the proposed method was evaluated by measuring the soil moisture profile at ten stations in RP. The results of this study revealed that the downscaled AMSR2 SM data had a higher accuracy in relation to the ground-based SSM data in terms of MAE (↓0.021), RMSE (↓0.02), and R (↑0.199) metrics. Moreover, the SMAR model was run using three different SSM input data with different spatial resolution: (a) ground-based SSM, (b) conventional AMSR2, and (c) downscaled AMSR2 products. The results showed that while the SMAR model itself was capable of estimating RZSM from the variation of ground-based SSM data, its performance increased when using downscaled SSM data suggesting the potential benefits of proposed method in different hydrological applications.

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