Soil moisture responses under different vegetation types to winter rainfall events in a humid karst region

Abstract Humid karst ecosystems are fragile, with precipitation being the main source of soil moisture recharge. The process of soil moisture recharge and usage varies by vegetation type. To analyze the dynamics of soil moisture under different vegetation types during rainfall events, we continuously monitored soil moisture in arable land, grassland, shrub, and forest areas at 10-minute intervals from November 6, 2019, to January 6, 2020.The arable land was used as a control group. Soil moisture under the different vegetation types responded to light, moderate, and rainstorm events with large rainfall amounts. However, only the soil moisture in the grassland areas responded to a light rainfall event with a rainfall amount of 0.87 mm. The largest soil moisture recharge (12.63 mm) and decline (2.08%) were observed for the grassland areas, with the smallest observed for the forest areas. While the grassland areas showed the greatest decline in soil moisture following rainfall, they were more easily recharged during the winter rainfall events. Soil moisture in forests and shrubs was less recharged than in grasslands but also declined less. Therefore, forests and shrubs are better at retaining soil moisture in winter, which is informative for the formulation of a regional vegetation recovery model.

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Soil Moisture Dynamics in Response to Precipitation and Thinning in a Semi-Dry Forest in Northern Mexico

Water ◽

10.3390/w13010105 ◽

2021 ◽

Vol 13 (1) ◽

pp. 105

Author(s):

Argelia E. Rascón-Ramos ◽

Martín Martínez-Salvador ◽

Gabriel Sosa-Pérez ◽

Federico Villarreal-Guerrero ◽

Alfredo Pinedo-Alvarez ◽

...

Keyword(s):

Soil Moisture ◽

Forest Management ◽

Water Availability ◽

Dry Forest ◽

Rainfall Events ◽

Rainfall Characteristics ◽

Northern Mexico ◽

The Difference ◽

The Impact ◽

Moisture Dynamics

Understanding soil moisture behavior in semi-dry forests is essential for evaluating the impact of forest management on water availability. The objective of the study was to analyze soil moisture based in storm observations in three micro-catchments (0.19, 0.20, and 0.27 ha) with similar tree densities, and subject to different thinning intensities in a semi-dry forest in Chihuahua, Mexico. Vegetation, soil characteristics, precipitation, and volumetric water content were measured before thinning (2018), and after 0%, 40%, and 80% thinning for each micro-catchment (2019). Soil moisture was low and relatively similar among the three micro-catchments in 2018 (mean = 8.5%), and only large rainfall events (>30 mm) increased soil moisture significantly (29–52%). After thinning, soil moisture was higher and significantly different among the micro-catchments only during small rainfall events (<10 mm), while a difference was not noted during large events. The difference before–after during small rainfall events was not significant for the control (0% thinning); whereas 40% and 80% thinning increased soil moisture significantly by 40% and 53%, respectively. Knowledge of the response of soil moisture as a result of thinning and rainfall characteristics has important implications, especially for evaluating the impact of forest management on water availability.

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Influence of rainfall events on soil moisture in a typical steppe of Xilingol

Physics and Chemistry of the Earth Parts A/B/C ◽

10.1016/j.pce.2020.102964 ◽

2020 ◽

pp. 102964

Author(s):

D.A.I. Haiyan ◽

W.A.N.G. Haimei

Keyword(s):

Soil Moisture ◽

Rainfall Events ◽

Typical Steppe

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Linking soil water and solutes fluxes to soil properties and vegetation types: insights from a case-study in the high tropical Andes of Ecuador

10.5194/egusphere-egu21-7934 ◽

2021 ◽

Author(s):

Sebastián Páez-Bimos ◽

Veerle Vanacker ◽

Marcos Villacis ◽

Marlon Calispa ◽

Oscar Morales ◽

...

Keyword(s):

Soil Moisture ◽

Water Conservation ◽

Water Flux ◽

Water Fluxes ◽

Vegetation Types ◽

Tropical Andes ◽

Conservation Area ◽

Solute Fluxes ◽

Doc Concentration ◽

Water Conservation Area

The high tropical Andes ecosystem, known as p&#225;ramo, provides important hydrological services to densely populated areas in the Andean region. In order to manage these services sustainably, it is crucial to understand the biotic and abiotic processes that control both water quality and fluxes. Recent research in the p&#225;ramo highlights a knowledge gap regarding the role played by soil-vegetation interactions in controlling soil-water processes and resulting water and solute fluxes.Here, we determine the hydrological and geochemical fluxes in four soil profiles in the p&#225;ramo of the Antisana&#180;s water conservation area in northern Ecuador. Water fluxes were measured biweekly with field fluxmeters in the hydrological year Apr/2019- Mar/2020 under two contrasting vegetation types: tussock-like grass (TU) and cushion-forming plants (CU). Soil solution was collected in parallel with wick samplers and suction caps for assessing the concentrations of dissolved cations, anions and organic carbon (DOC). In addition, soil moisture was measured continuously in the upper meter of the soil profile, i.e. first three horizons (A, 2A and 2BC), using water content reflectometers. The vertical water flux in the upper meter of each soil profile was simulated using the 1D HYDRUS model. We carried out a Sobol analysis to identify sensitive soil hydraulic parameters. We then derived water fluxes by inverse modeling, based on the measured soil moisture. We validated the calculated water fluxes using the fluxmeter data. Solute fluxes were estimated by combining the water fluxes and the soil solution compositions.Our preliminary results suggest that water fluxes and DOC concentration vary under different vegetation types. The fluxmeter data from the 2A horizon indicates that the cumulative water flux under TU (2.8 - 5.7 l) was larger than under CU (0.8 &#8211; 1.1 l) during the dry season (Aug-Sep and Dec-Jan). However, the opposite trend was observed in the wet season for maximum water fluxes. Moreover, the DOC concentration in the uppermost horizon was higher under CU (47.3 &#177;2.2 mg l-1) than under TU (3.1 &#177;0.2 mg l-1) vegetation during the monitoring period. We associate the water and solute responses under different vegetation types to the contrasting soil hydro-physical and chemical properties (e.g., saturated hydraulic conductivity and organic carbon content) in the uppermost soil horizon. Our study illustrates the existence of a spatial association between vegetation types, water fluxes and solute concentrations in Antisana&#180;s water conservation area. By modelling the hydrological balance of the upper meter of the soil mantle, the water and solute fluxes will be estimated for soils with different vegetation cover.&#160;

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Inferring hillslope response under seismic loading and rainfall: A case study from the SE Carpathian, Romania

10.5194/egusphere-egu21-3276 ◽

2021 ◽

Author(s):

Vipin Kumar ◽

Léna Cauchie ◽

Anne-Sophie Mreyen ◽

Philippe Cerfontaine ◽

Mihai Micu ◽

...

Keyword(s):

Soil Moisture ◽

Slope Stability ◽

Surface Runoff ◽

Dynamic Condition ◽

Seismic Loading ◽

Seismic Stability ◽

Seismic Load ◽

Stability Evaluation ◽

Rainfall Events ◽

Year 2000

Seismic stability evaluation plays a crucial role in landslide disaster risk reduction. Related modeling also has to consider the potential influences of the rainfall on the hillslopes. This study aims at understanding the relative influence of the seismic loading and extreme cumulative rainfall on a massive active landslide in the seismically active Vrancea-Buzau region of the Romanian Carpathians (45&#176; 30' 23" N, 26&#176; 25' 05" E). This region has been subjected to more than 700 earthquakes (M>4) events with the highest magnitude of 7.2 (Mw) during the year 1960-2019. Rainfall data of the year 2000-2019 revealed the occurrence of relatively intense rainfall events, especially during the last ten years. The landslide has an aerial dimension of ~9.1 million m&#178;. It hosts the small village of Varlaam at the toe along the Bisca River. The slope (with an average gradient of 15-20&#176;) is covered by shrubs and scattered trees near its borders and is relatively barren in the central part. Shales with some intercalated sandstone layers belonging to the Miocene thrust belt constitute the rocks of the slope. &#160;&#160;A first survey involving the multi-station array and related Horizontal-to-Vertical noise Spectral Ratio (HVSR) measurements was completed in summer 2019. The findings of the HVSR were processed using the inversion process to infer the shear wave velocity distribution with depth and to detect the sliding surface of the landslide. These velocities were further used to estimate the geotechnical properties of the subsurface using the empirical equations. The HVSR based depth profiles and the Unmanned Air Vehicle based topographic information were used to take four 2D slope sections. These sections were considered for 2D discrete element modeling based stability evaluation under static and dynamic condition along with sensitivity analysis. Static simulation was used to determine the Factor of Safety (FS) using the shear strength reduction approach. Ricker wavelet was used as input seismic load in the dynamic simulation. Potential run-out and flow characteristics of the slope material were explored using the Voellmy rheology based RAMMS software. The relationship between rainfall, surface runoff, and soil moisture was also explored to understand the hydrogeological influence on slope stability.Though the slope reveals meta-stability (1.0<FS<2.0) condition under static loading, displacement in the soil reaches up to 1.5 m that further increases to 2.8 m under dynamic loading. According to the topographic characteristics of the slope and to the presence of landslide material or intact bedrock near the surface, acceleration along the slope reaches a Peak Ground Acceleration in the range of 0.6 to 1.3g. Eight extreme rainfall events (>50mm/24 hours) during the year 2000-2019 are noted to temporally coincide with enhanced surface runoff and increased soil moisture in the region. Debris flow runout modeling indicated that the slope material may attain a maximum flow height and flow velocity of 13&#177;0.8 m and 5&#177;0.5 m/sec, respectively, along the river channel.Keywords: Landslide; Earthquake; Slope stability; Runout; SE Carpathian

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Variations of deep soil moisture under different vegetation types and influencing factors in a watershed of the Loess Plateau, China

Hydrology and Earth System Sciences ◽

10.5194/hess-20-3309-2016 ◽

2016 ◽

Vol 20 (8) ◽

pp. 3309-3323 ◽

Cited By ~ 35

Author(s):

Xuening Fang ◽

Wenwu Zhao ◽

Lixin Wang ◽

Qiang Feng ◽

Jingyi Ding ◽

...

Keyword(s):

Soil Moisture ◽

Influencing Factors ◽

Loess Plateau ◽

Vegetation Restoration ◽

Native Vegetation ◽

Watershed Scale ◽

Vegetation Types ◽

Deep Soil ◽

Soil Layers ◽

Management Measures

Abstract. Soil moisture in deep soil layers is a relatively stable water resource for vegetation growth in the semi-arid Loess Plateau of China. Characterizing the variations in deep soil moisture and its influencing factors at a moderate watershed scale is important to ensure the sustainability of vegetation restoration efforts. In this study, we focus on analyzing the variations and factors that influence the deep soil moisture (DSM) in 80–500 cm soil layers based on a soil moisture survey of the Ansai watershed in Yan'an in Shanxi Province. Our results can be divided into four main findings. (1) At the watershed scale, higher variations in the DSM occurred at 120–140 and 480–500 cm in the vertical direction. At the comparable depths, the variation in the DSM under native vegetation was much lower than that in human-managed vegetation and introduced vegetation. (2) The DSM in native vegetation and human-managed vegetation was significantly higher than that in introduced vegetation, and different degrees of soil desiccation occurred under all the introduced vegetation types. Caragana korshinskii and black locust caused the most serious desiccation. (3) Taking the DSM conditions of native vegetation as a reference, the DSM in this watershed could be divided into three layers: (i) a rainfall transpiration layer (80–220 cm); (ii) a transition layer (220–400 cm); and (iii) a stable layer (400–500 cm). (4) The factors influencing DSM at the watershed scale varied with vegetation types. The main local controls of the DSM variations were the soil particle composition and mean annual rainfall; human agricultural management measures can alter the soil bulk density, which contributes to higher DSM in farmland and apple orchards. The plant growth conditions, planting density, and litter water holding capacity of introduced vegetation showed significant relationships with the DSM. The results of this study are of practical significance for vegetation restoration strategies, especially for the choice of vegetation types, planting zones, and proper human management measures.

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Soil Management by Cover Crops in Vineyards for Climate Change Adaptation

Proceedings ◽

10.3390/proceedings2019030026 ◽

2019 ◽

Vol 30 (1) ◽

pp. 26

Author(s):

Marqués ◽

Bienes ◽

Ruiz-Colmenero

Keyword(s):

Climate Change ◽

Organic Matter ◽

Soil Moisture ◽

Soil Organic Matter ◽

Climate Change Adaptation ◽

Climatic Conditions ◽

Water Infiltration ◽

Soil Conditions ◽

Grass Cover ◽

Rainfall Events

The wine captures grapes variety nature and vinification techniques, but other aspects of soil, climate and terrain are equally important for the terroir expression as a whole. Soil supplies moisture, nitrogen, and minerals. Particularly nitrogen obtained through mineralization of soil organic matter and water uptake are crucial for grape yield, berry sugar, anthocyanin and tannin concentration, hence grape quality and vineyard profitability. Different climatic conditions, which are predicted for the future, can significantly modify this relationship between vines and soils. New climatic conditions under global warming predict higher temperatures, erratic and extreme rainfall events, and drought spells. These circumstances are particularly worrisome for typical thin soils of the Mediterranean environment. This study reports the effect of permanent grass cover in vineyards to maintain or increase soil organic matter and soil moisture. The influence of natural and simulated rainfalls on soils was studied. A comparison between minimum tillage (MT) and permanent grass cover crop (GC) of the temperate grass Brachypodium distachyon was done. Water infiltration, water holding capacity, organic carbon sequestration and protection from extreme events, were considered in a sloping vineyard located in the south of Madrid, Spain. The MT is the most widely used cultivation method in the area. The tradition supports this management practice to capture and preserve water in soils. It creates small depressions that accumulate water and eventually improves water infiltration. This effect was acknowledged in summer after recent MT cultivation; however, it was only short-lived as surface roughness declined after rainfalls. Especially, intense rainfall events left the surface of bare soil sealed. Consequently, the effects depend on the season of the year. In autumn, a rainy season of the year, MT failed to enhance infiltration. On the contrary, B. distachyon acted as a physical barrier, produced more infiltration (22% increase) and fewer particles detachment, due to increased soil structure stability and soil organic matter (50% increase). The GC efficiently protected soil from high-intensity events (more than 2 mm min-1). Besides, soil moisture at 35 cm depth was enhanced with GC (9% more than tillage). On average, soil moisture in GC was not significantly different from MT. These effects of GC on soil conditions created local micro-environmental conditions that can be considered advantageous as a climate change adaptation strategy, because they improved water balance, maintained a sustainable level of soil organic matter, therefore organic nitrogen, all these factors crucial for improving wine quality.

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Combined measurement and modeling of the hydrological impact of hydraulic redistribution using CLM4.5 at eight AmeriFlux sites

Hydrology and Earth System Sciences ◽

10.5194/hess-20-2001-2016 ◽

2016 ◽

Vol 20 (5) ◽

pp. 2001-2018 ◽

Cited By ~ 13

Author(s):

Congsheng Fu ◽

Guiling Wang ◽

Michael L. Goulden ◽

Russell L. Scott ◽

Kenneth Bible ◽

...

Keyword(s):

Soil Moisture ◽

Land Surface ◽

Bowen Ratio ◽

Hydraulic Redistribution ◽

Energy Budgets ◽

Vegetation Types ◽

Ecological Processes ◽

Community Land Model ◽

Hydrological Impact ◽

The Impact

Abstract. Effects of hydraulic redistribution (HR) on hydrological, biogeochemical, and ecological processes have been demonstrated in the field, but the current generation of standard earth system models does not include a representation of HR. Though recent studies have examined the effect of incorporating HR into land surface models, few (if any) have done cross-site comparisons for contrasting climate regimes and multiple vegetation types via the integration of measurement and modeling. Here, we incorporated the HR scheme of Ryel et al. (2002) into the NCAR Community Land Model Version 4.5 (CLM4.5), and examined the ability of the resulting hybrid model to capture the magnitude of HR flux and/or soil moisture dynamics from which HR can be directly inferred, to assess the impact of HR on land surface water and energy budgets, and to explore how the impact may depend on climate regimes and vegetation conditions. Eight AmeriFlux sites with contrasting climate regimes and multiple vegetation types were studied, including the Wind River Crane site in Washington State, the Santa Rita Mesquite savanna site in southern Arizona, and six sites along the Southern California Climate Gradient. HR flux, evapotranspiration (ET), and soil moisture were properly simulated in the present study, even in the face of various uncertainties. Our cross-ecosystem comparison showed that the timing, magnitude, and direction (upward or downward) of HR vary across ecosystems, and incorporation of HR into CLM4.5 improved the model-measurement matches of evapotranspiration, Bowen ratio, and soil moisture particularly during dry seasons. Our results also reveal that HR has important hydrological impact in ecosystems that have a pronounced dry season but are not overall so dry that sparse vegetation and very low soil moisture limit HR.

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Evaluation of the Performance of SM2RAIN-Derived Rainfall Products over Brazil

Remote Sensing ◽

10.3390/rs11091113 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1113 ◽

Cited By ~ 9

Author(s):

Franklin Paredes-Trejo ◽

Humberto Barbosa ◽

Carlos A. C. dos Santos

Keyword(s):

Soil Moisture ◽

Pearson Correlation ◽

European Space Agency ◽

Rainfall Events ◽

Error Components ◽

Space Agency ◽

Daily Scale ◽

Bioclimatic Conditions ◽

Heavy Rainfall Events

Microwave-based satellite soil moisture products enable an innovative way of estimating rainfall using soil moisture observations with a bottom-up approach based on the inversion of the soil water balance Equation (SM2RAIN). In this work, the SM2RAIN-CCI (SM2RAIN-ASCAT) rainfall data obtained from the inversion of the microwave-based satellite soil moisture (SM) observations derived from the European Space Agency (ESA) Climate Change Initiative (CCI) (from the Advanced SCATterometer (ASCAT) soil moisture data) were evaluated against in situ rainfall observations under different bioclimatic conditions in Brazil. The research V7 version of the Tropical Rainfall Measurement Mission Multi-satellite Precipitation Analysis (TRMM TMPA) was also used as a state-of-the-art rainfall product with an up-bottom approach. Comparisons were made at daily and 0.25° scales, during the time-span of 2007–2015. The SM2RAIN-CCI, SM2RAIN-ASCAT, and TRMM TMPA products showed relatively good Pearson correlation values (R) with the gauge-based observations, mainly in the Caatinga (CAAT) and Cerrado (CER) biomes (R median > 0.55). SM2RAIN-ASCAT largely underestimated rainfall across the country, particularly over the CAAT and CER biomes (bias median < −16.05%), while SM2RAIN-CCI is characterized by providing rainfall estimates with only a slight bias (bias median: −0.20%), and TRMM TMPA tended to overestimate the amount of rainfall (bias median: 7.82%). All products exhibited the highest values of unbiased root mean square error (ubRMSE) in winter (DJF) when heavy rainfall events tend to occur more frequently, whereas the lowest values are observed in summer (JJA) with light rainfall events. The SM2RAIN-based products showed larger contribution of systematic error components than random error components, while the opposite was observed for TRMM TMPA. In general, both SM2RAIN-based rainfall products can be effectively used for some operational purposes on a daily scale, such as water resources management and agriculture, whether the bias is previously adjusted.

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