scholarly journals Erratum for Drivers of woody canopy water content responses to drought in the Mediterranean‐type ecosystem

2020 ◽  
Vol 30 (7) ◽  
Keyword(s):  
Water Content ◽  
Mediterranean Type Ecosystem ◽  
The Mediterranean ◽  
Canopy Water

Soil moisture variation drives canopy water content dynamics across the western U.S.

2021 ◽  
Vol 253 ◽  
pp. 112233
Author(s):  
Drew S. Lyons ◽  
Solomon Z. Dobrowski ◽  
Zachary A. Holden ◽  
Marco P. Maneta ◽  
Anna Sala
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Moisture Variation ◽  
Canopy Water ◽  
Soil Moisture Variation

scholarly journals Multimodel assessment of climate change-induced hydrologic impacts for a Mediterranean catchment

2018 ◽  
Vol 22 (7) ◽  
pp. 4125-4143 ◽  
Author(s):  
Enrica Perra ◽  
Monica Piras ◽  
Roberto Deidda ◽  
Claudio Paniconi ◽  
Giuseppe Mascaro ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Climate Models ◽  
Actual Evapotranspiration ◽  
Soil Conditions ◽  
Hydrologic Models ◽  
The Future ◽  
The Mediterranean

Abstract. This work addresses the impact of climate change on the hydrology of a catchment in the Mediterranean, a region that is highly susceptible to variations in rainfall and other components of the water budget. The assessment is based on a comparison of responses obtained from five hydrologic models implemented for the Rio Mannu catchment in southern Sardinia (Italy). The examined models – CATchment HYdrology (CATHY), Soil and Water Assessment Tool (SWAT), TOPographic Kinematic APproximation and Integration (TOPKAPI), TIN-based Real time Integrated Basin Simulator (tRIBS), and WAter balance SImulation Model (WASIM) – are all distributed hydrologic models but differ greatly in their representation of terrain features and physical processes and in their numerical complexity. After calibration and validation, the models were forced with bias-corrected, downscaled outputs of four combinations of global and regional climate models in a reference (1971–2000) and future (2041–2070) period under a single emission scenario. Climate forcing variations and the structure of the hydrologic models influence the different components of the catchment response. Three water availability response variables – discharge, soil water content, and actual evapotranspiration – are analyzed. Simulation results from all five hydrologic models show for the future period decreasing mean annual streamflow and soil water content at 1 m depth. Actual evapotranspiration in the future will diminish according to four of the five models due to drier soil conditions. Despite their significant differences, the five hydrologic models responded similarly to the reduced precipitation and increased temperatures predicted by the climate models, and lend strong support to a future scenario of increased water shortages for this region of the Mediterranean basin. The multimodel framework adopted for this study allows estimation of the agreement between the five hydrologic models and between the four climate models. Pairwise comparison of the climate and hydrologic models is shown for the reference and future periods using a recently proposed metric that scales the Pearson correlation coefficient with a factor that accounts for systematic differences between datasets. The results from this analysis reflect the key structural differences between the hydrologic models, such as a representation of both vertical and lateral subsurface flow (CATHY, TOPKAPI, and tRIBS) and a detailed treatment of vegetation processes (SWAT and WASIM).

scholarly journals Factors determining the soil available water during the last two decades (1997–2019) in southern Spain

2021 ◽  
Vol 14 (19) ◽  
Author(s):  
José A. Sillero-Medina ◽  
Jesús Rodrigo-Comino ◽  
José D. Ruiz-Sinoga
Keyword(s):  
Climate Change ◽  
Water Content ◽  
Southern Spain ◽  
Retention Capacity ◽  
Essential Information ◽  
Hydrological Conditions ◽  
Available Water ◽  
Available Water Content ◽  
The Mediterranean ◽  
The Impact

AbstractAssessing soil hydrological conditions can provide essential information for understanding the environmental processes that affect ecosystem services and, particularly in the context of ongoing climate change. This is key in areas affected by water scarcity such as the Mediterranean belt. Therefore, the main goals of this research are (i) to assess the main rainfall dynamics and trends of some representative hotspots along with southern Spain and (ii) to determine the impact on the soil available water content (AWC) over the last two decades. An analysis of daily precipitation and soil hydrological conditions was combined with soil sampling (543) and laboratory analyses to evaluate the properties related to the soil infiltration and retention capacity. The results show that the organic factors control soil properties and their hydrodynamics in southern Spain. Furthermore, a general declining trend in soil water availability is observed over the last two decades. This is more extreme in arid and semi-arid areas, where there have been several years in the last decade with more than 200 days without the available water content. Moreover, in these areas, heavy rainfall during specific moments of the year is the key factor that manifests a greater incidence in areas with steeper slopes, which in turn, also conditions the biological factors and the hydrodynamics of the soil. In short, in the context of climate change, the analysis of soil hydrological dynamics could be used to identify biodiversity thresholds in the Mediterranean area and even to detect phenological changes in specific plant species.

Inferring the effects of surface canopy water on VOD estimation from L-band backscatter 

2021 ◽  
Author(s):  
Saeed Khabbazan ◽  
Paul.C. Vermunt ◽  
Susan.C. Steele Dunne ◽  
Ge Gao ◽  
Mariette Vreugdenhil ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Linear Relationship ◽  
Water Content ◽  
Growing Season ◽  
Empirical Parameter ◽  
Vegetation Water Content ◽  
L Band ◽  
Vegetation Water ◽  
Canopy Water ◽  
Effect Of Surface

<p>Quantification of vegetation parameters such as Vegetation Optical Depth (VOD) and Vegetation Water Content (VWC) can be used for better irrigation management, yield forecasting, and soil moisture estimation. Since VOD is directly related to vegetation water content and canopy structure, it can be used as an indicator for VWC. Over the past few decades, optical and passive microwave satellite data have mostly been used to monitor VWC. However, recent research is using active data to monitor VOD and VWC benefitting from their high spatial and temporal resolution.</p><p>Attenuation of the microwave signal through the vegetation layer is parametrized by the VOD. VOD is assumed to be linearly related to VWC with the proportionality constant being an empirical parameter b. For a given wavelength and polarization, b is assumed static and only parametrized as a function of vegetation type. The hypothesis of this study is that the VOD is not similar for dry and wet vegetation and the static linear relationship between attenuation and vegetation water content is a simplification of reality.</p><p>The aim of this research is to understand the effect of surface canopy water on VOD estimation and the relationship between VOD and vegetation water content during the growing season of a corn canopy. In addition to studying the dependence of VOD on bulk VWC for dry and wet vegetation, the effect of different factors, such as different growth stages and internal vegetation water content is investigated using time series analysis.</p><p>A field experiment was conducted in Florida, USA, for a full growing season of sweet corn. The corn field was scanned every 30 minutes with a truck-mounted, fully polarimetric, L-band radar. Pre-dawn vegetation water content was measured using destructive sampling three times a week for a full growing season. VWC could therefore be analyzed by constituent (leaf, stem, ear) or by height. Meteorological data, surface canopy water (dew or interception), and soil moisture were measured every 15 minutes for the entire growing season.</p><p>The methodology of Vreugdenhil et al.  [1], developed by TU Wien for ASCAT data, was adapted to present a new technique to estimate VOD from single-incidence angle backscatter data in each polarization. The results showed that the effect of surface canopy water on the VOD estimation increased by vegetation biomass accumulation and the effect was higher in the VOD estimated from the co-pol compared with the VOD estimated from the cross-pol. Moreover, the surface canopy water considerably affected the regression coefficient values (b-factor) of the linear relationship between VOD and VWC from dry and wet vegetation. This finding suggests that considering a similar b-factor for the dry and the wet vegetation will introduce errors in soil moisture retrievals. Furthermore, it highlights the importance of considering canopy wetness conditions when using tau-omega.</p><ul><li>[1] Vreugdenhil,W. A. Dorigo,W.Wagner, R. A. De Jeu, S. Hahn, andM. J. VanMarle, “Analyzing the vegetation parameterization in the TU-Wien ASCAT soil moisture retrieval,” IEEE Transactions on Geoscience and Remote Sensing, vol. 54, pp. 3513–3531, 2016</li> </ul>

Retrieving Grassland Canopy Water Content by Considering the Information from Neighboring Pixels

2017 ◽  
Vol 83 (8) ◽  
pp. 553-565
Author(s):  
Binbin He ◽  
Xingwen Quan ◽  
Dasong Xu ◽  
Changming Yin ◽  
Zhanmang Liao ◽  
...  
Keyword(s):  
Water Content ◽  
Canopy Water

scholarly journals Lizards and rabbits may increase Chagas infection risk in the Mediterranean-type ecosystem of South America

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Esteban San Juan ◽  
Raúl Araya-Donoso ◽  
Alejandra Sandoval-Rodríguez ◽  
Andrea Yáñez-Meza ◽  
Nicol Quiroga ◽  
...  
Keyword(s):  
South America ◽  
Infection Risk ◽  
Mediterranean Type Ecosystem ◽  
The Mediterranean

scholarly journals Testing the Relevance of Daily MODIS Data to Monitor Mediterranean Shrubland Canopy Water Content with Temporal Cross-Correlation Analyses

2013 ◽  
Vol 4 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Carole Delenne ◽  
Jean-Stéphane Bailly ◽  
Michel Deshayes
Keyword(s):  
Water Content ◽  
Forest Fire ◽  
Fire Hazard ◽  
Statistical Tests ◽  
Delay Effect ◽  
Field Surveys ◽  
Modis Data ◽  
Mediterranean Shrubland ◽  
Canopy Water ◽  
Water Indices

Drought alert systems for forest fire prevention often rely on vegetation water content (VWC) monitoring which is a key parameter in forest fire hazard. In southern France, VWC is now monitored through regular field surveys. Thanks to the theoretical sensitivity of shortwave infrared reflectance to VWC, MODIS satellite data are potentially able to monitor VWC depending on plant species VWC magnitude. In this paper, a specific statistical approach based on temporal cross-correlations is developed in order to test the correlation between two MODIS water indices and VWC measurements coming from field surveys. This test assesses the ability of daily MODIS data to monitor Mediterranean shrubland canopy water content and detect any delay effect between MODIS and field survey temporal series. Statistical tests are carried out for 29 sites containing 18 dominant shrubland Mediterranean species. 67% and 54% of significant correlation were found using respectively the NDII and NDWI indices from MODIS data. Correlation were found low with a dominant negative delay effect, i.e., with a MODIS signal that reacts a few days after the field VWC. Test results show that, even if deeper pre-processing of MODIS data may be required, site soil, site vegetation cover, and heterogeneity at MODIS pixel scale, as well as species VWC sensitivity make correlation between field VWC and MODIS water indices non univoque and highly variable. Many obstacles are still to overcome, for an accurate monitoring of Mediterranean shrubland canopy water content using MODIS daily data.

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