Studies on the Forest Dieback Phenomenon in a Semi-Arid Region Using Remotely Sensed Data

This paper presents a technique for the mapping of soil moisture and irrigation, at the scale of agricultural fields, based on the synergistic interpretation of multi-temporal optical and Synthetic Aperture Radar (SAR) data (Sentinel-2 and Sentinel-1). The Kairouan plain, a semi-arid region in central Tunisia (North Africa), was selected as a test area for this study. Firstly, an algorithm for the direct inversion of the Water Cloud Model (WCM) was developed for the spatialization of the soil water content between 2015 and 2017. The soil moisture retrieved from these observations was first validated using ground measurements, recorded over 20 reference fields of cereal crops. A second method, based on the use of neural networks, was also used to confirm the initial validation. The results reported here show that the soil moisture products retrieved from remotely sensed data are accurate, with a Root Mean Square Error (RMSE) of less than 5% between the two moisture products. In addition, the analysis of soil moisture and Normalized Difference Vegetation Index (NDVI) products over cultivated fields, as a function of time, led to the classification of irrigated and rainfed areas on the Kairouan plain, and to the production of irrigation maps at the scale of individual fields. This classification is based on a decision tree approach, using a combination of various statistical indices of soil moisture and NDVI time series. The resulting irrigation maps were validated using reference fields within the study site. The best results were obtained with classifications based on soil moisture indices only, with an accuracy of 77%.

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From hillslope to catchment scale hydrologic prediction in a semi-arid region with in-situ observations, satellite soil moisture products, and a distributed catchment model

10.5194/egusphere-egu2020-21765 ◽

2020 ◽

Author(s):

In-Young Yeo ◽

Ali Binesh ◽

Garry Willgoose ◽

Greg Hancock ◽

Omer Yeteman

Keyword(s):

Soil Moisture ◽

Arid Region ◽

Remotely Sensed ◽

Hydrologic Model ◽

Model Parameters ◽

Limited Region ◽

Semi Arid Region ◽

Catchment Model ◽

Semi Arid

The water-limited region frequently experiences extreme climate variability.&#160; This region, however, has relatively little hydrological information to characterize the catchment dynamics and its feedback to the climate system. This study assesses the relative benefits of using remotely sensed soil moisture, in addition to sparsely available in-situ soil moisture and stream flow observations, to improve the hydrologic understanding and prediction.&#160; We propose a multi-variable approach to calibrate a hydrologic model, Soil and Water Assessment Tool (SWAT), a semi-distributed, continuous catchment model, with observed streamflow and in-situ soil moisture.&#160; The satellite soil moisture products (~ 5 cm top soil) from the Soil Moisture and Ocean Salinity (SMOS) and the Soil Moisture Active Passive (SMAP) are then used to evaluate the model estimates of soil moisture over the spatial scales through time.&#160; The results show the model calibrated against streamflow only could provide misleading prediction for soil moisture. &#160;Long term in-situ soil moisture observations, albeit limited availability, are crucial to constrain model parameters leading to improved soil moisture prediction at the given site.&#160; Satellite soil moisture products provide useful information to assess simulated soil moisture results across the spatial domains, filling the gap on the soil moisture information at landscape scales. The preliminary results from this study suggest the potential to produce robust soil moisture and streamflow estimates across scales for a semi-arid region, using a distributed catchment model with in-situ soil network and remotely sensed observations and enhance the overall water budget estimations for multiple hydrologic variables across scales.&#160; This research is conducted on Merriwa catchment, a semi-arid region located in the Upper Hunter Region of NSW, Australia.

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Microtopographical Characteristics of Forest Dieback in a Semi-Arid Region Retrieved from Ground and Satellite Data

10.1109/igarss47720.2021.9554115 ◽

2021 ◽

Author(s):

Buho Hoshino ◽

Daishi Matsukawa ◽

Takashi Sasamura ◽

Tserendulam Tserenochir ◽

Uuganbayar Ganbold ◽

...

Keyword(s):

Satellite Data ◽

Arid Region ◽

Forest Dieback ◽

Semi Arid Region ◽

Semi Arid

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Aerosol iron solubility in a semi-arid region: temporal trend and impact of anthropogenic sources

Tellus B ◽

10.3402/tellusb.v62i2.16519 ◽

2010 ◽

Vol 62 (2) ◽

Author(s):

Ashwini Kumar ◽

M. M. Sarin

Keyword(s):

Arid Region ◽

Temporal Trend ◽

Anthropogenic Sources ◽

Iron Solubility ◽

Semi Arid Region ◽

Semi Arid

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The Molecular Characterization and Biological Assessment of the Leaves Extracts of Loofah Reveal their Nutraceutical Potential

Recent Patents on Food Nutrition & Agriculturee ◽

10.2174/2212798411999201110211931 ◽

2020 ◽

Vol 11 ◽

Author(s):

Takoua Ben Hlel ◽

Feten Belhadj ◽

Fatih Gül ◽

Muhammed Altun ◽

Ayşe Şahin Yağlıoğlu ◽

...

Keyword(s):

Fatty Acids ◽

Phenolic Compounds ◽

Hela Cell ◽

Arid Region ◽

Biological Properties ◽

Biological Assessment ◽

Omega 3 ◽

Hela Cell Lines ◽

Semi Arid Region ◽

Semi Arid

Background:: Luffa cylindrica is a plant that is widely distributed in Africa and Asia and it can be grown in regions with tropical or subtropical climates. Few patents dealt with Loofah biological properties, including some functional foods formulated from its leaves. Objective:: This study aimed to structurally and functionally characterize the bioactive compounds of L. cylindrica leaves grown in two different environments. Methods:: The extracts of L. cylindrica leaves collected from two Tunisian locations: Essouasi (LE), a semi-arid region and Medenine (LM) an arid region, were investigated for their phenolic compounds and fatty acids using HPLC/TOF-MS and GCMS techniques respectively. Furthermore, the antioxidant capacity was evaluated with DPPH, Chelating effect, Hydroxyl radical and Superoxide anion scavenging activities while the anticancer activity against HeLa cell lines was assessed using xCELLigence real time cell analyzer and lactate dehydrogenase cytotoxicity assay. Results:: The antiproliferative capacity of both extracts was time and dose-dependent with LE presenting the lowest HeLa cell index (CI = 0.035 ± 0.018, 250 μg/ml). LE also showed the best cytotoxic capacity (56.49 ± 0.8%) and antioxidant potential (IC50 = 54.41 ± 1.12 μg/ml for DPPH and 12.12 ± 0.07 μg/ml for chelating effet). 14 phenolic compounds were detected in LE with ferulic acid being the major compound (5128.5 ± 4.09 μg Phenols/g) while LM had only 6 phenolics. GCMS analysis showed the presence of omega-3 fatty acids in LE. Conclusions:: Our findings suggest that L. cylindrica leaves, especially when collected from semi-arid regions, are promising for formulating nutraceuticals of interest.

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Space-time monitoring of soil organic carbon content across a semi-arid region of Australia

Geoderma Regional ◽

10.1016/j.geodrs.2021.e00367 ◽

2021 ◽

Vol 24 ◽

pp. e00367

Author(s):

Patrick Filippi ◽

Stephen R. Cattle ◽

Matthew J. Pringle ◽

Thomas F.A. Bishop

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Content ◽

Arid Region ◽

Space Time ◽

Organic Carbon Content ◽

Soil Organic Carbon Content ◽

Semi Arid Region ◽

Semi Arid

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An investigation of the relationship between surface albedo and urban cover types in a semi-arid region

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1067/1/012021 ◽

2021 ◽

Vol 1067 (1) ◽

pp. 012021

Author(s):

Mustafa N Hamoodi ◽

Zainab R Mahdi

Keyword(s):

Arid Region ◽

Surface Albedo ◽

Semi Arid Region ◽

The Relationship ◽

Semi Arid

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Effect of Temperature on Sowing Dates of Wheat under Arid and Semi-Arid Climatic Regions and Impact Quantification of Climate Change through Mechanistic Modeling with Evidence from Field

Atmosphere ◽

10.3390/atmos12070927 ◽

2021 ◽

Vol 12 (7) ◽

pp. 927

Author(s):

Jamshad Hussain ◽

Tasneem Khaliq ◽

Muhammad Habib ur Rahman ◽

Asmat Ullah ◽

Ishfaq Ahmed ◽

...

Keyword(s):

Climate Change ◽

Grain Yield ◽

Arid Region ◽

Field Experiments ◽

Climatic Conditions ◽

Seasonal Temperature ◽

Sowing Dates ◽

Rcp 8.5 ◽

Semi Arid Region ◽

Semi Arid

Rising temperature from climate change is the most threatening factor worldwide for crop production. Sustainable wheat production is a challenge due to climate change and variability, which is ultimately a serious threat to food security in Pakistan. A series of field experiments were conducted during seasons 2013–2014 and 2014–2015 in the semi-arid (Faisalabad) and arid (Layyah) regions of Punjab-Pakistan. Three spring wheat genotypes were evaluated under eleven sowing dates from 16 October to 16 March, with an interval of 14–16 days in the two regions. Data for the model calibration and evaluation were collected from field experiments following the standard procedures and protocols. The grain yield under future climate scenarios was simulated by using a well-calibrated CERES-wheat model included in DSSAT v4.7. Future (2051–2100) and baseline (1980–2015) climatic data were simulated using 29 global circulation models (GCMs) under representative concentration pathway (RCP) 8.5. These GCMs were distributed among five quadrants of climatic conditions (Hot/Wet, Hot/Dry, Cool/Dry, Cool/Wet, and Middle) by a stretched distribution approach based on temperature and rainfall change. A maximum of ten GCMs predicted the chances of Middle climatic conditions during the second half of the century (2051–2100). The average temperature during the wheat season in a semi-arid region and arid region would increase by 3.52 °C and 3.84 °C, respectively, under Middle climatic conditions using the RCP 8.5 scenario during the second half-century. The simulated grain yield was reduced by 23.5% in the semi-arid region and 35.45% in the arid region under Middle climatic conditions (scenario). Mean seasonal temperature (MST) of sowing dates ranged from 16 to 27.3 °C, while the mean temperature from the heading to maturity (MTHM) stage was varying between 12.9 to 30.4 °C. Coefficients of determination (R2) between wheat morphology parameters and temperature were highly significant, with a range of 0.84–0.96. Impacts of temperature on wheat sown on 15 March were found to be as severe as to exterminate the crop before heading. The spikes and spikelets were not formed under a mean seasonal temperature higher than 25.5 °C. In a nutshell, elevated temperature (3–4 °C) till the end-century can reduce grain yield by about 30% in semi-arid and arid regions of Pakistan. These findings are crucial for growers and especially for policymakers to decide on sustainable wheat production for food security in the region.

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