Determination of crop evapotranspiration of table grapes in a semi-arid region of Northwest Mexico using multi-spectral vegetation index

2013 ◽  
Vol 122 ◽  
pp. 12-19 ◽  
Author(s):  
S. Er-Raki ◽  
J.C. Rodriguez ◽  
J. Garatuza-Payan ◽  
C.J. Watts ◽  
A. Chehbouni
Keyword(s):  
Arid Region ◽  
Vegetation Index ◽  
Crop Evapotranspiration ◽  
Table Grapes ◽  
Northwest Mexico ◽  
Semi Arid Region ◽  
Semi Arid

scholarly journals Soil Moisture and Irrigation Mapping in A Semi-Arid Region, Based on the Synergetic Use of Sentinel-1 and Sentinel-2 Data

2018 ◽  
Vol 10 (12) ◽  
pp. 1953 ◽  
Author(s):  
Safa Bousbih ◽  
Mehrez Zribi ◽  
Mohammad El Hajj ◽  
Nicolas Baghdadi ◽  
Zohra Lili-Chabaane ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Arid Region ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Cloud Model ◽  
Remotely Sensed Data ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Sentinel 2 ◽  
Reference Fields

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%.

scholarly journals Drivers and Environmental Impacts of Vegetation Greening in a Semi-Arid Region of Northwest China since 2000

2021 ◽  
Vol 13 (21) ◽  
pp. 4246
Author(s):  
Zhenzong Wu ◽  
Jian Bi ◽  
Yifei Gao
Keyword(s):  
Arid Region ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Agricultural Practices ◽  
Northwest China ◽  
Terrestrial Vegetation ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Dynamics Of Vegetation

The dynamics of terrestrial vegetation have changed a lot due to climate change and direct human interference. Monitoring these changes and understanding the mechanisms driving them are important for better understanding and projecting the Earth system. Here, we assessed the dynamics of vegetation in a semi-arid region of Northwest China for the years from 2000 to 2019 through satellite remote sensing using Vegetation Index (VI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS), and analyzed the interannual covariation between vegetation and three climatic factors—air temperature, precipitation, and vapor pressure deficit (VPD)—at nine meteorological stations. The main findings of this research are: (1) herbaceous land greened up much more than forests (2.85%/year vs. 1.26%/year) in this semi-arid region; (2) the magnitudes of green-up for croplands and grasslands were very similar, suggesting that agricultural practices, such as fertilization and irrigation, might have contributed little to vegetation green-up in this semi-arid region; and (3) the interannual dynamics of vegetation at high altitudes in this region correlate little with temperature, precipitation, or VPD, suggesting that factors other than temperature and moisture control the interannual vegetation dynamics there.

scholarly journals ECOLOGIA DE PEIXES DE RIACHOS INTERMITENTES

2021 ◽  
Vol 25 (02) ◽  
pp. 605-619
Author(s):  
Bianca de Freitas Terra ◽  
◽  
Elvio Sergio Figueredo Medeiros ◽  
Jorge Iván Sánchez Botero ◽  
José Luis Costa Novaes ◽  
...  
Keyword(s):  
Arid Region ◽  
Riparian Vegetation ◽  
Hydrological Cycle ◽  
Future Research ◽  
Intermittent Streams ◽  
Species Introduction ◽  
The Past ◽  
Semi Arid Region ◽  
Semi Arid

The ecology of fish from intermittent streams in the Brazilian semi-arid region is still little known. In the past twenty years, the number of researchers dedicated to this topic has increased considerably. However, significant gaps still exist when compared to the perennial streams of other regions of Brazil. Questions that address seasonal variations come up against the determination of capture methods and techniques that are efficient in the different phases of the hydrological cycle. In addition, techniques widely used in perennial systems, such as electrofishing, in most cases, have not been effective. Aspects related to biology, physiology, behavior, functional and taxonomic ecology of fish still need to be investigated taking into account seasonal and spatial scale variations. In view of the growing transformation imposed on the Brazilian semi-arid region by the extensive use of natural resources and by climate change, aquatic environments and their biodiversity are threatened by the transformation of riparian vegetation, the sewage release, the species introduction, the modification of its course and artificial perennialization. Thus, we will present and discuss, in this paper, the studies developed on the ecology of fish in the intermittent streams of the Brazilian semi-arid region and the gaps and challenges to be faced by future research.

scholarly journals Usefulness of class A Pan coefficient models for computation of reference evapotranspiration for a semi-arid region

MAUSAM ◽  
2021 ◽  
Vol 65 (4) ◽  
pp. 521-528
Author(s):  
PK SINGH ◽  
SK PATEL ◽  
P JAYSWAL ◽  
SS CHINCHORKAR
Keyword(s):  
Arid Region ◽  
Reference Evapotranspiration ◽  
Accurate Determination ◽  
Climatic Conditions ◽  
Gujarat State ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Statistical Criteria ◽  
Agricultural Organization

The reliability of estimates of reference evapotranspiration (ET0) using pan evaporation (Epan) depends on the accurate determination of pan coefficients (Kpan). Six ET0 models were evaluated for their usefulness using 33-year climatological dataset of a semi-arid region of the Gujarat state of India. The equations compared include Cuenca (1989), Allen and Pruitt (1991), Snyder (1992), Modified Snyder (Grismer et al., 2002), Orang (1998), and Pereira et al. (1995). The ET0 data, calculated using daily Kpan values from these equations, were compared to the Food and Agricultural Organization (FAO)-Penman-Monteith (FAO56-PM) method as a reference. Based on the visual comparison as well as from the statistical criteria, ET0 values computed using Modified Snyder and Orang model have very close agreement with the FAO56-PM method for daily, monthly, and annual estimates as compared to other approaches. The sequential performances of the explored models was found as: Modified Snyder (Eqn. 5) > Orang (Eqn. 6) > Cuenca Eqn. (2) > Allen & Pruitt (Eqn. 3) > Snyder (Eqn. 4) > Pereira et al. (Eqn. 7) model. Therefore, the Modified Snyder model (Grismer et al., 2002) could be recommended as the best model for ET0 computations under these prevailing climatic conditions for a semi arid region.

scholarly journals A relação entre litogia e morfologia das encostas das montanhas Tucson, Arizona

2008 ◽  
Vol 31 (1) ◽  
pp. 30-42
Author(s):  
Kamel Khanchoul ◽  
Robert Altschul
Keyword(s):  
Arid Region ◽  
Structural Characteristics ◽  
Size Analysis ◽  
Slope Length ◽  
Mountain Front ◽  
Semi Arid Region ◽  
The Relationship ◽  
Semi Arid

The relationship between lithology and slope morphology is investigated at eight sites on granitic, andesitic, and sedimentary hillslopes in the Tucson Mountains, Arizona. Several methods are used in the study. Topographic profiles are constructed. Skewness indices, slope length, and mean slope angles of the different slope profiles are computed and compared with each other. Debris size analysis has permitted for some profiles, the determination of hillfront/piedmont junctions. The nature and structural characteristics of the bedrock are the ones that determine the hillslope morphology in this semi-arid region. There are, as a matter of fact, variations in profiles on the same bedrock nature but differently exposed. More precise morphologic studies have been also done in comparing the different lithologic pairs. They have permitted to show some similarities in shapes. The granitic-andesitic slopes and andesiic-sedimentary slopes are the best comparisons which show the relationship between lithology and slope morphology. The granitic-sedimentary slope relationship is shown in the hillfront concavities, mountain front and piedmont mean slope angles.

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