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2021 ◽  
Vol 6 (24) ◽  
pp. 213-225
Author(s):  
Shazad Jamal Jalal ◽  
Tajul Ariffin Musa ◽  
Ami Hassan Md Din ◽  
Wan Anom Wan Aris

Gravity data and computing gravity anomalies are regarded as vital for both geophysics and physical geodesy fields. The mountainous areas of Iraq are characterized by the lack of regional gravity data because gravity surveys are rarely performed in the past four decades due to the Iraq-Iran war and the internal unstable political situation of this particular region. In addition, the formal map of the available terrestrial gravity which was published by the French Database of Bureau Gravimetrique International (International Gravimetric Bureau-in English) (BGI), introduces Iraq and the study area as a remote area and in white color because of the unavailability of gravity data. However, a dense and local (not regional) gravity data is available which was conducted by geophysics researchers 13 years ago. Therefore, the regional gravity survey of 160 gravity points was performed by the authors at an average 11 km apart, which was covers the whole area of Sulaymaniyah Governorate (part of the mountainous areas of Iraq). In spite of Although the risk of mine fields within the study area, suitable safe routes as well as a helicopter was used for the gravity survey of several points on the top of mountains. The survey was conducted via Lacoste and Romberg geodetic gravimeter and GPS handheld. The objective of the study is to determine and map the gravity anomalies for the entire study area, the data of which would assist different geosciences applications.


2021 ◽  
Vol 2 (1) ◽  
pp. 47-60
Author(s):  
Ousséni AROUNA ◽  
◽  
Issiaka SARE WARA ◽  
DJAOUGA Mama ◽  
ZAKARI Soufouyane ◽  
...  

La cartographie du stock de carbone permet d’enrichir les connaissances mais aussi la comparaison des diverses transformations du couvert végétal sur l’évolution du stock. La présente recherche vise à cartographier la variabilité spatiale du stock de carbone forestier dans la Réserve de Biosphère Transfrontalière du W au Nord-Bénin. Le modèle de régression non linéaire a permis de prédire la distribution spatiale de la biomasse et du carbone à partir des valeurs de NDVI. Il résulte de cette méthode que la biomasse totale produite dans les unités de végétation de la RBTW a été estimée à 39 988 935,73 tonnes. La quantité totale de carbone correspondante est de 19 474 611,70 tonnes. Concernant la quantité de dioxyde de carbone accumulée, elle a été évaluée à 71 471 824,94 tonnes. Par ailleurs, la quantité de biomasse estimée par placeau oscille entre 2,71 et 172,82 t/ha. Le potentiel de séquestration de carbone dans les savanes boisées et arborées fait respectivement 1,81 et 1,24 fois celui enregistré en moyenne dans la RBTW. Les savanes arbustives et les friches sont les unités qui piègent le moins de dioxyde de carbone soit 18 % et 2 % du total de CO2. Sur l’ensemble du secteur d’étude, la quantité de carbone enregistrée varie de 35,80 à 54,32 t/ha avec une moyenne de 41,24 ± 4,08 t/ha. La quantité moyenne dans le Parc est de 40,42 ± 2,85 t/ha alors qu’elle est de 41,95 ± 4,78 t/ha pour la périphérie. La distribution spatiale de la biomasse et du carbone montre que les fortes quantités de biomasse et de carbone sont enregistrées particulièrement au sud-ouest de la RBTW. Mapping of carbon stock allows for a better understanding but also for the comparison of various vegetation cover transformations on the evolution of the stock. The present research aims to map the spatial variability of forest carbon stock in the W Transboundary Biosphere Reserve in northern Benin. The non-linear regression model was used to predict the spatial distribution of biomass and carbon from NDVI. As a result of this method, the total biomass produced in the RBTW vegetation units was estimated to be 39,988,935.73 tons. The corresponding total amount of carbon is 19,474,611.70 tons. Regarding the amount of carbon dioxide accumulated, it was estimated at 71,471,824.94 tons. Furthermore, the estimated amount of biomass per plot varies between 2.71 and 172.82 t/ha. The carbon sequestration potential of these two units in woodlands and shrub savannahs is respectively 1.81 and 1.24 times that recorded on average in the RBTW. Shrub savannahs and wastelands are the units that sequestrate the least carbon dioxide at 18% and 2% of total CO2. Over the entire study area, the amount of carbon recorded ranges from 35.80 to 54.32 t/ha with an average of 41.24 ± 4.08 t/ha. The average amount in the Park is 40.42 ± 2.85 t/ha while it is 41.95 ± 4.78 t/ha for the periphery. The spatial distribution of biomass and carbon shows that high amounts of biomass and carbon are recorded in the south and particularly in the southwest of the RBTW.


2021 ◽  
Vol 885 (1) ◽  
pp. 012033
Author(s):  
E Zh Garmaev ◽  
B V Sodnomov ◽  
B Z Tsydypov ◽  
A A Ayurzhanaev

Abstract The air temperature, precipitation and NDVI trends were calculated for the wet (1982-1999) and dry (2000-2018) periods for the territory of Baikal Siberia and adjacent territories. Temperature rise is observed for the entire study area; at the same time, zones with low growth rates of surface temperature are interspersed with zones with high growth rates, both in latitudinal and longitudinal directions. The wet period is characterized by positive trends in the amount of precipitation for almost the entire study area. During the dry period, negative dynamics of the amount of precipitation is observed for the predominant part of this territory. As a result of the analysis of the spatial distribution of NDVI trends, it was revealed that during the wet period, positive trend values prevail – up to 77%. During the dry period, a multiple increase in negative NDVI trends in arid zones was established, which shows their greatest sensitivity to the moisture regime. For the first time, the shares of the contribution of the anthropogenic and climatic factors to the degradation of the soil and vegetation cover of Russia, Mongolia and China within the region under consideration have been revealed.


2021 ◽  
Vol 5 (2) ◽  
pp. 635-639
Author(s):  
Y. S. Onifade ◽  
V. B. Olaseni ◽  
I. G. Baoku ◽  
C. Eravwodoke

Geophysical investigation using the 2D Electrical Resistivity Tomography (ERT) was carried out to assess the subsurface of Ugoneki and its environs in order to investigate for minerals. A total of six (6) traverses, 200 m long each, three (3) transverse lines were in the North-South direction and the other three (3) traverses in the West-East direction using the Wenner electrode configuration. 2D Wenner resistivity data were acquired along each traverse. The data were inverted to reveal a spatially continuous resistivity distribution in 2D within the study area. The 2D results reveal a depth of 39.6 m across each traverse. Resistivity values vary from 87.1 – 3423 Ωm in the entire study area. From the standard resistivity table, the following solid and non-metallic type of minerals can be delineated in the study area which is representative of sandy clay, lateritic clay sand, sandstone and limestone with resistivity values that range from 87.1 – 89.9 Ωm, 1201 – 1462 Ωm, 2069 – 3423 Ωm, and 2069 – 3423 Ωm respectively. The implication of this research is to know the type and the particular location where these non-metallic solid minerals are located in the subsurface for future exploration. The results of resistivity values are compared with those in the literature and are found to be in good agreement. In order to quantify these minerals, it is also recommended to use higher dimension (3D) of resistivity method (ERT) in the study area.


Author(s):  
S. Anitha ◽  
K. T. Gurumurthy Ganapathi

An investigation was undertaken in Tommaladahalli (566.13 ha) micro-watershed of Tarikere taluk, Chikkamagaluru district of Karnataka to assess available nutrient status in the surface soils. About 118 surface soil samples were collected grid wise by using cadastral map at 250 m grid interval and were analyzed for their fertility status using standard procedures. Soil fertility maps were prepared by means of interpolation method called Krigging. The results revealed that the pH, electrical conductivity, and organic carbon were ranged from 5.37 to 9.06, 0.065 to 0.466 dS m-1 and 0.33 to 1.62 per cent respectively. The available N, P2O5, K2O were ranged from 175.6 to 545.6 kg ha-1, 11.8 to 61.1 kg ha-1 and 122.7 to 491.4 kg ha-1, respectively. The available nitrogen and phosphorus were low to medium, where as potassium content was medium to high in the entire study area. Micronutrients viz. zinc, iron and boron were sufficient and were ranged from 0.34 to 1.17 mg kg-1, 2.03 to 21.86 mg kg-1 and 0.30 to 0.89 mg kg-1 respectively.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2248
Author(s):  
Jakob Siedersleben ◽  
Stefan Jocham ◽  
Markus Aufleger ◽  
Robert Klar

For morphodynamic modelling, riverbed survey data are essential as the basis for the evaluation of temporal riverbed development, mesh creation, and model calibration. To study the effects of uncertain geometry input on these issues, datasets of different spatial resolutions were analysed. As a result, cross-profile data were derived from high-resolution survey data, which are available for a river reach in the Upper Danube in Bavaria for several periods. Finally, the prediction quality of simulations based on cross-profile and high-resolution spatial data was assessed. The analysis of both datasets shows continuous riverbed erosion but of different magnitudes. However, complex riverbed geometry due to, e.g., scours, is depicted poorly by cross-profile data. In more homogenously characterised reaches, cross-profile data significantly more closely represents the riverbed geometry than the high-resolution spatial data base. Local misinterpretation of riverbed geometry by cross-profile data leads to deviations of calibration parameters in the entire study area. Consequently, these deviations in calibration outcome effect the model predictions. In this case, cross-profile calibration generally induces higher transport capacities, leading to more erosion in the study area compared to the model based on high-resolution spatial calibration. The general shape of predicted riverbed geometries is found to be similar but with local deviations, which are not limited to areas with complex river geometry.


2021 ◽  
Vol 13 (15) ◽  
pp. 2884
Author(s):  
Stephen Prince ◽  
Uriel Safriel

Degradation in a range of land uses was examined across the transition from the arid to the semi-arid zone in the northern Negev desert, representative of developments in land use taking place throughout the West Asia and North Africa region. Primary production was used as an index of an important aspect of dryland degradation. It was derived from data provided by Landsat measurements at 0.1 ha resolution over a 2500 km2 study region—the first assessment of the degradation of a large area of a desert margin at a resolution suitable for interpretation in terms of human activities. The Local NPP Scaling (LNS) method enabled comparisons between the observed NPP and the potential, nondegraded, reference NPP. The potential was calculated by normalizing the actual NPP to remove the effects of environmental conditions that are not related to anthropogenic degradation. Of the entire study area, about 50% was found to have a significantly lower production than its potential. The degree of degradation ranged from small in pasture, around informal settlements, minimally managed dryland cropping, and a pine plantation, to high in commercial cropping and extreme in low-density afforestation. This result was unexpected as degradation in drylands is often attributed to pastoralism, and afforestation is said to offer remediation and prevention of further damage.


2021 ◽  
Vol 4 ◽  
pp. 47-50
Author(s):  
Yuliia Spinova

The article presents the results of mapping the biotopes of the “Kreidova Flora” Nature Reserve, which is one of the key areas of the eco-network of the local level of the newly created Kramatorsk district. This district includes almost entirely “Sviati Hory” National Nature Park, an object of the Nature Reserve Fund of Ukraine (NRF) with the highest amount of estimated points for a comprehensive assessment of sozological value, which belongs to a group of the first class. Two NRF objects (including the “Kreidova Flora” Nature Reserve) were from the group of the second class: one from the group of the third: nine from the group of the fifth class: and one from a group of the sixth class. The total number of points of the studied NRF objects of the newly created district is 465, which is a significant indicator. The key areas of the local level eco-network are the NRF with adjacent natural areas, which together form clusters. The ecological corridors of the local level are the river network of the district and the network of forest belts. As buffer zones for river-type eco-corridors, it is proposed to consider a minimum 200-meter water protection zone in accordance with Art. 87 of the Water Code of Ukraine. Restoration areas of the local econetwork of Kramatorsk district should be all areas with disturbed natural landscape (abandoned quarries, heaps), as well as abandoned agricultural lands, where it is proposed to introduce revalidation measures. The obtained maps and databases of distribution of different types of biotopes on the territory of the reserve will be the basis for its management plan, and this technique can be used within other structural elements of ecological networks. According to the same principle, it is considered necessary to conduct research in the entire study area, as well as other areas of Donetsk region.


2021 ◽  
Vol 13 (11) ◽  
pp. 2129
Author(s):  
Fei Zhao ◽  
Lu Song ◽  
Zhiyan Peng ◽  
Jianqin Yang ◽  
Guize Luan ◽  
...  

Using toponym data, population data, and night-time light data, we visualized the development index of the Yi, Wa, Zhuang, Naxi, Hani, and Dai ethnic groups on ArcGIS as well as the distribution of 25 ethnic minorities in the study area. First, we extracted the toponym data of 25 ethnic minorities in the study area, combined with night-time light data and the population proportion data of each ethnic group, then we obtained the development index of each ethnic group in the study area. We compared the development indexes of the Yi, Wa, Zhuang, Naxi, Hani, and Dai ethnic groups with higher development indexes. The results show that the Yi nationality’s development index was the highest, reaching 28.86 (with two decimal places), and the Dai nationality’s development index was the lowest (15.22). The areas with the highest minority development index were concentrated in the core area of the minority development, and the size varied with the minority’s distance. According to the distribution of ethnic minorities, we found that the Yi ethnic group was distributed in almost the entire study area, while other ethnic minorities had obvious geographical distribution characteristics, and there were multiple ethnic minorities living together. This research is of great significance to the cultural protection of ethnic minorities, the development of ethnic minorities, and the remote sensing mapping of lights at night.


2021 ◽  
Author(s):  
Zakaria Ouzerbane ◽  
Soumia Loulida ◽  
Abdellah El Hmaidi ◽  
Ali Essahlaoui ◽  
Mostafia Boughalem ◽  
...  

Abstract The coastal aquifer of the Essaouira syncline (Morocco) was studied to identify the main processes at the origin of the salinization of groundwater. In fact, a multicriteria analysis approach on hydrochemical data and physicochemical parameters of the Plio-Quaternary aquifer was used to understand their spatio-temporal variation and their origins. Currently, integrated water resources management has become paramount to both local, regional, national and international. This management is favored by extreme hydrological events (droughts or floods) which can have direct influences on human, economic and political aspects. Appropriate management of a resource requires its evaluation. The statistical study by Kohonen's self-organized classification (SOM) of hydrochemical data for the years 1995 and 2009 is used to process 47 samples distributed over the entire study area; it showed an evolution of the values of the parameters. Physico-chemical as a function of time and space with an increase in the values of the parameters, from the center of the study area towards the southwest.


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