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The role of tourism in rural development: Evidence from Iran 总被引：1，自引：0，他引：1
Nooripoor Mehdi Khosrowjerdi Madineh Rastegari Hamid Sharifi Zeinab Bijani Masoud 《GeoJournal》2021,86(4):1705-1719
GeoJournal - Tourism can play an important role in diversifying the rural economy and its expanding in rural areas contributes to the sustainability of the population and the economy of these areas... 相似文献
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Zeinab SALAH Ahmed SHALABY Allison L.STEINER Ashraf S.ZAKEY Ritesh GAUTAM Mohamed M.ABDEL WAHAB 《大气科学进展》2018,35(2):182-194
This study assesses the direct and indirect effects of natural and anthropogenic aerosols(e.g., black carbon and sulfate)over West and Central Africa during the West African monsoon(WAM) period(June–July–August). We investigate the impacts of aerosols on the amount of cloudiness, the influences on the precipitation efficiency of clouds, and the associated radiative forcing(direct and indirect). Our study includes the implementation of three new formulations of auto-conversion parameterization [namely, the Beheng(BH), Tripoli and Cotton(TC) and Liu and Daum(R6) schemes] in Reg CM4.4.1,besides the default model's auto-conversion scheme(Kessler). Among the new schemes, BH reduces the precipitation wet bias by more than 50% over West Africa and achieves a bias reduction of around 25% over Central Africa. Results from detailed sensitivity experiments suggest a significant path forward in terms of addressing the long-standing issue of the characteristic wet bias in Reg CM. In terms of aerosol-induced radiative forcing, the impact of the various schemes is found to vary considerably(ranging from-5 to-25 W m~(-2)). 相似文献
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During the Cenozoic numerous shallow epicontinental evaporite basins formed due to tectonic movements in the Northern Province of the Central Iran Tectonic Zone (the Great Kavir Basin). During the Miocene, due to sea‐level fluctuations, thick sequences of evaporites and carbonates accumulated in these basins that subsequently were overlain by continental red beds. Development of halite evaporites with substantial thickness in this area implies inflow of seawater along the narrow continental rift axis. The early ocean basin development was initiated in Early Eocene time and continued up to the Middle Miocene in the isolated failed rift arms. Competition between marine and non‐marine environments, at the edge of the encroaching sea, produced several sequences of both abrupt and gradual transition from continental wadi sediments to marginal marine evaporites in the studied area. These evaporites show well‐preserved textures indicative of relatively shallow‐brine pools. The high Br content of these evaporites indicates marine‐derived parent brines that were under the sporadic influence of freshening by meteoric water or replenishing seawater. However, the association of hopper and cornet textures denotes stratified brine that filled a relatively large pool and prevented rapid variations in the Br profile. Unstable basin conditions that triggered modification of parent brine chemistry prevailed in this basin and caused variable distribution patterns for different elements in the chloride units. The presence of sylvite and the absence of Mg‐sulphate/chlorides in the paragenetic sequence indicate SO4−depleted parent brine in the studied sequence. Petrographic examinations along with geochemical analyses on these potash‐bearing halites reveal parental brines which were a mixture of seawater and CaCl2‐rich brines. The source of CaCl2‐rich brines is ascribed to the presence of local rift systems in the Great Kavir Basin up to the end of the Early Miocene. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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A new C15 acetogenin, cyclic enyne (12E)‐cis‐maneonene‐E ( 1 ) and (12Z)‐trans‐maneonene‐B ( 2 ), together with different secondary metabolites including sesquiterpenoid 2,10‐dibromo‐3‐chloro‐α‐chamigrene ( 3 ) and fatty acid aldehydes ( 4–8 ) were isolated from the petroleum ether extract of a red alga, identified as Laurencia papillosa, collected from the Saudi Red Sea coast. The L. papillosa crude extract and its active ingredient acetogenin ( 1 ) have been evaluated for the ability to control two main economically important pests, the confused flour beetle larvae Tribolium confusum and Culex pipiens mosquito larvae. Compound 1 showed high potential as a natural insecticide against these two pests. In the case of T. confusum larvae, the LD50 values were 0.21 and 0.16% after 6 and 12 days of treatment with crude extract and acetogenin, respectively. On the other hand, the resulting LC50 values of mosquito larvae bioassay were 30.7, 36.9, and 41.8 ppm after 24 h treatment against 2nd, 3rd, and 4th larval instars, respectively. Also, an increase of the insecticidal effects against mosquito larvae was recorded after extending treatment time to 48 h. 相似文献
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Land use/cover change and driving force analyses in parts of northern Iran using RS and GIS techniques 总被引：3，自引：1，他引：2
To accomplish integrated watershed management and land use planning, it is necessary to study the dynamic spatial pattern of land use and cover change related to socioeconomical and physical parameters. In this study, land use and cover change detection was applied to the Lajimrood Drainage Basin in northern parts of Iran, an area characterized by rich and diversified agricultural and forest mosaic. The main of changes in the study area were forest–arable land transformation, which was only considered in this study. In order to detect these changes, at first, based on 1:25,000 digital topographic maps dated 1967 and 1994 and ETM+ satellite image dated 2002, land use map in these three dates were prepared. The results showed that the area with forest land use decreased about 3.2% in transition 1967–2002. Also, arable land increased about 36.9%. We suggested a method to analyze the driving forces and the spatial distribution of land use change. The maps of elevation, slope, and aspect were derived and classified by using digital elevation model (DEM). Also, the maps of distance from road, drainage network, and building area were selected as socioeconomical factors. These maps were overlaid and crossed with land use change map and land use change area ratio was computed. The results showed that the elevation, slope, and aspect were physical effective factors in land use changing. Also, by increasing the distance from building area and roads, deforestation rate was reduced. 相似文献
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Classification of mineralized areas into different geochemical classes in terms of prospectivity is crucial in the optimal management of exploration risk and costs. Machine learning (ML) algorithms can be served as appropriate alternatives for separating ore-related anomalies due to avoiding the assumptions of statistical distribution and compatibility with the multivariate nature of geochemical features. By hybridizing the ML with a metaheuristic algorithm called particle swarm optimization (PSO), this contribution aims to provide an innovative approach to optimize the classification of geochemical anomalies within the study area. The algorithm, PSO, is inspired by simulating the social behavior of flocks of birds in search of food. The Dagh-Dali ZnPb (±Au) mineral prospect in northwest Iran was subjected as a case study to examine the integrity of the proposed method. Mineralization-related features were extracted by applying principal component analysis (PCA) on metallogenic elements analyzed in soil samples as PC1 and PC2 with elemental assemblages of AgAuPbZn and PbZn, respectively. The silhouette index was employed to estimate the number of underlying geochemical clusters within the adopted feature space. To constitute a comparative analysis, two k-means clustering and PSO-based learning (PSO-L) algorithms were implemented to classify the gridded data of PC1 and PC2 within the study area. The results indicated that the use of PSO has improved the cost function of the clustering problem (up to 4%). Adapting the mineralization classes with the metallogenic evidence demonstrated by boreholes drilled in the study area indicated that PSO-L was superior to the traditional k-means method, improving the accurate estimation of subsurface mineralization classes by 7%. By overcoming the drawbacks of conventional methods for trapping at the local optima, PSO-based learning possesses the potential to highlight weak mineralization signals that are numerically located in boundary conditions. The results show that the proposed approach can serve as an effective medium for optimal modeling of geochemical classes and management of detailed exploration operations. 相似文献
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Zeinab?Aliabadian Mansour?SharafisafaEmail author Mohammad?Nazemi Alireza?Rezazadeh?Khamene 《Arabian Journal of Geosciences》2015,8(3):1229-1242
To transfer the excess water from Sabzkouh River in central Iran to cities beyond the river, a mechanized tunnel is being excavated. During construction and support installation in the first 100 m, tunnel roof collapse occurred and was followed by ground settlement, so that a cavity was developed in ground surface. The cavity had to be filled in a short time before rainy season, since the water flow through cavity could extend the collapse area in both tunnel roof and ground surface. In order to fill the cavity, some filling methods with different materials consist of in situ soil, lightweight concrete, and pumice aggregate lightweight concrete (PALWC) were suggested. To analyse the load distribution and minimize the costs, a three-dimensional analysis was carried out. Tunnel support system was simulated numerically to further evaluate loading state on support system under different material loadings. Mohr-Coulomb material model was used to allow material failure. The modelling procedure was based on actual construction procedure. Firstly, in situ model was modelled without any excavation and was run to establish pre-stresses and displacement, then slope was supported, the tunnel was excavated and support was installed and finally cavity was simulated. The numerical results show that filling the cavity with soil will result in over loading on the support system and leads to instability of the slope. Other two suggested filling materials have acceptable load on support system, but PALWC was selected as the best filling material having minimum loading and guarantees slope stability. 相似文献
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Hammad Tariq JANJUHAH Josep SANJUAN Mohammad ALQUDAH Mohamed K. SALAH 《《地质学报》英文版》2021,95(5):1668-1683
Carbonate rocks contain prolific hydrocarbon reserves all over the world, particularly in the Middle East. For exploration and production strategies, it is essential to understand carbonate reservoirs in terms of their internal characteristics, depositional environment, relative age, diagenetic processes and impact on petrophysical properties. This study has been performed on exposed Cretaceous, Paleocene and Miocene marine carbonate sedimentary sequences in two localities (Maghdoucheh and Qennarit) near the city of Sidon (Southern Lebanon). It represents the first comprehensive study that takes into consideration the carbonate reservoir facies, diagenetic history and reservoir quality in the area. Rocks at Maghdoucheh are mainly dominated by limestone beds showing sedimentary structures and erosive bases alternating with microfossil-rich silty marls, related to a shallowing upward sequence in a restricted marine platform environment. Shells of benthic foraminifera and mollusks dominate the fossil assemblage extracted from the studied rocks. The microfossil and nannofossil assemblage detected in the Maghdoucheh sections indicates a middle Miocene age. Rocks at Qennarit are composed of mudstone/wackestone limestone beds rich in planktonic foraminifera and nannofossils related to open marine conditions. Based on the nannofossil content, rocks from Qennarit 1 and 2 are Paleocene and Cretaceous in age, respectively. Four main types of microfacies have been identified, i.e. (1) microbioclastic peloidal calcisiltite, (2) pelagic lime mudstone and wackestone with planktonic microfossils, (3) grainstone/packstone with abundant foraminifera and (4) fenestral bindstones, mudstones and packstones with porostromate microstructures. The porosity-permeability (poro-perm) analysis of representative samples reveals moderate to good porosity but very low permeability. This is mainly due to the presence of large moldic pores that are isolated in nature. The diagenetic features are dominated by micritization and dissolution (both fabric selective and non-fabric selective). Among all diagenetic features, dissolution in both localities contributes to porosity enhancement, while micritization, cementation, compaction and the filled fractures have negative impacts on permeability; hence the overall reservoir quality. 相似文献
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