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Causes, Modeling and Mitigation of Urban Heat Island: A Review
H. M. Imran,
Mahaad Issa Shammas,
Ataur Rahman,
Stephanie J. Jacobs,
A. W. M. Ng,
Shobha Muthukumaran
Issue:
Volume 10, Issue 6, December 2021
Pages:
244-264
Received:
28 July 2021
Accepted:
20 October 2021
Published:
10 November 2021
Abstract: Urbanization leads to loss of vegetation and converting pervious areas into built-up and impervious areas, and consequently, urban areas expose higher temperatures as compared to surrounding rural areas, which is called Urban Heat Island (UHI). The UHI affects the urban environment and causes heat-related diseases and mortality that have increased over the last centuries. Considering the severity of the UHI problem, enormous research has been conducted and an extensive range of literature is available on this topic. This paper reviews the causes, modelling and mitigation strategies of the UHI. The urban infrastructure and anthropogenic heat sources are the main driving factors in developing the UHI in cities. Many approaches including observation and modelling techniques are used to understand the formation, causes and mitigation of the UHI. The formation and causes of the UHI largely depend on the size, shape and urban infrastructure of the cities as well as climatic conditions. Although various modelling techniques are used to study UHI, there are still lacks in all models to precisely represent the physical phenomena and complex urban infrastructure. Many UHI mitigation strategies are examined by numerous studies, while the increased urban vegetation is a more environmentally friendly solution. The study summarizes the important features and limitations of different modelling techniques and mitigation measures of the UHI. This study also identifies research gaps and proposes areas for further research.
Abstract: Urbanization leads to loss of vegetation and converting pervious areas into built-up and impervious areas, and consequently, urban areas expose higher temperatures as compared to surrounding rural areas, which is called Urban Heat Island (UHI). The UHI affects the urban environment and causes heat-related diseases and mortality that have increased ...
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Statistical Analysis of Ozone Weekend Effect in the Largest Cities in Poland
Issue:
Volume 10, Issue 6, December 2021
Pages:
265-274
Received:
27 September 2021
Accepted:
26 October 2021
Published:
10 November 2021
Abstract: This study examines O3, NOx, NO2 and NO data from five large cities in Poland (Warszawa, Kraków, Łódź, Wrocław and Poznań) over a three-year period (2015-2017) to quantify the phenomenon of ozone weekend effect. The seasonal and diurnal variations of O3 and NOx species, showing the interdependence these two gaseous species, were presented. The number of 8-hour running average values above the threshold of 60 ppb and 1-hour above 90 ppb shows that ozone exceeded amounts are more frequent on Saturday and Sunday compared to other days of the week. The analysis of day of the week variations of O3 indicates distinct, temporal pattern with maximum O3 concentrations during weekend (especially on Sunday) and minimum noted on Wednesday, Thursday and Friday (depending on the station). The analysis of existence of the ozone weekend effect was performed on the basis of average O3 concentration at the weekend and on the day of the lowest O3 concentration during the week. Calculations were performed for the period of the whole year and for individual seasons of the year. The results of performance the non-parametric U-Mann-Whitney test indicate that differences of O3 concentration between weekend and a specific day of the week were statistically significant for most cases, despite the significantly lower concentration of ozone precursors (NOx). The analysis of Ox concentrations indicates that limited processes of O3 titration by NO (ozone quenching hypothesis) are the main cause of the ozone weekend effect in the Polish cities.
Abstract: This study examines O3, NOx, NO2 and NO data from five large cities in Poland (Warszawa, Kraków, Łódź, Wrocław and Poznań) over a three-year period (2015-2017) to quantify the phenomenon of ozone weekend effect. The seasonal and diurnal variations of O3 and NOx species, showing the interdependence these two gaseous species, were presented. The numb...
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Statistical Regularity and Relation Between Small Earthquakes and Crustal Velocity Structure Beneath Bohai Sea and Its Surrounding Areas in China
Zhu Xinran,
Xue Peng,
Wang Wei,
Ni Yingying,
Pang Guanghua
Issue:
Volume 10, Issue 6, December 2021
Pages:
275-280
Received:
4 October 2021
Accepted:
8 November 2021
Published:
12 November 2021
Abstract: The Bohai Sea is a seismically active region in China, and the studying of the velocity structure of Bohai Sea and its relationship with earthquake may be helpful to the analysis and prediction of earthquakes. Now, ambient noise tomography is an effective tool to obtain crust and upmost mantle structure. In this paper, the S-wave velocity model of the crust beneath the Bohai Sea and its surrouding areas in China was constructed applying ambient noise tomography method, with steps of calculating cross correlations of all possible vertical-component data recorded in 2013 year, retrieving Empirical Green’s Functions (EGFs) for Rayleigh wave, measuring and assessing phase velocity-dispersion curves, creating the phase-velocity maps for the 8-35 s period of the Rayleigh wave, constructing the phase velocity maps and inverting the S-wave velocity structure. We work on the statistics and analysis of the characteristic relationship between crustal S-wave velocity and the temporal and spatial distribution of small earthquakes. The results from all available vertical profiles along different directions reveal that small earthquakes usually occur at the edge of the low-velocity anomaly within the shallow crust in a certain velocity range and, under special conditions, even in a distinct velocity contour. The locations of occurrence are closely related to undulating changes of the corresponding Moho morphology and the locally high Vs anomalies within the middle crust.
Abstract: The Bohai Sea is a seismically active region in China, and the studying of the velocity structure of Bohai Sea and its relationship with earthquake may be helpful to the analysis and prediction of earthquakes. Now, ambient noise tomography is an effective tool to obtain crust and upmost mantle structure. In this paper, the S-wave velocity model of ...
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Velocity Profile of Turbulent Clear Water Open-Channel Flows: Implication for Suspended Sediment Grains Transport
Issue:
Volume 10, Issue 6, December 2021
Pages:
281-291
Received:
4 October 2021
Accepted:
30 October 2021
Published:
17 November 2021
Abstract: Understanding sediment transport process requires adequate knowledge of the mechanism of grains motion which is primarily controlled by flow characteristics including the distribution of time-averaged streamwise velocities, Reynold shear stress distributions as well as the turbulence of flow. Knowledge of the velocity profile in both clear and sediment-laden flows provide clues to understanding this sediment transport mechanism. This paper presents the characterisation of turbulent flow velocity profile based on the physical expression of the mixing length theory as originally proposed by Prandtl, O’Brien and Bagnold, for the prediction of flow interaction with suspended sediment grains. The study utilises the most current flow velocity sampling technology to directly sample flow velocity fluctuations in six cases of open channel flume experiments to characterise the turbulent velocity profile and ascertain the turbulence model’s relevance and continuous application in solving sediment grain transport problems. With over 30,000 flow velocity data generated, the analysis demonstrates that, in all six clear water turbulent flows cases investigated, time-averaged velocity versus height is defined in the vicinity of the flow bed by the logarithmic law and well approximated by the turbulence model. Also, modelled and measured vertical streamwise velocities show a significant positive relationship with an R-squared value of almost unity.
Abstract: Understanding sediment transport process requires adequate knowledge of the mechanism of grains motion which is primarily controlled by flow characteristics including the distribution of time-averaged streamwise velocities, Reynold shear stress distributions as well as the turbulence of flow. Knowledge of the velocity profile in both clear and sedi...
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Research on Estimation of Wetland Area Based on Spacial Sampling Method-A Case Study of Ningxia Hui Autonomous Region in China
Ma Wei,
Zhang Yangwu,
Zhou Tianyuan,
Jiang Yafang,
Liu Zengli
Issue:
Volume 10, Issue 6, December 2021
Pages:
292-297
Received:
25 October 2021
Accepted:
15 November 2021
Published:
17 November 2021
Abstract: Investigation and monitoring of wetland is an important and fundamental work. Wetland area estimation by systematic sampling would have higher precision than that get by traditional random sampling. In this paper, wetland areas of different types in Ningxia were estimated by spacial sampling method, based on remote sensing data from 2015 to 2016. Results showed that: 1) According to the second national wetland resource inventory database, wetland area in Ningxia was 20.72×104 hm2, which decreased gradually from north to south, and Wuzhong had relatively largest areas of lakes and marsh wetland. 2) Based with 210 of 4 km×4 km quadrat sampling grids, estimation of wetland area in Ningxia was 21.70×104 hm2, with estimation accuracy of 94.53% and sampling accuracy of 99.78%, which was reliability but the sampling accuracy would decline with the proportion decrease of sampling wetland area. 3) Based with 61 of 4 km×4 km quadrat sampling grids, wetland area in Wuzhong was estimated as 52320.67 hm2 with estimation accuracy of 98.58%, occurred in a net increase of 731.78 hm2 from 2013 to 2016. In conclusion, the spacial sampling method proposed in this research for wetland resource inventory and dynamic monitoring is available and worth of spreading within certain realms, which would improve the protection, management, restoration and sustainable development for wetland resource.
Abstract: Investigation and monitoring of wetland is an important and fundamental work. Wetland area estimation by systematic sampling would have higher precision than that get by traditional random sampling. In this paper, wetland areas of different types in Ningxia were estimated by spacial sampling method, based on remote sensing data from 2015 to 2016. R...
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Impacts of Population Pressure on Agricultural Production and Farming Practices of Households: The Case of Essera Woreda in Dawro Zone, SNNPR, Ethiopia
Bekele Tona Amenu,
Getahun Shanko Mamo
Issue:
Volume 10, Issue 6, December 2021
Pages:
298-314
Received:
8 October 2021
Accepted:
1 November 2021
Published:
19 November 2021
Abstract: Agricultureasaprimaryeconomicactivityisthemajoreconomicbaseoftheworld’spopulation. Agriculture as a primary economic activity is the major economic base of the world’s population. More than 60 percent of the world population depends on agriculture for their livelihood. This study was conducted in Dawuro Zone Essera district achieve the general objective that assessed the impacts of population growth on agricultural production and farming practices. Essera district is 102,848, of whom 51.35% are male and 48.64% are female. This district falls into three agro-ecological regions, of which, kolla within (500-1500masl), weina-dega within (1501-2500 masl) and Dega above (> 2500 masl). To conduct this study, the cross-sectional survey design with the application of both qualitative and quantitative approaches were employed. The study involved a multistage sampling, i.e. a combination of purposive, stratified, and simple random sampling procedures to select the study area and sample households. To draw the samples, the households in the study area, Stratified random sampling technique was applied to collect information from respondents. Study area districts stratified into 3 stratums based on agro ecological zone, after this stratification in agro-ecological zone, kebeles that study has been undergone, selected purposively. That is kola whose elevation ranges from 1000m-1500m above sea level, woynadega whose elevation ranges from 1500m-2000m above sea level, and dega whose elevation ranges from 2000-3000m above sea level. Data that was made available through different instruments was analyzed using quantitative and qualitative techniques. Different tables, maps and figures were also used to illustrate the various aspects of the study. In the light of the theories considered and the finding of the study indicated, both the population pessimistic views of Malthusians and neo Malthusians and the optimistic views of Boserupian could not separately provides the complete explanations regarding the population and agricultural production relationship of this study. It was observed that, increase in population growth of the area associated with an increase in usage of modern inputs which increase in total crop outputs in general and yields for some crop types such as cereals in particular. Moreover, labor intensive land investment practices including tree planting; terracing, manuring croplands were increasingly under taking by peasants as result of rapid change in population size of the area. Farmers have to be advised to plant tree at area far away from land serving agricultural activities.
Abstract: Agricultureasaprimaryeconomicactivityisthemajoreconomicbaseoftheworld’spopulation. Agriculture as a primary economic activity is the major economic base of the world’s population. More than 60 percent of the world population depends on agriculture for their livelihood. This study was conducted in Dawuro Zone Essera district achieve the general obje...
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Holocene Climate Evolution and Neolithic Cultural Evolution Recorded in the Loess Profile in Central Shandong Province, China
Han Danmei,
Ding Min,
Peng Shuzhen,
Zhu Lidong,
Zhao Qiuyue,
Jin Hua,
Zhang Wei
Issue:
Volume 10, Issue 6, December 2021
Pages:
315-324
Received:
13 November 2021
Accepted:
6 December 2021
Published:
7 December 2021
Abstract: The ZQSC loess-paleosol profile was selected to investigate the environmental evolution and its correlation with the development of the Neolithic culture since Holocene in central Shandong Province of China. In the study, grain size, chromaticity, and magnetic parameters were considered as reliable proxies in reconstructing paleoclimate. Besides, the sedimentary age was obtained by 14C dating in Beta laboratory in 2017. The result indicated that the Holocene climate evolution can be divided into three stages: 1) The early Holocene (about 11.5-8.5 ka B.P.). In this period, the climate conditions of the late Last Glaciation were extended, characterized by a dry and cold climate. 2) The middle Holocene (about 8.5-3 ka B.P.). This stage is climatically suitable with the best condition of warmth and humidity. Besides, small fluctuations also existed, in the period of the 4.62-3.784 ka B.P., the climate event was occurred. Besides, numerous pottery shards were discovered in paleosol, corresponding to the occurrence of the transition from the prosperous Longshan culture to the sluggish YueShi culture, potentially related to the sudden temperature drop and the ancient flood event. 3) The late Holocene (about 3.0 ka B.P.-present). The climate condition of this stage was deteriorating steadily. In this period, the 2.948 ka B.P. climate event and buried pottery revealed a great correspondence with the dry and cold events of the Middle Western Zhou Dynasty.
Abstract: The ZQSC loess-paleosol profile was selected to investigate the environmental evolution and its correlation with the development of the Neolithic culture since Holocene in central Shandong Province of China. In the study, grain size, chromaticity, and magnetic parameters were considered as reliable proxies in reconstructing paleoclimate. Besides, t...
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Geochemical Characteristics and Genesis of Biotite Monzogranite in Southeastern Guangxi Province, South China
Tian Mengyu,
Di Yongjun,
Li Shusheng,
Zhang Sheng
Issue:
Volume 10, Issue 6, December 2021
Pages:
325-331
Received:
19 November 2021
Accepted:
7 December 2021
Published:
24 December 2021
Abstract: The South China Block experienced intense tectonic–magmatic evolution during the Indosinian period, which was recorded by Indosinian granite and has attracted numerous researchers. This paper presents data on the geochronology and geochemistry of Darongshan biotite monzogranite. LA–ICP–MS U–Pb zircon analyses yielded a weighted average age of 250.1±1.6 Ma, which represents the magma crystallization age of the Early Triassic. According to petrographic observation, the main diagenetic minerals of Darongshan biotite monzogranite are quartz, K-feldspar, plagioclase, biotite, and small amounts of cordierite, tourmaline, and garnet. Darongshan biotite monzogranite is aluminum-rich and high in silica. It shows weak negative Eu anomalies (δEu=0.13–0.57) and depleted HREEs. Darongshan biotite monzogranite exhibits significant negative anomalies of high field strength elements (HFSE, e.g., Nb, Ta, Ti, and P) and positive anomalies of large-ion lithophile elements (LILE, e.g., Rb, Th, U, and Pb). Geochemical analyses suggested that Darongshan biotite monzogranite has undergone highly differentiated evolution. According to this study, Darongshan biotite monzogranite is an S-type granite, and its source material developed from the remelting of ancient crustal material. The Darongshan biotite monzogranite granite formed in the island arc environment of oceanic subduction and orogenic stage, further confirming the geological records of the remaining oceanic basin in Qinfang.
Abstract: The South China Block experienced intense tectonic–magmatic evolution during the Indosinian period, which was recorded by Indosinian granite and has attracted numerous researchers. This paper presents data on the geochronology and geochemistry of Darongshan biotite monzogranite. LA–ICP–MS U–Pb zircon analyses yielded a weighted average age of 250.1...
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Application of Electrical Resistivity Techniques for Mapping Bitumen Saturated Zones and Its Geologic Implication over Agbagbu, Southwestern Nigeria
Issue:
Volume 10, Issue 6, December 2021
Pages:
332-345
Received:
26 August 2021
Accepted:
13 September 2021
Published:
31 December 2021
Abstract: Mapping of bitumen saturated zones in Agbabu, southwestern Nigeria was carried out using electrical resistivity techniques involving 2D resistivity imaging and vertical electrical sounding (VES). The main objective of the research work was to delineate the bitumen saturated zone and their geologic implication(s) especially on the groundwater development over the study area. For the 2D resistivity imaging, a total of four traverses were established in the NE-SW direction with each traverses covering a total distance of between 150m to 160m. Twenty vertical electrical soundings were also carried out with the results showing KQ and HA curve types being predominant. The results of 2D resistivity imaging showed that the underlaying bitumen impregnated layers was overlain by a protective clay layer which has some discontinuities (weak zones) with traverses 1and 4 showing the most vulnerable zones in terms of groundwater pollution while traverses 2 and 3 appears to be less vulnerable. The VES results showed that the bitumen impregnated layers was within the third and fourth layers with resistivities ranged between 86Ωm to 255Ωm and occurring at depths ranged between 1.5m to 6m. The geologic discontinuities across the study area coupled with the shallow depth of occurrence of bitumen might be a drawback to any meaningful groundwater development within the study area.
Abstract: Mapping of bitumen saturated zones in Agbabu, southwestern Nigeria was carried out using electrical resistivity techniques involving 2D resistivity imaging and vertical electrical sounding (VES). The main objective of the research work was to delineate the bitumen saturated zone and their geologic implication(s) especially on the groundwater develo...
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Seismotectonics of Vlora-Elbasani-Dibra Transversal Fault Zone (Albania): A Review
Issue:
Volume 10, Issue 6, December 2021
Pages:
346-357
Received:
6 December 2021
Accepted:
28 December 2021
Published:
31 December 2021
Abstract: The Vlora-Elbasani-Dibra transversal fault zone crosses from south-west to northeast the Albanides collision zone starting from Vlora area to the Dumre diapir and continuing from Elbasani Quaternary graben to Dibra area, within the internal Albanides extensional zone. The Vlora-Elbasani-Dibra seismogenic fault zone is expressed by an alignment of important historical and instrumental seismicity with 15 Ms > 6 earthquakes. The Vlora-Berati-Elbasani segment of this fault zone during the year 1851 has been activated along all is length. The geological and neotectonic investigations and the focal mechanism solutions of earthquakes that occurred along the Vlora-Elbasani-Dibra fault zone prove its division into two distinct fault zones: a) the Mali i Kanalit Block - Dumre diapir strike-slip fault zone NNE trending in transpression, and b) the Elbasan-Dibra normal fault zone NE trending in transtension. The Mali i Kanalit Block-Dumre diapir strike-slip zone NNE trending in transpression offsets dextrally and to SW the folds and thrusts of the Çika, Kurveleshi and Berati anticlinal belts of Ionian zone. The Neogene (mainly since Middle Miocene) offset of the Çika, Kurveleshi and Berati anticlinal belts from generally NW-SE trending to near N-S one has led to thrust’s steepening and turning into high-angle strike-slip faults due to NE-SW oblique compression from the Albanides collision zone. The Othoni Island-Dhermi strike-slip fault offsets the dextrally dragged Devolli (to the east of Dumre diapir), Osumi (near to Berati town), and Vjosa (west of Shkoza village) rivers’ valleys formed from the Middle Pleistocene (180,000 years) to historic times. The Othoni Island-Dhermi dextral strike-slip fault, that reaches the maximum velocity of greater than 5 mm/year to the south of it, is the only leading fault that shaped the Mali i Kanalit Block-Dumre diapir dextral strike-slip fault zone. Focal mechanism solutions of earthquakes that occurred on the Mali i Kanalit Block - Dumre diapir dextral strike-slip zone show their generation from strike-slip faults in transpressional motions. Focal mechanism solutions of earthquakes that occurred on the Elbasan-Dibra were generated from normal faults with dextral strike-slip movements.
Abstract: The Vlora-Elbasani-Dibra transversal fault zone crosses from south-west to northeast the Albanides collision zone starting from Vlora area to the Dumre diapir and continuing from Elbasani Quaternary graben to Dibra area, within the internal Albanides extensional zone. The Vlora-Elbasani-Dibra seismogenic fault zone is expressed by an alignment of i...
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