Erosion Rates in Dam Catchments in Jordan—Effects of Topography, Geology, and Urbanizations

Erosion as a natural process produces soils, which are very important natural resources for the fest land plant- and animal kingdoms. Loss of the soil cover reduces agricultural production, biodiversity, and the role of soil as a filter for infiltrating water to replenish the groundwater. It also threatens the food supplies. The knowledge of erosion rates of rocks and terrains is important for developing proactive measures to protect soils from erosion and loss. In this study, erosion rates of catchment areas were calculated based on dams’ catchment extensions and the sediment loads transported by flood flows into dams’ lakes. The study results show that the chemically, via floodwater, transported quantities of materials are negligible compared to the solid materials transported by the water. It calculates erosion rates ranging from 0.013 to 0.212 mm/yr (13 - 212 m/106 yr) for the different catchment areas. Erosion rates in Jordan are, generally, higher than those calculated for the different parts of the world ranging from 2.5 to 60 m/106 yr. This fact can be explained by the very steep topography, calcareous rock cover of the catchment areas and the barren rock exposures.

The Environmental Risks Posed by the Oil and Gas Development and Its Potential Impacts on Mangrove Ecosystems and the Coastal Community’s Well-Being

Guyana is an oil-producing country with oil and gas exploration and production operations approximately 190 km offshore. The coastal communities selected as the study areas in Region 1 and Region 2 are adjacent to the coast and 5 to 10 km inshore. In the event of oil spills, Shell Beach Protected Areas and the other selected communities will be negatively impacted, particularly the mangrove ecosystems and the community’s well-being. The research aims to investigate the potential environmental risks posed by oil and gas exploration and production activities. It followed a qualitative approach and employed semi-structured interviews with the Toshaos of the coastal communities. The data analysis strategy was thematic analysis using the Nvivo software. The major themes included community assets, the importance of mangrove ecosystems, and the impacts of mangrove ecosystem damage through oil spills. Oil spill pollution will negatively impact mangrove ecosystems and the coastal community well-being in Region 1 and Region 2. The major results include damage to cultural artefacts, saltwater intrusion of major creeks, reduced fish catch levels, and agriculture products, which are the main economic activities in the selected communities. Consuming contaminated agriculture and marine products will lead to adverse health problems. Mangrove ecosystems provide considerable benefits to coastal community residents, including shields against river bank erosion, natural habitats for wildlife and source of income, shared traditions, social values, recreational facilities, and tourist attractions. These benefits contribute to the overall coastal community’s well-being. The mangrove forests must be protected and conserved to avoid environmental damage.

The Mitigation Strategies for Managing the Potential Environmental Risks Posed by Oil and Gas Development on Mangrove Ecosystems in the Coastal Communities

Guyana is an oil-producing country vulnerable to potential oil spills and the environmental risks posed by oil and gas exploration and production activities. Despite the technologically advanced equipment employed by ExxonMobil Guyana and affiliates, an oil spill could occur due to accidents, equipment failures, or sabotages. The selected coastal communities as the study areas in Region 1 and Region 2 could be adversely affected, particularly the mangrove ecosystems. Potential oil spill pollution will adversely impact mangrove ecosystems in Region 1 and Region 2. Mangroves offer significant benefits to coastal communities, such as coastal defence and carbon sequestration, which puts Guyana on the world map. The research aimed to investigate the mitigation strategies to manage the potential environmental risks on mangrove ecosystems in the coastal communities of Region 1 and Region 2. It followed a qualitative approach and conducted semi-structured interviews with the Toshaos of the selected coastal communities. The data analysis strategy was thematic analysis using the Nvivo software. The major themes included legal and policy frameworks, oil spill response strategies, community-based involvement, and monitoring and enforcement of regulations. The significant results included reviewing and updating the regulatory framework for mangrove management and conservation;oil spills mitigation measures such as containment and shoreline protection and cleanup, cost recovery and compensation, and limited monitoring and law enforcement of mangrove management and conservation regulations by inter-agencies. The regulatory and institutional framework is outdated and needs to be amended. The agencies overseeing mangrove management and conservation have overlapping responsibilities and require more coordination. There should be greater collaboration among agencies for mangrove management and conservation and improved monitoring and enforcement programmes through institutional support.

Landslide initiation and runout susceptibility modeling in the context of hill cutting and rapid urbanization: a combined approach of weights of evidence and spatial multicriteria

Rainfall induced landslides are a common threat to the communities living on dangerous hillslopes in Chittagong Metropolitan Area, Bangladesh. Extreme population pressure, indiscriminate hill cutting, increased precipitation events due to global warming and associated unplanned urbanization in the hills are exaggerating landslide events. The aim of this article is to prepare a scientifically accurate landslide susceptibility map by combining landslide initiation and runout maps. Land cover, slope, soil permeability, surface geology, precipitation, aspect, and distance to hill cut, road cut, drainage and stream network factor maps were selected by conditional independence test. The locations of 56 landslides were collected by field surveying. A weight of evidence(Wo E) method was applied to calculate the positive(presence of landslides) and negative(absence of landslides) factor weights. A combination of analytical hierarchical process(AHP) and fuzzymembership standardization(weighs from 0 to 1) was applied for performing a spatial multi-criteria evaluation. Expert opinion guided the decision rule for AHP. The Flow-R tool that allows modeling landslide runout from the initiation sources was applied. The flow direction was calculated using the modified Holmgren's algorithm. The AHP landslide initiation and runout susceptibility maps were used to prepare a combined landslide susceptibility map. The relative operating characteristic curve was used for model validation purpose. The accuracy of Wo E, AHP, and combined susceptibility map was calculated 96%, 97%, and 98%, respectively.

Geochemical characteristics and origin of the Neoproterozoic high-K calc-alkaline granitoids in the northern part of Mandara hills,northeastern Nigeria

The high-K calc-alkaline granitoids in the northern part of the Mandara Hills are part of the wellexposed post-collisional plutons in northeastern Nigeria.The calc-alkaline rock association consists of quartz monzodiorite,hornblende biotite granite,biotite granites and aplite which intruded the older basement consisting mainly of low-lying migmatitic gneisses and amphibolites during the Neoproterozoic Pan-African Orogeny.Petrological and geochemical studies have revealed the presence of hornblende,iron oxide,and metaluminous to slightly peraluminous characteristics in the granitoids which is typical of I-type granite.The granitoids are also depleted in some high field strength elements(e.g.Nb and Ta) as well as Ti.Plots of Mg#versus SiO2 indicate that the granite was derived from partial melting of crustal sources.Lithospheric delamination at the waning stage of the PanAfrican Orogeny possibly triggered upwelling of hot mafic magma from the mantle which underplated the lower crust.This,in turn,caused partial melting and magma generation at the lower to middle-crustal level.However,the peculiar geochemical characteristics of the quartz monzodiorite especially the enrichment in compatible elements such as MgO,Cr,and Ni,as well as LILE element(e.g.K,Ce,Cs,Ba,and Sr),signify that the rock formed from an enriched upper mantle source.The emplacement of high-K granites in the Madara Hill,therefore,marked an important episode of crustal reworking during the Neoproterozoic.However,further isotopic work is needed to confirm this model.

Dinosaurs,birds and pterosaurs of Korea and geological heritage protection

Republic of Korea(South Korea)is one of the richest and most exciting regions on earth for the study of vertebrate ichnology.Very unique vertebrate fossils include dinosaurs,bird tracks,pterosaurs were discovered from more important sites.New finds of dinosaur skeletal remains have increased the number and diversity of known Korean dinosaur taxa.Other fossils including dinosaur tooth and skin impressions,pterosaur bonesand tooth,turtle bones and eggs,crocodile skull and tooth,lizard bone,wood fossils,and trace fossils.Many sites reveal the highest density of bird and dinosaur track levels anywhere in the world.In South Korea there is a comprehensive system of national and provincial parks as well as nearly 500 sites identified under national legislation as‘naturalmonuments',in which the Cretaceous sites are the most abundant,and the Mudeungsan National Geopark newly established was certificated as the UNESCO Global Geopark.

Using Time Series of Satellite Images to Detect Vegetation Cover Change in Dhaka City

The spatial land cover pattern of Dhaka city is restlessly altering as it has highest growing rates among megacities. Due to high urbanization rates, land use is changing from natural to man-made along with resource extractions that accelerate the land cover changes. This study has evidently given the glimpse of the raising concern by assessing the loss of vegetation coverage of Dhaka Metropolitan Area using multi-temporal Landsat imageries. 20 years satellite data have been used to detect the vegetation cover changes in Dhaka city with an interval of 10 years. Study reveals that 66.87 square kilometer vegetation coverage of Dhaka Metropolitan Area is lost during the whole time period. The rate of loss of vegetation coverage is very severe in Dhanmondi, Gulshan, Uttara, Demra, Mirpur, Sabujbagh, Ramna, Mohammadpur, Kafrul, Shyampur and so on. The overall precision of my Landsat-derived vegetation coverage maps is 92.5%.

Seismicity in the Bengal Basin:Threat for Future Massive Earthquakes

The 26 December 2004 earthquake off Sumatra coast focused world attention on the Sunda arc subduction zone.Bangladesh is along the strike of and within a rupture-distance from that enormous M-9.3 earthquake. This country is situated where the India-Sunda subduction zone rises from oceanic depths to subaerial exposure as a result of incipient continent collision where the trench meets the huge sediment

Natural Gas Management of Bangladesh:Energy Powerhouse of SE Asia?

Already Bangladesh has proven to be a natural gas giant in the region and to the energy producing community of the world.The Bangladesh sub-surface is according to the present knowledge mainly gas prone,with some potential for future oil discoveries. Within the 144549 km^2 territory,Bangladesh has

The need for data integration to address the challenges of climate change on the Guyana coast

Guyana’s capacity to address the impacts of climate change on its coastal environment requires the ability to mon-itor,quantify and understand coastal change over short-,medium-and long-term.Understanding the drivers of change in coastal and marine environment can be achieved through the accurate measurement and critical anal-yses of morphologies,flows,processes and responses.This manuscript presents a strategy developed to create a central resource,database and web-based platform to integrate data and information on the drivers and the changes within Guyana coastal and marine environment.The strategy involves four complimentary work pack-ages including data collection,development of a platform for data integration,application of the data for coastal change analyses and consultation with stakeholders.The last aims to assess the role of the integrated data sys-tems to support strategic governance and sustainable decision-making.It is hoped that the output of this strategy would support the country’s climate-focused agencies,organisations,decision-makers,and researchers in their tasks and endeavours.

Petrogenesis and Tectonic Implications of Peralkaline A-Type Granites and Syenites from the Suizhou-Zaoyang Region,Central China

In this study, we present systematic petrological, geochemical, LA-ICP-MS zircon U-Pb ages and Nd isotopic data for the A-type granites and syenites from Suizhou-Zaoyang region. The results show that the peralkaline A-type granites and syenites were episodically emplaced in Suizhou-Zaoyang region between 450±3 and 441±7 Ma which corresponds to Late Ordovician and Early Silurian periods, respectively. Petrologically, the syenite-peralkaline granite association comprises of nephefine normative-syenite and alkaline granite in Guanzishan and quartz normative syenite and alkafine granite in Huangyangshan. The syenite-granite associations are ferroan to alkali in composition. They depict characteristics of typical OIB （oceanic island basalts） derived A-type granites in multi-elements primitive normalized diagram and Ybffa vs. Y/Nb as well as Ce/Nb vs. Y/Nb binary plots. Significant depletion in Ba, Sr, P, Ti and Eu indicates fractionation of feldspars, biotite, amphiboles and Ti-rich augite. The values of eNd（t） in Guanzishan nepheline syenite and alkaline granite are ＋1.81 and ＋2.26, respectively and the calculated two-stage model age for these rocks are 1 040 and 1 003 Ma, respectively. On the other hand, the Huangyangshan alkaline granite has eNd（t） values ranging from ＋2.61 to ＋3.46 and a relatively younger two-stage Nd model age values ranging from 906 to 975 Ma, respectively. Based on these data, we inferred that the Guanzishan nepheline syenites and granites were formed from fractional crystallization of OIB-like basic magmas derived from upweliing of metasomatized lithospheric mantle. The Huangyangshan quartz syenite and granite on the other hand, were formed from similar magmas through fractional crystallization with low input from the ancient crustal rocks. Typically, the rocks exhibit Al-type granite affinity and classified as within plate granites associated with the Ordovician crustal extension and the Silurian rifting.

墨西哥湾盆地东南部区域构造演化过程探讨

墨西哥湾盆地东南部位于北美板块与加勒比板块碰撞交汇区域,是墨西哥湾地区构造最为复杂区域。涉及两大板块,北美板块和加勒比板块;两个二级板块,尤卡坦板块和巴哈马-佛罗里达板块。在总结前人研究成果基础上,结合深海钻探计划(DSDP)钻井资料以及最新二维地震数据,通过地震相特征识别,分析研究区构造演化过程,探讨板块之间相对运动对墨西哥湾盆地东南部区域的控制作用。结果表明:(1)墨西哥湾盆地东南部现今包含北古巴前陆盆地以及盆地北部被动大陆边缘的不规则中央裂陷区;(2)该区域经历多期构造活动,早侏罗世至中侏罗世中期南美板块与北美板块之间背向分离,白垩纪加勒比板块逆冲北美板块,晚白垩世早期海平面上升以及尤卡坦台地与佛罗里达台地抬升,白垩纪末期加勒比板块北侧古加勒比弧与北美板块碰撞拼合;(3)在早白垩世晚期,由于北美板块内部尤卡坦板块与巴哈马-佛罗里达板块之间的张裂运动,发育大量张性断层,产生NW-SE走向的地堑、半地堑构造样式。