Empirical assessment of rockfall and debris flow risk along the Karakoram Highway,Pakistan     

Ali  Sajid  Haider  Rashid  Abbas  Wahid  Basharat  Muhammad  Reicherter  Klaus 《Natural Hazards》2021,106(3):2437-2460

Natural Hazards - The Karakoram Highway links north Pakistan with southwest China. It passes through unique geomorphological, geological and tectonic setting. This study focused 200-km-long section...  相似文献   

Wetting Induced Deformation of Soils Triggering Landslides in Pakistan     

Riaz  Saima  Kikumoto  Mamoru  Basharat  Muhammad  Putra  Andius Dasa 《Geotechnical and Geological Engineering》2021,39(8):5633-5649

Geotechnical and Geological Engineering - Shallow and deep seated landslides in natural slopes are often induced by rainfall. The cause of the failure is usually considered to be due to the...  相似文献   

Prediction criteria for groundwater potential zones in Kemuning District,Indonesia using the integration of geoelectrical and physical parameters          下载免费PDF全文

Juandi Muhammad  Nur Islami 《地下水科学与工程》2021,9(1):12-19

The presence of groundwater is strongly related to its geological and geohydrological conditions.It is,however,important to study the groundwater potential in an area before it is utilized to provide clean water.Werner-Schlumberger’s method was used to analyze the groundwater potential while hydraulic properties such as soil porosity and hydraulic conductivity were used to determine the quality and ability of the soil to allow water’s movement in the aquifer.The results show that the aquifer in the Sekara and Kemuning Muda is at a depth of more than 6 meters below the ground level with moderate groundwater potential.It is also found that the aquifer at depths of over 60 m have high groundwater potential.Moreover,soil porosity in Kemuning is found to be average while the ability to conduct water was moderate.This makes it possible for some surface water to seep into the soil while the remaining flows to the rivers and ditches.  相似文献   

Volcanically Driven Terrestrial Environmental Perturbations during the Carnian Pluvial Episode in the Eastern Tethys     

Naveed Ur RAHMAN  XIAN Benzhong  FANG Linhao  CHEN Sirui  CHEN Peng  Zaheen ULLAH  WANG Pengyu 《《地质学报》英文版》2024,98(3):753-770

The Carnian Pluvial Episode (CPE) fingerprints global environmental perturbations and biological extinction on land and oceans and is potentially linked to the Wrangellia Large Igneous Province (LIP). However, the correlation between terrestrial environmental changes and Wrangellia volcanism in the Ordos Basin during the CPE remains poorly understood. Records of negative carbon isotopic excursions (NCIEs), mercury (Hg), Hg/TOC, and Hg enrichment factor (HgEF) from oil shales in a large-scale terrestrial Ordos Basin in the Eastern Tethys were correlated with marine and other terrestrial successions. The three significant NCIEs in the study section were consistently correlated with those in the CPE successions of Europe, the UK, and South and North China. The U-Pb geochronology indicates a Ladinian–Carnian age for the Chang 7 Member. A comprehensive overview of the geochronology, NCIE correlation, and previous bio- and chronostratigraphic frameworks shows that the Ladinian–Carnian boundary is located in the lower part of Chang 7 in the Yishicun section. HgEF may be a more reliable proxy for tracing volcanic eruptions than the Hg/TOC ratio because the accumulation rates of TOC content largely vary in terrestrial and marine successions. The records of Hg, Hg/TOC, HgEF, and NCIEs in the Ordos Basin aligned with Carnian successions worldwide and were marked by similar anomalies, indicating a global response to the Wrangellia LIP during the CPE. Anoxia, a warm-humid climate, enhancement of detrital input, and NCIEs are synchronous with the CPE interval in the Ordos Basin, which suggests that the CPE combined with the regional Qinling Orogeny should dominate the enhanced rate of terrigenous input and paleoenvironmental evolution in the Ordos Basin.  相似文献   

Socio-political and ecological stresses on traditional pastoral systems: A review     

Muhammad  Khurshid  Mohammad  Nafees  Abdullah  Khan  Mehmet  Somuncu  Ashfaq  Ahmad Khan  Wajid  Rashid 《地理学报(英文版)》2019,29(10):1758-1770

Journal of Geographical Sciences - Pastoralism is a viable socio-economic system-shaped by landless and agro-pastoral communities in many pastoral regions of the world. This system is mainly based...  相似文献   

A Holistic Approach to Upwelling and Downwelling along the South-West Coast of India     

Phiros Shah  R. Sajeev  K. J. Thara  Grinson George  Muhammad Shafeeque  S. Akash 《Marine Geodesy》2019,42(1):64-84

An attempt has been made to develop a holistic understanding of upwelling and downwelling along the south-west coast of India. The main objective was to elucidate the roles of different forcings involved in the vertical motion along this coast. The south-west coast of India was characterized by upwelling during the south-west monsoon (May to September) and by downwelling during the north-east monsoon and winter (November to February). The average vertical velocity calculated along the south-west coast from the vertical shift of the 26?°C isotherm is 0.57?m/day during upwelling and 0.698?m/day during downwelling. It was concluded that upwelling along the south-west coast of India is driven by offshore Ekman transport due to the alongshore wind, Ekman pumping, horizontal divergence of currents and by the propagation of coastally trapped waves. Whereas downwelling along the coast is driven only by convergence of currents and the propagation of coastally trapped Kelvin waves. Along the west coast of India, the downwelling-favorable Kelvin waves come from the equator and upwelling-favorable waves come from the Gulf of Mannar region.  相似文献   

Intraspecific morphometric diversity of barramundi (Lates calcariferBloch, 1790) in the waters of southern Bangladesh     

Md Reaz CHAKLADER  Ashfaqun NAHAR  Md Abu HANIF  Muhammad A. B. SIDDIK 《海洋湖沼学报（英文）》2019,(4):1393-1402

A total of 160 barramundi's (Lates calcarifer Bloch, 1790) sampled from four rivers (Tentulia, Balaswar, Bakkhali, and Andarmanik) along the southern coastal region of Bangladesh were investigated in terms of morphometric characters to reveal the intraspecific variation. Twenty-five morphometric measurements were extracted using the conventional method and subjected to multivariate analyses (i.e., principal component analysis (PCA), discriminate function analysis (DFA), cluster analysis (CA)) to distinguish individuals from different rivers. The result demonstrated that twenty-two out of 25 measurements was statistically significant (Univariate ANOVA) among all four populations. PCA analysis of morphometric characters resulted in two principal components, PC I and PCⅡ which accounted for 79.25% and 4.28% of the total data variance. PC I-PC Ⅱ plot explained 83.53% of total variance differentiated the population of L. calcarifer into two groups. Discriminate analysis correctly classified about 88.1% of the examined fish into the four areas. The UPGMA dendrogram showed that Bakkhali populations were the most morphologically different populations in comparison to other populations, while Andarmanik and Balaswar populations were very close to each other. The strong morphometric variation between Bakkhali and Tentulia, Andarmanik and Balaswar was observed in the present study, suggested the evidence of the separate stock population of barramundi in these locations, which might require distinct stock management strategies for resource sustainability in the waters of southern Bangladesh. However, if these findings are supported by further molecular markers and geometric morphometry, this would be a strong indication of different stocks of this population in the four rivers of southern Bangladesh.  相似文献   

Detrital apatite fission track constraints on Cenozoic tectonic evolution of the northeastern Qinghai-Tibet Plateau,China: Evidence from Cenozoic strata in Lulehe section,Northern Qaidam Basin     

Ding-ding Du  Cheng-jun Zhang  Muhammad Saleem Mughal  Xiao-yu Wang  Dembele Blaise  Jun-ping Gao  Yuan Ma  Xin-rong Luo 《山地科学学报》2018,15(3):532-547

The Northern Qaidam Basin is located at the northeastern part of the Qinghai-Tibetan Plateau. It contains very thick Cenozoic terrestrial clastic sediments, which records the formation of the northern Qaidam Basin due to compressional deformation during the Indo-Asian collision. In this paper, we used detrital apatite fission-track thermochronology, including 4 sandstones and 2 conglomerates samples from the Lulehe section, to reveal the Cenozoic evolution of the northern Qaidam Basin. Fission-track dating indicated the source region of the Lulehe section has experienced important cooling and uplifting in the Late Cretaceous (at ~85.1 Ma and ~65 Ma) and the Eocene (~52 Ma), respectively. The AFT age distribution on the section suggested that the provenance of Lulehe section sediments were mainly derived from the south Qilian Shan (Qilian Mountains) and Altun Shan (Altun Mountains), and two significantly provenance changes may occur at 43.4-46.1 Ma and ~37.8 Ma, respectively. The results may have strong constrains on the Cenozoic deformation and tectonic evolution of the northern Qaidam Basin and Qinghai-Tibet Plateau.  相似文献   

Statistically downscaled probabilistic multi‐model ensemble projections of precipitation change in a watershed     

Muhammad Z. Hashmi  Asaad Y. Shamseldin  Bruce W. Melville 《水文研究》2013,27(7):1021-1032

This paper presents the development of a probabilistic multi‐model ensemble of statistically downscaled future projections of precipitation of a watershed in New Zealand. Climate change research based on the point estimates of a single model is considered less reliable for decision making, and multiple realizations of a single model or outputs from multiple models are often preferred for such purposes. Similarly, a probabilistic approach is preferable over deterministic point estimates. In the area of statistical downscaling, no single technique is considered a universal solution. This is due to the fact that each of these techniques has some weaknesses, owing to its basic working principles. Moreover, watershed scale precipitation downscaling is quite challenging and is more prone to uncertainty issues than downscaling of other climatological variables. So, multi‐model statistical downscaling studies based on a probabilistic approach are required. In the current paper, results from the three well‐reputed statistical downscaling methods are used to develop a Bayesian weighted multi‐model ensemble. The three members of the downscaling ensemble of this study belong to the following three broad categories of statistical downscaling methods: (1) multiple linear regression, (2) multiple non‐linear regression, and (3) stochastic weather generator. The results obtained in this study show that the new strategy adopted here is promising because of many advantages it offers, e.g. it combines the outputs of multiple statistical downscaling methods, provides probabilistic downscaled climate change projections and enables the quantification of uncertainty in these projections. This will encourage any future attempts for combining the results of multiple statistical downscaling methods. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Application of Generalized Likelihood Uncertainty Estimation (GLUE) at different temporal scales to reduce the uncertainty level in modelled river flows     

Ragab Ragab  Alexandra Kaelin  Muhammad Afzal  Ioanna Panagea 《水文科学杂志》2020,65(11):1856-1871

ABSTRACT

In this study, the distributed catchment-scale model, DiCaSM, was applied on five catchments across the UK. Given its importance, river flow was selected to study the uncertainty in streamflow prediction using the Generalized Likelihood Uncertainty Estimation (GLUE) methodology at different timescales (daily, monthly, seasonal and annual). The uncertainty analysis showed that the observed river flows were within the predicted bounds/envelope of 5% and 95% percentiles. These predicted river flow bounds contained most of the observed river flows, as expressed by the high containment ratio, CR. In addition to CR, other uncertainty indices – bandwidth B, relative bandwidth RB, degrees of asymmetry S and T, deviation amplitude D, relative deviation amplitude RD and the R factor – also indicated that the predicted river flows have acceptable uncertainty levels. The results show lower uncertainty in predicted river flows when increasing the timescale from daily to monthly to seasonal, with the lowest uncertainty associated with annual flows.  相似文献