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41.
Zahra Saleh 《Arabian Journal of Geosciences》2014,7(10):4235-4243
In the present research, biostratigraphy and paleoecology of the Asmari Formation at the Shajabil anticline, northwest Yasuj in the Izeh zone are discussed. The Asmari Formation at the studied area is Rupelian–Chattian to Burdigalian in age. In the study, 18 genera and 29 species of benthic foraminifera have been identified. Besides, the following biozones which reflect Rupelian–Chattian to Burdigalian age are identified for the Asmari Formation: (1) Lepidocyclina–Operculina–Ditrupa; (2) Archaias asmaricus–Archaias hensoni–Miogypsinoides complanatus; (3) Peneroplis farsenensis_Elphidium sp.14–Miogypsina sp.; (4) Borelis melo–Borelis melo curdica. Relying on fossils, Coral and Corallinacea have been detected depositional environment. The paleo-ecological factors are identified for the Asmari Formation at the study area: water salinity, 34 to more than 50 psu; water depth of 90 to 0 m; water temperature of 14 °C to more than 27 °C in a subtropical to tropical environment, oligotrophoic to mesotrophic conditions. 相似文献
42.
The present study aimed at identifying the salinity source in the groundwater of Lenjanat Plain. To do so, non-isotopic geochemical methods were employed: groundwater samples were collected seasonally from 33 wells widespread in the area, and physicochemical parameters as well as major and minor elements were measured in the 132 samples. The data collected from the field and laboratory measurements were interpreted through statistical and hydrogeochemical graphs, mass ratios and saturation indexes obtained from modeling. The results revealed that hydrogeochemical properties of the study aquifer were controlled by rock/water interactions including ion exchange, dissolution of evaporation deposits (halite and gypsum) and precipitation/dissolution of carbonates. Based on the values of Cl/Br ratio in Lenjanat groundwater (329–4,492), dissolution of evaporation deposits in aquifer was the main cause for groundwater salinity. Considering the Lenjanat groundwater geochemical properties, the data confirm the reported Cl/Br ratios for groundwater affected by the dissolution of evaporation deposits (Cl/Br > 300) and overlaps with the range of Cl/Br ratios for domestic sewage effluent groundwater. Selecting the best chemical components and their ratios in non-isotopic geochemical methods provides an accurate distinction between sources of groundwater salinity. 相似文献
43.
A new modelling framework capable of incorporating detailed one‐dimensional models in a catchment context is presented which can be used to asses the hydrological implications (recharge, discharge, salt movement) of different land uses on different parts of the catchment. The modelling framework incorporates farming systems models and, thus, simulates crop and pasture production, whilst also accounting for lateral fluxes of water (surface and subsurface) and groundwater recharge and discharge. The framework was applied to Simmons Creek catchment, a subcatchment of the Billabong Creek in southern New South Wales, comprising gentle uplands and substantial low‐relief areas containing swamps. An integrated approach incorporating soil, hydrology, hydrogeology, and terrain analysis resulted in interpretation of landscape function and the necessary parameterization of the modelling framework. Current land use (crop rotation and pasture) and an alternative land use (10% trees on uphill units and pasture in the lower lying lands) were simulated to compare the relative contribution of parts of the catchment with total recharge. Comparison between current and alternative land use over 44 years of simulations indicated a decrease of mean annual drainage from 39 to 29 mm year?1 and an average reduction of the groundwater level of about 0·4 m. A more substantial decrease in water‐table depth would require targeted tree planting over larger areas. This can be investigated further with the spatial framework. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
44.
This simulation study explores opportunities to reduce catchment deep drainage through better matching land use with soil and topography, including the ‘harvesting’ (evapotranspiration) of excess water running on to lower land units. A farming system simulator was coupled with a catchment hydrological framework to enable analysis of climate variability and 11 different land‐use options as they impact the catchment water balance. These land‐use options were arranged in different configurations down a sequence of three hydrologically interconnected slope units (uphill, mid‐slope and valley floor land units) in a subcatchment of Simmons Creek, southern New South Wales, Australia. With annual crops, the valley floor land units were predicted to receive 187 mm year?1 of run‐on water in addition to annual rainfall in 1 in 10 years, and in excess of 94 mm year?1 in 1 in 4 years. In this valley floor position, predicted drainage averaged approximately 110 mm year?1 under annual crops and pastures, whereas permanent tree cover or perennial lucerne was predicted to reduce drainage by up to 99%. The planting of trees or lucerne on the valley floor units could ‘harvest’ run‐on water, reducing drainage for the whole subcatchment with proportionately small reduction in land areas cropped. Upslope land units, even though often having shallower soil, will not necessarily be the most effective locations to plant perennial vegetation for the purposes of recharge reduction. Water harvesting opportunities are site specific, dependent on the amounts and frequency of flows of water to lower landscape units, the amounts and frequency of deep drainage on the different land units, the relative areas of the different land units, and interactions with land use in the different slope positions. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
45.
Yves Missenard Omar Saddiqi Jocelyn Barbarand Pascale Leturmy Geoffrey Ruiz Fatima‐Zahra El Haimer Dominique Frizon de Lamotte 《地学学报》2008,20(3):221-228
In North Africa, the High Atlas belt culminates at more than 4000 m. In Morocco, recent work shows that a lithospheric thinning explains about 1000 m of the mean topography, the remaining topography being related to crustal shortening. We combine regional geology with new apatite fission‐track (AFT) ages to constrain the timing of these events in the Marrakech High Atlas (MHA). In the inner belt, 10 AFT ages are comprised between 9 ± 1 and 27 ± 3 Ma. These Neogene ages indicate that the MHA underwent significant denudation during that time. In the southern foreland domain of the belt, three samples give scattered AFT ages between 27 ± 2 and 87 ±5 Ma. Geological evidences allow us to constrain the age of a major denudation event during Middle Miocene age. We propose that it is linked to the thermal doming highlighted in the whole Moroccan Atlas domain. 相似文献
46.
Over the past decade, land development activities on hillsides in northern Utah have resulted in a significant increase in
landslide activity throughout the region. The majority of recent landslides are shallow and they occurred on cut gentle slopes
especially during spring and early summer due to snowmelt induced elevated groundwater tables. The geologic material documented
at numerous landslide sites is a soft gray-green completely decomposed Norwood Tuff. The present study addresses the mechanism
of a shallow landslide in completely decomposed Norwood Tuff based on field, laboratory and numerical investigations. Detailed
slope surface geometry obtained from laser-scan surveys together with strength and stress–strain parameters derived from laboratory
triaxial tests on undisturbed samples of completely decomposed Norwood Tuff collected from the landslide site are employed
with finite-element modeling to examine the effects of ground surface deformation patterns on the yielding behavior of the
slide mass. The numerical results indicate a gradual retreat of the yield zone with progressive landslide deformation, which
eventually becomes concentrated within the accumulation zone of the landslide, compared to a well-developed yield zone within
the entire slide mass at the onset of landslide movement. Limit equilibrium stability analyses along potential sliding surfaces
of extent limited within the yield zone of the displaced slide mass produce lower safety factors than an analysis based on
the original sliding surface comprising the entire slide mass. 相似文献
47.
Data inadequacy is a common problem in designing or updating groundwater monitoring systems. The developed methodologies for the optimal design of groundwater monitoring systems usually assume that there is a complete set of data obtained from existing monitoring wells and provide a revised configuration for the system by analyzing the current data. These methodologies are not usually applicable when the current groundwater quantity and quality data are highly sparse. In this paper, a new simulation–optimization approach based on Bayesian maximum entropy theory (BME) is proposed for revising spatial and temporal monitoring frequencies in a sparsely monitored aquifer. The BME is used to simulate the spatial and spatiotemporal variations of groundwater indicators, incorporating the space/time uncertainties due to insufficient data. Comparing the obtained estimations with observations, the best BME model was selected to be linked with an optimization model. The main goal of optimization was to find out the spatial and temporal sampling characteristics of the monitoring stations using the concepts of Entropy theory and a groundwater vulnerability index. The results show the BME estimations are less biased and more accurate than Ordinary Kriging in both spatial and spatiotemporal analysis. The improvements in the BME estimates are mostly related to incorporating hard (accurate) and soft (uncertain) data in the estimation process. The applicability and efficiency of the proposed methodology have been evaluated by applying it to the Tehran aquifer in Iran which is suffering from high groundwater table fluctuations and nitrate pollution. Based on the results, in addition to the existing monitoring wells, seven new monitoring stations have been proposed. Few stations which potentially can be removed or combined with other stations have been identified and a monthly sampling frequency has been suggested. 相似文献
48.
Quantifying the uncertainty of semiarid flash floods using generalized likelihood uncertainty estimation 总被引：1，自引：0，他引：1
This paper aims to address the question of how the parameter uncertainty associated with a mixed conceptual and physical based rainfall-runoff model (AFFDEF) has influences on flood simulation of the semiarid Abolabbas catchment (284 km2), in Iran. AFFDEF was modified and coupled with the generalized likelihood uncertainty estimation (GLUE) algorithm to simulate four flash flood events. Analysis suggests that AFFDEF parameters showed non-unique posterior distributions depending on the magnitudes and duration of flash flood events. Model predictive uncertainty was heavily dominated by error and bias in soil antecedent moisture condition that led to large storage effect in simulation. Overall, multiplying parameter for the infiltration reservoir capacity and multiplying parameter for the interception reservoir capacity along with potential runoff contributing areas were identified the key model parameters and more influential on flood simulation. Results further revealed that uncertainty was satisfactorily quantified for the event with low to moderate flood magnitudes while high magnitude event exhibited unsatisfactory result. 相似文献
49.
Kayhomayoon Zahra Ghordoyee Milan Sami Arya Azar Naser Kardan Moghaddam Hamid 《Natural Resources Research》2021,30(6):4165-4185
Natural Resources Research - In this study, a new 3-stage approach that consists of clustering, simulation, and optimization stages is proposed for the simulation of groundwater level (GWL) in an... 相似文献
50.
Zahra Yazdi Alireza Jafari Rad Mehraj Aghazadeh Peyman Afzal 《Journal of the Indian Society of Remote Sensing》2018,46(10):1581-1593
The Sonajeel prospect is located in the Arasbaran belt which is one of the significant copper mineralization belts in NW Iran. There are mostly Eocene volcano-sedimentary rocks and Post Eocene intrusive units which are the source for mineralization in the area. ASTER multispectral images were used for delineation of alteration zones as a key feature of porphyry copper mineralization. Due to the need for geometric correction and ortho-rectification of the ASTER images, a high resolution QuickBird image with pixel width of about 60 cm (in PAN) was employed as a reference image in order to boost the rectification process. Ortho-rectification has been done by using digital elevation model which is created by topographic map in scale 1:1000. Potassic alteration as one of the essential alteration types in porphyry copper deposits, distributed mostly in the north of the Sonajeel prospect that determined by Thermal infrared bands processing. Phyllic and argillic alteration zones detected by creating relative absorption band-depth grids which are comparable to field observations. Moreover, silica rich areas which are remnants of hydrothermal circulation and form at the top of porphyry copper systems were detected for recognition of epithermal deposits (with 1 km distance from Sonajeel porphyry system). Finally, Remote Sensing results were compared by field evidences especially for determination of an epithermal system. Most parts of the alteration zones were observed of the surface confirmed with the remote sensing alteration (in average about 75% matched fittingly), displayed concentrations anomalous in the NE and NW parts of the studied area. 相似文献