Agriculture is being main stay of Pakistan economy and it’s very significant to monitor the existing agricultural areas and its changes, due to different aspects like salinity and waterlogging, which reduce the ferti...Agriculture is being main stay of Pakistan economy and it’s very significant to monitor the existing agricultural areas and its changes, due to different aspects like salinity and waterlogging, which reduce the fertility of agricultural lands adversely. Managing salinity so as to minimize its environmental impact is a prerequisite for the long-term sustainability of irrigated agriculture. It is ironic that the irrigated areas are those that are afflicted most by the twin menaces of waterlogging and salinity. Geospatial technology was used to assess the waterlogging and salinity condition in Nara canal command area, during the last two surveys conducted in years 1977-1981 and 2001- 2003 respectively. After analyzing the results in detail, we obtain a clear relationship among salt affected soils, and waterlogged areas reveal that 0.2% to 1.25% of salt affected areas fall under the shallow zone with high water table. The spatial distribution of water table shows various trends among the water tables, and the surface salinity of surface saline areas has been increased due to waterlogging caused by unmanaged spatial drainage system.展开更多
Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an ab...Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an abundant component.Vanadium is an essential tool to determine the relationship of the Earth with extra-terrestrial bodies.In the Yangtze region,the black rocks of the Early Cambrian Niutitang Formation are highly enriched in the concentration of V,Co,Ni and Mo.These sediments are comprised of a high total organic carbon content,and the average concentration of vanadium is over 240 ppm.Here we discuss the mechanisms and conditions that were responsible for the accumulation of vanadium in these black sediments in the Yangtze region.The oxygenated ocean water is favorable for the dissolved vanadate species Ⅴ(Ⅴ).Therefore,in oxic ocean-water,it can be reduced by organic matters or by H_(2)S to vanadyl ions Ⅴ(Ⅳ),which can facilely be adsorbed to the tiny particles and finally deposit into the sediments with the settling of the particles.The presence of V_(2)O_(3) in the Niutitang Formation indicates the isomorphism state of vanadium existence in the clay minerals.Clays and pyrite are the most favorable mineral for vanadium enrichment.However,it is suggested the quartz of non-biogenic origin might be unfavorable for vanadium enrichment.Vanadium is mainly derived from the diagenetic transformation of its precursor(porphyrin pigments and chlorophyll)from the organism.During the Early Cambrian period,the massive transgression in the sea level created a favorable environment for organisms to survive.Additionally,the hydrothermal activities brought massive nutrient supply in the form of vanadium and other metal elements from the deep Earth.These creatures consumed the vanadium-rich nutrients,which became a part of their bodies in the form of hard and soft parts.Later on,when these organisms died and were submerged in the sediments.After the diagenetic actions,this vanadium became a part of these black sediments along with organic carbon.Therefore,these black rocks in the Yangtze region are enriched in vanadium and organic carbon.It is suggested the various processes such as adsorption,complexation,and reductions are the main factors responsible for the precipitation of dissolved vanadium into the organically rich sediments.展开更多
This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,a...This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.展开更多
The global cryosphere is experiencing accelerated melting due to climate change.Currently,the Karakoram anomaly is under discussion with a debate about the possibility that the anomaly may have recently ended.This stu...The global cryosphere is experiencing accelerated melting due to climate change.Currently,the Karakoram anomaly is under discussion with a debate about the possibility that the anomaly may have recently ended.This study aims to evaluate the up-to-date changes in snow cover in the western Karakoram region.We observed the snow cover changes in Passu and Ghulkin valleys in the Hunza River basin(HRB)of the Karakoram through multitemporal Landsat satellite data between 1995 and 2022.We found a significant reduction in snow cover in these valleys,with an average reduction rate of 0.42 km~2/yr,resulting in a total reduction of~11.46 km~2 between 1995 and 2022.This reduction in snow cover is consistent with the mass loss of glaciers in the Karakoram region in recent years.The decline in snow cover in these valleys is also consistent with the meteorological data.The temperature in summer(June)has significantly increased whereas the precipitation in the accumulation season(March)has decreased.These rapid changes suggest that it is crucially important to monitor the snow cover on a regular basis to support downstream management of snowmelt runoff.In addition,there is a need of planning for mitigation and adaptation strategies for snow-related hazards.展开更多
The Niutitang Formation in the South China Block might be a source of hydrocarbon as it contains an enormous quantity of organic matter.Black rock of the Early Cambrian Niutitang Formation is widely distributed in the...The Niutitang Formation in the South China Block might be a source of hydrocarbon as it contains an enormous quantity of organic matter.Black rock of the Early Cambrian Niutitang Formation is widely distributed in the Yangtze region,but detailed geochemical understanding of it is still emerging.This research discusses the detailed geochemical characteristics of the Niutitang Formation to reconstruct the paleoenvironmental conditions,employing total organic carbon(TOC)content,major,trace,and rare earth element data.For this purpose,black rock specimens of the Niutitang Formation from two outcrop sections were utilized for geochemical characterization,and the results compared with another eight sections from the South China Block.The average total organic carbon in these sediments is significantly higher(5.80 wt.%).In the platform region,lower quantities of TOC indicate a poor potential to produce hydrocarbons.At the same time,significantly higher TOC is observed in the deep shelf and slope sediments,indicating a significant potential to produce hydrocarbons.The average Ce,Eu and Y anomalies from both Longbizui and Sancha sections studied are 0.74,0.86,1.77,1.07,and 1.19,1.30,respectively.The chemical index of alteration(CAI)throughout the Yangtze block is higher(averaging 71.32)than that of Post Archean Australian Shale(PAAS 69),indicating a moderately weathered source of the Niutitang Formation relative to PAAS.As the sediments are moderately weathered,this suggests these rocks might have been derived from felsic rocks,mainly granite-granodiorite.The normalization of REEs in the black rocks reveals a reduction of light REEs with increase in heavy REEs enrichment.Similarly,a positive Eu anomaly,negative Ce anomaly,and a moderate Y/Ho(34.61)are clues to a hybrid depositional mechanism associated with hydrothermal action and terrigenous input.These anomalies are also evidence of upwelling in the paleo-ocean and mixing of organic matter,which created anoxic bottom water during the deposition of the Niutitang Formation in the basin and upper oxic water conditions before deposition.The main controlling factors for the distribution of rare earth elements in these black rocks of the Niutitang Formation are pH,terrigenous input,source rock composition,tectonism,an upwelling mechanism,and hydrothermal activity.展开更多
Hydrographic surveying in reservoirs is a key activity in order to collect data for a variety of purposes like estimation of storage capacity, rate and pattern of sediment deposition, movement of underwater sediment d...Hydrographic surveying in reservoirs is a key activity in order to collect data for a variety of purposes like estimation of storage capacity, rate and pattern of sediment deposition, movement of underwater sediment delta and reservoir routing, etc. These parameters play a pivotal role in any planning, management and operation activity of the reservoirs. Traditional approaches to perform hydrographic surveying in Indus Basin are time consuming, laborious, comparatively inaccurate and costly. As water resources are under immense pressure due to a variety of factors, such inefficient methods are not acceptable for efficient water management. In this study, an integrated approach for hydrographic surveying is introduced and evaluated in terms of its efficiency in comparison with the traditional methods of hydrographic surveying. The approach develops an integrated environment of hydrographic surveying comprising human, hardware and software. The process of surveying starts from in-house planning using specialized geo-spatial softwares. Then, on site a combination of computer hardware, echosounder, differential global positioning system (DGPS), survey vessel and survey crew is made. Post-processing is performed after conducting a survey in order to improve quality of data by filtering errors and producing the end product like reservoir underwater terrain, development of reservoir stage-area and stage-storage relationships, etc. The study was applied to Tarbela Reservoir, Pakistan.展开更多
The Lower Indus Basin is the leading hydrocarbon-bearing sedimentary basin in Pakistan.This study has been conducted on the Sawan gas field located in the Lower Indus Basin,adjacent to a few other wellknown gas fields...The Lower Indus Basin is the leading hydrocarbon-bearing sedimentary basin in Pakistan.This study has been conducted on the Sawan gas field located in the Lower Indus Basin,adjacent to a few other wellknown gas fields of Pakistan like Kadanwari,Qadirpur,and Miano gas fields.This research aims to present the spatial distribution and reservoir potential of the productive zones of the Lower Goru Formation.The present study utilized various two-dimensional(2D)seismic lines and well-log data(Sawan-01 and Sawan-02)to investigate the structural and stratigraphic features of the area.The stratigraphic layers are mildly deepening in the southeast direction.The 2D seismic interpretation of the research area identifies the existence of extensional remanents,i.e.,normal faults.These extensional structures are associated with horst and graben geometry that acts as a trapping mechanism for hydrocarbons.Wireline logs are used to identify the reservoir's diverse lithology and petrophysical properties.Petrophysical results indicate fair to good effective porosities,low shale volume,and high hydrocarbon saturation(>55%),signifying good reservoir potential in C interval of the Lower Goru Formation.展开更多
文摘Agriculture is being main stay of Pakistan economy and it’s very significant to monitor the existing agricultural areas and its changes, due to different aspects like salinity and waterlogging, which reduce the fertility of agricultural lands adversely. Managing salinity so as to minimize its environmental impact is a prerequisite for the long-term sustainability of irrigated agriculture. It is ironic that the irrigated areas are those that are afflicted most by the twin menaces of waterlogging and salinity. Geospatial technology was used to assess the waterlogging and salinity condition in Nara canal command area, during the last two surveys conducted in years 1977-1981 and 2001- 2003 respectively. After analyzing the results in detail, we obtain a clear relationship among salt affected soils, and waterlogged areas reveal that 0.2% to 1.25% of salt affected areas fall under the shallow zone with high water table. The spatial distribution of water table shows various trends among the water tables, and the surface salinity of surface saline areas has been increased due to waterlogging caused by unmanaged spatial drainage system.
基金the National Natural Science Foundation(NNCF)of China for awarding us pecuniary aid with Grant Numbers 41572099,and 41872127 to accomplish this scientific research.
文摘Vanadium in the black rocks has economic and environmental impacts.In sediments,it is broadly disseminated as a multivalent metal element mainly sensitive to redox settings.Globally in petroleum,it is considered an abundant component.Vanadium is an essential tool to determine the relationship of the Earth with extra-terrestrial bodies.In the Yangtze region,the black rocks of the Early Cambrian Niutitang Formation are highly enriched in the concentration of V,Co,Ni and Mo.These sediments are comprised of a high total organic carbon content,and the average concentration of vanadium is over 240 ppm.Here we discuss the mechanisms and conditions that were responsible for the accumulation of vanadium in these black sediments in the Yangtze region.The oxygenated ocean water is favorable for the dissolved vanadate species Ⅴ(Ⅴ).Therefore,in oxic ocean-water,it can be reduced by organic matters or by H_(2)S to vanadyl ions Ⅴ(Ⅳ),which can facilely be adsorbed to the tiny particles and finally deposit into the sediments with the settling of the particles.The presence of V_(2)O_(3) in the Niutitang Formation indicates the isomorphism state of vanadium existence in the clay minerals.Clays and pyrite are the most favorable mineral for vanadium enrichment.However,it is suggested the quartz of non-biogenic origin might be unfavorable for vanadium enrichment.Vanadium is mainly derived from the diagenetic transformation of its precursor(porphyrin pigments and chlorophyll)from the organism.During the Early Cambrian period,the massive transgression in the sea level created a favorable environment for organisms to survive.Additionally,the hydrothermal activities brought massive nutrient supply in the form of vanadium and other metal elements from the deep Earth.These creatures consumed the vanadium-rich nutrients,which became a part of their bodies in the form of hard and soft parts.Later on,when these organisms died and were submerged in the sediments.After the diagenetic actions,this vanadium became a part of these black sediments along with organic carbon.Therefore,these black rocks in the Yangtze region are enriched in vanadium and organic carbon.It is suggested the various processes such as adsorption,complexation,and reductions are the main factors responsible for the precipitation of dissolved vanadium into the organically rich sediments.
文摘This study is aimed to delineate the subsurface structural elements using geophysical techniques in the Haraza area of Pakistan.We investigated the Oghi and Battal thrust faults,sedimentary and metasedimentary wedge,and the absolute crustal thickness based on terrestrial gravity data.Unlike seismic survey relying on wave propagation,magnetic survey is based on both attraction and repulsion,and electrical and electromagnetics on induction.The attractive gravity field produces relatively simpler patterns of anomalies,like a series of highs and lows over regions with undulating basements and buried structures.A qualitative interpretation of gravity data reveals a good deal of information.During the collision of Indian and Eurasian Plates,compressional structures were developed in the Lesser Himalayas or northwest of the Hazara Kashmir Syntaxis.The study mainly focuses on the western limb of the Hazara Kashmir Syntaxis.The regional and local Bouguer anomalies were incorporated to delineate the regional structural units.The gravity model is computed through geophysical technique along with profile A-A'from Mansehra to the Battal area that demarcates the blind Oghi Thrust and emergent Battal Thrust.Tanol Formation of Precambrian age demarcates the Oghi Thrust near Kotli Pine while the Battal Thrust is demarcated within the Mansehra Granite of Cambrian to Ordovician age near Battal.Along with the Battal Thrust,fault gouge and breccias have been observed during the field studies.The total thickness of the sedimentary/metasedimentary wedge in the Mansehra and Battal areas was estimated to be 13.6 km and 14.2 km.In comparison,the total thickness of crust in the Mansehra and Battal areas was 51.6 km and 52.2 km,respectively.
基金supported by ICIMODfunded by the governments of Afghanistan,Australia,Austria,Bangladesh,Bhutan,China,India,Myanmar,Nepal,Norway,Pakistan,Sweden,and Switzerland。
文摘The global cryosphere is experiencing accelerated melting due to climate change.Currently,the Karakoram anomaly is under discussion with a debate about the possibility that the anomaly may have recently ended.This study aims to evaluate the up-to-date changes in snow cover in the western Karakoram region.We observed the snow cover changes in Passu and Ghulkin valleys in the Hunza River basin(HRB)of the Karakoram through multitemporal Landsat satellite data between 1995 and 2022.We found a significant reduction in snow cover in these valleys,with an average reduction rate of 0.42 km~2/yr,resulting in a total reduction of~11.46 km~2 between 1995 and 2022.This reduction in snow cover is consistent with the mass loss of glaciers in the Karakoram region in recent years.The decline in snow cover in these valleys is also consistent with the meteorological data.The temperature in summer(June)has significantly increased whereas the precipitation in the accumulation season(March)has decreased.These rapid changes suggest that it is crucially important to monitor the snow cover on a regular basis to support downstream management of snowmelt runoff.In addition,there is a need of planning for mitigation and adaptation strategies for snow-related hazards.
基金supported by the National Natural Science Foundation of China(Nos.41572099 and 41872127).
文摘The Niutitang Formation in the South China Block might be a source of hydrocarbon as it contains an enormous quantity of organic matter.Black rock of the Early Cambrian Niutitang Formation is widely distributed in the Yangtze region,but detailed geochemical understanding of it is still emerging.This research discusses the detailed geochemical characteristics of the Niutitang Formation to reconstruct the paleoenvironmental conditions,employing total organic carbon(TOC)content,major,trace,and rare earth element data.For this purpose,black rock specimens of the Niutitang Formation from two outcrop sections were utilized for geochemical characterization,and the results compared with another eight sections from the South China Block.The average total organic carbon in these sediments is significantly higher(5.80 wt.%).In the platform region,lower quantities of TOC indicate a poor potential to produce hydrocarbons.At the same time,significantly higher TOC is observed in the deep shelf and slope sediments,indicating a significant potential to produce hydrocarbons.The average Ce,Eu and Y anomalies from both Longbizui and Sancha sections studied are 0.74,0.86,1.77,1.07,and 1.19,1.30,respectively.The chemical index of alteration(CAI)throughout the Yangtze block is higher(averaging 71.32)than that of Post Archean Australian Shale(PAAS 69),indicating a moderately weathered source of the Niutitang Formation relative to PAAS.As the sediments are moderately weathered,this suggests these rocks might have been derived from felsic rocks,mainly granite-granodiorite.The normalization of REEs in the black rocks reveals a reduction of light REEs with increase in heavy REEs enrichment.Similarly,a positive Eu anomaly,negative Ce anomaly,and a moderate Y/Ho(34.61)are clues to a hybrid depositional mechanism associated with hydrothermal action and terrigenous input.These anomalies are also evidence of upwelling in the paleo-ocean and mixing of organic matter,which created anoxic bottom water during the deposition of the Niutitang Formation in the basin and upper oxic water conditions before deposition.The main controlling factors for the distribution of rare earth elements in these black rocks of the Niutitang Formation are pH,terrigenous input,source rock composition,tectonism,an upwelling mechanism,and hydrothermal activity.
文摘Hydrographic surveying in reservoirs is a key activity in order to collect data for a variety of purposes like estimation of storage capacity, rate and pattern of sediment deposition, movement of underwater sediment delta and reservoir routing, etc. These parameters play a pivotal role in any planning, management and operation activity of the reservoirs. Traditional approaches to perform hydrographic surveying in Indus Basin are time consuming, laborious, comparatively inaccurate and costly. As water resources are under immense pressure due to a variety of factors, such inefficient methods are not acceptable for efficient water management. In this study, an integrated approach for hydrographic surveying is introduced and evaluated in terms of its efficiency in comparison with the traditional methods of hydrographic surveying. The approach develops an integrated environment of hydrographic surveying comprising human, hardware and software. The process of surveying starts from in-house planning using specialized geo-spatial softwares. Then, on site a combination of computer hardware, echosounder, differential global positioning system (DGPS), survey vessel and survey crew is made. Post-processing is performed after conducting a survey in order to improve quality of data by filtering errors and producing the end product like reservoir underwater terrain, development of reservoir stage-area and stage-storage relationships, etc. The study was applied to Tarbela Reservoir, Pakistan.
文摘The Lower Indus Basin is the leading hydrocarbon-bearing sedimentary basin in Pakistan.This study has been conducted on the Sawan gas field located in the Lower Indus Basin,adjacent to a few other wellknown gas fields of Pakistan like Kadanwari,Qadirpur,and Miano gas fields.This research aims to present the spatial distribution and reservoir potential of the productive zones of the Lower Goru Formation.The present study utilized various two-dimensional(2D)seismic lines and well-log data(Sawan-01 and Sawan-02)to investigate the structural and stratigraphic features of the area.The stratigraphic layers are mildly deepening in the southeast direction.The 2D seismic interpretation of the research area identifies the existence of extensional remanents,i.e.,normal faults.These extensional structures are associated with horst and graben geometry that acts as a trapping mechanism for hydrocarbons.Wireline logs are used to identify the reservoir's diverse lithology and petrophysical properties.Petrophysical results indicate fair to good effective porosities,low shale volume,and high hydrocarbon saturation(>55%),signifying good reservoir potential in C interval of the Lower Goru Formation.
