Firoz Khan | HNB Garhwal University (original) (raw)

Papers by Firoz Khan

This work aims to deal with the morphometric analysis of the Panzara River Basin (PRB) watershed,... more This work aims to deal with the morphometric analysis of the Panzara River Basin (PRB) watershed, a tributary of the Tapi River in Maharashtra, India. In this study, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) and Survey of India (SOI) toposheets have been used along with various parameters like linear, areal, and relief aspects in Geographical Information System (GIS) environment. Out of total 293 number of streams in the watershed, 226, 54, 12, and 1 are of first, second, third and fourth orders respectively. PRB watershed is of 4th order and less elongated in shape, having lower peak flows of longer duration with dendritic pattern and having coarse drainage texture. The bifurcation ratio lies between 6 and 7, indicating that geological structure doesn't have more influence on drainage patterns. The area forms a rugged topography having an elevation range from 123 to 1199 m above Mean Sea Level (MSL). Variables like Stream Frequency and Drainage Density shows impermeable surface of PRB watershed which causes higher water discharge volume and speed in the basin so that the probability is maximum for frequent floods. The results indicates that PRB is having high slope in SW part as compare to NE part and having very low gradient ratio. These variables also shows a temporal variation in the water flowing speed in the stream when the flood reaches its peak. The outcomes of this work can suggest and recommend a better mechanism for proper watershed management in the PRB.

मानव जीवन को सुचारू रूप से चलाने के लिए मनुष्य को स्वस्थ बुद्धि एवं शरीर की आवश्यकता होती है जिनक... more मानव जीवन को सुचारू रूप से चलाने के लिए मनुष्य को स्वस्थ बुद्धि एवं शरीर की आवश्यकता होती है जिनके लिए स्वच्छ एवं संतुलित पर्यावरण परम आवश्यक है। स्वच्छ और संतुलित पर्यावरण से अभिप्राय एक ऐसे वातावरण से है, जिसमें प्रत्येक आवश्यक घटक एक निधारित मात्रा एवं अनुपात में मौजूद होता है। लेकिन कभी-कभी मानव द्वारा या अन्य कारणों से वातावरण में एक अथवा अनेक घटकों की मात्रा या तो जरूरत से अधिक बढ़ जाती है या घट जाती है। इस स्थिति में वातावरण प्रदूषित हो जाता है। प्रदूषित वातावरण मानव जीव जगत के लिए किसी न किसी रूप में हानिकारक प्रभाव जरुर डालता है। वातावरण में इस अनचाहे बदलाव में औद्योगिकीकरण, शहरीकरण, बढ़ती जनसंख्या, कृषि का गहनीकरण, ऊर्जा उपयोग में वृद्धि, परिवहन में वृद्धि, विभिन्न गैसों की उच्च मात्रा में निकासी, अनियोजित भूमि-उपयोग नीतियाँ तथा मानवविकास की प्रक्रियाए आदि का अहम् योगदान है। वातावरण के घटकों के आधार पर पर्यावरणीय प्रदूषण को मुख्यत; जल प्रदूषण, मृदा प्रदूषण, वायु प्रदूषण एवं ध्वनी प्रदूषण आदि भागों में बाँटा जा सकता है।

The present study aims to conduct a morphometric analysis of the Girna River Basin watershed, a t... more The present study aims to conduct a morphometric analysis of the Girna River Basin watershed, a tributary of the Tapi River in Maharashtra, India. A detailed morphometry analysis was performed using remote sensing and GIS using a Digital Elevation Model (Aster DEM) and SOI toposheets, and various drainage basin parameters such as Linear, Areal, and Relief aspects were also calculated. The Girna River Basin comprises 2,137 streams and has 6th order stream networks, in which 1,071, 526, 261, 125, 107, and 47 are the first-, second-, third-, fourth-, fifth-, and sixth-order streams, respectively. The Girna River Basin is 6th order stream with a circular shape, dendritic pattern, coarse drainage texture, and longer flow duration in lower areas. The bifurcation ratio lies between 1 and 2, indicating that the geological structure does not have a significant impact on the drainage patterns. The present study indicates various parameters of the Girna River Basin, which indicates that the basin has a high slope in the northwestern part, whereas most of the area has a low slope angle and a very low gradient ratio. The stream order helps understand the estimation of floods near the basin area because high stream order rivers have a high chance of floods. Determining the water discharge

Quaternary International, 2024

We present monsoon variability records for the Holocene using multi-proxy approach (environmental... more We present monsoon variability records for the Holocene using multi-proxy approach (environmental magnetism, carbon isotope, and total organic carbon) from a 146 cm thick sedimentary profile in the Kotikanasar meadow (Chakrata), Northwest Himalaya. The chronology of the record was constrained by five AMS 14 C ages. The carbon isotope (δ 13 C) and Total Organic Carbon (TOC) data highly variable which vary between − 26.62‰ and − 22.46‰ (C 3-plants) and 0.1-~4%, respectively, indicating paleo-vegetation history and productivity of the studied area. The environmental magnetism is highly fluctuating in the Early Holocene with high concentrations of magnetic minerals during the high monsoon conditions and vice-versa. Intense Indian Summer Monsoon (ISM) phases were identified during the Early and Late Holocene i.e., ~9.2 to 7.4 ka, and ~4.8 ka to Modern which shows warm and wet climate. While decline in the ISM intensity during ~7.4 to 4.8 ka which indicates cold and dry climatic condition in the Northwest Himalayan regions. From ~9.2 to 7.4 ka, highly fluctuating climate linked with the Early Holocene warming. Sediment profile exhibits aridity in climate accompanying with the high influence of mid-latitude westerlies during ~7.4 to 4.8 ka from Northwest Indian regions. Hence the longterm fluctuation in the climate governed by the changes in the North Atlantic Ocean circulation as well as variations in the incoming solar radiations.

Journal of Earth System Science, 2021

A short-lived flashflood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himal... more A short-lived flashflood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalaya, killed 65 people with 141 reported missing (official estimate) and devastated two hydropower projects. Geomorphological observations supported by meteorological data suggest that the flood was triggered by a combination of avalanche and debris flow. The Dhauli Ganga valley has preserved ponded sedimentary sequences (laminated sand and silty-clay), suggesting that the valley is prone to episodic mega foods in the recent geological past. Considering that the receding glaciers in the higher Himalaya have left behind enormous sediment, unusual weather events are likely to generate such disasters more frequently as the climate becomes warmer. Thus, the study calls for not only incorporating the disaster risk assessment in the developmental planning of the Himalayan region but also recommends routine monitoring of the potential areas of structural failures in the glaciated valleys along with supra-glacial lakes.

Bulletin of Pure and Applied Sciences-Geology , 2022

In recent years, diatom studies have been consisting of different approach i.e., taxonomic study,... more In recent years, diatom studies have been consisting of different approach i.e., taxonomic study, contamination history, paleoclimate etc. The significant study has been reported from the different part of the Indian subcontinent. Especially in India, from the last several decades the study on diatom shifted from taxonomical classification to palaeothermometry study using isotopic analysis. To know the present status and get the future direction it is very important to review the past studies which not only gives the ample information about the records available but also benefitting to get future direction. In the present review we present the comprehensive review on records available from three different geopolitical regions. The review on these three regions shows that most of the work Indian parts in past decades diatom is mostly used for taxonomical and pollution study. However, baseline information on diatom diversity has not been examined in many Indian regions. In recent time the study has been shifted in the direction towards palaeothermometry reconstruction using advance analytical techniques such as stable isotope and others.

Journal of Earth System Science, 2022

We present millennial to centennial-scale monsoon variability during the Late-Pleistocene to Holo... more We present millennial to centennial-scale monsoon variability during the Late-Pleistocene to Holocene using multi-proxy data from 100 cm thick peat deposit in the Baspa Valley, northwest Himalaya. Based on high-resolution mineral magnetism, carbon isotope, and total organic carbon data supported by radiocarbon dating, four climatic phases of alternating strengthened and weakened Indian summer monsoon (ISM) are identiBed for the last 20 kyr in the higher central Himalaya. Periods of strengthened ISM are dated to 15 to 14 ka, 10 to 7 ka, 2.4 to 1.3 ka, and 243 yr BP to present, which is ascribed to the post-Older Dryas associated with an increase in solar insolation. The phases of weakened ISM are bracketed between 20 and 15 ka, 14 to 10 ka, 7 to 2.4 ka, and 1300 to 243 yr BP. These phases are attributed to global cooling events, i.e., the Last Glacial Maximum (LGM), Younger Dryas (YD), and the Middle to Late Holocene. They govern by changes in the solar insolation.

JOURNAL GEOLOGICAL SOCIETY OF INDIA, 2021

A flash flood that originated from Raunthi Gad-a tributary of the Rishi Ganga river, in Garhwal H... more A flash flood that originated from Raunthi Gad-a tributary of the Rishi Ganga river, in Garhwal Himalaya, caused unprecedented loss to lives and damaged two hydropower projects on 7 th Februray 2021. In order to asses the flood magnitude, the flow parameters of the flood were calculated using the super-elevation of the flood marks preserved in the flood affected valleys. The textural characteristics of the flood deposits in the upper reaches of the valleys indicate dominance of debris flows. The peak discharge upstream of the confluence of Rishi Ganga and Dhauli Ganga was around 1.1x10 5 m 3 /s, which was four order of magnitiude higher than the normal peak discharge (~ 3 m 3 /s). The flow achieved a velocity of 30±3 m/s. An exponential reduction in the flow velocity (from ~37 to 2 m/s) with distance is observed. For which the river gradient and increase in sediment load is implied flow that along its entrained way downstream between Raini and Tapovan. Considering the sensitivity of paraglacial zones to climate change, the paper calls for detailed studies pertaining to the response of paraglacial zones to extreme weather events. Importnatly, it is necessary to have more hydrological data covering multiple valleys for predictive model simulation of the nature and magnitude of such disasters in future.

Bulletin of Pure and Applied Sciences-Geology, 2021

Sedimentation in lakes occurs from the time of its formation and continues till the final deposit... more Sedimentation in lakes occurs from the time of its formation and continues till the final deposition. The
rate of sedimentation varies depending upon climate, geology, soil cover and relief. In the present study,
an attempt has been made to investigate the distribution and variation of sedimentation rate in Indian
lakes. For this purpose, Indian lakes are classified into three zones viz., North Indian lakes (NIL), Central
Indian lakes (CIL), South Indian lakes (SIL) and 27 sampling points distributed throughout India has
been considered among all three zones. Correlation of rate of sedimentation data with catchment area,
surface area and lithology is done in order to understand the controlling factors, rainfall and temperature
data are also taken into consideration to know the effect on the sedimentation rate. In all three zones, the
highest precipitation observed 2488, 1800 and 4000 mm/yr in the Nainital lake, Chilika lake and Pookot
lake, respectively and temperature fluctuations in the northern region of India is higher than the central
and southern region. The results showed that the NIL have relatively higher sedimentation rate compared
to the CIL and SIL due to slopy terrain, higher precipitation, temperature and lithological inconsistency in
northern Indian region whereas all these factors are less effective in other two zones with a minor
contribution from other independent factors. NIL have ~0.634-0.804 cm/yr and ~0.636-1.117 cm/yr more
sedimentation rate than CIL and SIL, respectively.

Journal of Earth System Science, 2021

A short-lived CashCood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalay... more A short-lived CashCood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalaya, killed 65 people with 141 reported missing (ofBcial estimate) and devastated two hydropower projects. Geomorphological observations supported by meteorological data suggest that the Cood was triggered by a combination of avalanche and debris Cow. The Dhauli Ganga valley has preserved ponded sedimentary sequences (laminated sand and silty-clay), suggesting that the valley is prone to episodic mega foods in the recent geological past. Considering that the receding glaciers in the higher Himalaya have left behind enormous sediment, unusual weather events are likely to generate such disasters more frequently as the climate becomes warmer. Thus, the study calls for not only incorporating the disaster risk assessment in the developmental planning of the Himalayan region but also recommends routine monitoring of the potential areas of structural failures in the glaciated valleys along with supra-glacial lakes.

This work aims to deal with the morphometric analysis of the Panzara River Basin (PRB) watershed,... more This work aims to deal with the morphometric analysis of the Panzara River Basin (PRB) watershed, a tributary of the Tapi River in Maharashtra, India. In this study, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) and Survey of India (SOI) toposheets have been used along with various parameters like linear, areal, and relief aspects in Geographical Information System (GIS) environment. Out of total 293 number of streams in the watershed, 226, 54, 12, and 1 are of first, second, third and fourth orders respectively. PRB watershed is of 4th order and less elongated in shape, having lower peak flows of longer duration with dendritic pattern and having coarse drainage texture. The bifurcation ratio lies between 6 and 7, indicating that geological structure doesn't have more influence on drainage patterns. The area forms a rugged topography having an elevation range from 123 to 1199 m above Mean Sea Level (MSL). Variables like Stream Frequency and Drainage Density shows impermeable surface of PRB watershed which causes higher water discharge volume and speed in the basin so that the probability is maximum for frequent floods. The results indicates that PRB is having high slope in SW part as compare to NE part and having very low gradient ratio. These variables also shows a temporal variation in the water flowing speed in the stream when the flood reaches its peak. The outcomes of this work can suggest and recommend a better mechanism for proper watershed management in the PRB.

मानव जीवन को सुचारू रूप से चलाने के लिए मनुष्य को स्वस्थ बुद्धि एवं शरीर की आवश्यकता होती है जिनक... more मानव जीवन को सुचारू रूप से चलाने के लिए मनुष्य को स्वस्थ बुद्धि एवं शरीर की आवश्यकता होती है जिनके लिए स्वच्छ एवं संतुलित पर्यावरण परम आवश्यक है। स्वच्छ और संतुलित पर्यावरण से अभिप्राय एक ऐसे वातावरण से है, जिसमें प्रत्येक आवश्यक घटक एक निधारित मात्रा एवं अनुपात में मौजूद होता है। लेकिन कभी-कभी मानव द्वारा या अन्य कारणों से वातावरण में एक अथवा अनेक घटकों की मात्रा या तो जरूरत से अधिक बढ़ जाती है या घट जाती है। इस स्थिति में वातावरण प्रदूषित हो जाता है। प्रदूषित वातावरण मानव जीव जगत के लिए किसी न किसी रूप में हानिकारक प्रभाव जरुर डालता है। वातावरण में इस अनचाहे बदलाव में औद्योगिकीकरण, शहरीकरण, बढ़ती जनसंख्या, कृषि का गहनीकरण, ऊर्जा उपयोग में वृद्धि, परिवहन में वृद्धि, विभिन्न गैसों की उच्च मात्रा में निकासी, अनियोजित भूमि-उपयोग नीतियाँ तथा मानवविकास की प्रक्रियाए आदि का अहम् योगदान है। वातावरण के घटकों के आधार पर पर्यावरणीय प्रदूषण को मुख्यत; जल प्रदूषण, मृदा प्रदूषण, वायु प्रदूषण एवं ध्वनी प्रदूषण आदि भागों में बाँटा जा सकता है।

The present study aims to conduct a morphometric analysis of the Girna River Basin watershed, a t... more The present study aims to conduct a morphometric analysis of the Girna River Basin watershed, a tributary of the Tapi River in Maharashtra, India. A detailed morphometry analysis was performed using remote sensing and GIS using a Digital Elevation Model (Aster DEM) and SOI toposheets, and various drainage basin parameters such as Linear, Areal, and Relief aspects were also calculated. The Girna River Basin comprises 2,137 streams and has 6th order stream networks, in which 1,071, 526, 261, 125, 107, and 47 are the first-, second-, third-, fourth-, fifth-, and sixth-order streams, respectively. The Girna River Basin is 6th order stream with a circular shape, dendritic pattern, coarse drainage texture, and longer flow duration in lower areas. The bifurcation ratio lies between 1 and 2, indicating that the geological structure does not have a significant impact on the drainage patterns. The present study indicates various parameters of the Girna River Basin, which indicates that the basin has a high slope in the northwestern part, whereas most of the area has a low slope angle and a very low gradient ratio. The stream order helps understand the estimation of floods near the basin area because high stream order rivers have a high chance of floods. Determining the water discharge

Quaternary International, 2024

We present monsoon variability records for the Holocene using multi-proxy approach (environmental... more We present monsoon variability records for the Holocene using multi-proxy approach (environmental magnetism, carbon isotope, and total organic carbon) from a 146 cm thick sedimentary profile in the Kotikanasar meadow (Chakrata), Northwest Himalaya. The chronology of the record was constrained by five AMS 14 C ages. The carbon isotope (δ 13 C) and Total Organic Carbon (TOC) data highly variable which vary between − 26.62‰ and − 22.46‰ (C 3-plants) and 0.1-~4%, respectively, indicating paleo-vegetation history and productivity of the studied area. The environmental magnetism is highly fluctuating in the Early Holocene with high concentrations of magnetic minerals during the high monsoon conditions and vice-versa. Intense Indian Summer Monsoon (ISM) phases were identified during the Early and Late Holocene i.e., ~9.2 to 7.4 ka, and ~4.8 ka to Modern which shows warm and wet climate. While decline in the ISM intensity during ~7.4 to 4.8 ka which indicates cold and dry climatic condition in the Northwest Himalayan regions. From ~9.2 to 7.4 ka, highly fluctuating climate linked with the Early Holocene warming. Sediment profile exhibits aridity in climate accompanying with the high influence of mid-latitude westerlies during ~7.4 to 4.8 ka from Northwest Indian regions. Hence the longterm fluctuation in the climate governed by the changes in the North Atlantic Ocean circulation as well as variations in the incoming solar radiations.

Journal of Earth System Science, 2021

A short-lived flashflood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himal... more A short-lived flashflood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalaya, killed 65 people with 141 reported missing (official estimate) and devastated two hydropower projects. Geomorphological observations supported by meteorological data suggest that the flood was triggered by a combination of avalanche and debris flow. The Dhauli Ganga valley has preserved ponded sedimentary sequences (laminated sand and silty-clay), suggesting that the valley is prone to episodic mega foods in the recent geological past. Considering that the receding glaciers in the higher Himalaya have left behind enormous sediment, unusual weather events are likely to generate such disasters more frequently as the climate becomes warmer. Thus, the study calls for not only incorporating the disaster risk assessment in the developmental planning of the Himalayan region but also recommends routine monitoring of the potential areas of structural failures in the glaciated valleys along with supra-glacial lakes.

Bulletin of Pure and Applied Sciences-Geology , 2022

In recent years, diatom studies have been consisting of different approach i.e., taxonomic study,... more In recent years, diatom studies have been consisting of different approach i.e., taxonomic study, contamination history, paleoclimate etc. The significant study has been reported from the different part of the Indian subcontinent. Especially in India, from the last several decades the study on diatom shifted from taxonomical classification to palaeothermometry study using isotopic analysis. To know the present status and get the future direction it is very important to review the past studies which not only gives the ample information about the records available but also benefitting to get future direction. In the present review we present the comprehensive review on records available from three different geopolitical regions. The review on these three regions shows that most of the work Indian parts in past decades diatom is mostly used for taxonomical and pollution study. However, baseline information on diatom diversity has not been examined in many Indian regions. In recent time the study has been shifted in the direction towards palaeothermometry reconstruction using advance analytical techniques such as stable isotope and others.

Journal of Earth System Science, 2022

We present millennial to centennial-scale monsoon variability during the Late-Pleistocene to Holo... more We present millennial to centennial-scale monsoon variability during the Late-Pleistocene to Holocene using multi-proxy data from 100 cm thick peat deposit in the Baspa Valley, northwest Himalaya. Based on high-resolution mineral magnetism, carbon isotope, and total organic carbon data supported by radiocarbon dating, four climatic phases of alternating strengthened and weakened Indian summer monsoon (ISM) are identiBed for the last 20 kyr in the higher central Himalaya. Periods of strengthened ISM are dated to 15 to 14 ka, 10 to 7 ka, 2.4 to 1.3 ka, and 243 yr BP to present, which is ascribed to the post-Older Dryas associated with an increase in solar insolation. The phases of weakened ISM are bracketed between 20 and 15 ka, 14 to 10 ka, 7 to 2.4 ka, and 1300 to 243 yr BP. These phases are attributed to global cooling events, i.e., the Last Glacial Maximum (LGM), Younger Dryas (YD), and the Middle to Late Holocene. They govern by changes in the solar insolation.

JOURNAL GEOLOGICAL SOCIETY OF INDIA, 2021

A flash flood that originated from Raunthi Gad-a tributary of the Rishi Ganga river, in Garhwal H... more A flash flood that originated from Raunthi Gad-a tributary of the Rishi Ganga river, in Garhwal Himalaya, caused unprecedented loss to lives and damaged two hydropower projects on 7 th Februray 2021. In order to asses the flood magnitude, the flow parameters of the flood were calculated using the super-elevation of the flood marks preserved in the flood affected valleys. The textural characteristics of the flood deposits in the upper reaches of the valleys indicate dominance of debris flows. The peak discharge upstream of the confluence of Rishi Ganga and Dhauli Ganga was around 1.1x10 5 m 3 /s, which was four order of magnitiude higher than the normal peak discharge (~ 3 m 3 /s). The flow achieved a velocity of 30±3 m/s. An exponential reduction in the flow velocity (from ~37 to 2 m/s) with distance is observed. For which the river gradient and increase in sediment load is implied flow that along its entrained way downstream between Raini and Tapovan. Considering the sensitivity of paraglacial zones to climate change, the paper calls for detailed studies pertaining to the response of paraglacial zones to extreme weather events. Importnatly, it is necessary to have more hydrological data covering multiple valleys for predictive model simulation of the nature and magnitude of such disasters in future.

Bulletin of Pure and Applied Sciences-Geology, 2021

Sedimentation in lakes occurs from the time of its formation and continues till the final deposit... more Sedimentation in lakes occurs from the time of its formation and continues till the final deposition. The
rate of sedimentation varies depending upon climate, geology, soil cover and relief. In the present study,
an attempt has been made to investigate the distribution and variation of sedimentation rate in Indian
lakes. For this purpose, Indian lakes are classified into three zones viz., North Indian lakes (NIL), Central
Indian lakes (CIL), South Indian lakes (SIL) and 27 sampling points distributed throughout India has
been considered among all three zones. Correlation of rate of sedimentation data with catchment area,
surface area and lithology is done in order to understand the controlling factors, rainfall and temperature
data are also taken into consideration to know the effect on the sedimentation rate. In all three zones, the
highest precipitation observed 2488, 1800 and 4000 mm/yr in the Nainital lake, Chilika lake and Pookot
lake, respectively and temperature fluctuations in the northern region of India is higher than the central
and southern region. The results showed that the NIL have relatively higher sedimentation rate compared
to the CIL and SIL due to slopy terrain, higher precipitation, temperature and lithological inconsistency in
northern Indian region whereas all these factors are less effective in other two zones with a minor
contribution from other independent factors. NIL have ~0.634-0.804 cm/yr and ~0.636-1.117 cm/yr more
sedimentation rate than CIL and SIL, respectively.

Journal of Earth System Science, 2021

A short-lived CashCood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalay... more A short-lived CashCood in Rishi and Dhauli Ganga rivers on 7th February 2021, Uttarakhand Himalaya, killed 65 people with 141 reported missing (ofBcial estimate) and devastated two hydropower projects. Geomorphological observations supported by meteorological data suggest that the Cood was triggered by a combination of avalanche and debris Cow. The Dhauli Ganga valley has preserved ponded sedimentary sequences (laminated sand and silty-clay), suggesting that the valley is prone to episodic mega foods in the recent geological past. Considering that the receding glaciers in the higher Himalaya have left behind enormous sediment, unusual weather events are likely to generate such disasters more frequently as the climate becomes warmer. Thus, the study calls for not only incorporating the disaster risk assessment in the developmental planning of the Himalayan region but also recommends routine monitoring of the potential areas of structural failures in the glaciated valleys along with supra-glacial lakes.