The article deals with at-site flood frequency analysis for different gauging stations of the Chenab River in Pakistan.The study aimed at recommending the most suitable probability distribution and efficient method of parameter estimation for each gauging site.Generalized extreme value, generalized logistic, Gumbel, generalized Pareto, and reverse Gumbel probability models are fitted to the annual peak flow/discharge.For each gauging site, the parameters of these distributions are estimated through L-moments, maximum likelihood, least squares, weighted least squares, and relative least squares methods.For each site, the probability models with a particular estimation method are ranked on the basis of goodness-of-tests and accuracy measures, and then the most suitable pair of model and estimation method is identified through a total rank.The results indicate that the generalized Pareto distribution is the best fit for Marala, Khanki, Qadirabad, and Punjnad, while the generalized extreme value distribution is the most suited for the Trimmu gauging site.As far as the estimation method is concerned, least squares and weighted least squares methods are more accurate for most of the gauging sites.Finally, for each gauging site, the best-suited probability model is used to estimate the annual peak flow and to construct associated confidence intervals for different return years.

The Kohat fold-thrust belt (KFTB) in the northwestern Himalayan foreland provides a unique opportunity to investigate strain partitioning and the role of evaporitic decollement in fold-thrust belts (FTBs) propagation through magnetic fabrics analysis. Using anisotropy of magnetic susceptibility (AMS) as a strain marker through analog models of FTBs, have already demonstrated the impact of high and low friction decollement in the magnetic fabrics development. In order to validate the accuracy of such model and to enhance the understanding of strain partitioning in FTBs with low-friction decollements, an integrated framework combining AMS and structural analyses was applied to the KFTB. AMS investigations of oriented cores from the Siwalik strata of 72 sites, acquired at different structural levels within the KFTB, highlight distinct magnetic fabric patterns. The lowfriction decollement-proximate Siwalik strata exhibit Type-I sedimentary magnetic fabrics, the decollementdistal strata possess intermediate fabrics and the decollement front strata exhibit Type-VI tectonic fabrics. Collectively, the AMS parameters analysis and magnetic fabrics classification reflect the influence of structural controls on magnetic fabrics development. The Type-I sedimentary magnetic fabrics in the Early Miocene Kamlial Formation signify paleo-Indus flow direction towards southeast direction in the KFTB. A new conceptual schematic model integrated with bootstrapped AMS ellipsoids along different structures of the KFTB emphasize the influence of decollement friction, intensity of deformation and FTB propagation over weak layers.

Flooding in Pakistan is generally contributed from rivers and floods are generally caused by heavy concentrated rainfall in the river basins during the monsoon season (July through September). Pakistan has a long history of floods and associated damages. Due to global climate change and its impact on Pakistan in recent years, the frequency and intensities of floods and corresponding damages have increased manifold. In the recent history, Pakistan has experienced unprecedented flooding in Khyber Pakhtunkhwa (KPK) in 2010 and 2022; occurrence of the flood events in upper most reaches of northern areas have proved that the climate change has severely impacted our region. In this study, 20 CMIP-6 General Circulation Models (GCMs) have been selected for the individual river basins of KPK namely Swat, Panjkora, Chitral, Kabul, Kurrum, Gomal and DI Khan. These models have undergone qualitative evaluations to determine their suitability for further analysis. The scrutiny of model selections is based on specific criteria, including daily frequency of data, availability of SSP 2-4.5 (middle of the road) and SSP 5-8.5 (business as usual) scenarios, and correlations between observed and climate model data, which helps exclude the least reliable GCMs. Based on the criteria, daily data for both baseline and future scenarios have been downloaded and processed for 20 GCMs that passed the initial evaluation. Subsequently, these shortlisted GCMs underwent additional assessments for dry, wet, hot, and cold conditions (delta approach method). As a result, five GCMs in each catchment have been selected as the most suitable candidates for conducting future climate projections. Statistical downscaling technique was opted for and corrected precipitation data from Quantile Delta Mapping (QDM) approach. To estimate the return period of maximum daily precipitation, the widely used Generalized Extreme Value (GEV) distribution was employed. Results indicates an adjustment factor for design rainfall under a 100-year return period in KPK, Pakistan, range from 1.2–21.3% due to climate change, also factors have been calculated for various return periods in study. This study offers valuable insights for engineers, planners, and various departments to the rising risk of extreme rainfall and to flooding. Understanding these impacts is crucial for developing effective adaptation strategies to mitigate the effects of climate change in the region.

The decision support system for agro-technology transfer (DSSAT) is a worldwide crop modeling platform used for crops growth, yield, leaf area index (LAI), and biomass estimation under varying climatic, soil and management conditions. This study integrates DSSAT with satellite remote sensing (RS) data to estimates canopy state variables like LAI and biomass. For LAI estimation, Moderate Resolution Imaging Spectroradiometer (MODIS) product (MCD15A3H for LAI and MOD17A2 / MOD17A3 products for biomass) are used. Field data for Sheikhupura district is provided by National Agriculture Research Council (NARC) and used for the calibration and validation of the model. The results indicate strong agreement between the DSSAT and RS derived estimates. Correlation coefficients (R²) for LAI varied from 0.82 to 0.90, while for biomass ranged from 0.92 to 0.99 over two farms and two growing seasons (2012-2014). The index of agreement (D-index) ranged from 0.79 to 0.96 across the two farms and two growing seasons (2012-2014) affirming the model's durability. However, the biomass estimated from RS data is underestimated due to saturation phenomenon in the optical RS. The performance metrics, comprising the coefficient of residual mass (CRM) and normalized root mean square error (nRMSE), further substantiate the approach utilized. This study will help decision and policymakers and researchers to apply geospatial techniques for the sustainable agriculture practices.

The Palaeocene Lockhart Formation, a carbonate-rich succession abundant in Larger Benthic Foraminifera, represents a significant potential hydrocarbon reservoir extending throughout the Kohat, Potwar and Hazara basins of Pakistan. This study examines two stratigraphic sections of the Lockhart Formation in the Hazara Basin—Bagran and Karhaki—providing crucial insights into its biostratigraphy and microfacies analysis. The formation comprises medium- to fine-grained limestone with shale intercalations, exhibiting argillaceous to compacted textures. Biostratigraphic analysis revealed a diverse assemblage of Larger Benthic Foraminifera, with 23 species identified across 9 genera, including Miscellanea miscella, Lockhartia haimei, Lockhartia conditi and Ranikothalia sindensis. These fossils indicate deposition within Shallow Benthic Zone (SBZ) 4 during the Late Thanetian, suggesting a dynamic palaeoenvironment. Seven distinct microfacies types were identified: bioclastic mudstone, mixed bioclastic wackestone, miliolidal bioclastic wackestone, foraminiferal wackestone–packstone, foraminiferal wackestone, foraminiferal packstone and bioclastic foraminiferal packstone. These microfacies indicate varied depositional settings, from shallow subtidal and lagoonal to shallow restricted and open marine environments, spanning inner ramp to distal mid-ramp conditions. This research advances our understanding of Late Thanetian depositional environments within the Lockhart Limestone, with implications for regional sedimentology, palaeogeographic reconstruction and reservoir characterisation.

Spatiotemporal variations in temperature (T) and equivalent temperature (Te) significantly impact agricultural production across Pakistan, highlighting the need for enhanced weather and climate modeling. This study utilized four reanalysis datasets spanning a 38-year period (1981–2018): the fifth-generation European Center for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis (ERA5), Interim ECMWF reanalysis (ERA-Interim), Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA2), and the Japanese 55-year reanalysis (JRA55). We employed National Oceanic and Atmospheric Administration/Advanced Very High-Resolution Radiometer (NOAA/AVHRR) Normalized Difference Vegetation Index (NDVI) data, a proxy for crop health, to assess the relationship between T, Te, and NDVI. This relationship is examined via regression and correlation analyses, and significance is assessed using the Mann–Kendall test and t-test. Our results show that near-surface T significantly contributes to the magnitude of Te (> 90

Sustainable management of river systems is a serious concern, requiring vigilant monitoring of water contamination levels that could potentially threaten the ecological community. This study focused on the evaluation of water quality in the Jhelum River (JR), Azad Jammu and Kashmir, and northern Punjab, Pakistan. To achieve this, 60 water samples were collected from various points within the JR Basin (JRB) and subjected to a comprehensive analysis of their physicochemical parameters. The study findings indicated that the concentrations of physicochemical parameters in the JRB water remained within safety thresholds for both drinking and irrigation water, as established by the World Health Organization and Pakistan Environmental Protection Agency. These physicochemical parameters refer to various chemical and physical characteristics of the water that can have implications for both human health (drinking water) and agricultural practices (irrigation water). The spatial variations throughout the river course distinguished between the upstream, midstream, and downstream sections. Specifically, the downstream section exhibited significantly higher values for physicochemical parameters and a broader range, highlighting a substantial decline in its quality. Significant disparities in mean values and ranges were evident, particularly in the case of nitrates and total dissolved solids, when the downstream section was compared with its upstream and midstream counterparts. These variations indicated a deteriorating downstream water quality profile, which is likely attributable to a combination of geological and anthropogenic influences. Despite the observed deterioration in the downstream water quality, this study underscores that the JRB within the upper Indus Basin remains safe and suitable for domestic and agricultural purposes. The JRB was evaluated for various irrigation water quality indices. The principal component analysis conducted in this study revealed distinct covariance patterns among water quality variables, with the first five components explaining approximately 79% of the total variance. Recommending the continued utilization of the JRB for irrigation, we advocate for the preservation and enhancement of water quality in the downstream regions.

Alpine lakes are aquatic ecosystems that maintain and regulate water supply for the downstream streams, rivers, and other reservoirs. This study examined the water characteristics of various alpine lakes in Gilgit-Baltistan, Northern Pakistan. For this purpose, water was sampled and investigated for basic parameters, anions, and cations using the multi-parameter analyzers and atomic absorption spectrophotometer. Physicochemical parameters of alpine lakes were noted under the World Health Organization water guidelines, except for fluoride (F−) and turbidity in 4.3

The evolution of Jurassic carbonates is globally significant for understanding the depositional framework, diagenetic phases and sedimentary characteristics of shallow marine shelf deposits. For this purpose, two outcrop sections of the Jurassic carbonates with a road distance of 121 km in the Trans Indus Ranges, NW Himalayas, were included in this study. Geological fieldwork was conducted for sedimentological data, and representative samples were collected for microfacies analysis and diagenetic evolution complemented by carbon and oxygen isotope analysis. Results show that eight microfacies were identified in both sections where mudstone microfacies was only present in the Chichali section, whereas wackestone and packstone facies widely existed in both sections. The diagenetic evolution interpreted that dolomitization and stylolization were pronounced in the Paniala section, while micritization and calcite cementation were prevalent in the Chichali section. The interpreted depositional setting implies the wide range from supratidal to outer ramp shallow marine for the Chichali section, suggesting a wide range and relatively deeper environment, alongside merely intertidal to middle ramp settings for Paniala section. Diagenetic evolution suggests marine to meteoric influence in the Chichali section, while burial and uplift phases were dominant in the Paniala section. The diagenetic events were also validated by the isotopic analysis, where most of the samples with values up to −4‰ VPDB δ18O, corresponding to a carbon isotope range of up to +4‰, were interpreted as the burial phase of diagenesis; meanwhile, a few samples with −2 δ13C and −7‰ VPDB δ18O isotope signatures were marked as meteoric influx in the Paniala section. This study indicates the diversity of the depositional environment and diagenetic heterogeneity by integration of thin sections using isotope data, which are quite applicable to shallow marine carbonates.

Abstract The lithostratigraphy, biostratigraphy and depositional environments of the Cretaceous successions Pakistan were investigated to reveal the major geological events, including local, regional and global scale tectonics, phases of volcanism, basin condensation, emergence of structural highs and episodes of non-deposition. The succession is entirely missing at Salt Range, but were excellently exposed in Kirthar-Sulaiman Fold-Thrust belts. Such deviating nature (e.g., Hazara, Kalla Chitta, Surghar & Kohat) suggesting episodical tectonic activities were associated with inter-intra rifting and drifting of the India-Madagascar-Seychelles and Antarctica-Australian Plates during Cretaceous time. Correspondingly, several unconformities within the Cretaceous succession at numerous stratigraphic intervals consistently attest the effect of tectonics throughout the period. The recognized unconformities over Kawagarh, Lumshiwal, Parh and Fort Munro formations testify episodic uplifts on local and/or regional scales during the Coniacian-Santonian, Coniacian-Maastrichtian, Campanian and Maastrichtian in response to the separation of Madagascar from the India-Seychelles plate. In contrast, there was continuous sedimentation of carbonate, clastic and/or submarine volcanics in the Kirthar and Indian-Eurasian suture zone. Significant geological events in the restricted regions e.g., local scale submarine volcanism (Bibai Formation), ironstone deposition (Dilband Formation) and basin condensation (Khuzdar) were also associated with such rifting-drifting phases along the WNW margin of the Indian Plate.

Pakistan is a water-stressed country with a maximum carryover storage capacity of thirty days. The situation demands effective water management policies for preparedness and water governess in the country. Therefore, it is imperative to produce accurate seasonal forecasts by understanding the association between basin antecedent conditions and climate indices. This study investigates the suitability of various climate indices to forecast seasonal streamflow in the Upper Indus Basin (UIB) at Tarbela dam, Pakistan. The major influencing factors of streamflow in the UIB are snow water equivalent, temperature, precipitation and information on relevant large-scale climate indices. We evaluated the suitability of nine climate indices - Trans-Niño Index (TNI), Oceanic Niño Index (ONI), Tropical Pacific Sea Surface Temperature (SST) in various regions (Nino1+2, Nino4, Nino34, Nino3.4), Southern Oscillation (SOI), Indian Ocean Dipole Mode Index (DMI) and Indian Ocean Basin-Wide (IOBW) - to model the streamflow over the 38 years (1982 -2019) by performing seasonal hindcast analysis at Tarbela dam. The results revealed that IOBW is highly correlated (r = 0.73, mean percentage error (APE) = -0.46%, mean absolute percentage error (MAPE) = 6.06%) with the streamflow at the basin level. Climate indices combined with mean basin snow water equivalent, temperature and precipitation can produce a reasonable seasonal forecast at Tarbela dam. Among nine indices, IOBW produces more accurate results. We have also seen that climate indices are highly correlated with temperatures in Upper Indus basin and this factor is main contributor to runoff prediction considering snow and glacier runoff dominancy in this catchment.

This study estimates the timing of unconformity between marine–continental transitional sequence of the Kuldana Formation and continental sequence of the Murree Formation for the first time across the Hazara-Kashmir syntaxis, western Himalaya, Pakistan. The ages of the studied units are constrained using detrital zircon U–Pb geochronology. The maximum depositional ages constrained by weighted mean and youngest detrital zircon age are 37 ± 1.7 Ma and 22.5 ± 0.6 Ma for top of Kuldana and base of Murree formations, respectively. Based on this age, the duration of hiatus is estimated to be ~ 14.5 Ma. The comparison of this unconformity and sedimentation pattern along strike suggests that the initial collision occurred in the central segment causing its early uplift and erosion with development of the unconformity. The sedimentation in the central segment culminated at ~ 37 Ma and resumed at ~ 22.5 Ma. The wider gap in central segment becomes narrower at western and eastern margin suggesting discontinuous deposition due to gradually closure of western and eastern margin. This supports the diachronous collision of the Indian and Asian plates with initial contact at the central segment.

Facies analysis and T-R sequence stratigraphic approach of Late Permian to Jurassic sedimentary units in Western Salt Range, Pakistan were accomplished to construe the depositional environments and basin evolution. The analysis affirms the rendition of sequence stratigraphic trends and paleogeography of first megasequence phase of Neo-Tethys Sea. Sedimentological contingents, T-R sequence stratigraphic framework and sea level curve of the strata argue active tectonic's effects on sedimentation. During Late Permian, the rift related magmatic activities deceased, which imparted to the onset of transgression and deposition of shelf carbonates with retrogradational (transgressive) parasequence sets in Wargal Formation. Respective rifting and tectonic uplift events induced the sea level fall ascertaining the onset of terrigenous shelves and deltaic successions in terminal Permian and Early-Mid Triassic with an enlighten switch from agradational to progradational parasequence sets (regressive parasequences) in Chhidru, Mianwali and Tredian formations. The closure of Paleo-Tethys and emergence of semi-arid hot tropical climate throughout Late-Triassic, led the onset of tidal-lagoonal environments and deposition of retrogradational (transgressive) parasequence sets in Kingriali Formation. During Early Jurassic, a well-known northward drift of Pangaea ensued in global cooling and increased humidity, which consequently stimulated clastic-carbonate sedimentation of Datta and Samana Suk formations with progradational and retrogradational parasequence sets respectively.

This study reports the detrital zircon U–Pb ages of the post collisional Chitarwatta Formation, exposed along the western margin of the Indian plate at the Sulaiman fold–thrust belt (SFB), Pakistan. The Chitarwatta Formation overlies the shallow marine carbonate sequence of the Kirthar Formation and represents an Oligocene–Miocene transitional marine sequence. The sequence consists of sandstone, siltstone, and mudstone. The sandstone consists predominantly (79–82%) of quartz grains. The framework grains are sub-angular to sub-rounded and show recycled orogenic provenance. The detrital zircon U–Pb age data show the dominant population between 390 Ma and ~1100 Ma, which is ~70% of the total population. In addition to this, a significant percentage of the younger detrital ages exist between ~40 Ma and ~120 Ma. This younger age cluster indicates the northern sources, including the Kohistan–Ladakh arc (KLA) and Karakoram block (KB), whereas the provenance for the 390–1100 Ma detrital zircon is likely the Higher Himalaya (HH), with contribution from Tethyan Himalaya (TH). This post-collisional scenario suggests that the Chitarwatta Formation received detritus from the northern sources through a drainage system, named as the Indus drainage system. A comparison with the coeval units in the north (Murree Formation, Dagshai Formation, and Dumre Formation) suggests that the sediments may have been delivered through the same drainage system that shares similar detritus. Relying on the contribution of the HH detritus, we propose that the HH uplifted during the Oligocene–Miocene along the Main Central Thrust (MCT) and provided detritus to the foreland basin.

Climate change in Pakistan has a great impact on the spatial and temporal variation of precipitation and ultimately alters the frequency and duration of droughts. In this study, spatial and temporal trend analyses of precipitation and droughts were observed at 58 meteorological stations across Pakistan from 1981 to 2018. The existing trend analysis methods were evaluated to address the issue of serial correlation in the climatic data. Results of precipitation analysis showed significant decreasing trends in winter (November, December) and significant increasing trends were observed in summer (June and September) at a confidence level of 95 percent. The magnitude of the precipitation trends showed the highest variation during summer season and the least variation in winter season. Rotated Principal Component (RPC) analysis showed the severe droughts (high positive loading) in southeastern side (Sindh province) of Pakistan due to lack of summer rains. Furthermore, variance correction approaches are identified as the most suitable in coping with the effect of serial correlation. The highest drought frequencies were observed in the southern areas of Pakistan and the drought events are expected to occur more frequently in the late winter, early spring, and early autumn, while droughts were expected to occur least frequently in summer.

Deep‐water massive sandstones (DWMS) are characterized by large volumes of sand accumulations which are considered as potential reservoir intervals in deep‐marine environments. Lithological variations and bed thickness statistics are used to interpret the distribution of massive sandstones in a deep‐marine fan‐lobe system. These massive sandstones are interpreted based on lithological heterogeneities and detailed facies analysis in seventeen exposed sections of the Late Palaeogene deposits in Sabah, NW Borneo. Sedimentary logs containing details of lithology textures and structures were used to recognize nine sedimentary facies of DWMS. These lithofacies were then grouped into three sedimentary facies associations: (1) massive facies association with basal part of turbiditic Bouma sequence, (2) massive facies association having soft‐sediment deformation structures, and (3) massive facies association with erosional features. The facies analysis portrays inner to middle submarine fan deposition and was later applied to reconstruct the distribution of a channel‐lobe complex. Individual sandstone bed thicknesses vary from 1 m to more than 8 m and the number of massive sandstones in submarine lobes range from less than 10% to more than 50%. The thicknesses of massive sandstones in channels are more than 8 m, whereas distal lobes have thicknesses from 1–2 m only. These sandstones are concentrated in channels, proximal and medial lobe settings that can also be verified from calculating the average of all maximum thickness of massive sand intervals that is, 8.91 m. The lithological heterogeneities and the processes associated with the deposition of these massive sandstones are vital for potential hydrocarbon reservoirs in the deep‐marine environments around the globe.

Sedimentology, petrography, and geochemistry of the Ispikan Conglomerate of southwest Makran have been studied to establish its stratigraphic position, age, provenance, and depositional environment. Very thin to massive beds, poor sorting, no fabric, and poor grading are the common features. It is composed of mostly reworked, medium- to coarse-grained pebbly sandstone, siltstone, and discontinuous lenses of matrix- and clast-supported conglomerate. The sandstone is composed of angular to sub-angular, poorly sorted, immature grains having Q72F13L15 as average composition. Pebbles are of mostly metamorphic and acidic igneous origin. Large angular boulders (~1.5m) of sandstone indicate quick debris flow conditions. Geochemical discriminants suggest the derivation of Ispikan sediments from an active continental margin. The Nb and Zr/Th and Ba/Y values indicate the continental island arc setting, whereas a high K/Rb ratio points to the derivation of detritus from an acid and intermediate source. Ispikan Conglomerate is interpreted as an Eocene olistostrome formed after a localized submarine debris flow triggered by slope failure.