Indus River Research Articles

Snow runoff modelling in the upper Indus River Basin and its implication to energy water food nexus

Pakistan's hydropower sector depends heavily on glacier and snowmelt water that originates from the Upper Indus Basin (UIB). It is expected that climate change may adversely affect future hydropower generation capacity as a result of fluctuations in the magnitude, seasonality and hydrological extremes of the Indus River flow. This study employed the Degree-Day Snowmelt Runoff Model alongside the Moderate Resolution Imaging Spectroradiometer MODIS and daily ground-based hydro-meteorological data to model the snowmelt runoff response in the UIB. The results indicated a significant increase in the annual and seasonal runoff under both RCP4.5 and RCP8.5 scenarios, suggesting more water availability for hydropower and irrigation. By the end of the century, annual river flow is projected to increase by 28 % to 69 % under the RCP4.5 and RCP8.5 climate scenarios. Consequently, rise in annual river flow is expected to increase the electricity generation capacity of future hydropower projects by 93 % to 167 % under the RCP4.5 and RCP8.5 scenarios, respectively. The construction of robust multipurpose dams may potentially reduce flood risks in downstream areas during peak flows, while also supplying water for hydropower generation and irrigation during low flows. This, in turn, may enhance the resilience of both the hydropower and agriculture sectors in the face of climate change.

Socio-Economic Implications of Snow Cover Area in the Upper Indus Basin

The Indus River, one of the principal waterways in Asia, specifically the Indian Subcontinent, originates from the Himalayan Region and Qinghai-Tibet Plateau. Understanding snow cover dynamics is one of the most vital components for effective hydrological resource management and assessing the impacts of local, regional, and global climatic variations. Variations in the radiation of snow microstructures and snowpacks have profound socio-economic and environmental consequences, affecting agricultural productivity, reservoir supply for factories, environmental sustainability, governance of land resources, and overall community resilience. Fluctuations in snowmelt patterns can lead to water shortages or surplus, influencing food security and economic stability in a country largely dependent on agriculture. Utilizing Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, this study assesses the implications of Snow Cover Area (SCA) on water security and livelihood of agricultural-related sectors. A comparative analysis of snow cover reveals a shifting trend in the accumulation period, with notable anomalies affecting the agricultural output, which affects the household income related to the agricultural sector. This research underscores the necessity of adapting water management strategies to align with evolving snow cover dynamics to mitigate potential socio-economic risks.

A Multi-criterian Approach to Identify Groundwater Potential Zones in the Subarnarekha River Basin Using Integrated Analytical Hierarchy Process and Geospatial Technology

The intense extraction of groundwater and changing climate patterns have strained global groundwater supplies. As the demand for drinkable water rises worldwide, assessing groundwater availability and aquifer output becomes increasingly important. Geographic information systems (GIS) are being used more frequently for groundwater exploration due to their speed and provision of preliminary data. This study focuses on mapping groundwater availability in a minor tropical river basin in India, using a combination of GIS and the analytical hierarchy process (AHP). Ten thematic layers were generated and analyzed, including Geology, Geomorphology, Land use and land cover (LULC), Lineament density, Drainage density, Rainfall, Soil type, Slope, Topographic Wetness Index ( TWI), and curvature to delineate groundwater potential zones. AHP was employed to assign weights to each category based on their water retention properties. The resulting map was validated against existing groundwater data, demonstrating an accuracy of approximately 85%. The groundwater potential zones were classified as high, moderate, and, low. The moderate potential zone covered 59% of the basin, while the low and high potential zones constituted 29% and 11% respectively. High and low potential regions were limited to small sections of the basin. In conclusion, this research successfully mapped the groundwater availability in the Rarhu River watershed using GIS and AHP. The findings highlight the distribution of different groundwater potential zones, providing valuable information for sustainable water resource management in the area.

HEAVY AND TRACE METALS CONTAMINATION IN THE SOIL AND TAP WATER OF QASIMABAD, HYDERABAD, SINDH PAKISTAN

This research intends to analyse the impacts of automobile exhaust pollutants on roadside soil anditscontamination in thewater supply network through faulty rusted pipes ofQasimabad town of Hyderabad City. Qasimabadis recently established in 1988 along the flood plains of River Indus. The results unveilthe causes of contamination and to propose the possible mitigations, the majority ofthe people consume drinking water through theunderground pipe network and tap water was found highly contaminated in the area due to the presence of heavy metals such as cadmium, chromium, iron and lead.

Impact of lining of irrigation canals on groundwater recharge: A case study from Punjab province in Indus River basin of Pakistan

The Canal irrigation network of Pakistan's Indus River Basin (IRB) is one of the world's largest gravity-flow networks, with a significant portion located in Punjab province. The conveyance, delivery, and application of this water to the irrigated crops in the basin result in the loss of more than 50% of its water. This loss of water from the irrigation system is a major source of recharge for the large alluvial aquifer underlying the IRB. Canal lining is carried out as a measure to reduce seepage losses from the conveyance system of irrigation water. On the other hand, canal lining is considered a barrier to aquifer recharge. A study titled “Impact assessment of canal lining in Punjab,” funded by JICA, has been carried out in order to interrogate the comparative performance of lined and unlined canals and their impact on groundwater recharge. We measured seepage losses from 14 selected irrigation-lined canals in Punjab province under actual field conditions using ponding and/or inflow-outflow methods. Results have been compared with pre-lining seepage rates. The results indicate that canal lining has reduced seepage losses by 78%. The heavy pumping in fresh groundwater areas invites saline groundwater from adjacent saline zones. The canal flows at the head have reduced the recharge to groundwater by 9%. Nonetheless, saving from seepage losses by canal lining has increased available water for crops, but it has decreased groundwater recharge.

Assessment of pesticide residues: a comprehensive analysis of seasonal trends and health implications

This study assessed the presence of eight pesticide residues in the Indus River, Mianwali, Pakistan, focusing on three sampling sites (S1, S2, and S3) in water, sediment, and the fish species Cyprinus carpio during both dry and wet seasons. Analysis was conducted using gas chromatography with an electron capture detector. Results indicated elevated pesticide concentrations in both seasons, with levels of 0.84 and 0.62 μg/L in water, 12.47 and 9.21 μg/g/dw in sediment, and 17.33 and 12.17 μg/g/ww in fish, with higher concentrations observed during the dry season. Cypermethrin and carbofuran were the primary pesticides detected in water, while endosulfan and cypermethrin were dominant in sediment and fish tissue, often exceeding standard safety thresholds. Principal Component Analysis (PCA) and cluster analysis revealed stronger correlations between sediment and fish muscle, with varying associations among pesticides across seasons. The Hazard Index (HI) surpassed 1 in both seasons, signaling potential health risks to humans. These findings underscore the substantial risk agricultural pesticides pose to the aquatic ecosystem and food chain, highlighting the urgent need for sustainable agricultural practices and stricter regulations to minimize pesticide use and encourage eco-friendly pest management strategies.

The Spine of Haryana: Ecological and Historical Significance of Aravalli Hills

Natural resources are crucial for the development of civilizations; men-nature relationship is the axis of it and the Aravalli hills in India hold significant importance as the oldest mountain range on earth. Spanning across four states, they play a crucial role in shaping the climate and biodiversity of the region. Not only do they act as a watershed between the Indus and Ganga basins, but their forested patches also serve as a vital defence against air pollution and soil erosion. Recognizing their ecological value, the Ministry of Environment and Forest of India has implemented regulations to protect the Aravalli Range from activities causing environmental degradation. However, despite these efforts, the range faces threats such as deforestation, land degradation, encroachments, developmental activities, and mining, leading to adverse consequences like desertification, dust storms, loss of biodiversity, and air pollution. It is imperative to address these challenges to safeguard the ecological balance and natural heritage of the Aravalli hills. The aim of this present paper is to highlight the ecological as well as other importance of Aravalli hills in Haryana.

Evolution of the Late Cretaceous orbitoidal foraminifera and implications for the taxonomy and biostratigraphy in the Eastern Neo-Tethys, Lower Indus Basin, Pakistan: A biometric approach

In the eastern Neo-Tethys realm, the Late Cretaceous larger benthic foraminifera (LBF) Orbitoides and Omphalocyclus are poorly known. Herein, Orbitoides and Omphalocyclus populations from the Fort Munro Formation in Rakhi Nala Section, Lower Indus Basin, Pakistan are investigated. This work documents the most primitive evolutionary stages of these genera in the eastern Neo-Tethys. In Orbitoides, the average values of the size of embryon (Li + li) for the 18 investigated samples range between 477 and 516 µm and the average E values range between 4.2 and 4.7. In Omphalocyclus, the embryons are always trilocular and their sizes range between 112 and 485 μm, with an average between 153 and 287 μm. The E values range between 2 and 3, with an average of 2.3. Based on the average values of E and size of the embryon (Li + li), the populations of Orbitoides and Omphalocyclus have been attributed to the O. media and O. omanensis species, respectively. A late Campanian age is assigned to the Fort Munro Formation based on the recognition of O. media and O. omanensis. The detailed biometric study reveals primitive species of Orbitoides and Omphalocyclus from Pakistan (a part of eastern Neo-Tethys) in the Asian biogeographic province (ASP) during the late Campanian.

Projecting irrigation demand under IPCC climate change scenarios using WEAP modeling in the Rechna Doab, Pakistan

Pakistan is currently facing significant water scarcity issues, intensified by climate change. The main water source, the transboundary Indus River system, faces challenges such as water management, limited data availability, and inadequate management, leading to a gap between water demand and supply across various sectors. Agriculture, which consumes over 95 % of the country’s water resources, contributes nearly 25 % to the GDP, but is heavily dependent on irrigation due to limited rainfall. With rainfall meeting only 15 % of crop water requirements, groundwater plays a critical role, covering 40–60 % of irrigation needs. This study focuses on the Rechna Doab in the Indus Basin Irrigation System (IBIS) using the WEAP (Water Evaluation and Planning) model to assess the supply-demand gap under IPCC's climate change scenarios from Assessment Report Six (AR6). The main findings indicate: (1) Under SSP 8.5, unmet demand in the Upper Chenab Canal and other regions will increase by 33–47 % by mid-century; (2) demand site coverage will decline significantly, especially in Lower Gugera and Jhang branches; (3) groundwater dependency will increase substantially in response to the growing supply-demand gap. This work contributes to improving water management in Rechna Doab by providing a clear framework for adapting water resources to climate change using WEAP projections under various IPCC scenarios.

Monsoon control on evolution of the western Indian aeolian landscape: Insights from U-Pb detrital zircon geochronology and Sr-Nd-Hf isotope studies of the Thar Desert sand dunes

Evolution of landscape is linked to the interplay of tectonics, lithology, and climate. To better understand the evolution of aeolian landscape of the western Indian subcontinent and its major driver/s, we carried out a quantitative provenance analysis of the sand dunes of Thar Desert and desert river Luni using whole rock Sr-Nd-Hf isotopes and detrital zircon U-Pb geochronology. Our findings show Himalayan origin for the Thar sands. River Indus consistently contributed about 30–40 % of the total dune sand across the desert. The sand dunes in the north and the west of the desert are dominated by sediments derived from the source rocks drained by Sutlej river and its tributary Beas river whereas the dunes of central Thar are dominated by sediments supplied by rocks drained by Jhelum, Ravi and Chenab rivers. Analysis of detrital zircon U-Pb age spectra of sediments from desert river Luni reveal that dune sand of southern Thar Desert forms nearly 80 % of its present-day sediment load. Notably, the Thar dune sands show remarkable compositional similarity to the early to middle Holocene Indus delta sediments suggesting shared source/s. Existing paleolimnological and climatic records suggest a wetter environment in the Thar during early to middle Holocene. This evidence coupled with compositional similarities between the Thar dunes and the Indus delta sediments from the same period, indicate a probable extension of the Indus-Sutlej floodplain into southeast Thar during that time. Subsequent aridification of the region in the late Holocene likely led to seasonal winds recycling this fluvial sand to form the present-day Thar dunes, and shaping the current aeolian landscape in western India.

Aufeis thickness and volume estimations from stereo satellite imagery and terrestrial photographs: Evidence from Central Ladakh, India

Aufeis – a phenomenon associated with permafrost and the cold arid region of Ladakh – serves as a critical water resource for local communities. In several tributaries of the Indus River, aufeis accumulation is enhanced in ice reservoirs (commonly known as “artificial glaciers”) to store winter baseflow for crop irrigation during the water-scarce period in spring. This study investigates aufeis thickness and volume across four study sites in the Trans-Himalaya of Central Ladakh: the ice reservoirs of Phuktse and Igoo and the catchments of Gya and Sasoma, where natural aufeis fields occur. Aufeis thickness and volume estimates were derived via differencing of digital elevation models calculated from very high-resolution stereo Pléiades imagery and terrestrial photographs. The study revealed ice thickness up to a maximum of 3 m and could further demonstrate the amplification effect of the walls of the ice reservoirs on aufeis accumulation in both, differenced elevation from Pléiades and terrestrial photographs. Aufeis volumes across the four study sites range from 34,106 ± 13,440 m3 in Phuktse up to 105,790 ± 28,511 m3 in Sasoma, indicating substantial amounts that need to be considered in future hydrological studies in the region. While the approach with terrestrial photographs is especially suitable for local studies, the results from very high-resolution stereo satellite data are promising for aufeis studies on large spatial scales. It represents an important contribution for the understanding of spatial aufeis patterns in the Trans-Himalaya and affected regions worldwide.

The Early Cretaceous Sembar Formation, Southern Indus Basin, Pakistan: Biomarkers and Trace Element Distributions to Investigate the Sedimentary Palaeoenvironment and Organic Matter Input.

The Early Cretaceous clay-rich facies of the Sembar Formation represent the most significantly occurring organic-rich sediments in the Southern Indus Basin of Pakistan. In this study, detailed geochemical research of total organic carbon, biomarker, mineralogy and trace elemental compositions, together with kerogen microscopic analysis, were carried out and used to understand the organic matter input and the dispositional environmental setting of the organic-rich Sembar shale. The Sembar shales have high organic matter, as indicated by the total organic carbon (TOC) content of up to 2.31 wt %. These shales contain a high abundance of liptinites (i.e., alginite and bituminite), with significant reactive vitrinite maceral, reflecting a mixed-organic matter with a high contribution of marine-derived input. The biomarker distributions evidence the finding of mainly marine organic matter. The biomarker characteristics such as Pr/Ph, Pr/n-C17, Ph/n-C18, and tricyclic terpane ratios together with C27-C29 regular sterane distributions show that the source of organic matter was primarily marine-derived from mainly phytoplankton algae, along with amounts of land plant input, and accumulated under a low oxygenated environment. The Sembar shale facies are characterized by high Mo trace element content and high V/Ni and Mo/TOC ratios, suggesting anoxic and nonsulfidic environmental conditions during time deposition. The geochemical proxies such as the Sr/Ba ratio and gammacerane/C30 hopane (G/C30) index suggest that the Sembar shale facies were deposited in a relatively low moderate stratified water column. The higher gallium (Ga) than rubidium (Rb), with high Ga/Rb ratios, indicates a high abundance of the kaolinite mineral, thereby deducing the subaerial weathering during the warm and humid climatic conditions. In this case, these warm and humid climatic conditions cause an influx of masses of nutrients, which could be attributed to increasing marine primary bioproductivity. These large masses of nutrients into the photic zone are also attributed to the presence of the upwelling system during the deposition time. Therefore, such conditions of bioproductivity and preservation of organic matter (OM) resulted in the accumulation of organic carbon in the shale facies of the Early Cretaceous Sembar Formation.

Mio‐Pliocene paleo‐course of Indus River in Upper Sutlej‐Zhada basin: Implication of tectonic uplift on river piracy and drainage reorganization in SW Tibet and NW Himalaya

AbstractWe analysed the elevated low‐relief relict landscapes in the transient Upper Satluj‐Zhada basin and the adjoining region in the tectonically active north‐western (NW) Himalaya–south‐western (SW) Tibetan orogen to understand the evolution of the regional landscape and drainage system under the influence of the Karakoram Fault‐Leo‐Pargil Horst system. This elevated low relief landscape represents the Mio‐Pliocene establishment of a new river network, which testimonies the present Sutlej River, which has been experiencing a transient surface uplift‐incision regime since (~4–1 Ma) with a local base level at the confluence of the Sutlej and Spiti River. The Miocene exhumation of the Ayilari Range and Leo‐Pargil Horst across the Karakoram fault (KF) system led to headward erosion, which abandoned the Paleo‐Sutlej‐Indus drainage system, which in turn caused drainage reversal along Qusum detachment (QD) and produced southward migration of the Paleo‐Sutlej River towards the mountain front. Our results indicate that the Upper Indus River has significantly lower χ‐ranges at higher elevations as compared with the adjacent Upper Sutlej River at lower elevations, which corresponds with a river piracy model that incorporates area gain‐loss feedback. The Upper Sutlej River in the Zhada basin is characterized by a comparable series of coplanar slope‐break knickpoints at ~4000–4500 m elevation, and their adjoining divides are in a state of disequilibrium as a consequence of the very high rapid incision across the Leo Pargil Horst, which drives the regional gradation process. The headward‐eroding Upper Indus River captured the proto‐Sutlej due to a base‐level change of >~1500 m, which significantly impacted the regional growth pattern and tectonics. The Mio‐Pliocene sedimentation pattern of the Upper Sutlej‐Zhada basin in the SW Tibet–NW Himalaya reflects this regional drainage capture, tectonic uplift and paleo‐drainage reorganization. The present finding has wider implications for the Mio‐Pliocene reorganization of drainage systems and the possible linkage of the Upper Indus River with the Paleo‐Sutlej over the Zhada basin.

Distributed modelling of snow and ice melt in the Naltar Catchment, Upper Indus basin

Energy balance distributed modelling in High Mountain Asia (HMA) is important to examine glaciological and hydrological processes and assess changes in streamflow in the current and future climate. In this study, the Physically based Distributed Snow Land and Ice Model (PDSLIM) using detailed observed meteorological data at hourly scale is employed to simulate the hydrological response of the Naltar catchment, 242.62 km2 in size, (in the Karakoram region in Pakistan to simulate its glaciers’ mass balance as well as daily runoff. The results exhibited overall satisfactory performance in terms of coefficient of determination (R2 = 0.96) and Nash-Sutcliffe Efficiency (NSE=0.95) modelled against satellite-based snow cover areas, for internal model verification, in eight years. The results of runoff simulations compared for external model verification, with observed daily discharge resulted in NSE 0.90 and 0.89 for calibration and validation period respectively. Flow composition analysis revealed that the streamflow regime of Naltar catchment is composed to 40 % by glacier runoff, 42 % by sub-surface runoff and 18 % by surface runoff. The eight year mean value of net mass balance exhibited a slightly negative mass balance (−0.810 ± 0.31 m w.e. a-1) less pronounced than that observed globally in several continental glaciers distinct from the Greenland and Antarctic ice sheets in the current climate. It seems that the ‘Karakoram anomaly’, i.e. the balanced to slightly positive glacier budgets observed in the region in the recent decades, a unique dynamics worldwide, has a moderate impact in the central Karakoram. Overall, the distributed energy-balance model PDSLIM, so far tested in the Alps, results to be a suitable tool to estimate energy and mass balance in the glacierized catchments of Karakoram and Himalaya and to better understand snow and ice melt runoff dynamics and floods in highly complex and glacierized mountain basins in the current and, in our research perspective, in the future climate.

Spatiotemporal Characteristics and Triggers of Flash Droughts across All the River Basins in India

Abstract Flash droughts (FDs) have attracted widespread attention in recent years due to their sudden onset and rapid intensification with significant impacts on ecosystems, water resources, and agriculture. These features of FDs pose unique challenges for their forecast, monitoring, and mitigation. The impact of FDs on society can vary depending on several factors, such as the frequency of their occurrence, rate of intensification, and mean severity, which are not well understood and remain unclear specifically over India. This study developed a novel approach to quantitatively define FD based on the aridity index. This new approach was used to examine spatiotemporal characteristics (including trends) and triggers of FDs over 25 river basins across India from 1981 to 2021. The hydrometeorological conditions, including soil moisture percentiles, anomalies of precipitation, temperature, and vapor pressure deficit were investigated at different stages of FD. Results suggest that FDs with high intensification rates are more common in humid areas compared to subhumid and semiarid areas. Both precipitation and temperature are primary triggers of FDs over a major part of the study area. The individual effects of soil moisture and precipitation also act as a trigger across some regions (like northeast India and the Western Ghats). Additionally, atmospheric aridity can create conditions conducive to FDs, and when combined with depleted soil moisture, it can accelerate their rapid onset. Besides the scientific novelty, the findings of this study will facilitate policymakers to formulate effective strategies to mitigate the consequences of FDs on water resources and agriculture in India. Significance Statement Flash droughts have attracted widespread attention due to their sudden onset and rapid intensification with significant impacts on multiple vectors. The impact of flash drought on society depends on their frequency, rate of intensification, and mean severity, which are not well understood and remain unclear specifically over India. This study develops a novel approach to quantitatively define flash drought based on the aridity index. This new approach is used to examine spatiotemporal characteristics and triggers of flash drought over 25 river basins across India from 1981 to 2021. Besides the scientific novelty, the findings of this study will facilitate policymakers to formulate effective strategies to mitigate the consequences of FDs on water resources and agriculture in India.

Evaluating hydrological responses of satellite precipitation products over an Indian tropical catchment through a distributed physical model

AbstractSignificant advancements in satellite‐based precipitation retrieval algorithms have led to the development of continuous, quasi‐global precipitation products, offering unique opportunities for hydrometeorological and climate research. In this context, six satellite‐based precipitation products (SPPs), including CHIRPS, CMORPH, GSMaP, IMERG, MSWEP, and PERSIANN, were thoroughly investigated for their application in hydrological simulations over the Wardha River basin in India. The observed gridded precipitation product developed by India Meteorological Department (IMD) has been used as reference data to evaluate the performance of SPPs. Hydrological variables such as runoff, soil moisture (SM) and evapotranspiration (ET) were simulated using the Variable Infiltration Capacity model. The performances of SPPs are critically assessed using various statistical metrics, including Pearson's correlation coefficient (R), Klinga‐Gupta Efficiency (KGE), Percent Bias (PBIAS), root mean square error (RMSE), and the RMSE to standard deviation ratio (RSR). The model‐simulated discharge was compared with streamflow observations at a single gauging site, while a spatially distributed comparison was conducted between simulated SM and ET and satellite‐based SM and ET. The IMD dataset consistently shows superior performance for discharge simulation at both daily and monthly scales, with KGE values of 0.85 and 0.91, respectively. Among SPPs, MSWEP and CHIRPS excel in simulating daily and monthly discharge, respectively. For ET simulation, CHIRPS outperforms IMD and other SPPs, achieving an overall KGE value of 0.37. In contrast, PERSIANN is the most effective for simulating SM compared to other precipitation products.

PNN Enhanced Seismic Inversion for Porosity Modeling and Delineating the Potential Heterogeneous Gas Sands via Comparative Inversion Analysis in the Lower Indus Basin

Seismic inversion has been in use for the last two decades to measure inverted impedances using an integrated data set approach. This research focuses on the application of multi-attribute seismic inversion and the geostatistical probabilistic neural network (PNN) approach for determining rock properties and litho-fluid classification in the Mehar-Mazarani Field of the Lower Indus Basin (LIB), Pakistan. The study compares five different inversion techniques, including model-based inversion (MBI), colored inversion (CI), linear sparse spike inversion (LSSI), band-limited inversion (BLI), and maximum likelihood sparse spike inversion (MLSSI). The inverted outputs, such as acoustic P-impedance (Zp), density (ρ), porosity (φ), and shale volume (Vsh), were analyzed in Paleocene and Cretaceous geological complex reservoirs to identify gas-bearing zones. The results indicated the existence of gas between 1630 and 1700 ms (ms) and corresponding depth ranges from approximately 3200 m up to 4200 m with varying thickness. Amongst the inversion techniques, MBI demonstrated greater accuracy, with inverted density volumes showing a strong correlation coefficient of 0.98 and the lowest root mean square error (RMSE) and relative error of 0.10 m/s * g/cc. A geostatistical PNN approach was employed to estimate variations in Vsh and φ within the sand reservoir. MBI again yielded more reliable results, with a strong correlation between the measured and inverted attributes. High φ and low Vsh were observed in predetermined low-impedance zones. Overall, MBI is proven to be the most accurate and reliable technique, providing clear identification of the gas occurrence. This research highlights the effectiveness of seismic inversion, particularly the application of MBI, in determining rock properties and identifying gas-bearing zones within the Mehar-Mazarani gas field.

Qualitative analysis of rivers sand sources (Silica sand, Ravi river sand, Indus river sand, and Jhelum river sand) for metal casting: a comparative study

Abstract Recent geological investigations revealed extensive use of Silica sand in Pakistan resulting in depletion of tectonic resources. Hence, it is important to explore cost-effective and alternative sources of sand for its applications. Also, Pakistan has a river network that provides river sand as a potential substitute for Silica sand. However, it is essential to systematically study and assess the potential applicability of river sand as an alternative to Silica sand. In this context, this study examined sand samples collected from various rivers in Pakistan to investigate their suitability for metal-casting molds. For that purpose, random samples were selected from major rivers in Pakistan for characterization by utilizing chemical composition analysis, microscopy, XRD, TGA-DSC (thermogravimetric analysis), clay content analysis, grain size distribution analysis, pH measurement, green and dry compression strength testing, shear strength testing, permeability analysis, shatter index analysis, compactibility testing, and Specific gravity measurement. The chemical composition analysis revealed that all types of sands contained over 90% SiO2 content. The mechanical tests demonstrated that river sand exhibited acceptable mechanical properties, with a moisture content ranging from 4.5-5%. The pH value of all the sands exceeded 7, making them suitable for casting purposes. These investigations suggest that river sand can be effectively utilized in casting applications by implementing pre-processing techniques and incorporating additives.

Spatiotemporal variation and teleconnections of extreme precipitation in the Upper Indus Basin: insights for natural hazard assessment

ABSTRACT The study investigates trends and teleconnections of extreme precipitation events in the Upper Indus Basin (UIB) within the Indian region, part of the crucial geo-ecological Hindu Kush Himalayan Mountain system. Utilizing high-resolution (10 km × 10 km) HAR data from 2002 to 2013, we analyzed 11 indices established by the Expert Team on Climate Change Detection and Indices (ETCCDI) to observe variations in extreme precipitation at the monthly, seasonal, and annual time scale. The result shows an increase in dry and wet extreme precipitation frequency and intensity, increasing monsoon precipitation and a shift of winter precipitation, increasing continuous dry days. Using the APHRODITE daily (0.25° × 0.25°) data from 1952 to 2014, continuous wavelet transform and wavelet coherence analysis indicate significant periodicities and correlations with large-scale climate anomalies such as the El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). Wavelet coherence analysis reveals that monthly extreme precipitation events significantly correlate with ENSO at a 3–5 years periodicity, while annual extremes show significant coherence with NAO at 8–10 years and over 16 years periodicities. The study highlights the impact of global climate change on regional precipitation and the need for adaptive water management policies to mitigate flood risks during the rainy season and address water scarcity in the dry season.

Decadal hydrological impact assessment of evolving land use and land cover in an Indian river basin: a multi-model approach

ABSTRACT All river basins have ever-evolving land use and land cover (LULC) attributes. The impact of these changes may not be significant on short time scales (i.e., monthly, seasonal, yearly), but over a decadal scale, they can substantially alter the hydrological processes of the basin. This study comprehensively quantifies the impacts of LULC changes over Cauvery basin in India using LULC maps from four decades spanning from 1980 to 2020. Simulations were performed using the Soil and Water Assessment Tool (SWAT) with various datasets. To isolate the effects of LULC changes, two sets of SWAT models were developed: A-set models for calibration and validation to establish basin parameters and B-set models to examine LULC change impacts while isolating other factors such as terrain and climate changes. Key findings include a significant increase in urban areas (0.87% in 1985 to 5.54% in 2015), a decline in vegetation cover (25.34% in 1985 to 21.32% in 2015), and an increase in the Curve Number and average annual surface runoff, highlighting the impact of LULC changes on hydrological processes. The A-set models achieved R-squared values of 0.831, 0.728, 0.715, and 0.757, while the B-set models showcased significant changes in hydrological parameters due to LULC changes.