Decadal trends in precipitable water vapor over the Indus River Basin using ERA5 reanalysis data

Precipitable Water Vapor(PWV)constitutes a pivotal parameter within the domains of atmospheric science,and remote sensing due to its profound influence on Earth’s climate dynamics and weather patterns.It exerts a significant impact on atmospheric stability absorption and emission of radiation,thus engendering alterations in the Earth’s radiative equilibrium.As such,precise quantification of PWV holds the potential to enhance weather prognostication and fortify preparedness against severe meteorological phenomena.This study aimed to elucidate the spatial and temporal changes in seasonal and annual PWV across the Indus River Basin and its sub-basins using ERA5 reanalysis datasets.The present study used ERA5 PWV(entire atmospheric column),air temperature at 2 m(t2m)and 500 hPa(T_500hPa),evapotranspiration,and total cloud cover data from 1960 to 2021.Theil Sen slope estimator and Mann-Kendall test were used for trend analysis.Correlation and multiple regression methods were used to understand the association of PWV with other factors.The findings have unveiled the highest increase in mean PWV during the monsoon(0.40 mm/decade),followed by premonsoon(0.37 mm/decade),post-monsoon(0.27 mm/decade),and winter(0.19 mm/decade)throughout the study period.Additionally,the mean PWV exhibited the most pronounced positive trend in the sub-basin Lower Indus(LI),followed by Panjnad(P),Kabul(K),and Upper Indus(UI)across all seasons,except winter.Annual PWV has also risen in the Indus basin and its sub-basins over the last six decades.PWV exhibits a consistent upward trend up to an elevation of 3500 m within the basin which is most pronounced during the monsoon season,followed by the pre-monsoon.The escalating PWV within the basin is reasonably ascribed to increasing air temperatures,augmented evapotranspiration,and heightened cloud cover.These findings hold potential utility for pertinent authorities engaged in water resource management and planning.

Comprehensive isotopic characterization of the hydrological processes of the Indus river basin(IRB):A comparison between Upper Indus Basin(UIB)and Lower Indus Basin(LIB)

The Indus river basin(IRB)is one of the most depleted water basins globally,having significant challenges for its water sector.Monitoring of stable isotope composition(δ^(18)O and δ^(2)H)across IRB is a critical aspect that can provide deeper insights for investigating complex hydrological processes.This work analyses the spatial pattern of the isotopic signature using a comprehensive compilation of available datasets of the Global Network of Isotopes in River(GNIR)and Global Network of Isotopes in Precipitation(GNIP),along with the previously published isotopic studies in the Indus basin.Additionally,this work provides a detailed comparison of the isotopic signature of the Upper Indus Basin(UIB),and Lower Indus Basin(LIB).The IRBs waterline was found to beδ^(2)H=7.89×δ^(18)O+13.51,which shows a close similarity with the Global Meteoric Water Line(GMWL),indicating the meteoric origin of the water with insignificant secondary evaporation prevailing across the basin.The Main Indus Channel(MIC)river water line(δ^(2)H=8.88×δ^(18)O+26.05)indicates a major contribution from the meteoric origin(precipitation/rain)of water with minimal effect of evaporation processes.The water line for UIB samples,(δ^(2)H=7.88×δ^(18)O+11.94)was found to be moderately higher in slope than LIB samples(δ^(2)H=7.17×δ^(18)O+7.16).However,the slopes of both UIB and LIB river water lines closely approached the slope of GMWL and were consistent with the slope of IRB water line,which indicates similarity in contribution of water sources.The higher slope and intercept in UIB suggest that meteoric water sources contributed to streamflow viz.from snow/glacier with insignificant evapotranspiration,which is also validated by the scarce vegetation cover in the UIB.However,the lower slope and intercept in LIB suggest stream water contribution from significantly evaporated groundwater and precipitation with a complete homogenization of discharge coming from the UIB.Results substantiate that distinct isotopic signatures found in different stretches of the IRB and along the MIC are caused by variations in basin characteristics,hydro-meteorological processes,water mixing,and minor influence of anthropogenic variables.

Evaluating spatial and elevation-wise daytime/nighttime LST trends across the Indus River Basin

Land surface temperature(LST)is a crucial parameter for understanding the Earth's surface energy balance,which provides insights into climate dynamics and local environmental conditions.Thus,the present study aims to evaluate the spatial and elevation-wise trends in the daytime,nighttime,and mean LST across the Indus River Basin(IRB)using MODIS 8-day product for the period between 2002 and 2022.The elevation,cloud cover,and land cover type data are used for explaining the emerging LST trends.The Theil slope estimator and MannKendall significance test were used for estimating the seasonal and annual LST trends.The findings show warming in mean daytime(0.020-0.024℃/yr)(except winter and post-monsoon),nighttime(0.013-0.049℃/yr),and mean(0.001-0.042℃/yr)LST in all the seasons(highest in monsoon).The annual mean nighttime LST(0.025℃/yr)is rising significantly faster than the mean daytime LST(0.0016℃/yr),showing the presence of a“nighttime warming effect”,which possibly increases human discomfort,particularly during the warm pre-monsoon and humid monsoon season.Elevation-dependent warming(EDW)is predominant in mean daytime LST in two elevation zones,namely(i)0-3 km and(ii)above 4 km,in all seasons,except in post-monsoon.In contrast,EDW in mean nighttime LST is observed up to 3 km and above 6 km in the basin in all the seasons,excluding post-monsoon.The warming trend in LST may be attributed to rising atmospheric moisture,cloud cover,declining snow cover,and changes in land cover to non-vegetated land.However,further investigations will involve exploring the underlying factors contributing to the observed anomalies in nighttime LST,considering variables such as regional energy balance and atmospheric stability.This research contributes to an understanding of the thermal dynamics in the mountain basin,aiding in climate studies,land management,and the development of effective adaptation strategies in the IRB.

Biological Status of Indus River Dolphin （Platanista Minor Owen） in Indus River, Northern Pakistan

A study was aimed to determine the biological status of the Indus river dolphin, Platanista minor Owen in Indus river with respect to distribution, threats and protection throughout its range in Northern Pakistan. For this purpose, a survey was conducted in an area of 103.5 km including the Indus river and its tributaries in March 2009 for estimating its distribution and population size using both direct observations of the dolphin as well as indirect evidences from its signs. The best group size was estimated with an abundance of 54 dolphins. Approximately 53.7% （1.07 dolphin＆m） of the dolphin-population occurred in 27 km from Miran onward to Ramak, however, 38.9% （0.46 dolphin/km） occurred in 46 km from Dera Ismail （D.I.） Khan bridge to Miran, moreover, 7.4% （0.13 dolphin/kin） occurred in 30.5 km from Saggu, near Meetapur-village to D.I. Khan bridge in the Indus river. The highest density was found between Miran and Ramk. A pronounced increase in dolphin encounter rate and abundance were observed in a downstream-direction. Threats to dolphins include too much vessel-traffic, disturbance by the crane, duck-hunters, and no effective-protection. Dolphins are particularly vulnerable to the high levels of anthropogenic activities because of their restricted habitat. Threats vary geographically in their importance, but generally include accidental killing during fishing-operations, habitat-loss and population-fragmentation from water development. Deliberate killing for dolphin products also threatens the dolphins. Potential for protections and possibilities for dolphin eco-tourism measures must be taken.

Population exposure to precipitation extremes in the Indus River Basin at1.5℃,2.0℃and 3.0℃warming levels

Adverse effects of extreme events are the major focus of climate change impact studies.Precipitation-related extremes has substantial so-cioeconomic impacts under the changing climate.Quantifying population exposure to precipitation extreme is the fundamental aspect ofpopulation risk assessments in the climate hotspot of Indus River Basin.This study investigates the population exposure to precipitation ex-tremes at 1.5℃,2.0℃,and 3.0℃global warmings in the Indus River Basin using daily precipitation data,and projected population undershared socioeconomic pathways(SSPs).The IntensityeAreaeDuration method was applied to detect the extreme precipitation event by tracingthe rainstorm process,calculated based on five downscaled and bias-corrected Global Climate Model(GCM)outputs from Coupled ModelIntercomparison Project Phase 5(CMIP5)under four Representative Concentration Pathways(RCP2.6,RCP4.5,RCP6.0,and RCP8.5).Theexposure of the population is finally estimated by combing SSP1 with 1.5℃,SSP2 with 2.0℃,and SSP5 with 3.0℃warming levels.Resultsshow that warming over the Indus River Basin is projected to be higher than that of the global average.Both the extreme precipitation events andpopulation exposure are projected to increase with warming level.With regard to the reference period(1986e2005),the frequency,duration,andimpacted area of extreme precipitation are projected to increase by 13.2%,7.4%,and 1.6%annually under 1.5℃in the Indus River Basin,respectively.Whereas,an additional 0.5℃and 1.5℃warming can lead to further increase in the frequency of 16.6%,17.3%,as well as theduration of 8.6%,12%,and areal coverage of 2.1%,5.3%,respectively.The population exposure to extreme precipitation is projected to increaseby 72.4%,122.7%,and 87.6%,respectively,at SSP1 with 1.5℃,SSP2 with 2.0℃and SSP5 with 3.0℃warming levels compare to thereference period.The demographic change is responsible more for the tremendous increment of population exposure in the Indus River Basin.Ifthe population was held constant to the level of 2010,the increase of population exposure would be 4.4%,8.8%,and 17.6%,respectively,at1.5℃,2.0℃,and 3.0℃warming levels.Spatially,the prominent increment of population exposure is projected in the central and southwesternIndus River Basin.This study highlights that limiting the increase of temperature to 1.5℃can substantially reduce population exposure toextreme precipitation events in the Indus River Basin,compared to an additional warming.Simultaneously,urge paid to formulate policies onpopulation growth to reduce future exposure.

Proximate composition and elemental analysis in soft tissues of freshwater mussels （Anodonta anatina） from the Chashma Lake, River Indus Pakistan

BACKGROUND： Aquatic invertebrates are playing an important role in assessment of the water contaminants and also serve as a major component of food chain. Freshwater mussels are considered to be the good bioindicator species of aquatic environment and widely used to determine the metals load. METHODS： Proximate composition and elemental analysis were carried out in edible （foot, mantle） and non-edible portion （gills） of freshwater mussels （Anodonta anatina） harvested from various site of Chashma Lake, River Indus Pakistan. RESULTS： The nutritional components were varied among the studied portion and muscular foot found to be the best part for consumption. Protein and fat contents were significantly higher in foot （15.90±0.88%, 1.19 ±0.26%） as compared to mantle （10.78±2.24%, 0.27±0.09%） and gills （6.44± 1.22%, 0.53 4-0.15%） respectively. For the macro minerals mantle had high concentration of Ca （46838±984 mg/kg）, Na （2706±343 mg/kg）, P （6921± 1063 mg/kg） and Mn （7207± 1046 mg/kg） as compared to foot. CONCLUSIONS： Heavy metals （Cd, Cu, Cr） concentration in edible portions were lower than the permissible limit by WHO whereas the concentration of Pb was slightly higher than the recommended value that might be the risk for the consumers. Being filter feeder gills accumulated the high concentration of all the metals and found to be the key portion for biomonitoring studies. Freshwater mussels of Chashma Lake Indus River are the rich source of protein and all the other micro and macro minerals therefore could be used as an excellent source of food.

Assessing Multidimensional Vulnerability of Rural Areas to Flooding:An Index‑Based Approach

Vulnerability assessment is essential for understanding and launching effective flood risk reduction strategies.This study aimed to examine the vulnerability of flood-prone rural communities in southern Punjab,Pakistan to external shocks.The concept of vulnerability encompasses a range of dimensions,including physical,social,institutional,environmental,economic,and attitudinal.Using a composite index method,indices were developed for each dimension and combined to create a multidimensional measure of vulnerability.A sample of 365 communities was selected using the Yamane sampling technique,and data were collected through a questionnaire containing 65 indicators across all dimensions.Descriptive statistics and ANOVA tests were used to analyze the data.The results show that communities near the Chenab River had higher attitudinal and institutional vulnerability compared to other communities.High attitudinal vulnerabilities were as sociated with poorly perceived flood risks and low preparedness measures,whereas institutional vulnerabilities were driven by conventional flood protection strategies,lack of institutional trust,and lack of flood risk awareness.This research provides insights into the various components of vulnerability in flood-prone rural communities in Pakistan and demonstrates a useful methodology that can be applied to other disasters at different spatial scales.