Groundwater Investigation by Using Resistivity Survey in Peshawar, Pakistan

Resistivity survey was conducted in Peshawar to investigate groundwater using Terrameter SAS 4000. Six sites were selected for the studies through feasibility survey to identify feasible points for conducting survey. Data collected was analyzed using 1X1D software which uses principal of conventional theory of curve matching. Resistivity values were compared with standard table of resistivity values of geological formations through which depths to water table was estimated, which were compared to the existing surrounding wells. These local results showed that shallow depths estimated for groundwater table were at Pakistan Forest Institute as saturated sand and gravel, for an average depth to water table of 23 m with respect to ground surface. In University Campus/Professor Colony, Biotechnology, Hayatabad Township site 1, and Site 2 the local groundwater level mostly in sand and gravel materials were at depths of 41 m, 37 m, 92 m and 82 m for different resistivity values. Study concludes that Instead of natural surface flow and seepage, there should be storage in the permeable zone or open dug wells within the planned storages for artificial recharge. Furthermore use of geophysical tools for groundwater investigation provides easy and quick approach as compared to conventional methods of groundwater investigations. Keywords: Groundwater. Resistivity survey. Terrameter SAS 4000. 1X1D software. Geophysical tools. Georefrencing

Regional Groundwater Flow Assessment in a Site Specific Portion of Peshawar Valley In Pakistan

A research study was conducted in selected sites of Peshawar for development of ground water mapping by utilization of Resistivity survey with the help of Terrameter SAS 1000/4000 along with 4 electrodes and other accessories for data collection, 20 sites were selected for data collection in various parts of Peshawar where data was collected with standard electrode array of Schlumburger array with 300 m spacing on each side of the instrument. Coordinates and elevation from mean sea level of each site were recorded with global positioning system (GPS).  Arc GIS was utilized for geo referenced map of the study area where the survey points were plotted. Another tool Surfer was utilized for contours development for ground water levels. The analysis of resistivity data were executed with the help of 1X1D software on the basis of which the ground water level were calculated which were also compared with existing water table of the area in surroundings and were in good match. The results indicate that the area has different pattern of ground water flow as the ground water in University Campus was toward Pakistan Forest Institute area as the elevation of ground water was at a depth of 339 m as compare to Works directorate of Agriculture University where the elevation was 334 m while in Malakandhir Farm the direction of flow was toward New Professor Colony Site where elevation of ground water was at a height of 319 m as compare to rest of profiles in the area  which elevation was 323 m with respect to mean sea level for Biotechnology profile 359 m from mean sea level for Veterinary hospital and 351 m for military profile. In Hayatabad the flow pattern was also different as the in Phase 3 the ground water flow was toward Phase 3 civil quarters with an elevation of 339 m form mean sea level which was lower than rest of the site in the area while in Phase 7 the ground water flow was toward Behram Market which was at an elevation of 335 m from mean sea level.  The study indicates that among all the surveyed sites the critical zone with low water table was Hayatabad where further detailed study of ground water exploration along with artificial recharge techniques were recommended to restore the depletion of water table. Keywords: Terrameter, Schlumberger Electrode Configuration, 1X1D, Ground water flow, Artificial Recharg

Assessment of multi-components and sectoral vulnerability to urban floods in Peshawar – Pakistan

Over the last two decades, urban floods and their impacts have been on the rise worldwide, owing to both climatic changes and human activities. The present study examines different at-risk elements, such as residential, commercial, and critical facilities, to evaluate their multi-components of vulnerability to urban floods in Peshawar, Pakistan. Based on the impacts of urban floods, the weightage of each component of the vulnerability for the selected elements at risk is defined. This study presents and uses the modified Fisher's ideal quantity index to combine the different vulnerability components into a single value. Additionally, the Patnaik and Narayan vulnerability index is employed to generalize sector-wise vulnerabilities across the study area. The results show that the old physical infrastructure of commercial and manufacturing units in the Kohati Gate area is highly vulnerable to urban floods, while the residential units are the least susceptible due to their distanced location from the drainage system. In Hayatabad, encroachments along the torrent's sides, affecting housing and educational institutions, contributed to increased vulnerability to urban floods, despite their relatively lower physical vulnerability. The study provides a new platform for understanding the multi-components of vulnerability to urban floods and tackling the challenges posed by urban floods effectively

Comparing Multiple Precipitation Products against In-Situ Observations over Different Climate Regions of Pakistan

Various state-of-the-art gridded satellite precipitation products (GPPs) have been derived from remote sensing and reanalysis data and are widely used in hydrological studies. An assessment of these GPPs against in-situ observations is necessary to determine their respective strengths and uncertainties. GPPs developed from satellite observations as a primary source were compared to in-situ observations, namely the Climate Hazard group Infrared Precipitation with Stations (CHIRPS), Multi-Source Weighted-Ensemble Precipitation (MSWEP), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR) and Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis (TMPA). These products were compared to in-situ data from 51 stations, spanning 1998–2016, across Pakistan on daily, monthly, annual and interannual time scales. Spatiotemporal climatology was well captured by all products, with more precipitation in the north eastern parts during the monsoon months and vice-versa. Daily precipitation with amount larger than 10 mm showed significant (95%, Kolmogorov-Smirnov test) agreement with the in-situ data, especially TMPA, followed by CHIRPS and MSWEP. At monthly scales, there were significant correlations (R) between the GPPs and in-situ records, suggesting similar dynamics; however, statistical metrics suggested that the performance of these products varies from north towards south. Temporal agreement on an interannual scale was higher in the central and southern parts which followed precipitation seasonality. TMPA performed the best, followed in order by CHIRPS, MSWEP and PERSIANN-CDR

Climate change will exacerbate population exposure to future heat waves in the China-Pakistan economic corridor

The China-Pakistan Economic Corridor (CPEC) is a climate change-sensitive region, facing frequent and intense heat waves (HWs). The CPEC is expected to experience a simultaneous increase in population and temperature in the coming decades, which could exacerbate human exposure to future HWs. However, it is unknown how much of the population would likely be exposed to HWs in the CPEC under changing climate. This study used the Coupled Model Inter-comparison Project 6 (CMIP6) models and population projections to estimate population exposure to daytime, nighttime, and compound HWs in the CPEC during 2071–2100, relative to 1985–2014 under four Shared Socioeconomic Pathways (SSPs). The results indicate that the study region will probably experience the highest number of nighttime HWs, followed by daytime and compound HWs in the northern, southwestern, and southern parts of the CPEC. The largest population would likely be exposed in the eastern and southwestern CPEC under SSP3-70|SSP3, followed by SSP5-8.5|SSP5, SSP2-4.5|SSP2, and SSP1-2.6|SSP1. The results reveal that the climatic and interactive effects could significantly escalate the population exposure to future HWs in the CPEC. The probability of 2015-HWs-like events and population exposure to such extremes would probably be higher in the eastern CPEC. The return period of 2015-HW-like events would decrease, which indicates their frequent occurrence under the selected SSPs. The findings of the study highlight the need for urgent actions to limit greenhouse gas emissions and to adopt effective adaptation measures in order to avoid the negative consequences of HWs on the local population in the future

Characteristics of human thermal stress in South Asia during 1981–2019

Climate change has significantly increased the frequency and intensity of human thermal stress, with relatively more severe impacts than those of pure temperature extremes. Despite its major threats to public health, limited studies have assessed spatiotemporal changes in human thermal stress in densely populated regions, like South Asia (SAS). The present study assessed spatiotemporal changes in human thermal stress characteristics in SAS, based on daily minimum, maximum, and mean Universal Thermal Climate Indices (i.e. UTCI _min , UTCI _max , and UTCI _mean ) using the newly developed high-spatial-resolution database of the thermal-stress Indices over South and East Asia for the period 1981–2019. This study is the first of its kind to assess spatiotemporal changes in UTCI indices over the whole of SAS. The study also carried out extreme events analysis of the UTCI indices and explored their nexus with El Niño-Southern Oscillation (ENSO) index. Results revealed a significant increase in heat stress in SAS, with the highest human thermal stress in western Afghanistan, the Indo-Gangetic Plain, and southeastern, and central parts. The extreme event analysis showed that the study region is likely to observe more frequent and intense heat extremes in the coming decades. The correlation of UTCI indices with ENSO exhibited a robust positive coherence in southeastern and central India, southern Pakistan, and northwestern Afghanistan. The findings of the study are critical in understanding human thermal stress and adopting effective risk reduction strategies against heat extremes in SAS. To better understand the dynamic mechanism of thermal extremes, the study recommends a detailed investigation of the underlying drivers of UTCI variability in SAS

Spatiotemporal Characteristics and Trend Analysis of Two Evapotranspiration-Based Drought Products and Their Mechanisms in Sub-Saharan Africa

Drought severity still remains a serious concern across Sub-Saharan Africa (SSA) due to its destructive impact on multiple sectors of society. In this study, the interannual variability and trends in the changes of the self-calibrating Palmer Drought Severity Index (scPDSI) based on the Penman–Monteith (scPDSIPM) and Thornthwaite (scPDSITH) methods for measuring potential evapotranspiration (PET), precipitation (P), normalized difference vegetation index (NDVI), and sea surface temperature (SST) anomalies were investigated through statistical analysis of modeled and remote sensing data. It was shown that scPDSIPM and scPDSITH differed in the representation of drought characteristics over SSA. The regional trend magnitudes of scPDSI in SSA were 0.69 (scPDSIPM) and 0.2 mm/decade (scPDSITH), with a difference in values attributed to the choice of PET measuring method used. The scPDSI and remotely sensed-based anomalies of P and NDVI showed wetting and drying trends over the period 1980–2012 with coefficients of trend magnitudes of 0.12 mm/decade (0.002 mm/decade). The trend analysis showed increased drought events in the semi-arid and arid regions of SSA over the same period. A correlation analysis revealed a strong relationship between the choice of PET measuring method and both P and NDVI anomalies for monsoon and pre-monsoon seasons. The correlation analysis of the choice of PET measuring method with SST anomalies indicated significant positive and negative relationships. This study has demonstrated the applicability of multiple data sources for drought assessment and provides useful information for regional drought predictability and mitigation strategies

Innovative methods in soil phosphorus research: A review

Phosphorus (P) is an indispensable element for all life on Earth and, during the past decade, concerns about the future of its global supply have stimulated much research on soil P and method development. This review provides an overview of advanced state-of-the-art methods currently used in soil P research. These involve bulk and spatially resolved spectroscopic and spectrometric P speciation methods (1 and 2D NMR, IR, Raman, Q-TOF MS/MS, high resolution-MS, NanoSIMS, XRF, XPS, (µ)XAS) as well as methods for assessing soil P reactions (sorption isotherms, quantum-chemical modeling, microbial biomass P, enzymes activity, DGT, 33P isotopic exchange, 18O isotope ratios). Required experimental set-ups and the potentials and limitations of individual methods present a guide for the selection of most suitable methods or combinations