Journal of Institute of Science and Technology

Application of Geospatial Techniques for Artificial Recharge to Groundwater in Ratu Khola Watershed, Central Nepal

Yagya Murti Aryal — 2023-02-28

Water levels in many existing ponds and shallow tube wells are found lowering day by day in the Bhabar and Terai regions of Nepal. For the sustainable management of the groundwater, development of artificial recharge ponds is considered the best approach in this region. The suitable site selection for the artificial recharge ponds requires surface as well as sub-surface geological investigation along with other land use-related characteristics. The study area is a part of the Ratu Khola watershed in the Mahottari and Dhanusa districts and encompasses parts of the Siwalik, Bhabar, and Middle Terai regions from an aspect of the geological division. The present study has aimed to find suitable sites for the artificial recharge pond. For this purpose, extensive fieldwork was carried out to gather data related to geology, geomorphology, water table, and soil characteristics. However, slope and drainage density maps were developed from the Digital Elevation Model (DEM). The thematic layers of different parameters such as geology, geomorphology, slope, water table, drainage density, land use land cover, and soil type were prepared by using GIS and RS. Based on the field data and prepared maps the suitable sites for artificial recharge ponds were analyzed. The Analytic Hierarchy Process (AHP) method was adopted to assign rank and reclassify the prepared maps. The total area was differentiated into five classes to assess the suitable sites for artificial recharge ponds. These five classes are named as the most suitable, highly suitable, moderately suitable, low suitable, and unsuitable depending on the score of the suitability analysis. The most suitable, highly suitable, moderately suitable, low suitable, and unsuitable area for groundwater recharge is found at about 3%, 7%, 24%, 32%, and 34% respectively. Finally, the ROC/AUC curve was prepared using primary data (point data) collected from the field. An overall accuracy of 82.3% was achieved in this study and is considered satisfactory.

Influence of Southern Oscillation Index on Rainfall Variability in Nepal during Large Deficient Monsoon Years

Damodar Bagale — 2023-03-19

The study was conducted using rainfall time-series data for 42 years from 1977 to 2018. We have identified seven large monsoon deficient years. Among these years, 1992, 2009, and 2015 consisted of El Niño episodes which quantify significant rainfall deficits 19.29, 13.6, and 17.59 % respectively from an average rainfall. With some exceptions, all El Niño years observed deficit rainfall. On El Niño years averaged deficit rainfall was approximately nine percent below than the average monsoon rainfall. The eastern region observed the large deficient monsoon years frequently than the central and western regions of Nepal. The central region recorded large spatial variability of average summer rainfall ranging from less than 200 mm/months in lesser Himalayans to more than 3,000 mm/months in mid-mountainous region. The western region had observed a large deficient summer monsoon anomaly 45 % in the year 1979. Similarly, the central region had 31 % deficient summer monsoon anomalies in 1992, and the eastern region observed 25 % deficient anomalies in 1982. There was a strong correlation between the Nepal Summer Monsoon Rainfall (NSMR) and Southern Oscillation Index (SOI). Generally, large negative/positive magnitude of SOI on the Indian and Pacific Ocean has link to weakening/strengthening NSMR.

Distribution Records and Conservation Status of Turtles in Chitwan, Nepal

Shyam Kumar Pun — 2023-06-16

Turtle is one of the oldest reptile groups of which 18 species are reported in Nepal. Eight sites were surveyed for turtles in Chitwan. Data were collected by both direct and indirect methods. Nine turtle species and a total of 36 specimens were recorded in Chitwan. Indotestudo elongata and Nilssonia hurum were the most frequently recorded species. Morphometric measurements of seven turtles were also recorded. Madi (41.7%) was found to contain the highest species richness in the study area. This study also provides information on anthropogenic threats and potential remedies that will help to prevent the extinction of Nepal's turtles.

Estimating the Effects of Nonpharmaceutical Interventions of COVID-19 in Sudurpaschim Province, Nepal

Nar Bahadur Chanda — 2023-06-16

Due to ongoing viral evolution and frequent outbreaks, responding to the pandemic has been challenging for countries with limited resources, like Nepal. In this study, we retrospectively estimated the impact of nonpharmaceutical interventions (NPIs) in Sudurpashchim province of Nepal using COVID-19 second wave data (20 March-31 August 2021) by using the mathematical model. We estimated extremely low (2%) detection of new cases in Sudurpashchim, and only 10% border screening with Antigen tests among the returnees in Sudurpashchim from India during the Delta surge which was not sufficient to lower the burden of the pandemic. The lockdown implemented during the pandemic was successful in lowering the disease burden. The control interventions were effective which reduced the 34% of new cases and 28% of active cases during the peak time and overall cases by 12.3% from 20 March-31 August 2021. During the peak of the pandemic, control intervention reduced the number of patients in regular beds by 27%, ICU by 31%, and ventilators admissions each by 33%. Our results explore that, without sufficient detection of new cases in the community, border screening alone is not sufficient for the diseases control. Therefore, in the absence of pharmaceutical interventions, it is important to combine social distance with adequate case detection, which is made even more effective by perfect border screening, to reduce the burden of the pandemic.

Half-Cauchy Chen Distribution with Theories and Applications

Arun Kumar Chaudhary — 2023-06-21

In this article, we have suggested the three-parameter half-Cauchy Chen distribution which has been derived by compounding a continuous Chen distribution with the half-Cauchy family of distribution. The hazard rate function (HRF), quantile function, reversed hazard rate function, survival function, cumulative distribution function (CDF), probability density function (PDF), kurtosis, and skewness of the suggested distribution are some of its statistical properties and characteristics that are explored. Utilizing the methods of LSE, CVM, and MLE, the parameters of the new distribution are computed. All the calculations are performed with the aid of R programming software. To assess the application of the new distribution, two real data sets are analyzed and performed the goodness-of-fit. It is found that the half-Cauchy Chen distribution outperformed a few other existing distributions. We hope that this distribution will contribute to the field of real data analysis.

Hydrochemistry of Kupinde Lake at the Lesser Himalaya in Karnali Province, Nepal

Chandra Bahadur Sunar — 2023-06-26

Hydrochemical assessment of the freshwater lakes provides important insights into the sources of dissolved ions, geochemical processes, and anthropogenic activities taking place in the environment. This study focuses on the assessment of hydrochemistry and water quality of Kupinde Lake, Karnali Province, Nepal. Surface water samples were collected from 24 different locations of the lake in October 2021 and analyzed for 18 different physico-chemical parameters. The pH, temperature, electrical conductivity and total dissolved solids were measured on-site, and concentration of major ions (Ca²⁺, Mg²⁺, Na⁺, K⁺, NH₄⁺, HCO₃^-, Cl^-, SO₄^2-, PO₄^3-, NO₃^-), including hardness and free CO₂ were measured in the laboratory. The results revealed that lake water was alkaline with abundance of the major ions in the following order: Ca²⁺> Mg²⁺> Na⁺> K⁺> NH₄⁺ and HCO₃^- > Cl^-> SO₄^2- > PO₄^3- > NO₃^- for the cations and anions, respectively. The lake water was dominated by Ca-HCO₃, indicating calcium carbonate dominated lithology in the area. Gibb’s plot and Piper diagram illustrated rock weathering as the most dominant process in controlling the hydrochemistry of the lake basin. The suitability of water for drinking and irrigation was determined using geochemical indices and WHO standards. The results indicated that the Kupinde Lake water could be used for drinking and irrigation purposes in terms of measured hydrochemical variables.

Analysis of X-Ray Emission From Source TXS 0506+056 Using Xmm-Newton Observations

Rajendra Neupane — 2023-06-27

We report the findings of analysis of X-ray flares in TXS 0506+056 using XMM-Newton data obtained from the maximum likelihood analysis. Two publicly available XMM-Newton X-ray observations for TXS 0506+056 were analyzed to study the spectrum and light curves. The spectrum curves revealed two energy bumps, with the lower energy bump at 0.5 keV and the higher energy bump at 6 keV. For observational IDs 0083960101 and 0083960201, the integrated flux for hard X-ray (2–10 keV) is 1.835 10^-12 ergs cm^-2 s^-1 and 1.813 10^-12 ergs cm^-2 s^-1 with corresponding uncertainty range of (1.754–1.913) 10^-12 ergs cm^-2 s^-1 and (1.490–3.515) 10^-12 ergs cm^-2 s^-1, respectively. The best fit models for X-ray data observations of observational IDs of 0083960101 and 0083960201 were phabs (gaussian+power-law) and Tbabs (gaussian+log-parabola) with reduced chi squared values of 1.56 and 1.05, respectively. A turning point at around 2 keV appeared in the spectrum curve, suggesting that the gaussian model only applies for soft X-ray (0.3–2 keV), while the power law and the log parabola model are the best fit models for hard X-ray (2–10 keV). Observation ID 0850780101 shows that the source TXS 0506+056 has a fractional variability of 1.4 %, while Observation ID 0850780201 shows a higher fractional variability of 3.0 % which indicates brightness varies over time. A greater disparity in the source's rise time suggests a higher degree of variability in its brightness.

Evaluation of Disturbance Zonation of Bagmati River System using Benthic Macroinvertebrates in the Kathmandu Valley, Nepal

Pratik Shrestha — 2023-06-30

The existence of Nepal's holy river, Bagmati, which flows through the core of Kathmandu Valley has been menaced by many anthropogenic threats. It is necessary to identify how vulnerable it has been. This research focuses on the evaluation of disturbance zonation to analyze the Bagmati River System’s spatial biological health. Benthic macroinvertebrates (BMIs) were used as biological indicators and were sampled from upstream to downstream using a multi-habitat sampling approach during the post-monsoon period in 2021. The Ganga River System Biotic Score/Average Score per Taxa (GRSBIOS/ASPT) was used to assess river water quality. From the sampling of 21 sites, a total of 5839 individual BMIs from 51 Families and 11 Orders were recorded. Upstream accounted for more than 30% of all the families, making upstream rich in taxonomic preferences, which steadily decreased from midstream to downstream. Facultative taxa were widely distributed in both upstream and midstream, but sensitive taxa were limited to upstream only. There are no signs that facultative and sensitive taxa existed downstream and were fully dominated by pollution-tolerant species. According to classification, the upstream river within Shivapuri Nagarjun National Park of the Bagmati River System was clean and was categorized as Class I, whereas rivers from the boundaries of the protected area to downstream were categorized as Class IV-V with few sites as Class II and Class III, indicating that this stretch of the river was extremely polluted. Water resource managers should utilize the study's findings to assess and restore the water's quality using biological indicators.

Mixing Properties of Cu-Mg Liquid Alloy Using Exponential Model

Shahsit Kumar Yadav — 2023-06-30

The Redlich-Kister (R-K) polynomial has been generally used to model the mixing properties of binary and higher order alloys. The interaction energy parameters of the R-K polynomial are assumed to be either linear or exponentially temperature-dependent. When these parameters are assumed to be linear temperature-dependent, the computed thermodynamic functions sometimes show unusual trends. But when they are assumed to be exponential temperature-dependent, such trends do not appear in the theoretical calculations. Therefore, the mixing properties of Cu-Mg liquid alloy have been studied using the exponential temperature-dependent parameters of the above-mentioned model. These parameters for excess Gibb’s free energy of mixing have been optimised using the experimental values of enthalpy of mixing and excess entropy of mixing. The study of thermodynamic properties involves the measurement of excess Gibb’s free energy of mixing, enthalpy of mixing and activities of monomers at different temperatures. Likewise, the assessment of surface property includes surface tension and surface concentration. Similarly, the structural properties have been studied by computing concentration fluctuation in long wave-length limit and short-range order parameter at different temperatures. The investigation revealed that the exponential model can explain mixing behavior of Cu-Mg liquid alloy and the system is found to have strong compound forming tendency at its melting temperature. This mixing tendency has been observed to decrease with the increase in temperature above its melting temperature.