International Journal of Hydrology Science and Technology (16 papers in press)

Regular Issues

• Assessment of flood controlling ability of hypothetical flood control dams by HEC-HMS model in catchment area of Koyna Dam in India  
  by Sanjay Doiphode 
  Abstract: Floods are major disasters that occur on a global scale. The construction of flood control dam (FCD) is considered sustainable, eco-friendly and effective flood control method due to its ability to quickly mitigate flood effects. HEC-HMS software has been successfully used by various researchers to simulate the rainfall-runoff correlation. The Koyna Dam in India is a conservation dam that was not designed for flood control. Due to the geographical nature and urbanisation of the area, it is difficult to implement traditional flood mitigation measures in Patan, Karad and Sangli City and its nearby area which is prone to flooding on downstream side of the Koyna Dam. Hence different approaches of implementing FCD in the watershed area of the Koyna Dam have been proposed to reduce the risk of flooding. In the Koyna watershed using spatial data and GIS software, 30 hypothetical FCD sites were identified and evaluated via HEC-HMS modelling. To quantify the effect of the provision of FCD, the flood attenuation ratio (FAR) and flood storage ratio (FSR) were used. The simulation results showed that the Koyna Dam watershed is conducive to the implementation of flood control dams. During heavy rainfall FCD will retain approximately 3.20 thousand million cubic feet (TMC) water, with an 11% reduction in flood volume approaching the dam and a 41% reduction in the peak inflow at the Koyna Dam.
  Keywords: HEC-HMS; flood control dam; FCD; Koyna dam; design storm; intensity duration frequency; IDF; morphometric analysis.
  DOI: 10.1504/IJHST.2024.10066827
   
  
• Quantisation in hydrogen atom below Bohr radius: a dark matter approach  
  by A.S. Abdel-Rahman, Youssef A. Sabry 
  Abstract: One of the most important physical problems is explaining dark matter, while current mechanics is not applicable. The core of dark matter has a very large attenuation coefficient against the wave function. If hydrogen atom is attracted to a dark matter, quantum mechanics fails to show the atoms energy levels. The modified Schrodinger equation recently published succeeds in approaching a minimal length to the order of Plancks length for the particle in the 1D-box problem; it is applied for the hydrogen atom problem in order to show quantisation in the attenuation coefficient even if its size becomes narrower than the Bohr radius and energy levels become positive. This methodology shows a new integer denoted by a dark-quantum number up to about two-thirds of the reciprocal of the usual atom radius. This approach can explain the Hawking radiation of the black holes, which is extremely faint and not easy for detection.
  Keywords: quantisation; hydrogen atom; Bohr radius; dark matter; Hawking radiation.
  
  
• Modification of the Bayesian calibration of the spatially distributed parameters for a groundwater flow model  
  by Anton Nuzhny, Elena Saveleva, Kirill Smirnov 
  Abstract: The paper is devoted to the problem of calibration of spatially distributed parameters of direct numerical simulation models. This problem is relevant to groundwater flow modelling requiring spatial distribution of filtration coefficients of media. The Bayesian calibration algorithm is being considered. It uses assumptions on the spatial correlation of a distributed parameter as a priori information. The standard formulation of the algorithm estimates the field of derivatives of the observed parameters over the calibrated one. Direct numerical estimation of this field is associated with significant computational costs. The paper proposes an algorithm where derivatives are calculated on a limited set of spatial points, with the entire field restored by approximation. Such an approach significantly reduces the computational cost of calibration. Several approximation algorithms are considered. The applicability of the approximation is demonstrated by numerical examples dealing with groundwater flow modelling.
  Keywords: distributed parameters; numerical simulation; Bayesian calibration; ill-passed problem; groundwater.
  
  
• River process in active Ganges floodplain region using DSAS  
  by Md. Ismail Hossain, Kazi Md. Fazlul Haq, S.M. Sium 
  Abstract: The dynamics of river processes influence the demographic and socio-economic fabric within the active floodplain zones of Bangladesh .This research examines the impact of river processes on Bangladeshs floodplain zones, focusing on the River Padmas erosion, sediment deposition, and shoreline changes from 1973 to 2020 using Landsat imagery and Digital Shoreline Analysis System (DSAS). The river shows a right bank shift in Nawabganj, Natore, and Manikganj, while shifting left in Shariatpur, Madaripur, Faridpur, Rajbari, and Kushtia, resulting in a rectilinear course in Rajshahi. Shariatpur and Chandpur experienced the most significant shoreline changes, with severe erosion between 1990 and 1995 and peak sediment deposition from 1975 to 1987. Over 47 years, 1,193,625 acres eroded, and 1,177,662.5 acres were deposited. Nawabganj saw the highest erosion rate, and Pabna and Rajbari had the highest deposition rate. This study highlights the importance of geospatial techniques for developmental planning in the Ganges floodplain.
  Keywords: erosion; deposition; digital shoreline analysis system; DSAS; end point rate; EPR; active Ganges floodplain.
  
  
• Estimation of antecedent moisture conditions using satellite remote sensing data and in-situ ground measurements in rainfall-runoff modelling  
  by Hansa Ayvaz, Paweł Gilewski, Małgorzata Loga 
  Abstract: Accurate estimation of antecedent moisture conditions (AMCs) is crucial for predicting catchment responses to precipitation in rainfall-runoff modelling. This study aims to explore the impact of precipitation data source and processing on AMC group estimation, utilising global precipitation measurement (GPM) satellite data and rain gauge data in a mountainous catchment. Various spatial interpolation methods were applied for spatial distribution of rain gauge data. The study demonstrated the influence of precipitation data source and processing on AMC group assignment, which is prone to misclassification near threshold values. We examined the effect of applying a buffer zone around limit values on the assigned AMC classification. Rigid AMC group assignment based on thresholds overlooks the need for further model calibration despite the assigned AMC. Analyses showed the selection of the interpolation method has little influence on AMC classification. GPM products provide consistent precipitation information, unlike rain gauge data affected by inconsistent measurement networks.
  Keywords: antecedent moisture condition; AMC; global precipitation measurement; GPM; IMERG; mountainous catchment; rainfall runoff modelling.
  DOI: 10.1504/IJHST.2025.10070985
   
  
• Optimisation strategy for run-of-river small hydropower plants using an e-flow approach to balance generated power and river ecological sustainability: a case study in Indonesia  
  by Andre Prasetya, Achmad Riadi, Akbar Wibawa Muhammad 
  Abstract: Achieving clean energy transitions while maintaining ecological integrity is essential for meeting sustainable development goals (SDGs). This study optimises the operation of a run-of-river small hydropower plant (SHP) in Indonesia, balancing energy production with river ecological sustainability. Using artificial neural networks (ANN) and response surface methodology (RSM), the study evaluates power generation under various environmental flow (e-flow) scenarios. Based on one year of hourly operational and hydrological data from an SHP with a 2 x 350 kW capacity, the Q25MAF scenario was found to offer the optimal balance, increasing e-flow discharge by 89.8% while reducing power generation by only 20.54%. This scenario supports continuous operation and contributes to clean energy, climate action, and aquatic ecosystem preservation. The findings offer a practical framework for sustainable SHP operations in regions with diverse hydrological and operational conditions.
  Keywords: small hydropower plant; SHP; environmental flow; river ecological sustainability; artificial neural network; ANN; response surface methodology; RSM; optimisation; Indonesia.
  DOI: 10.1504/IJHST.2025.10071072
   
  
• Spatial and temporal variation of drought in Sichuan Province, China based on SPEI analysis  
  by Yaotian Tian, Enhao Zhang, Ke Mou, Haoran Shi, Shuang Chen, Hui Chen 
  Abstract: Drought variation is of great significance to agricultural production and social stability. Meteorological data during 1965-2019 in Sichuan Province was used. Drought variation was explored based on standardised precipitation evapotranspiration index (SPEI), drought frequency, and drought station ratio. The results showed that SPEI totally increased over time. Moderate drought was most severe, occurring in FebruaryApril. Mild drought was prevalent in January, November, and December. SPEI decreased from northeast to southwest. From southeast to northwest, the SPEI tendency rate increased gradually. Average drought frequency was 31.86%. Mild, moderate, severe, and extreme drought frequency was 14.89%, 10.86%, 4.34%, and 1.77%, respectively. Drought station ratio decreased over time. There were 20, 16, 9, and 2 events of local, partial regional, regional, and panregional drought, respectively. The results of this study provide a reference for drought prevention in Sichuan Province.
  Keywords: standardised precipitation evapotranspiration index; SPEI; precipitation; drought frequency; drought station ratio; drought change; China.
  DOI: 10.1504/IJHST.2025.10071552
   
  
• Simulation of floods using merged satellite and gauge precipitation data  
  by Obaid Khalid, Mohammad Masood, Ghulam Nabi, Hafiz Waseem Sajjad, Jahanzaib Jafar 
  Abstract: Four merging techniques: linearised weighting (LW), multiple linear regression (MLR), inverse root-mean-square error (IRMSE), weighting and optimal interpolation (OI) were applied to merge widely used satellite precipitation datasets (SPDs). Statistical evaluation was done using: root mean square error (RMSE), Pearson correlation coefficient (r) and bias. While Nash-Sutcliffe efficiency (NSE), coefficient of determination (R2) and percent bias (PBIAS) were used to assess the SWAT model performance. Peak events were evaluated using peak rate discharge errors (Ens and Erp). The statistical evaluations proved OI, the most suitable data merging technique. Hydrological assessment showed that the observed and simulated flows have a strong correlation for both the gauge and the merged data. For peak evaluation, the values of Ens and Erp were close to their optimal values of 1 and 20, respectively. Peak rate discharge error (Erp) has lesser values for the merged data as compared to the gauge data, advocating its use for hydrological modelling in data scares regions.
  Keywords: flood simulation; satellite precipitation data; ungauged sites; data merging methods; SWAT model; Swat River basin.
  DOI: 10.1504/IJHST.2025.10071810
   
  
• Investigation of BMPs to control erosion and nutrient losses using SWAT model  
  by Bidare Phalanetra Deepthi, Pushpa Tuppad, K.S. Lokesh 
  Abstract: The Upper Cauvery Basin faces water quality issues due to sediment erosion and nutrient loss from agricultural non-point source pollution, as cropland dominates the region. Identifying critical source areas (CSAs) is vital for selecting best management practices (BMPs) to mitigate this deterioration. This study used the flow-calibrated SWAT model to identify CSAs and evaluate the effectiveness of structural BMPs contour farming, filter strips, streambank stabilisation, porous gully plugs and non-structural BMPs no-till, cover crops, manure incorporation at hydrological response unit (HRU), subbasin, and watershed levels. Simulations showed streambank stabilisation was most effective for sediment reduction at the watershed scale (57.27%), while filter strips reduced sediment significantly at the subbasin (37.91%) and HRU (43.75%) levels and performed best for total nitrogen (TN) and total phosphorus (TP) reduction. Among non-structural BMPs, no-till reduced sediment, and manure incorporation reduced TN and TP. Structural BMPs proved more effective overall than non-structural BMPs.
  Keywords: best management practices; BMPs; structural BMP; non-structural BMP; SWAT; sediment erosion; nutrient loss.
  DOI: 10.1504/IJHST.2025.10072454
   
  
• Spatial pattern of volcanic spring in the Holocene stratovolcano and volcanic complex under the diversity of geomorphological aspects: a study from Central Java, Indonesia  
  by Suhadi Purwantara, Arif Ashari, Nurul Khotimah, Sutanto Tri Juni Putro 
  Abstract: This paper analyses the distribution pattern of springs and evaluates the influence of the diversity of geomorphological aspects on the distribution pattern of springs. This study collected data through observation, remote sensing, literature study, and documents. A survey was carried out using a systematic sampling method. Data were analysed by geographic information system analysis using the average nearest neighbour, supported by statistical analysis of comparative tests. There are several significant findings in this study. First, the distribution of springs in the stratovolcano has a clustered pattern. Second, the distribution in the volcanic complex is random. Third, the formation of radial valleys due to denudation triggers the emergence of springs. Last, the average discharge and water quality are relatively the same. In summary, this study provides new insights into the distribution pattern of springs in stratovolcano and volcanic complexes in wet tropical climates, which is still very limited in the previous literature.
  Keywords: spring; stratovolcano; volcanic complex; Central Java; Indonesia.
  DOI: 10.1504/IJHST.2025.10072939
   
  
• Rainfall prediction using soft computing techniques: a case study of Purna River Basin  
  by Darshan J. Mehta, Nisarg Nanavati, Sanjaykumar M. Yadav 
  Abstract: Rainfall is the most significant climate element affecting the livelihood and well-being. For a country like India whose economy depends on agriculture, accurate rainfall data is important. The main challenge is to build a model on a long-term rainfall prediction. The Purna River is main source of water for agriculture as well as domestic in Navsari District. The objective of the study is to predict rainfall with the help of soft computing technique. The studies are carried out using specifically artificial neural network (ANN). The first step in water resource management is the correct forecasting of rainfall. Accuracy was evaluated using mean square error method, and results showed that the artificial neural network (ANN) based prediction model showed an acceptable level of accuracy performance. To achieve these models are developed with the different input parameters namely 'humidity', 'temperature' and 'wind speed'. For the analysis, the dataset of 21 years periods (1999–2020) is used for training and testing. Model performance is evaluated using statistical metrics such as mean square error (MSE). These findings hold the key to revolutionising 'water resources planning', 'flood preparedness' and 'risk assessment' in the region with potential applicability to similar regions worldwide.
  Keywords: rainfall prediction; water resources management; soft computing; Purna River Basin; artificial neural network; ANN.
  DOI: 10.1504/IJHST.2024.10066670
   
  
• Water balance analysis of a typical temporary pond in the Flooding Pampa (Argentina) during a dry period  
  by Ninoska Briceño, Ilda Entraigas, Carlos Scioli, Martin Blanco 
  Abstract: Knowledge of wetlands water balance constitutes a tool that allows quantitative evaluation of water dynamics. The Flooding Pampa (Argentina) is characterised by scarce topographic slopes and significant development of temporary ponds. A water balance was performed for analysing the dynamics of a Pampasic pond. During the analysed period, water inputs into the pond originated primarily from surface runoff from the surrounding areas and, secondarily, from direct precipitation; while the outputs were mainly due to runoff through the outlet channel and evapotranspiration, since the underground flow was almost insignificant. The latter parameter also had the particularity that it was expressed only unidirectionally (from the pond to the aquifer). Vertical processes (precipitation, evapotranspiration and infiltration) contributed to 38% of the balance, compared to horizontal processes (surface runoff) that represented 62%. The results serve as a basis for facing the study of the response of these systems in different scenarios.
  Keywords: water balance; temporary pond; Flooding Pampa; wetland; plain; Argentina; hydrology; dry period; water dynamics; aquifer.
  DOI: 10.1504/IJHST.2025.10067534
   
  
• Numerical evaluation of flash floods protection training works  
  by Imran Zia, Muhammad Masood, M. Awais Zafar, Ghulam Nabi, Hassan Qasim 
  Abstract: Sanghar Hill Torrent emanates from the foothill of Koh-e-Suleman Mountain range and outfalls in river Indus. The flood reaction time is very short and high flow concentration (above 200,000 cusecs) affects the local population in the vicinity. In this study numerical modelling has been done using HEC-RAS for the evaluation of sediment behaviour and various scenarios of the flood protection training works. Simulation results of the selected scenarios at vulnerable reaches revealed that flood bunds at certain reaches on both sides with the proposed bridge having skew alignment serve the purpose of protection against flood discharge up to 229,000 cusecs. Flood discharge of 268,000 cusecs, also remained within acceptable limits against the protection works. Whereas, high erosion was observed downstream of the proposed bridge and in front of Basti Bhutta Sharki, Basti Jhuk Manjkota and Basti Lalu, which should be protected with appropriate training, works.
  Keywords: hill torrents; flood protection; training works; numerical evaluation; HEC-RAS.
  DOI: 10.1504/IJHST.2025.10071851
   
  
• Investigating wave parameters within climate change threat in the Mediterranean: a case study of the Nile Delta, Egypt  
  by Ahmed S.A. Ibrahim, Anas M. El-Molla, Hany G.I. Ahmed 
  Abstract: Within the context of climate change threat to Nile Delta coast, in Egypt, and the significance of determining its impact on waves' parameters. The research involves reviewing climate change literature, calibrating and validating MIKE 21 for accurate results. Confident with the calibration and validation results, MIKE 21 was tooled to synthesise near-shore long-term series wave data set, spanning over 83 years (i.e., 1940–2022) along the Delta coast, where six points along the Delta were selected to designate the mean and maximum wave. Ridge regression was employed to obtain the time series trends for the minimum, and maximum of the wave height so as period. Results were obtained; analysed and presented on graphs, where the graphs highlighted the seasonal and monthly variations at the investigated sites. The seasonal trend analysis revealed the most significant increase in wave height during spring at 0.31 cm/year, while wave period peaked in summer at 0.007 sec/year. Furthermore, the monthly trends indicated a maximum rise in wave height in December at 0.64 cm/year, while the wave period showed its greatest increase in May at 0.017 sec/year.
  Keywords: climate change; long-term trend; wave parameters; MIKE 21; Nile Delta; Egypt.
  DOI: 10.1504/IJHST.2025.10072698
   
  
• Techno-social flood assessment in a data-scarce region: a case of Tinau River, Nepal  
  by Pankaj Adhikari, Utsav Bhattarai, Rohini Devkota, Vishnu Prasad Pandey 
  Abstract: Flood assessment studies are limited in developing nations largely owing to scarce hydro-meteorological data. This research estimates flood risk and analyses public preferences for adaptation measures in a flood-prone data scarce Tinau River Basin in southern Nepal. A two-dimensional hydraulic analysis was performed in HEC-RAS to model flood behaviour and estimate the risks. Potential adaptation measures were identified from literature, and the local people were asked to rank them on preferences for 2-year and 50-year return period floods. Results show that about 597,000 m2 of land (mostly settlements) is at extreme risk from a 50-year flood. Likewise, reinforced cement concrete (RCC) embankments were the most preferred adaptation measure. This study aids in understanding of flood risk and community preferences, informing policymakers and practitioners in managing flood risk in data-scarce environments
  Keywords: flood modelling; HEC-RAS 2D; risk assessment; flood adaptation measures; people's perception; Tinau River; Nepal.
  DOI: 10.1504/IJHST.2025.10072797
   
  
• Temperature variability and trend analysis in the high-altitude Gilgit River Basin: a statistical assessment using Mann-Kendall and Sen's slope methods  
  by Hammad Mehmood, Atta-Ur-Rahman 
  Abstract: This study analyses long-term temperature variations in the Gilgit River Basin, North Pakistan, using data from four meteorological stations (Gilgit, Gupis, Uskhor, and Yasin) over the period 1990–2022. The analysis employed the Mann-Kendall trend test and Sen's slope estimator to detect and quantify temperature trends across different temporal scales and spatial locations within the basin. Results reveal significant spatial heterogeneity in temperature patterns, with Gupis station showing a statistically significant increasing trend in mean maximum temperature (Sen's slope = 0.0316°C/year, p < 0.05) and Gilgit station exhibiting a significant increase in mean minimum temperature (Sen's slope = 0.0343°C/year, p < 0.01). Seasonal analysis identified pronounced warming trends during spring months (Sen's slope ranging from 0.0484 to 0.0807°C/year), while winter temperatures remained relatively stable. The spatial variability in temperature trends suggests that local factors, including topography and land use changes, play crucial roles in modulating climate change impacts within the basin. These findings have important implications for water resource management, agricultural planning, and climate change adaptation strategies in the region. The study contributes to our understanding of climate change impacts in high-mountain regions and provides valuable insights for policymakers and resource managers working in the Hindu Kush-Karakoram-Himalaya (HKH) region.
  Keywords: temperature trends; Mann-Kendall test; Sen's slope estimator; SSE; climate change; Gilgit River Basin; high-mountain hydrology; seasonal variation.
  DOI: 10.1504/IJHST.2025.10070097