International Journal of Hydrology Science and Technology (13 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
   
  
• Sediment yield estimation and watershed prioritisation based on the risk of erosion in Laga Dadhi Water Supply Dam, Addis Ababa, Ethiopia  
  by Alemu Osore Aga, Mezgebu Geme Worku, Amare Tura, Miliyon Dida Feye, Firaol Bedada Kopesa, Ashenafi Dechasa 
  Abstract: Sedimentation caused by soil erosion from poor land practices and improper management systems is a critical problem for many reservoirs. Hence, the goal of this study is to model sediment yield and deposition in Laga Dadhi water supply dam/reservoir. SWAT model was used to simulate stream flow, sediment yield, and then selected best management practices. As a result, the annual average sediment yield of 17.78 t/ha/yr was estimated for the reservoir. From 13 sub-basins, 11 were grouped from moderate to very high (13.27-32.16 t/ha/yr) sediment yield sub-basins and selected for sediment management scenarios. The scenario's result indicated that the annual average sediment reduction at treated sub-basins after application of terracing, grassed waterway, contouring, and filter strips were 80.10%, 75.31%, 68.7%5, and 62.29% respectively. From best management scenarios terracing and grassed waterways scenarios resulted in the maximum sediment yield reduction in the watershed area. The findings of this study help policy makers to make better and well-informed decisions regarding to best management strategies.
  Keywords: SWAT model; sediment yield; best management practices; BMPs; Laga Dadhi reservoir; river basin management; Ethiopia.
  DOI: 10.1504/IJHST.2025.10073270
   
  
• Challenges of implementing integrated water resources management: a review of climate-driven land cover changes and water security issues in the Caribbean Community and Jordan  
  by Ramgopaul Roop, Mohammed Matouq, Abhishek Tiwary, Ana Paula Fonseca, Miles Weaver 
  Abstract: Climate change has intensified hydrometeorological hazards droughts, floods, storms, and heat stress threatening water quality, availability, and land sustainability. This study explores barriers to implementing integrated water resources management (IWRM) in response to climate impacts on land and water systems. It reviews global trends in climate driven land cover change and water insecurity, then compares the experiences of two contrasting regions: the Small Island Developing States of the Caribbean Community (CARICOM) and Jordan. Despite distinct geographies, both face escalating vulnerabilities from limited arable land, population pressures, and developmental needs. Using decade-long longitudinal data, the study analyses national adaptation policies, particularly in agriculture and water management. Findings show both regions have tailored policies but lack adequate financial resources to implement them effectively. The study underscores the urgent need for international support, technological innovation, and policy guidance to strengthen resilience and sustainable development in water-scarce regions under climate stress.
  Keywords: CARICOM; climate change; integrated water resource management; land use; small island developing states; SIDS; Jordan.
  DOI: 10.1504/IJHST.2025.10073369
   
  
• Sensitivity analysis of different aridity indices in the Iraq region  
  by Omar M.A. Mahmood Agha 
  Abstract: This study seeks to explore the sensitivity of different aridity indices of Iraq to climatic variables such as precipitation, temperature, and evapotranspiration. Different aridity indices such as Lang, De Martonne, Erinc, UNESCO, and UNEP indices were applied in the assessment of dryness in various regions of Iraq. Sensitivity analysis was done to assess the impact of a variation in climatic factors like rainfall, temperature, and evapotranspiration on the aridity indices. Sensitivity from the standard deviations of the variables was applied to ascertain its impact on the aridity index. The analysis revealed that rainfall had the highest impact with sensitivity coefficients ranging from 0.31 to 0.66. The temperature sensitivity ranged between the relatively low values of 0.02 to 0.07. The study concluded that the UNEP index was best to represent aridity in Iraq because it is more sensitive to climatic variables, especially evapotranspiration.
  Keywords: sensitivity; aridity; Iraq; precipitation; temperature; evapotranspiration; UNEP; Lang; De Martonne; UNESCO.
  DOI: 10.1504/IJHST.2025.10073386