International Journal of Hydrology Science and Technology (5 papers in press)

Regular Issues

• Understanding the impact of geodetic measurements uncertainty on drought assessment: a case study of Europe  
  by Artur Lenczuk, Christopher Ndehedehe, Anna Klos, Janusz Bogusz 
  Abstract: A changing climate reveals that drought are becoming more severe and frequent, with cascading impacts on the environment, and people. As opposed to meteorological-based drought indices, GRACE and GPS observations have provided new capabilities and insights that improve understanding of drought dynamics. However, there are also limitations in the use of geodetic data. Thus, we examine the impact of GRACE and GPS residual errors on defined droughts estimating DSI and its uncertainty based on various approaches. Our results indicate the largest uncertainties above 35 degree. We observe a good spatial consistency in displacement uncertainties between GPS and both GRACE-type data for Western Europe, with relative RMS values over 20%. In comparison to original DSI, uncertainties contain 20% and 100% of DSI signal at 48% and 5% of stations for MSC JPL and GPS, respectively. For TCH method, we identify region-dependent hot spots and north-south strips for displacements and DSI, respectively.
  Keywords: global positioning system; GPS; GRACE; vertical displacements; DSI uncertainty; three-corner hat method; drought.
  DOI: 10.1504/IJHST.2026.10080309
   
  
• Water resource collection, treatment and recycling devices for green building construction  
  by Xue Han 
  Abstract: This article also constructed an optimised device data transmission method and a water resource collection and reuse cycle system, including precipitation collection and reuse and domestic and office wastewater collection and utilisation. The optimised device was tested, and the economic benefits, treatment effects, water quality categories, and recycling effects before and after optimisation were compared. The annual economic benefits from optimisation were 8.95 million yuan higher than before. The optimised chemical oxygen demand (COD), turbidity, and conductivity values were all lower than those before optimisation, indicating that the optimised device has a good treatment effect. The optimised water quality categories were divided into class II, class III, class IV, class V and below class V. The proportion of class II that meets the requirements increased by 30.8% compared to before optimisation.
  Keywords: green building construction; water use devices; water harvesting and reuse recycling system; three method water purification integrated plant; green building construction site water.
  DOI: 10.1504/IJHST.2026.10080961
   
  
• Assessment of bathymetric dataset discrepancies at Al Mismari Reef using historical nautical charts and multibeam bathymetry  
  by V.R. Shamji, Faisal Alsaaq 
  Abstract: This study quantifies bathymetric discrepancies at Al Mismari Reef (21.3247 N, 39.0319 E), northwest of Jeddah, Saudi Arabia, by comparing the 500 m depth contour from the 1988 British Admiralty Chart BA 2658 against a 0.5 m resolution multibeam echo sounder (MBES) DTM acquired in 2024 using a Kongsberg EM710 processed in CARIS HIPS and SIPS. The 500 m contour was the only chart feature within the survey footprint suitable for comparison. Across 4,167 points over 5.39 km, the mean depth difference was 72.262 m (RMSE = 76.368 m; SD = 24.708 m; maximum = 139.502 m), with 90% exceeding 50 m. These discrepancies reflect horizontal positioning limitations (?200500 m) of the pre-GPS era amplified by the steep fore-reef slope. The observed differences represent dataset discrepancies rather than confirmed seabed change, confirming the inadequacy of BA 2658 for modern navigational applications.
  Keywords: multibeam echo sounder; bathymetry; dataset discrepancy; Red Sea; BA 2658 nautical chart; IHO S-44; uncertainty analysis; Al Mismari; digital terrain model; DTM.
  DOI: 10.1504/IJHST.2026.10081121
   
  
• Spatiotemporal variability of annual maximum daily precipitation in the Central Zagros Mountains, Iran  
  by Dariush Rahimi, Fatemeh Bashirian, Mehrangiz Solimani 
  Abstract: Thresholds are critical parameters for the functioning of any system. Alterations in thresholds indicate the occurrence of anomalies, and changes in the system. Annual maximum daily precipitation (AMDP) is one of the climatic thresholds that precipitate climate hazards. Changes in extreme precipitation provide evidence of climate change. In this study, the trend of AMDP in the mountainous areas of Central Zagros was examined utilising the Pettitt test (the significance level alpha = 0.05). The AMDP and the ratio of daily precipitation to annual precipitation were analysed during the period 19572023. The test results confirmed the existence of an increasing trend of AMDP at two weather stations: Shahrekourd (43.18%) and Lordegan (39.58%). However, the index of the ratio AMDP to annual precipitation was significant and increased at four weather stations: Shahrekourd (43.60%), Lordegan (38.40%), Borujen (86.47%), Kouhrang (27%). These changes, which have occurred since the 2000s and are more pronounced in the northeast region, have increased the probability of heavy rain and urban flooding. Consequently, flood control management should be reevaluated.
  Keywords: maximum precipitation; extreme value; global warming; Pettitt test; threshold.
  DOI: 10.1504/IJHST.2026.10081376
   
  
• The most suitable eco-drainage system to be implemented in a peri urban district of a large Indonesian tropical regency  
  by Sugihhartati Dj Rachmawati, Mohammad Handy Mahendra, Gina Salsabila 
  Abstract: Eco-drainage systems can address flooding and water scarcity in Margahayu District a peri urban in Bandung Regency, West Java, Indonesia but, their effectiveness depends on selecting the systems based on local conditions. Rainwater harvesting contributes the largest to water supply (32.81%) but requires higher cost and space, while infiltration wells and bio-pores contribute less (12.20% and 1.84%) but support groundwater recharge and runoff reduction. After appropriate treatment, harvested rainwater can serve as a potential potable water source, with a payback period of approximately three years when replacing tanker-supplied water. No single system is optimal; thus, an integrated approach combining rainwater harvesting as the primary water source with infiltration wells and bio-pores as supporting systems offers a balanced solution. Context-specific planning that assess both hydrological and economic factors can enhance water availability, reduce flooding, and promote more resilient and sustainable urban environments.
  Keywords: bio-pores; cost; flooding; infiltration wells; payback period; potable water source; rainwater harvesting; space; water scarcity.