Session 27 - Hydrology and water resources management

[CEST2019_00641] Evaluation of a new millifluidic device for the consistent determination of oil droplet biodegradation kinetics
by Kapellos G.E., Nagarajan M.B., Kalogerakis N., Doyle P.S.

Natural seeps and accidental releases of crude oil in the sea result in swarms of droplets that are carried away by underwater sea currents. The droplets may be created either at the sea surface during the breakup of an oil slick by sea waves, or at the seafloor during the extrusion of crude oil from natural cracks or broken wellheads. A high concentration of oil droplets in seawater disturbs the established ecosystem dynamics and poses a significant risk of toxic effects to fish and other marine animals. The fate of underwater droplet swarms is determined by natural attenuation processes, mainly dissolution into the seawater and biodegradation by oil-eating microbes. Using microfabrication techniques (photolithography and 3D printing), we have developed a new millifluidic device that enables the generation of oil droplet populations with desired size and, subsequently, the entrapment, long-term incubation and microscopic imaging of the droplets while they undergo microbial degradation. Here, we will present experimental results on the biodegradation of hexadecane droplets by Marinobacter sp. microbes in synthetic saltwater.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:00 to 13:15
Oral presentation in Hydrology and water resources management
[CEST2019_00544] Overrated Credence to the Outdated Sand Mining Legislations : A Hydrologically Challenged Measure
by Sasi V.

The recent floods in the 'God's own Paradise'(Kerala) reminds the Indian Sub-Continent as well as the Global spectators of not just heavy rainfall but also the 'hungry water effect' from deranged desiltation. Laws from the first decade of independence decide the commercial desiltation permits and procedures in most parts of the country with renewed guidelines. The presentation attempts to map the in-river sand mining in all the Indian States, analyze the spatial extent and technology used, resulting degradation of the completely dug-out rivers, alterations in the geomorphology, base flow and river course, conditional water flow into the distributing channels which tend to stand at a higher surface than the further lowered river bed, impact on the continued cultivation in delta regions triggering the contingencies of extreme drought and flood. Poor and delayed adherence to the ecological economic estimates of this evolving nation and the enviro-legal regime can be traced as barriers of environmental restoration. Rampant dredging often with the under and over utilization of mining techniques, reluctant attitude to alternative construction materials raise serious economic & environmental concerns questioning the future livability of the Sub-continent.

Session: 27, Room: C, at Fri, 09/06/2019 - 12:45 to 13:00
Oral presentation in Hydrology and water resources management
[CEST2019_00510] An Agent Based Modelling tool exploring decision-making processes for flood risk management
by Koutiva I., Makropoulos C.

Cities at risk of extreme hydro-meteorological events need to be prepared to decrease the extent of the impacts. However, the majority usually reacts to the catastrophe, having failed to proactively prepare against extremes. This can be a result of both absent structural protection measures and problematic governance. While for the first, models exist that can simulate the effect, the effect of the latter is difficult to quantify. This work aims to explore how the different decisions authorities make, regarding for example: whether or not to cooperate with someone; build something; assign funding to something else etc., affect the flood risk management of an area. For that matter, the Institutional Analysis Framework was used to conceptualise the decision-making processes of authorities responsible for flood risk management. Based on this, an Agent Based Modelling tool has been created, enabling the exploration of the system’s behaviour under different decisions and risk scenarios. The tool has used as a case study the responsible authorities for flood protection in the city of Rethymno, Greece. The tool has a user-friendly interface enabling the end-user to explore the drivers of decision-making processes under different conditions.

Session: 27, Room: C, at Fri, 09/06/2019 - 12:30 to 12:45
Oral presentation in Hydrology and water resources management
[CEST2019_00491] The Intensity – Duration (I-D) curves towards to a spatially distributed flood early warning tool (F-EWT)
by Feloni E., Baltas E.

Attica region suffers from rainfall events of high intensity, inducing flash-floods and significant damages in the urbanized areas. This analysis concerns the determination of the maximum intensity-duration thresholds regarding flooding (F) or non-flooding (NF) regime, using the available precipitation records and the dataset of Fire Service operations in flooded properties for the period 2005-2016. Each event is classified as ‘F’ or ‘NF’ in case of flooded properties or not, respectively. As expected, ‘F’ events prevail for the higher rainfall intensities. Based on this characteristic, it was found that when excluding outlies in these two groups of events, then two clear limits of I-D are determined using a power-law equation. The first one (‘lower limit’) defines the area below which floods are absent and above which flood occur or not, while the second (‘upper limit’) defines the minimum limit of maximum intensities above which only events linked to flooding are observed. Based on these limits, a Flood Early Warning Tool (F-EWT) that provides the corresponding limits of cumulative precipitation as a function of the event’s duration is defined and evaluated indicatively for the severe flood event of October 24, 2014.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:27 to 13:30
Flash presentation in Hydrology and water resources management
[CEST2019_00398] Water Sustainability: Evaluation of Alternative Water Supply Methods in Greek and European Islands
by Tsesmetzis G., Kondili E.M., Kaldellis J.K.

Water is a very valuable natural resource absolutely necessary for life. Lately water resources are facing high pressure from continuously increasing demand. Besides, various areas face water shortage due to decrease of precipitation, irrational use, losses and mainly very high rates of tourism, especially in areas with water shortage and/or very limited water availability. Various water supply methods are applied in different cases in order to satisfy water demand, such as dams, desalination units, reuse of wastewater treatment plants effluents and water transport. Each of these methods has different environmental and social impacts. The objective of the work is to present the progress of our on-going research work concerning the identification of the parameters defining water sustainability and the evaluation of these alternative water supply methods. To that effect, the various alternative water supply methods are analysed in terms of technical and economic as well as feasibility characteristics taking also into account their properly defined and measured sustainability according to a set of indicators that has been suggested in the literature to assess it. A multicriteria optimisation model is developed for the quantitative assessment of the various water supply methods.

Session: 27, Room: C, at Fri, 09/06/2019 - 12:15 to 12:30
Oral presentation in Hydrology and water resources management
[CEST2019_00362] Water security of rural water supply systems in super typhoon Haiyan affected areas
by Gomba F.

The rural water supply systems in the countryside necessitate sustainability and security assessment to ensure long-term and safe water supply to target beneficiaries. The study aimed to analyse the hidden threatening factors in water supply system along technical requirements. It also predicts the probability of incidents and security degree of the system. The rural water supply system in typhoon Haiyan affected areas was rehabilitated and constructed through national and international funds. It sampled about 5,921 rural water supply systems constructed and installed in 75 municipalities in Eastern Visayas. The water supply system sampled were: 13 Eastern Samar; 13 from Samar; 12 from Northern Samar; 13 from Leyte; 14 from Southern Leyte; and 1 from the Province of Biliran. The water security was assessed and analyzed according to the following indicators: demand and availability, natural factors affecting safety and quality, and policies and management mechanism. The water criteria was analysed using Analytic Hierarchy Process. The study found out that the natural factors such as floods, drought, eathquake have highest computed possibility values. The water security of the water supply systems in typhoon Haiyan affected areas has to implement control measures to minimize the degree of damange due to natural factors..

Session: 27, Room: C, at Fri, 09/06/2019 - 12:00 to 12:15
Oral presentation in Hydrology and water resources management
[CEST2019_00299] Dam break analysis using HEC-RAS techniques. Case study: Cal Alb dam (NE Romania)
by Urzică A., Huțanu E., Mihu-Pintilie A. ,Stoleriu C.C.

Along with the understanding of the importance of a water resource in the vicinity of a human settlement, human societies have begun to build weirs, dams or hydraulic structures to use more efficiently the natural resource. One of the most important works that can be done in the course of a river is the construction of dams for the formation of storage areas. The importance of storage areas is given by their extensive use, whether used for flood defense, pisciculture, water supply or recreation. The Cal Alb lake is located in the Başeu river basin, which is further located on the territory of Botoșani county. Botoșani county is statistically mentioned as the second county in Romania with the largest surface of water. Cal Alb lake has an area of 180 ha and a retention volume of 16.3 million m3. Immediately downstream of the Cal Alb lake are built 20 polders and 4 ponds, but with a much lower retention volume. The present study aims to model flood caused by the failure of the dam of Cal Alb lake and its impact both on the elements of retention of the downstream storage areas and on the localities in the surrounding area.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:18 to 13:21
Flash presentation in Hydrology and water resources management
[CEST2019_00308] Exceptional flood events in the summer of 2018 in the Trebes-Negel Representative Basin (Romania)
by Paveluc L.E., Grozavu A., Cojoc G.M. , Hutanu E.

In the summer of 2018, the general unstable weather throughout the central and eastern parts of Romania has led to significant rainfall, sometimes exceeding 60 mm/day, and therefore to a massive runoff on the slopes that rapidly increased the flow on tributaries and the main course of the river Trebes from the Moldavian Subcarpathians. The majority of the hydrometric basin stations recorded exceedances of the caution levels, and the hydrometric station Bacau registered the maximum historical level (H= 348 cm). In order to demonstrate this, there were performed analysis and data processing using programs and hydraulic calculations for different probabilities.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:21 to 13:24
Flash presentation in Hydrology and water resources management
[CEST2019_00293] The role of hydro-technical works in diminishing flooded areas. Case study: the June 1985 flood on the Miletin River
by Huțanu E., Urzică A., Paveluc L.E., Stoleriu C.C., Grozavu A.

Hydro-technical constructions are very important in diminishing flooded areas and associated damage in the event of a flood. The case study for the Miletin River in the Moldavian Plateau (Eastern Romania) focusses on the historical floods of June 1985. The floods recorded at the Miletin River hydrometric stations are: 106 m3/s for Nicolae Balcescu station and 204 m3/s for Şipote station. Our analysis involves a series of simulations of a flood flow constant using the hydrological data associated with the 1985 flood. The mathematical modelling base is the high-grade terrain model (LiDAR raster type). Two flood scenarios have been carried out: the first one was based on the running of a constant flow considering the present hydro-technical constructions and works; the second scenario implied running the same flow, but without hydro-technical constructions. Bands of flooding associated to the two scenarios were generated. Flooded areas and damages were determined considering the modification of the bed by these works. Comparative analysis of flooded areas scenarios reveals, in the case of the same amount of precipitation, a downward trend in flood flows due to the presence of the hydro-technical constructions.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:15 to 13:18
Flash presentation in Hydrology and water resources management
[CEST2019_00105] The role of catchment properties on the importance of initial hydrologic conditions for seasonal hydrological forecasting in alpine areas
by Stergiadi M., Avesani D., Righetti M., Borga M., Zaramella M.

A well-known approach to seasonal hydrological forecasting involves the use of ensembles as forcing to a hydrological model, based either on historical meteorological data (Ensemble Streamflow Prediction, ESP) or on forecasts produced by one or more dynamic climate models (multi-model approach). This work aims at investigating the role of initial hydrologic conditions (ICs) and seasonal climate forecast skill on the accuracy of seasonal hydrologic predictions in alpine regions, as a function of catchment properties. The Integrated Catchment-scale HYdrological Model (ICHYMOD) is employed, forcing it with historical meteorological data and multi-model ensemble climate predictions produced by the climate forecast systems NCEP CFSv2 and ECMWF SEAS5 (the latter analysis is not included in the present work). The hydro-climatic prediction system is tested on two catchments in the Eastern Italian Alps, that are different in terms of orography and soil/groundwater storage capacity. The diverse catchment properties result in differential parameterization of the subsurface processes in the hydrological model, hence in a different impact of the initial hydrologic conditions on the seasonal runoff predictions.

Session: 27, Room: C, at Fri, 09/06/2019 - 13:24 to 13:27
Flash presentation in Hydrology and water resources management