Morphometric analysis for flood flow formation feature identification (on example of Ulaanbaatar agglomeration)

Water flows with significant flow rate feature a high destructive force and can lead to catastrophic consequences. Fluvial processes caused by uneven distribution of rain precipitation over the area pose risks to the developed inland foothill territories. The purpose of this study is to carry out a quantitative morphometric analysis of the territory in order to identify the formation features of flood flows. The analysis and ranking of catchment basins are performed using a basin approach. On the basis of SRTM images and the use of stock cartographic material in the GIS program the authors have built specialized electronic maps that allow to obtain quantitative parameters reflecting the morphometry of the basins under analysis including basin geometry, drainage network and terrain relief. On example of the Ulaanbaatar agglomeration territory it is shown how initial morphometric parameters of basins and watercourses (length, width, area, perimeter, erosion dissection, drainage network density, terrain relief coefficient, Melton coefficient, etc.) form the features of flood flow. For developed territories, the initial data on the catchment basin morphometry constitute the basis for compilation of specialized maps to be used in planning and construction. The combination of morphometric indicators on the territory of the Ulaanbaatar agglomeration indicates that there is possibility of large flood formation and development of dangerous mudstone flows in some catchment basins.

Analysis of the Effect of Climate Change on Flood Flows of Kemer Ağva River, Antalya

The environment and atmosphere are largely polluted due to increased urbanization, especially greenhouse gases from industrial and residential areas, and the trend of warming air on a global scale is increasing. In the event that global climate change persists for many years, it is expected that there may be significant increases in the severity, frequency and activity of hydrological natural disasters such as floods caused by these events, as well as extreme weather events. In recent years, Turkey has seen an increase in summer temperatures caused by climate change, a decrease in winter precipitation, and sudden and heavy rains and flood. Especially in the Western Mediterranean basin, heavy rainfall and flood events have started to be seen frequently due to climatic changes. In this study, current flood flow rates in Antalya Kemer Agva Stream and flood flow rates of 2050, 2075 and 2100 projections of HadGEM2-ES, MPI-ESM-MR and CNRM CM 5.1 climate models outputs were determined according to RCP 4.5 and RCP 8.5 scenarios. With this study, it has been revealed that the flood flows in the Kemer Agva basin will increase in the period until 2050 compared to the current situation, and will decrease in the periods of 2075 and 2100.

On the need for streamflow drought frequency guidelines in the U.S.

Extreme drought and resulting low streamflows occur throughout the U.S., causing billions of dollars in annual losses, detrimentally impacting ecosystems, as well as agricultural, hydropower, navigation, water supply, recreation, and a myriad of other water resource systems, leading to reductions in both the effectiveness and resiliency of our water resource infrastructure. Since 1966, with the introduction of Bulletin 13 titled ‘Methods of Flow Frequency Analysis’, the U.S. adopted uniform guidelines for performing flood flow frequency analysis to ensure and enable all federal agencies concerned with water resource design, planning, and management under flood conditions to obtain sensible, consistent, and reproducible estimators of flood flow statistics. Remarkably, over one-half century later, no uniform national U.S. guidelines for hydrologic drought streamflow frequency analysis exist, and the various assorted guidelines that do exist are not reliable because (1) they are based on methods developed for floods, which are distinctly different than low streamflows and (2) the methods do not take advantage of the myriad of advances in flood and low streamflow frequency analyses over the last 50 years. We provide a justification for the need for developing national guidelines for streamflow drought frequency analysis as an analog to the existing national guidelines for flood frequency analysis. Those guidelines should result in improved water resources design, planning, operations, and management under low streamflow conditions throughout the U.S. and could prove useful elsewhere.

Relationships between Peri-Urbanization Processes and Multi-Hazard Increases: Compared Diachronic Analysis in Basins of the Mediterranean Coast

This paper analyzes the relationships between the peri-urbanization process in the surroundings of cities and the increase in the synergistic dangers of flooding and water erosion. An analysis and an evaluation of the conditions causing the flooding in peri-urban basins are carried out, comparing the conditions before and after the peri-urbanization process. For this purpose, a diachronic analysis of the morphological and functional conditions of the territory that conditions flooding and associated dangers is provided. The conditions for the generation of runoff, the incorporation of solids into the flood flow, and the characteristics of urban planning are evaluated in 1956 (date before the peri-urbanization process) and 2010 (the peak of the urbanization process in the area) in order to analyze the changes in the land use model and their consequences on the increase in risk. The study is applied to four river basins (44 km2 in total) with varied land use models, in order to collect representative scenarios of the peri-urban coastal basins of the Spanish Mediterranean region. The results show that the risk factors that undergo the most significant changes are the runoff threshold, the vegetation cover, and the soil structure. It is concluded that peri-urbanization constitutes a territorial risk-causing process, and attention is drawn to the convenience of going beyond the sectoral approach in the study of hazards, coming to understand them as a multi-hazard process in which causes have a direct relationship with the underlying territorial model.

Ablation of apoptosis-stimulating of p53 protein 1 protects mice from acute hepatic injury and dysfunction via NF-κB pathway in CCl4-induced hepatotoxicity

Acute liver injury (ALI) is characterized by apoptosis, inflammation, and oxidative stress, and pathogenic mechanism of ALI is poorly understood. Apoptosis-stimulating of p53 protein 1 (ASPP1) is involved in environmental responses, tumor growth, and NF-KB activity, which is of critical importance to ALI. However, the role of ASPP1 in ALI remains largely unexplored. The current study aimed to determine the role of ASPP1 in ALI induced by CCl4 and the underlying mechanism. ASPP1 expression was detected in wild type (WT) mice with ALI induced by CCl4. The function of ASPP1 in ALI induced by CCl4 was investigated using conventional knockout ASPP1 mice. ASPP1 expression significantly increased in ALI mice at 24 hours after CCl4 injection. Deletion of ASSP1 ameliorated apoptosis, inflammation, and necrosis in ALI relative to WT mice. In addition, deficiency of ASPP1 improved liver flood flow as well as ALT and AST levels. The levels of phosphorylated p65 and phosphorylated IκBα were lower in ASPP1-/- mice than in WT mice with ALI. These results implicate that deletion of ASPP1 may act via inhibition of the NF-κB pathway and protect mice from ALI, which may be a new potential therapeutic target for the treatment of ALI.

Optimized Vegetation Density to Dissipate Energy of Flood Flow in Open Canals

Vegetation along the river increases the roughness and reduces the average flow velocity, reduces flow energy, and changes the flow velocity profile in the cross section of the river. Many canals and rivers in nature are covered with vegetation during the floods. Canal’s roughness is strongly affected by plants and therefore it has a great effect on flow resistance during flood. Roughness resistance against the flow due to the plants depends on the flow conditions and plant, so the model should simulate the current velocity by considering the effects of velocity, depth of flow, and type of vegetation along the canal. Total of 48 models have been simulated to investigate the effect of roughness in the canal. The results indicated that, by enhancing the velocity, the effect of vegetation in decreasing the bed velocity is negligible, while when the current has lower speed, the effect of vegetation on decreasing the bed velocity is obviously considerable.

INTEGRATING DIGITAL ELEVATION MODEL, LANDUSE/LANDCOVER AND FLOOD FREQUENCY ANALYSIS: A DETERMINISTIC APPROACH TO FLOOD INUNDATION AND RISK MODELING OF MAKURDI ALONG ITS RIVER BENUE REACH

The study applied GIS techniques to integrate Digital Elevation Model (DEM), Landuse/Landcover (LULC) and flood frequency analyses to determine extent of flood hazard inundation of Makurdi town along its River Benue reach following extreme discharges and stage levels. Annual maximum stage and discharge data from 1914 to 2015 was analyzed using Gumbel’s distribution to predict flood flow for different return periods (T): 5, 10, 25, 50, 75, and 100. A goodness of fit test was conducted using Chi square statistics, which was insignificant indicating that River Benue at Makurdi flood flow fits the Gumbel distribution. Combining this result with DEM and classified LULC data, the GIS spatial analyst tool was used to estimate the areal extent of landuse that will be inundated per return period. The result shows extent of flood inundation based on current landuse pattern for the respective return periods of predicted extreme stage / discharge likely due to climate change to be as follows: bareland (1.69, 1.74, 1.78, 1.84, 1.83, 1.89 km2); settlement/built-up (5.38, 5.50, 5.63, 5.76, 5.76, 6.02 km2); farmlands (272.27, 283.59, 295.10, 306.43, 306.43,and 317.49 km2); Vegetation (91.56, 95.26, 98.78, 102.45, 102.48, and 105.95 km2); water bodies (0.21,0.21, 0.22,0.22,0.22, and 0.22 km2) and Wetlands (44.14, 45.80, 47.48, 30.36,49.42 and 50.78 km2). This reveals a general increase in the extent of flood inundation at progressive recurrence interval, and predicted rising extreme river stage heights / discharge except for the flood with 50 year recurrence interval. The study recommends that NEMA and Benue State Urban Development Board

SEL VƏ DAŞQIN AXINLARINDA DAĞ ÇAYLARI MƏCRASININ YUYULMA DƏRİNLİYİNİN TƏYİNİ

The article is dedicated to the determination of the wash depth of mountain rivers in floods and overflows. As well-known, hydrotechnical equipment is exposed to destructive damages of the floods and overflows. The undersurface of bridge basement and coast guards are washed away, the surface of drainage devices in water supply and dams (Düker) at river crossings are opened up. Therefore, the protection of the equipment against the destructive damage of the floods and overflows should be ensured. To this aim, first of all, the depth of the fortification of the equipment basement in riverbeds and the width through which the river can flow should be determined and the works of installing coast guards should be accordingly implemented. Since the flow regime of rivers due to floods in the course of mountain riverbeds dramatically changes, the width, depth, roughness and cross-sectional area of the riverbed also changes. To that reason, in the smallest case, calculation formulas includes the average width and wash depth of the riverbed in the course of the floods and overflows, average diameter of undersurface soils, the slope of the location of hydrotechnical structures, velocity due to the average diameter of the riverbed soils and so on. The article contains the analyses of theoretical and practical materials about the floods and overflows in mountain rivers. For the rivers flowing through the southern hills of Great Caucasus Mountains, the expressions for determining the riverbed parameters and hydrological parameters of rivers are used. According to the expressions, average width due to non-washing of the riverbed in floods in accordance with flood flow and slope of the studied part of the riverbed, the average depth of the riverbed crossing the flood, the average velocity of the flow and the wash depth in accordance with them are determined. basing on all these, the determining method of the wash depth of mountain riverbeds in floods have been worked out and determining the wash depth have been recorded. The studied methodology can be used in determining the riverbed parameters in floods and overflows. Keywords: Flood, riverbed deformation, mountain river, wash depth, average diameter of undersurface sediments, riverbed stability, flood velocity

Experimental and numerical investigation of water-surface characteristics at crossing connected non-orthogonally to four flat channels

Most studies on the flood flow characteristics at a crossing focus on channels connected orthogonally or at right angle, but studies on non-orthogonally connected channels remain limited. In this study, hydraulic-model experiments and numerical simulations are performed to analyze the characteristics of the water-surface variation in and around a crossing connected non-orthogonally to four flat channels. Comparison of the measured and simulated water depth distributions in and around the crossing indicates that the results are in relatively good agreement. In the experiment where the angle between two upstream channels is 45°, the water flow pattern in and around the crossing corresponds approximately to Type I proposed by Mignot et al. (2008). However, it was found that there is no any flow type to correspond to the water flow pattern measured in the case of the angle of 135°. For analyzing the variation of the water depth in and around the crossing with inflow, numerical simulation is performed by setting the inflow ratio of the two inlet channels to one, three, and six, respectively.