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Social Aspects of Flooding
Published in Saeid Eslamian, Faezeh Eslamian, Flood Handbook, 2022
Mir Bintul Huda, Nasir Ahmad Rather, Saeid Eslamian
Urbanization is a phenomenon that has inundated the whole world. With the advent of the latest technologies and the prospect of achieving a better standard of living, migration from rural to urban places occurs at a large scale. It is an imbalance in nature that adds up as a major cause of flooding. If the drainage basin is radically urbanized, the river is more susceptible to flooding than the basin which is less populated and has human interferences at a lower level. Urbanization of a place involves major changes in terms of alterations of the natural setup. A major portion of the cover is made devoid of soil and vegetation by way of deforestation and is replaced by impermeable surfaces, concrete being the most common one. These impermeable surfaces increase the direct contribution of runoff to the river without any substantial infiltration. In addition to urbanization, one of the contributing human factors for flooding is climate change. Climate change is a phenomenon that is a consequence of human interference in the natural working of the environmental setup. The warming of the climate globally induces erratic and frequent storm events which lead to large floods.
All about Water
Published in Frank R. Spellman, The Science of Water, 2020
Drainage basins collect surface water and direct it on its gravitationally influenced path to the ocean. The drainage basin is normally characterized as an area measured in square miles, acres, or sections. Obviously, if a community is drawing water from a surface water source, the size of its drainage basin is an important consideration.
Image Segmentation
Published in Vipin Tyagi, Understanding Digital Image Processing, 2018
In general, a watershed or drainage basin or catchment basin is defined as an area or ridge of land that separates waters flowing to different rivers, basins, or seas. Figure 7.16 illustrates catchment basin and watershed lines (lines dividing two or more catchment basins). This concept of watershed can be applied in image processing to segment the image if the bright areas of the image are treated as high elevation (watershed lines) and the dark areas are assumed to be at a low elevation (catchment basin). Hence, all dark areas are analogous to watershed and bright areas are analogous to watershed lines. The process is as follows:
Assessment and mapping of flash flood hazard severity in Jordan
Published in International Journal of River Basin Management, 2023
Lubna AlMahasneh, Doaa Abuhamoor, Khaldoun Al Sane, Nizar Jamal Haddad
The second factor in the formula is the rainfall intensity (i, depth/time). It has been selected based on storm characteristics that could cause flood, which is assumed greater than 30 mm/h and has occurred within 30 min. The rainfall gauging stations which have Intensity Duration Frequency (IDF) information were used (Consulting Engineering Center, 2011). Then, assuming frequency of high flood magnitude that has occurred at 50 years return period (Cutter et al., 2003; Ministry of water and irrigation, 2001 and Ge et al., 2013). Moreover, the third factor in the formula is Basin/catchment area (A, area). It is an area of land where precipitation which collects and drains off into a common outlet. The drainage basin includes all the surface water from rain runoff, snowmelt, and nearby streams that run down slope towards the shared outlet, as well as the groundwater underneath the earth’s surface. Drainage basins connect into other drainage basins at lower elevations in a hierarchical pattern, with smaller sub-drainage basins, which in turn drain into another common outlet (Council, 2006).
Assessment and analysis of morphometric characteristics of Lake Tana sub-basin, Upper Blue Nile Basin, Ethiopia
Published in International Journal of River Basin Management, 2023
Bitew G. Tassew, Mulugeta A. Belete, K. Miegel
Drainage density is the ratio of the total length of the stream in a given drainage basin and the area of that drainage basin (Strahler, 1964). It reflects the interaction between climate and the geological setup (Singh et al., 2019). Horton (1945) also mentioned that there is a high correlation among drainage density, precipitation and evaporation. Drainage density also indicates landscape dissection and runoff potential measurements which determine the length of streams per unit area of a drainage basin. It is a measure of the texture of the network, and indicates the balance between the erosive power of overland flow and the resistance of surface soils and rocks. The factors that affect the drainage density are lithology, climate, topography, soil infiltration capacity and vegetation cover. If the lithologies are less permeable then the drainage densities are higher (Farhan & Anaba, 2016; Horton, 1945; Strahler, 1964). On the other hand, permeable rocks with a high infiltration rate reduce overland flow and consequently drainage density is low (Kaur et al., 2014 Nag & Chakraborty, 2003; Vaidya et al., 2013;).