Flood Risk

Different approaches to the control of floodplain ‘encroachment’ exist in France and in England and Wales. In France, a ‘coercive’ approach emphasises strong central government intervention within a system of designated risk zones for all natural hazards. In England and Wales, a more ‘cooperative’ approach prevails, with the dominant power being with democratically elected local authorities. Ideas and policies are

Assessment of flood risk zonation and landscape vulnerability to
flood are fundamental aspects in flood risk management. Landsat
8 Operational Land Imager (OLI) and ASTER DEM data were used
to assess landscape vulnerability to flood inundation and flood risk
in Malda district of West Bengal state, India. Flood inundation
map was prepared on the basis of water and non-water pixels on
images (before and during the flood event). Flood risk map was
prepared using equal interval of separation based on elevation
and inundated flooded area. Flood inundation map was overlaid
on the pre-monsoon land use/land cover map to produce
landscape vulnerability to flood. The results revealed that 19%
area of the district was flooded during monsoon flood event in
2014 and the agricultural area was most affected land use,
sharing 62% of the total flood affected area, followed by river bed
(21%), built up (7%) and vegetation (5%). The flood risk map of
the district shows that temporary river islands, sand banks along
the Ganga river course lie in low flood plain and were considered
under high risk zone. The flood plain alongside minor stream
drainage in southern, north-western and in between them comes
under medium flood risk zones. Flood risk is low in areas which
are away from the rivers. Non flooded areas were identified in
high lands of eastern region of the district. Landscape vulnerability
map shows that the blocks located along the Ganga river namely
Kaliachak I, Kaliachak II, Kaliachak III, Manikchak, Ratua I were
highly vulnerable to flood. The study suggests that efforts should
be made to remove the sediments for increasing the depth of
river. Spurs and bed bars should be constructed to avoid great
loss of prime agricultural land, property and lives of people.

The  article  provides  a  proposal  for  a  mapping  vulnerability  catalogue  adapted  to  the  requirements  of  implementation  of  measures  in  the  framework  of  european  risk management, and more specifically, to those expressed in the risk management plans in the ARPS (Potential  Significant  Risk  Areas)  through  local  plans.  The  paper  ponders  the  concept  of vulnerability to risk, and point out inaccurate aspects that hinder the development of consensus-based vulnerability mapping. Examples of the proposed mapping applied to the area of flooding of the river Guadalhorce (Málaga) are attached

In Flood Control 2015, technology is used as a means to enable people to better assess and respond to risky situations. From manager to citizen, people make decisions depending upon the circumstances at hand. If there is more certainty about the current situation, and if pertaining information is purposefully provided, the adverse consequences of flooding can be limited. By making smart use of the most advanced information and technology available, Flood Control 2015 makes it possible to take informed action. As illustration of the applicability and need of the Flood Control 2015 advances, ample use was made of these innovations not only within the Netherlands, but also in Indonesia and the US. Improved flood forecasting systems or real-time monitoring of flood defences are not objectives in themselves. A characteristic feature of the Flood Consortium 2015 is that it develops knowledge and tools that are suitable for use in day-to-day practice of several professional disciplines, not only for those responsible for operational water management but also for decision-makers on different levels, crisis managers, communication advisors, news agencies and the emergency services. All of the aforementioned benefit from the yields of this program. Let us not forget about the communities within the areas at risk who will now be better equipped to help themselves and their neighbours by using this improved information and means of communication.

In this paper, principal component analysis (PCA) was used to delineate the raingauge network of Tanzania into homogeneous groups. The monthly rainfall records for the years 1961 -1990 inclusive at 150 raingauge stations used in the study were extracted from the records at the Directorate of Meteorology, Tanzania. The spatial patterns of the rotated PCA dominant modes delineated Tanzania's raingauge network into 15 homogeneous groups. Statistical tests, climatological information, topographic features and other data supported the physical reality of the 15 delineated groups. The delimited rainfall regions may be useful for Tanzania in agricultural planning, the assessment of water resources potential, delineation of drought or flood risk zones and as a basis of ensuring collection of climatologically representative rainfall data by the inclusion of a station(s) from each homogeneous rainfall region.

Flood risks not only include loss of human lives and properties, but also the transportation and communication. One major road in Kuching, the Kuching-Batu Kawa-Bau Expressway is often flooded and interrupted by floodwaters from Sarawak River. The Sarawak State Government had announced to build a flood bypass channel in Sarawak River to mitigate flood under the Ninth Malaysian Plan. This paper is a study on the effects of the structure in the flooding of the mentioned road stretch. The January 2004 event which is locally known as a 100-year flood, was run through a developed river model incorporated with the bypass facilities. The model had indicated a reduction of 53% of flooded road. Similarly, modelling of 10 and 50-year design floods had predicted over 50% of reduction. The bypass channel was said to be able to alleviate the flooding on the major road stretch.

The 1 st Doctoral Day Organized by the Laboratory of Geodynamics and Natural Resources aims to introduce young people and former PhD students whose idea is to improve the quality of research and achieve better results. The figurative works whose collection gives a global idea on the diversity of the subjects of research in the laboratory geodynamics and natural resources.

Ground Penetrating Radar (GPR) can assist decision making in a number of fields by enhancing our knowledge of subsurface features. Non-destructive investigations and controls of civil structures are improving day by day, however the scientific literature reports only a few documented cases of GPR applications to the detection of voids and discontinuities in hydraulic defense structures such as river embankments and levee systems. We applied GPR to the monitoring of river levees for detecting animal burrows, which may trigger levee failures by piping. The manageability and the non-invasiveness of GPR have resulted to be particularly suitable for this application. First because GPR is an extensive investigation method that enables one to rapidly cover a wide area, locating voids that are difficult and costly to locate using other intrusive methods. Second, GPR returns detailed information about the possible presence of voids and discontinuities within river embankments. We document a series of successful GPR applications to detect animal burrows in river levees.

Flooding is a natural phenomenon in Albania. The floods are flashy and flood – waters occupy the floodplain; in the biggest rivers, close to the rivermouth area, these waters inundate the floodplain for several weeks.Attempts have been made to alleviate flood situation in Albania by building protective dykes and creating upstream storage. Although many of these measures have been beneficial, they also served to encourage further encroachment upon river floodplains, thereby raising the potential for flood damage. Actually, more than half of the Albanian population lives very close to the rivermouth areas, where the risk of flooding is higher. The structural solution is only a partial one; the only long-term solution consists of keeping flood-vulnerable development and uses out of the floodplain. In order to evaluate the flood potential, a statistical study in national scale was carried out. The peak discharges for different return periods are computed using statistical method and a map of the flood potential for the country is designed. Those constructions had a relevant protective role during the flooding of the winter 1970-71. Non structural measures consist of measures undertaken for flood warning or flood forecasting or different studies like flood-mapping, estimation of inundation risk and inundation zones and possible damages.