News Update on Flood April-21
 Flood power
Channel boundary shear stress and stream power per unit boundary area are very useful concepts in assessing the role of rare, great floods in producing major geomorphic responses in fluvial systems. These variables were determined for the largest known flash floods in small drainage basins and for six historic dam-failure floods, predominantly in the United States. Even more powerful floods can be analyzed by paleohydraulic procedures. The Pleistocene Missoula floods and floods on the planet Mars approached ultimate limits of flood power defined by the onset on cavitation in fluvial flows.
 Flood geomorphology
Flood geomorphology is here considered to be the study of the role of floods in shaping the landscape, including the analysis of flood causes, flood processes, resistance factors to flood-induced landscape change, and changes in flood-related processes and forms through time. The 27 papers (abstracted separately) are arranged in sections: 1) external controls and geomorphic measurements; 2) flood erosional and depositional processes; 3) the interactions of floods, climate and landscapes; 4) paleofloods; 5) environmental management.
 An extension of the flood pulse concept
The flood pulse concept of Junk, Bayley and Sparks is a major contribution to our understanding of river–floodplain interactions and has become an important paradigm in lotic ecology. The concept is based mainly on large tropical lowland rivers. Floodplains may, however, develop in all geographical areas and at different locations along a river corridor. We extend this concept to temperate areas by including information derived from near‐natural proglacial, headwater and lowland floodplains. Specific attention is directed to the role of temperature as a major determinant of floodplain ecology. Further attention is directed to the importance of expansion–contraction cycles occurring well below bankfull (‘flow pulse’ versus ‘flood pulse’). Selected examples are presented that highlight the complexity of expansion–contraction events and their consequences on habitat heterogeneity and functional processes.
 Institutional Approach to Flood Disaster Management in Nigeria: Need for a Preparedness Plan
The failure of the country’s intervention strategies to satisfactorily ameliorate the sufferings of flood victims and speed-up the recovery processes justify the need for the adoption of a more efficient and innovative response plan to tackle flood emergency conditions in Nigeria. Going through the history of institutional response arrangements during flood episodes, this paper discovered the absence of well-articulated, organized institutional structure to co-ordinate response activities during emergency conditions. Existing response procedures were found to be adhoc, ineffective and poorly coordinated notwithstanding the plethora of agencies involved. Lagos state government has, however, developed a preparedness plan which is currently assisting all stakeholders, including those living in flood-prone areas, to anticipate/ implement recovery measures speedily in order to reduce flood damage potentials.
 Application of Pollution Indices for the Assessment of Heavy Metal Pollution in Flood Impacted Soil
The flood in 2012, which was recorded as the most devastating in the past 40 years in Nigeria, that caused colossal loss in material wealth, could also be a source of heavy metal pollution, especially at the lower reaches of the flood where deposition of flood transported materials occurs. Heavy metals (Fe, Ni, Cd, Cr, Zn, Cu and Pb) concentrations were determined in soil samples from two locations, an area submerged by the flood water (flooded) and an area at a higher elevation than the flood water (unflooded), which served as the control. The soil pH, texture, Total Organic Carbon, and Cation Exchange Capacity were also determined. Standard laboratory methods were employed for all the analyses. The soil in this study was characterized as sandy/clay/loam soil following the particle size analysis, with an average pH of 4.6 in the flooded soils and 6.5 in the unflooded soils. Total Organic Carbon (TOC) ranged from (0.936-1.989)% in the flooded soil and (0.663-0.939)% in the unflooded soil. Cation Exchange Capacity (CEC) was higher in the flooded soil (1.936-3.234) meq/100 g, than in the unflooded soil (1.164-1.722) meq/100 g.
 Baker, V. and Costa, J.E., 1987. Flood power. In Catastrophic flooding (pp. 1-21). Allen & Unwin; Binghamton Symposia in Geomorphology, International Series, 18.
 Baker, V., Kochel, R.C. and Patton, P.C., 1988. Flood geomorphology. In Flood geomorphology. Wiley-Interscience.
 Tockner, K., Malard, F. and Ward, J.V., 2000. An extension of the flood pulse concept. Hydrological processes, 14(16‐17), pp.2861-2883.
 Obeta, M.C., 2014. Institutional approach to flood disaster management in Nigeria: need for a preparedness plan. Current Journal of Applied Science and Technology, pp.4575-4590.
 Inengite, A.K., Abasi, C.Y. and Walter, C., 2015. Application of pollution indices for the assessment of heavy metal pollution in flood impacted soil. International Research Journal of Pure and Applied Chemistry, pp.175-189.