Researchpaper.docx

RESEARCH PAPER

Topic: FLOODS

INTRODUCTION

Floods are one of the most common hazards in the United States. Flood effects can be local , impacting a neighborhood or community, or very large, affecting entire river basins and multiple states. However not all floods are alike. While some develop slowly , sometimes over a period of days, flash floods develop quickly, sometimes in just a few minutes and without any visible signs of rain A flood is defined as an excess water or mud or land that is normally dry. A flood is a condition that occurs when water overflows the artificial or natural boundaries of a stream , or other body of water onto normally dry land. Floods often happen due to heavy rainfall or thawing snow Flash floods are the most dangerous kinds of floods, because they combine the destructive power of a flood with incredible speed and unpredictability. Flash floods occur when excessive water fills normally dry creeks or riverbeds along with currently flowing creeks and rivers, causing rapid rises of water in a short amount of time. They can happen with little or no warning

ABSTRACT Floods are the natural hazards that produce the highest number of casualties and material damage in the Western Mediterranean. An improvement in flood risk assessment and study of a possible increase in flooding occurrence are therefore needed. To carry out these tasks it is important to have at our disposal extensive knowledge on historical floods and to find an efficient way to manage this geographical data. In this paper we present a complete flood database spanning the 20th century for the whole of Catalonia (NE Spain), which includes documentary information (affected areas and damage) and instrumental information (meteorological and hydrological records). This geodatabase, named Inungama, has been implemented on a GIS (Geographical Information System) in order to display all the information within a given geographical scenario, as well as to carry out an analysis thereof using queries, overlays and calculus. Following a description of the type and amount of information stored in the database and the structure of the information system, the first applications of Inungama are present.

LITERATURE REVIEW The concept of flooding has a multi-disciplinary definition based on the interest of the defining discipline. However, flood is generally taken to include ‘any case where land not normally covered by water becomes covered by water’ (FWMA, 2010: Pt 1). In recent decades there have been raging scientific and media debates on likely changes in flood regimes generated by landuse changes and climate change (Ranzi et al, 2002). The crux of most of these debates is centred on the simulated risk from such flood events. These risks are related to human health, infrastructure, socio-economic well-being of affected individuals and damage also to archaeological relics. Methods of evaluating and assessing flood risk have been developed in the field of insurance, technological and environmental fields (Molak, 1997; Jones, 2001). Although river flooding is often related to natural disasters, the impacts of human activities such as urbanization have been observed by many scholars (Sala and Inbar, 1992; Kang et al, 1998; Ranzi et al, 2002). Flood risk is expressed in terms of the probability of occurrence of adverse effects of flood related hazards and vulnerability with potential consequences (Mileti, 1999; Merz, et al, 2007; FWMA, 2010). Although a number of approaches have been tested for flood events prediction, hydraulic models have been specifically designed to predict flood inundation (Horritt and Bates, 2002). Consequently, in the development of an effective and efficient flood risk management strategy hydraulic, hydrologic and socio-economic factors must be taken into

DISCUSSION As most people are well aware, the immediate impacts of flooding include loss of human life, damage to property, destruction of crops, loss of livestock, and deterioration of health conditions owing to water borne disease. As communication links and infrastructure such as power plants, roads and bridges are damaged and disrupted , some economic activities may come to stand still, people are forced to leave their homes and normal life is disrupted Similarly, disruption to industry can lead to loss of lively hoods. Damage to infrastructure also causes long term impacts, such as disruption to supplies of clean water, water waste treatment , electricity, transport, communication, education, and healthcare. Loss of livelihoods, reduction in purchasing power and loss of land and value in the flood plains can leave communities economically vulnerable.