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Saturday, February 12, 2011

Methodology For estimation Of Natural Hazard Vulnerability In Us Using Remote Sensing

Introduction

Coastal zone is defined as "the coastal waters (including the lands therein and thereunder) and the adjacent shorelands (including the waters therein and thereunder), strongly influenced by each other and in nearnessy to the shorelines of the several coastal states, and includes islands, transitional and intertidal areas, salt marshes, wetlands, and beaches." Coastal locations were some of the first located in the country, and have always accounted for a major percentage of the total population. They were the customary centers for transportation, tourism, recreation, industrial fishing, and other industry. This coastal zone remains a crucial segment of the nation's total economy. A variety of natural hazards usually threaten this coastal zone. Severe meteorological events such as hurricanes, tropical cyclones, and nor'easters are particularly harsh on coastal areas, often resulting in damages from high winds, storm surge, flooding, and seaboard erosion. Tsunamis, whose destructive force is characterized by potentially devastating flood inundation, are uniquely coastal events resulting from offshore earthquakes, landslides, or volcanic activity. Coastal locations are also subjected to the impacts of long-term hazards such as chronic coastal erosion, inherent sea-level rise, and global atmosphere change.

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Coastal hazard events can significantly work on or even alter the natural environment. Their impacts are ordinarily not carefully to be "disastrous" unless they involve damages to human populations and infrastructure. When population and asset are not present, hazards are merely natural processes that alter the environment. When population and asset is present then the impacts of hazards are viewed quite differently. The customary focus is no longer on the natural processes linked with a major hazard event, but instead on the disastrous results that can be measured by lives lost, asset damages, and economic and environmental impacts.

The impacts of natural hazards are becoming increasingly high-priced and devastating. Hazard impacts on the natural environment become more devastating because human development has altered the quality of natural systems to recover from such events. Experts believe that the statistics on disaster losses continue to rise worldwide due to a blend of factors that comprise a rise in the estimate of hazard events due to global atmosphere turn or natural cyclical trends, and an growth in human exposure in hazardous locations.

Some of the decrease in disaster damages worldwide could also be the corollary of improvements in disaster monitoring and reporting capabilities, particularly in developing countries. But disaster loss increases in the United States seem to be most closely tied to increased human exposure in high risk areas such as the nation's coasts.

The United States has an gigantic and diverse coastline that supports a disproportionate percentage of the nation's population. The nation's 451 coastal counties comprise just over 50 percent of the U.S. Population, yet only inventory for about 20 percent of the total U.S. Land area. while the last decade, 17 of the 20 fastest growing counties were located along the coast. In addition, 19 of the 20 most densely populated counties in the nation are coastal counties. These coastal counties possess economic gain straight through natural resources, maritime trade and commerce. These coastal counties also possess economic loss due to the natural hazards, overexploitation and exponential population growth. An assessment of both the economic gain and economic loss is briefly discussed as follows.

Economic gain in U.S. Coastal zone

Nature narrative (May 1997), a group of ecologists estimated the value on ecosystem in the coastal zone. They estimated that the worth of the services for maritime ecosystems is roughly trillion per year. according to Sea Technology magazine, the value of goods and services sold by the ocean/marine industry was estimated in 1995 as billion annually. Offshore oil and gas yield has become very important and the 1996 value was more than billion and the each year offshore yield is increasing. according to the National Oceanic and Atmospheric supervision (Noaa), 77 million pounds (meat weight) of shellfish were harvested from U.S. Coastal waters in 1995, with a dockside value of 0 million.

Current Noaa estimates with regard to the recreational uses of U.S. Coastal areas includes: roughly 94 million population boat and fish annually; the mean American spends 10 recreational days on the coast each year; The coasts (excluding the Great Lakes coastline) reserve 25,500 recreational facilities; More than 180 million Americans visited ocean and bay beaches in 1993; Recreational fishing contributes .5 billion annually to the U.S.
economy; Coastal recreation and tourism originate to billion annually.

Economic loss in U.S. Coastal zone

Disaster losses in the United States coastal zone are currently estimated conservatively at billion annually. The disaster loss between 1975 and 1994 is estimated as 0 billion. 80 percent of the losses were imposed by meteorological events and 10 percent were the corollary of earthquakes and volcanoes. A great earthquake (magnitude 8 or larger) has not struck a major metropolitan area since the 1906 San Francisco earthquake. An greatest or catastrophic hurricane (Class 4 or 5) has not directly struck a major urban area since the one that hit Miami, Florida, in 1926. Yet even without such disasters, which might originate losses well over 0 billion, the total costs of natural hazards, such as greatest weather, drought, and wildfires, are estimated at billion per year for the past 5 years, or roughly billion per week. In the United States, the direct costs to fix the damage mean about billion per year, of which over billion is due to tornadoes, hurricanes, floods and earthquakes.

The Fema coastal erosion study conducted by The Heinz center for Science, Economics and the Environment estimates that roughly 25 percent of homes and other structures within 500 feet of the U.S. Coastline and the shorelines of the Great Lakes will fall victim to the effects of erosion within the next 60 years. Especially hard hit will be areas along the Atlantic and Gulf of Mexico coastlines, which are thinkable, to inventory for 60 percent of nationwide losses. The narrative estimates that costs to U.S. Homeowners will mean more than a half billion dollars per year, and that added development in high erosion areas will lead to higher losses. Thirty-four floods have been reported in Wake County (data source: Ndcd and Sheldus). The total coastline of mapped seaboard of Gulf of Mexico coast is about 8058 km out of which 3387 kms is in very high risk, 1056 kms is in high risk, 2968 km is in gently risk and 547 kms is in low risk type due to sea level rise. So the 42 % of the coast line is in high risk, 37 % moderate risk and 8 % low risk (Robert Thieler et.al. 2001).

Hurricane Mitch, one of the most powerful and damaging storms experienced in Central America, struck between 26 October and 1 November 1998. A type V hurricane, the event was characterized by laberious rainfall and high winds, dumping a year's worth of precipitation in less than one week on the region, causing the overflow of rivers, floods, mudslides and landslides. Thousands of population were killed and left homeless. Mitch caused billions of dollars of damage, and left huge tasks of reconstruction, resulting in the loss of decades of development efforts in the region.

The Economic Commission for Latin America and the Caribbean (Eclac) estimates that the direct cost of replacing the lost and damaged infrastructure in the region after Hurricane Mitch is some Us,000 million (Caballeros, 1999).

Recent large-scale disasters such as Hurricane Mitch and Georges, and the earthquake in Armenia, Colombia have demonstrated the vulnerability of society. It is widely recognized that recent population growth, rapid urbanization and the socioeconomic buildings in Central America have increased vulnerability of these countries to natural hazards.

These disasters faced by the inhabitants both by natural and anthropological effects lead to the formation of legislation / laws to govern.

Legislation & major acts in U.S. Coastal Zone

The economic loss and economic yield as such felt by the inhabitants of the Earth has resulted in the formation of legislation. This legislation is framed for the sustainable use of the ready natural resources. When the loss is severe or the gain is enormous; the laws needs some correction hence they were amended periodically. Some of the Laws and Acts pertaining to U.S. Coastal zone were National Environmental procedure Act, Clean water Act, maritime Protection, research and Sanctuaries Act, Ocean Dumping Act of 1972, Water Resources development Act of 1996, Coastal Zone supervision Act of 1972, maritime beast safety Act of 1972, Magnuson-Stevens Fishery Conservation and supervision Act of 1976 Endangered Species Act 1973, Nation wise Invasive Species Act of 1996, Oil Pollution Act of 1990, total environmental response, compensation, and liability act of 1980, Rivers and Harbor Act of 1899, The Submerged Lands Act of 1953, The Fish and Wildlife Coordination Act of 1934, Land and Water Conservation Fund Act of 1965, Outer Continental Shelf Lands Act, resource Conservation and saving Act of 1976 and The Coastal Barriers Resources Act of 1982.

Hence in order to amend these laws the integration in different fields is attempted and discussed as follows.

Results And Discussion

Assessment of Natural Hazard

Natural hazard is a phenomenon which occurs in nearnessy and poses a threat to people, structures or economic assets and may cause disaster. They are caused by meteorological, biological, geological, seismic, hydrological, or conditions or processes in the natural environment. Hazard assessment is the process of estimating, for defined areas, the probabilities of the occurrence of potentially - damaging phenomenon of given magnitudes within a specified duration of time. Hazard assessment involves prognosis of formal and informal historical records, and skilled interpretation of existing meteorological, topographical, geological, geomorphologic, hydrological, and land-use maps.

Office of United Nations development Relief organization (Undro), defines the term vulnerability as: "The degree of loss to a given element or set of elements at risk resulting from the occurrence of a natural phenomenon of a given magnitude. It is expressed on a scale from 0 (no damage) to 1 (total damage)". The vulnerability of an element is usually expressed as a percentage loss (or as a value between 0 and 1) for a given hazard severity level. The quantum of loss used depends on the element at risk, and accordingly may be measured as a ratio of the numbers of persons killed or injured to the total population, as a fix cost or as the degree of physical damage defined on an appropriate scale. In a large estimate of elements, like construction stock, it may be defined in terms of the proportion of buildings experiencing some single level of damage.

Assessment is an interdisciplinary process under-taken in phases and absorbing on-the-spot surveys and the collation, assessment and interpretation of data from discrete sources with regard to both direct and indirect losses, short- and long-term effects. It involves determining not only what has happened and what aid might be needed, but also defining objectives and how relevant aid can no ifs ands or buts be provided to the victims. It requires concentration to both short-term needs and long-term implications.

The United States is becoming more vulnerable to natural hazards mostly because of changes in population and national wealth density. Due to this, population and infrastructure have become concentrated in disaster-prone areas. Natural Hazards threaten the sustainable development of United States, destroying years of development efforts and investments, placing new demands on society for reconstruction and rehabilitation, and shifting development priorities away from long-term goals while immediate needs are met. For most of the 20th century, the United States has largely spared the price for catastrophic natural disaster. critical enlarge has been made in insight the discrete impacts that hazards furnish on human and natural environments. Numerous research activities have been undertaken following the major hazard events of the past few years. Unfortunately, much of this research is piecemeal and has not been incorporated into any type of total database on disaster losses.

Natural hazards such as hurricanes and earthquakes do not have to become natural disasters. With proper planning, including proper environment management, much of the risk can be reduced. The risks posed by natural hazards in United States are exacerbated by group and environmental trends such as rapid urbanization and unplanned human settlements, poorly engineered construction, lack of adequate infrastructure, poverty, and inadequate environmental practices such as deforestation and land degradation.

Given the critical costs of the nation's catastrophic natural disasters, focus has shifted in recent years to enlarge beyond crisis preparedness and response to comprise a more long-term emphasis on disaster loss reduction. Hence it requires for a quantitative assessment of natural hazards vulnerability for coastal zone. This quantitative assessment of natural hazards is aimed to minimize whether an individual's or a community's vulnerability to hereafter disaster damages. Over the years, enlarge has been made in reducing hazard impacts straight through good predictions, forecasts, and warnings, particularly for meteorological hazards such as coastal storms and floods. normal improvements in hurricane and tsunami prediction, and river and lake level forecasting, have been inherent using the latest in computer modeling technology. Noaa's National Weather assistance (Nws) is currently working with several new technological systems that are intended to significantly enhance hereafter flood forecasting capabilities. Though there were lot of techniques ready to assess vulnerability due to natural hazard quantitatively still it is critical to rejoinder the scientific and technological data needs throughout the discrete hazards-related disciplines and integration. Although critical enlarge has been made in the research and science linked with natural hazards while the past 20 years, and improvements in technology and insight about natural hazards and how to way its vulnerability quantitatively requires a real-time networked scientific database.

Universities and research institutions (particularly the National Science Foundation), along with government agencies such as Noaa and Usgs that allege scientific hazards-related responsibilities, have contributed to advances in the scientific study of natural hazards. There is now more quantitative data ready about the origins and behavior of hazard events but the opinion of integration of the ready data sets is lagged.

This study is to concentrate all the fields acting in coastal zone for the assessment of vulnerability. Maps delineating hazard-prone areas at national, state, and local levels are needed to supply more total hazards assessment using data on a variety of natural phenomena, including coastal storms, floods, tsunamis, hurricanes, typhoons, landslides, wildfires, drought, earthquakes, etc. Much of this data already exists, but issues such as data integration, compatibility, scales, accuracy, and resolution need to be addressed to make the data useful at the local level. good methodologies and models are also needed for conducting hazard vulnerability assessments that can concentrate extremely variable local conditions and characteristics. This calls for the site exact models for good estimates.

Computer-based geographic data systems could be used to analyze hazards data and supply national risk assessment data to state and local governments in quick and easy manner. exact models could be generated by using the Gis software. New high-resolution remote sensing capabilities could be examined for use in large-scale risk and vulnerability assessment. Hence, remote Sensing and Gis is to be intergrated and modeled for the assessment of quantitative natural hazard vulnerability.

Improvements in monitoring, data collection, and data processing inventory for most of the advancements made in short-term weather-related forecasting. good modeling capabilities, along with a more appropriate insight of variables, such as global atmosphere turn and sea-level rise, are needed to enhance long-range forecasting and planning for coastal hazard impacts.

Gis integration / modeling for natural hazard vulnerability

Gis is one of the powerful tools which can be used for the assessment of Natural Hazards Vulnerability (Nhv). Due to these techniques, natural hazard mapping and vulnerability assessment could be performed for the coastal zone. These maps will help the authorities for quick assessment of inherent impact of a natural hazard and initiation of appropriate measures for reducing the impact. This data will help the planners and decision-makers to take determined steps in time.

Gis applications in the coastal zone are diversified and case-based. Applications studies such as (a) coastal mapping, (b) environmental monitoring, (c) coastal process modelling, (d) navigation and port facilities management, (e) coastal environmental / hazard assessment, (f) coastal supervision / strategic planning, and (g) coastal ecological modeling could be done straight through Gis.

Coastal Mapping is in general focused on thematic mapping in the coastal zone, such as mapping chlorophyll concentration using Tm data (Chen et al. 1996). Environmental monitoring is one of the disposition tasks in Czm, which comprise monitoring water quality and habitat/biodiversity, and beach watch. Coastal processes modeling of physical environment turn in the coastal zone includes the simulation of effects of sea-level rise (Ruth and Pieper 1994, Grossman and Eberhardt 1992, Zeng and Cowell 1998, 1999, Hennecke 2000), the assessment of human intervention of seaboard turn (Huang et al. 1999), the use of historical data to predict hereafter coastline turn (Sims et al. 1995) and the study of beach morphodynamics (Humphries and Ligdas, 1997). There are an additional one two subcategories of the applications of hazards, namely, short-term and long-term tasks. The former is exemplified with monitoring and predicting oil spill (Belore, 1990), while the latter is demonstrated by coastal hazard / vulnerability assessment due to atmosphere turn (Lee et al. 1992, Sims, et al., 1995; Deniels et al. 1996, Hickey et al. 1997, Zeng and Cowell 1999, Hennecke et al. 2000, Esnard et al. 2001). Coastal supervision / strategic planning involve assessing sustainability of the environment, group and economic viability. The above said studies carried out in coastal zone are to be integrated using remote sensing and Gis for analysis.

The categories of Gis applications in coastal zone could be broadly categorized into three levels.

a) Level 1: as data supervision and mapping tools,

b) Level 2: as basic data prognosis (query) and mapping tools, and

c) Level 3: as decision-supporting tools (modelling / simulation).

Most current implementations of Coastal Gis are still at Level 1 and Level 2. It is thinkable, that Level 3 implementations will rapidly growth in the near hereafter as the chronic correction in Gis functions and more user-friendly interface become ready in the market. Hence for the study of Quantitative assessment of Natural Hazard Vulnerability Level 3 application is to be adopted.

The two basic arrival / analysis, which should be followed for geospatial database development were given below.

Integrated approach:

a) integration of different level of application,

b) integration of vector and raster (data and functions),

c) integration of knowledge of different expertise, and

d) integration of different scales in time and space.

Because of the nature of integration, Gis applications should think long-term integration. This includes the vertical integration that involves different application (and potential) levels, and horizontal integration that involves other interest groups. Therefore, issues must be addressed from database design, data sharing to tool-making (analysis functions) and feel sharing.

Multi-criteria analysis

a) multi - factors controls

Since coastal principles has a involved hierarchical buildings with multi-forcing exerting on each of subsystem, no mater which aspect of the principles to be investigated, multi-variable prognosis is an critical methods in the coastal environment.

b) multi - discipline arrival for decision Other than the multi-factors, there are many interest groups of coastal community, therefore, good solutions to any coastal issues can only be derived from multidiscipline approach.

Output of the analysis

I. Historical and real-time data with respect to natural hazards will be gathered by satellite remote sensing, aerial photographs and by other approved means and integrated with Gis Rdbms. This results in an total geo- database.

Ii. Through the modeling technique and by using the Gis Rdbms we can evaluate the likelihood of experiencing exact natural hazard in the future, and an assessment of intensity and probable level of impact.

Each natural hazard will be evaluated for three characteristics:

1. Likelihood of Occurrence, i.e., thinkable, frequency;

2. Likely Range of Impact, i.e., predictable size and location of impact; and

3. Probable Level of Impact, i.e., estimated strength and damage potential.

Iii. The level of severity of natural hazards will be quantified in terms of the magnitude of the occurrence as a whole (event parameter) or in terms of the corollary the occurrence would have at a single location (site parameter).

Iv. For quantitative natural hazard vulnerability, some weight value has to be added to the attribute column (slope, subsurface geology, current action, wave action, meterology, wind operation etc). The values that will be given in the attribute columns could be calculated with the help of the equation 1 modeled in Gis environment.

Natural hazard = (Wgeology + Wslope + Wwind + Wmeteo + Wsiesmisivity

+ Wgeomorphology + Wetc...) (1)

Based on the above formula, natural hazard vulnerability values could be retrieved by clicking on any land parcels from the coastal zone map. Such kind of values will have no meanings for the end users. To make the corollary more acceptable, a isolate domain is to be created in which the resultant values will be divided into three classes: very high, high, moderate and low hazard areas
Weights Class:

Values below than 30 Low hazard Area

Values between 30-40 Moderate Hazard Area

Values between 40-50 High Hazard Area

Values between 50-60 Very High Hazard Area

V. Hazard mitigation plan is to be industrialized and it will possess these five steps -

o identification of natural hazards that could impact the community,

o assessment of the community's vulnerability to natural hazards,

o assessment of the community's quality to rejoinder to a natural disaster,

o assessment of the community's current policies and ordinances that work on hazard mitigation, and

o development of hazard mitigation strategies that can be implemented to cut hereafter vulnerability.

Vi. By using all the above factors site exact models for the assessment of natural hazard vulnerability could be generated using Gis for U.S. Coastal zone. This will serve as an input for added amendment of legislation implicated with U.S coastal zone.

Conclusion

U.S. Coastal counties possess economic gain straight through natural resources, maritime trade and industry and economic loss straight through natural hazards, overexploitation and exponential population growth. About 80 percent of the losses were by meteorological events and 10 percent were by earthquakes and volcanoes. Hence in order to minimize the loss due to natural hazard a computer based geospatial database methodology is adopted for natural hazards data retrieval and to supply national risk assessment data to the state and local governments. Site exact models were proposed for U.S. Coastal zone by integrating Gis software and high-resolution remote sensing to quantify the large-scale risk and vulnerability. This modeling study could also be applied to developing countries such as India, Pakistan, Srilanka etc. For the natural hazard vulnerability assessment in their coastal zones.

Methodology For estimation Of Natural Hazard Vulnerability In Us Using Remote Sensing

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