It is essential to build human community that could able to cope with the disastrous effects in terms of protection, evacuation, management and mitigation by understanding its quality. Overlap of different age group populations especially younger and older group bare a significant importance in this case. Young people and elderly people serve as spatial criterion of risk potential against disaster. Distribution of younger and older population can be observed through the niche index, shows overlapping values of these two populations that express the quality of the community. These indices used as ecology, are employed as measurement techniques and are interpreted in terms of safety and communication that proposes disaster risk evaluation which may possibly pertain to damage reduction (Kanjitani,Y et al, 2005).
For evaluating the community’s status of recovery from a disaster, it is look at the invisible community environment as well as the physical recovery situation. Ecological modeling is one possibility for evaluating the quality of life because the human community is considered to have several features in common with animal communities, especially in terms of pursuing safety (Kanjitani,Y et al, 2005). In a human community, youths are a strategic segment of the population and organized youth can bring about critical changes in society. Their concentration in a community indicates healthy condition of such community. Thus, if the elderly population of a community becomes concentrate and polarized and young population relatively segregated from the elderly, that makes the quality of community deteriorated after the disaster, even in the area where building recovery speed is relatively fast.
Background of the Study:
Since the second half of the 1960s ecologists have developed several indices of the spatial overlapping of animal species. On existence and competition analysis, using these indices is called niche analysis, which is a method of analyzing overlap of spatial distribution of animals (Kanjitani,Y et al, 2005). Makawa and Okanda (1997) first applied niche analysis is to human community viability problem, with a view toward analyzing the urban disaster risk potential in a city. By analogy, they claimed that niche overlap offers an effective means of measuring the ecological risk potential of particular species spatially co-existing with or spatially segregated from others. This result implies that the level of niche overlap between different types of people in a human community such as young people and elderly people, serves as a spatial criterion of risk potential against disaster.
However, although several niche-overlapping criteria have been developed by ecologists, they have not been well compared and examined in an actual case study. Also no assumption free evidence proves that the niche index can reduce disaster damage that can evaluate the quality of human community life in terms of the cohabitative communication level and risk potential. In this study, particularly, it intended to compare niche indices with spatial correlation and association measures in spatial statistics.
Rationale of the Study:
The spatial and temporal distribution of age groups assumed that different degrees of overlap between age groups, which is referred to as the cohabitative communication level, represent the health of the community in daily life including safety in case of disasters. In both case of safety and communication assumptions, the ‘niche index’ can be a good measure for evaluating the quality of community life and monitoring the invisible and constantly changing human community situation (Kanjitani,Y et al, 2005). It is assumed that the loss of elderly people is reduced to a greater when the working age people are located close to the elderly, as compared with the situation in which the working-age people are located far from the elderly i.e. the more the young people are segregated from the elderly, the more the community become deteriorated. This measurement study through niche index of a disaster-affected community implies the scale of deterioration of that community.
In Bangladesh, various types of disaster are affected which deteriorates the community’s health in terms of safety, security, excavation and communication. Community health against disaster indicates the deterioration level of a community. Community health relates to the population and resource allocation and their availability, affordability against disaster. In a human community, youth are considering as powerful widget of influencing community condition, as they are active portion of the human society. Bracketed within the age group of 15-30 years, the youth constitute over 30% of the population of the Bangladesh. And around 6% of the total population of Bangladesh constitutes the elderly population who are slow imperceptive, progressive degenerative process advancing with chronological age, leading to increased functional deterioration and vulnerability. The rate of their increase is fairly high, i.e. the elderly population (aged 60 above) in Bangladesh in 1911, 1951, 1981, 1991 and 2000 were 1.37, 1.86, 4.90, 6.05 and 7.25 millions respectively and the projected figures for, 2015 and 2025 are 12.05 and 17.62 millions (Banglapedia,2007). In the case of risk potential against disaster this change in population will have serious consequences in disaster affected community. The ratio of the young and elderly people as well as their overlapping values has a great importance for seeking out the risk evaluation and potentiality against disaster in relation to the damage and recovery condition of a community. As a consequence, community health identification through niche index can be used for the implementation of disaster recovery program and for overall planning of disaster affected region.
Goal and Objectives of the Study:
Many developed countries have taken development initiatives through discovering the community’s invisible environment of different degrees of overlap between age groups. In Bangladesh, no mentionable work has so far been reported on the spatial age group distribution to understand the community health.
A goal of this dissertation is to obtaining spatial overlap degrees in a simple interpretable manner and encounters between different species.
The study has been selected to accomplish the following objectives,
To develop appropriate niche indices that can evaluate the quality of human community life in terms of the cohabitative communication level and risk potential.
To categorize the effect of disaster through damage analysis.
To determine the state of physical recovery from a disaster.
To make comparison between two disaster-affected regions of which one has relatively more deteriorated condition and attaining their comparative strength against disaster by niche indices.
Few research works were conducted on the niche index and its application on human community. Some of them are given below:
Kanjitani,Y., Okada, N., and Tatano, H. (2005)” Measuring quality of human community life by spatial-temporal age group distributions- a case study of recovery process in a disaster affected region”. Natural hazard review. In this paper calculated spatial-temporal age group distribution through niche index for disaster risk evaluation in Kobe city, Japan. This city was severely damaged by the 1995 Grat Hanshia-Awaji earthquake, it is inferred that the niche index may possibly to damage reduction. Further, community health in the recovery process in the Nagata Ward, Kobe city is evaluated by using the niche indices and related statistical tests. The results show that the quality of the community deteriorated after the disaster even in the area where the building recovery speed was relatively rapid.
Ohta, Y., Koyama, M., and Watoh, Y. (2000). “Estimation of survival rate curve at the 1995 Hyogoken Nanba Earthquake Association for the Development of Earthquake prediction”. In this paper, the smash up and injure condition of earthquake are analyzed and predicted its development by raising the quality of human community in terms of its age group distribution. It showed that the survival rate of persons trapped in the debris decreased sharply over time. It considered the working age people can be the most powerful rescuers and inferred that the number of rescued people depends significantly on the numbers of working-age people are located nearby.
Kobeno Kyokunwo Tsutaerukai, (1996). “Records of Kobe damaged by the Hanshin-Awaji earthquake”. In this paper, a significant importance has given for young-elderly cohabitation and damage reduction effects. It described verve of working-age people during disaster. In fact, the results of survey of this paper indicate that 20.6% of people started search and rescue activity within one or two hours, including one third of the people who wet in the 30-50 year old age group.
Stuart H. Hurlbert (1990). “The measurement of niche overlap and some relatives” In studies of species interaction and community structure it is useful quantify the degree to which two species overlap in their utilization of space, food and other resources. Resources state abundance or availability has correspondingly varied meanings. For spatial overlap, it usually measured by as area or volume. In relation to dietary overlap, abundance can be measured as the standing crop of each dietary category, corrected perhaps for differences in productivity or renewal rate, cost of capture, food value and so on.
Properties of the niche overlap index:
Some researchers was developed niche index and given their further modification. There are different ideologies of these niche indices varied according to the model. Niche index model developed by various researchers are mention as below with their properties and variables:
Maekawa and Okada Model (1997)1:
Maekawa and Okada used the following niche overlap index, which was originally developed by Whittaker and Fairbanks (1958);
Where j=1…………L represent districts of the area to be analyzed; Phj and Pij represent the relative abundance of species ‘h’ and species ‘i’ in district j, respectively; j is generally called and environmental resource; in several cases, it represents the spatial districts determined by the distribution of food, water, etc, and so forth. The numbers of species h and I in district j are nhj and nij respectively.
As the spatial distribution of a particular species overlaps to a grater extent with that of another species, Chi approaches 1.
Conversely, Chi approaches 0, as the spatial distribution of a particular species is increasingly segregated from that of another species.
Levins model (1968)2:
Levins was developed niche index, which has more ecological significance than the index provided by Whittaker and Fairbanks (1958). Levin’s index is defined as:
This niche index examines whether the probability that one species meets another species is larger than its probability that meeting the same species.
Pianka Model (1973)3:
This model is the further modified version of Levins model which as follows to make the index take a value between 0 and 1.
Value more than 1 i.e. αhi>1, indicates the concentration of defined two different species which results healthy human community in the sense of spatial age group distribution.
Value less than 1 i.e. αhi<1, express the segregation of these species that implies the conversing result of αhi>1.
Pearson product-moment correlation Model:
In spatial statistics, this type of overlapping problem is treated as a spatial correlation and spatial association problem (e.g. Haining, 1990)4. The Pearson product-moment correlation is one of the measures of spatial correlation and is expressed by:
Where, y1 and y2 indicates the means of y1j and y2j. Substituting Phj and Pij for y1j and y2j respectively. Pearson product-moment is a standardized version of Pianka’s index.
Expansion of Niche overlaps indices:
Niche overlaps indices expansion is applicable when both the risk potential indicator and the community cohabitative communication level indicator reflected area sizes and a ratio of elderly people to young people. By using only relative abundance, following types of initiative recognition will not be reflected, which are-
If the number of elderly people and young people are not identical and if activity area sizes are different then cohabitative communication levels between distinct age groups should also different.
If the number of elderly people is larger than the number of young people, it indicates a higher risk potential.
Hulbert niche index Model (1978)5:
Hulbert took into account the available resource amount and proposed the modified niche index. As resources, food, water and anything that is necessary for survival are used, area size can be considered to be one of the resources. To explain Hulbert’s index, a meeting ratio is first introduced, as follows;
Where aj= amount of resources i.e. area size and nhj and nij = numbers of species h and i, respectively, in district j.
If the species are uniformly distributed over the space/resources i.e. number of the species are proportional to the area sizes, then the expected value of a meeting ratio is obtained as the following equation.
Then Hulbert’s niche index LO is given as:
The niche overlap index LO uses the meeting ratio, which has in ecological interpretation, and considers the distribution of the amount of resources. Basically,
LO=1 implies that the degree of overlap of different species is identical. That means, it is uniformly distributed.
LO>1 implies that species are more concentrated and overlapped in districts with a smaller area size.
LO The appendix shows how a proportion of species among the total number of all kinds of species affects the index values of Chi (Levins model). It demonstrate that two areas with the same niche index value do not necessarily produce the same previous niche overlap index.
(Kanjitani,Y. et al, 2005)6 proposed model:
Taking the idea of Levins (1968) into account a new niche index Ohi based on Hulbert’s index. This new niche overlap index Ohi can be expressed as:
v Ohi become larger if different species have more attached than the same species do. Thus it expresses more concentration of the different species and less concentration of the same species.
Ohi is different from the index of Levins, in that Ohi reflects the amount of resources. To consider the property in detail Ohi induces as follows:
The niche index Ohi consists of two different terms. The first term is a ratio of species i to species h, and the second term is the extended overlap measure of Levins (1968) based on Hulbert (1978), which is weighted by the distribution of resources in each districts. In this study, nh is assumed as the number of elderly people; ni ,is the number of young people, and aj, is the living area size.
If nh becomes large and the overlap degree between the elderly and the young becomes small, then Ohi tends to become small. Thus, Ohi represents an elderly people concentration/polarization property.
Methodology has an importance to make research work trouble-free, orderly, regular and efficient. It describes the procedures to be followed for data collection and analysis of the data in conformation with the research. In order to obtain the objectives, a series of studies are conducted such as field investigation, data collection and observation, analysis and evaluation.
“Conceptualization” is nothing but the reflection of initial thinking. It characterizes the terms and conditions through which the whole research moves on. The very beginning of this study is to clear the perception and understanding of the niche indices, its variables of application, perception of determining the damage with necessary information and data, clear concept about recovery and its rating analysis. Then state the problems. Depending on the problems, the objectives of this thesis were developed.
Literature review is very essential to develop skill of a researcher to conduct any research work. The term “Literature review” means studying various reports, books and various local and international journals for clearing various concept to understand the relationship between the cohabitative community structure of different age groups overlaps and the disaster.
Basically, theoretical framework is the models, theories, method through which a researcher can find the result of his proposal or can satisfy his ultimate outcome. It helps to determine the variable in relation to the goals and objectives.
Defining Goal and Objectives:
Defining the Goal and Objectives is another important stage of the methodology. In this stage, goal and objectives are formulated and further redefined if it seems to be necessary. A well define goal and objective can make the researcher’s work easy and simple.
Data needs mean identifying various information which was essential or very important to achieve the goal and objectives of the study. It can be classified into the following two groups, as primary data needs and secondary data needs.
Primary data needs:
Primary data needs were as follows,
Impact of disaster on the study area.
Characteristics of disastrous effects. .
Strength ness identification of the concern communities against disaster.
Population allocation of different two groups in the study area
Secondary data needs:
Secondary data needs were as follows
Total population of the study areas in 2004 and 2008;
Number of household, road length, amount of agricultural land and crops with its damage and recovery status;
Total area of homestead and living, in respect of para/ neighbor
After the assessment of Data needs, Data were collected from various sources, for this study, necessary data and information were collected from two of sources, such as, primary sources and secondary sources.
Primary data collection
It is very important to collect field data and information from the study area to serve the thesis work. those necessary data and information were collected by using two techniques, which are Field survey and Questionnaire survey.
Total population; male female ratio; age structure; population distribution
BBS, TMSS, USO
Area of different Land use
Proportion of different type of land use such as agri-land, water bodies, homestead land, non agriculture land.
BBS, UAO, TMSS
No of household, amount of crops, roads length.
Reconnaissance survey, Field survey
BBS, TMSS, UAO
No of damage house, road length, amount of crops, amount of land
CLP, UED, PIO, World Vision.
No of rebuild house, road length, land formation by the river.
UAO, CLP, TMSS, UED
Background of Disaster
Disastrous effects, limit of damage
District map, Upazila map
Banglapedia, Union parisod
Field survey: At first a field survey was conduct to collect field level data and information. Field survey includes an empirical field observation and informal questionnaire and discussion with the local people with the help of those data then the Questionnaire was constructed.
Questionnaire survey: In order to have overall data from the village a questionnaire survey was conducted in every para/ neighbor. In respect of para a person has given the answer for the whole. Because it is much hard to get overall information by individual. A person who are well known about the respective para he was requested to give information.
Secondary data collection:
The secondary information collected through different books published and unpublished thesis and reports; papers; journals; magazines; map and other related documents from different sources. The information collected from secondary sources was USO (Upazila statistics office), PIO (project implementation office), CLP (Char livelihood project), UAO (Upazila agricultural office), TMSS (Thengamara Mohila Sabuj Songha), GBS (Gramin Bikas Songstha), UED (Upazila Engineering Department), UP (Union Parisod), World Vision, Population census report-Bangladesh Bureau of Statistics (BBS), publication, journals, web sites etc.
This thesis aims at obtaining niche index by spatial temporal age group distribution for disaster risk potential evaluation. For this purpose several niche model have been developed which are- Maekawa and Okada Model (1997); Levins model (1968); Pianka Model (1973); Pearson product-moment correlation Model; Hulbert niche index Model (1978). Data have been analyzed and formulated according to the indication of these models i.e. young and elderly age group populations, area size, resources of having damage and recovery criteria.The general and advanced statistical and analytical tools were used to study the observations involved in the study area. Data are found from questionnaire survey processed by MS Excel. After data analyses, following three tasks are performed,
Ascertaining damage ratio of the study area.
Determination recovery ratio of the concern area.
Obtaining values of niche indices of young and elderly population in different two regions.
At last, the final report will be prepared with necessary charts, diagrams and photographs.
Chapter 01: Introduction will provide ideal about the research problem, its background and rationality and it also discuss about the goal and objectives of dissertation. At last, methodology of the dissertation will be discussed.
Chapter 02: Study area profile, indication the condition of study area against disaster and its justification to be developed and compared the values of niche indices between two communities. Description demographic condition, land use, production and roads for two concern communities. Two Unions are considered in sense of community in this study.
Chapter 03: Damage analysis, damages that occurred by disaster are elaborated and estimated in this part. Temporary damage and permanent or complete damages are vividly shown and described with the measurement of damage ratio.
Chapter 04: Recovery analysis, the speed and efficiency of recovery for damage condition is analyzed in this chapter. The trends of recovery of various aspects of damage whether they improved or worsted are identified and its measures according to the damage amount are estimated through recovery ratios.
Chapter 05: Development of niche index, in this chapter, firstly, concern demographic condition (young and elderly population) are analyzed in terms of their growth and decay trends, trends of density in each location. Secondly, niche indices are developed through calculated the values of respective variables and described the quality of the community according to the result of niche index over time.
Chapter 06: Comparison analysis and result formulation, a calculative comparison is made between two concern communities of what their level of damage condition and its recovery as well, in order to make difference about their recovery speed. Built an innovative comparison and differences theoretically and graphically of the niche indices for seeking out the prioritize result in terms of healthiness between these communities.
Chapter 07: Conclusion, final statements of the dissertation, consist the invisible quality of the concern communities, potential impact of being healthier and forecast threats to the community that is less healthy according to the cohabitative communication level of young and elderly population.
Limitation of the Study
For conducting this research work, the following short comings have been faced:
Apparently it seems to have a lot of time confined for completing the whole thesis work but if the scheduled undergraduate class, class projects, exam etc are considered it gets a limited short time period having for the successful completion of the task through attaining its targeted objectives.
This thesis paper has to complete individually, so it is really difficult to do the task preciously and accurately and cover all the issues related to the study.
Financial shortage of the project was the major problem for the study and collecting relevant documents and information relating the study. The transport cost to visit the study area is very high and related costs worked as obstacles for the completion of the study.
Expected Outcomes of Dissertation
Damage and recovery status against disastrous effects.
Young-elderly cohabitative communication level of community health.
Comparative healthier result between two concern communities.
STUDY AREA PROFILE:
Disaster is indeed, the extreme event of nature, which harms the people, animal and plants as well as all living organisms in a board sense. Sarikandi, known as one of the flood prone Upazilas of Bogra district as well as in Bangladesh, which is situated on the bank of mighty river Jamuna and Bangali. It is around 230 km far from the capital city Dhaka and lies in the northwest region of Bangladesh. Sariakandi is seem to be one of the most vulnerable Upazila (MVUs) by its elevation, especially for flood, river erosion, coldwave and tornado in often.
Sariakandi Upazila at a GlanceÒ
Population: Population 229563; male 50.93 percent, female 49.07 percent; Muslim 96.67 percent, Hindu 3.18 percent , others 0.15 percent.
Administration: Sariakandi thana, now an upazila, was established in 1886. It consists of one municipality, 13 union parishads, 107 mouzas and 190 villages.
Landuse: Arable land 19909.75 hectares fallow 1925.13; single crop 45percent, double crop 40 percent, and treble crop land 15 percent. Arable land under irrigation 57 percent.
Land control: Among the peasants, 40 percent are landless, 35 percent small peasant, 20 percent intermediate and 5 percent rich; cultivable land per head 0.09 hectare.
Communication: Roads: pucca 15 km, semi pacca 7, mud road 222 km; waterways 16 nautical mile.
Background of the Disastrous Threat
The effects of disaster in Sariakandi Upazila from 1984 to 2007 are listed in the following table:
Table 2-1: Background of the disasterous treats of Sariakandi Upazila
|Year||Types of disaster (considering river erosion as a continual process)||Effects|
|1984||Flood||Does harm but no death|
|1996||Flood, Tornado||Does harm but no death; no record about Tornado|
|1997||Cold Wave||no record|
|1999||Flood||Does harm but no death|
|2000||Cold Wave||Death occurred (2+)|
|2002||Flood||Death occurred (4+), Crops damage|
|2003||Flood, Cold Wave, Tornado||Death occurred (4+), Crops damage and Death occurred (2+) respectively.|
|2004||Cold Wave, Flood||Does harm but no death, Crops damage|
Disastrous Effects of JamunaRiver
The gigantic river Jamuna that run over the study area has disastrous effects, which are very hard to specify for the study area only. To realize the condition of the study area, its nature should be discussed.
Actually, Jamuna is the downstream course of the Brahmaputra which took place after the Earthquake and catastrophic flood in 1787. Within Bangladesh territory, Brahmaputra-Jamuna is 276 km long, of which jamuna is 205 km.
The width of the river varies from 3 km to 18 km but the average width is about 10 km. In the rainy season, the river is nowhere less than five kilometres broad.
During 1981 to 1993, a total of about 729,000 people were displaced by River Bank erosion. More than half of the displacement was along the Jamuna to be quite stable.
Of all the rivers, the Jamuna has by far the highest land area under chars. In 1992, the total area of char in the Jamuna was about 100,000 ha, compared to 75,000 ha all other rivers together. Also, in terms of percentage of total within-bank area covered by chars, the Jamuna has a higher figure than the other rivers
This resulted in a continuous process of char formation and river widening in the Jamuna during the last 27 years (average widening 125 m/year), whereby relatively fine bank material was eroded and coarser material got accreted. In the upper reach of the Jamuna, newly accreted soils consist mainly of coarse sand and are less suitable for agricultural activities
Specific study area discription:
Sariakandi Upazila as well as JamunaRiver rally round for specifying the study areas which are Fulbari Union and Hatsherpur Union. The features of disaster are not same in these two union, Fulbari union is considered to be a relatively less disaster prone region and Hatsherpur union is considered to be a relatively high disaster affected region to make comparison of their strength against disaster in term of cohabitative communication health along with their damage and recovery level.
Fulbari Union profile:
Fulbari union is relatively big union among the others unions of Sariakandi Upazila.this union is measured as low disaster prone region which is remarked by 15% (the level of vulnerability), in sense of disastrous effects (flood, riverbank erosion and cold wave) and affect by disaster (affected no of families) (World Vision, 2008). There are 26 villages with more than 100 paras and 8614 households (TMSS, 2008) in Fulbari Union. Each village constitutes about 7-10 paras which are mostly linear pattern (household is built one after another) and contain about 50-130 households. People are generally built their home on a large plot of land except poor people. This homestead lands are usually or habitually high elevated and conditioned above the highest flood level. The household structure as a rule is consisting ponds or cow house in front side and bamboo cluster in back side of households.
Population: Total number of population is 68889 in which 52.41% male and 47.59% female (TMSS, UAO). People are mostly agricultural based employee. Some of them are poorest of the poor. In Fulbari Union, number of agri-family is 7699 and the number of family those have no land is 1955 (UAO, 2007).
Landuse: Landuse is categorized into several criteria such as agricultural land, homestead land, pond garden &bamboo cluster, road and bazaar, water bodies’, rice mill &other. On these criterion land is occupied 1955, 205, 28, 43, 42, 91 and 14 hectors (UAO, 2007) respectively. The occupation of land by each criterion is given in the following table
Table 2-2: Landuse condtion of Fulbari Union
|agri-land (hector)||Homestead land||Pond||Garden &Bamboo cluster||Road and Bazar||Water bodies||Rice mill &other||Total|
Landuse percentage of each criterion against total land are given in the following figure:
Production: Again, agricultural land provides two kinds of production facility, which are single crop production and double crop production. Normally low land provides single crop production as it is drown during flood and up land provides double crop production, as it is not easily drown during flood. In this Union low, lands are amount to 12% and up land are 88%.
Roads: Around 82.43 km road is surrounded across the Union. Basically, two types of road provide transportation facility, namely earthen and paved road and their service ratio are 0.89 and 0.21 respectively. As a rule, paved roads are servicing by the name of upazila and union road and earthen roads are village road. But now a day, village roads are starting include to become paved through the initiatives collaborated by the government and NGO’s. The scenario of types of road and its servicing length across the Union are given below:
Table 2-3: Detail condition of road in Fulbari Union
Hatsherpur Union Profile
Hatsherpur Union is known as one of the high-risk unions in Shariakandi Upazila. This Union is affected tremendously by flood, riven bank erosion and cold wave and is remarked its vulnerability level by 35% (World Vision, 2008). There are 15 villages in this union, of them three villages are settle on the alluvial land called ‘Char’. Villages are mostly linear patter or as the pattern of road because houses are built beside the both sides of road. People, who lost their property by riverbank erosion, are inhibiting beside the road, and others have the condition as same as Fulbari Union.
Population: Comparatively less population are living in Hatsherpur Union. The number of total population is 32899 which is around half of the population of Fulbari Union. Male and female population’s ratios are 51.55% and 48.45% (TMSS, 2008). People are mostly depended on agricultural land in terms of production and employment. Thus, people become impecunious when they lost their agricultural land. The number of agricultural family and landless family is fluctuating over time (river erosion and accretion made this condition). In 2007, agricultural land owned family number was 4654 and 2766 number of families were than landless (UAO).
Landuse: Most of the lands are occupied by the river Jamuna and than agricultural land which is characterized as low land except negligible amount of up land. Lands occupied by pond, garden and bamboo cluster, rice mill etc are very small in amount. The proportion of land used by roads is comparatively higher than that of Fulbari Union. The land use table and figure of Hatsherpur Union are given in the following manner.
|Agri-land||Homestead land||Pond||Garden &Bamboo cluster||Road and Bazar||Water bodies||Rice mill &other||Total|
Table 2-4: Landuse condition of Hatsherpur Union
Production: During flood and heavy rain, low lands are happened to be drowned under water. This is why it cannot produce double production. Most amounts of lands in Hatsherpur Union have ruined production and as such characterized to be single crop production’s land.
Roads: In this Union, roads are served for three purposes, to transport goods and services; to protect the river water to damage crop and households; and to use to be a place of human settlement for whom, who lost their property by river erosion. Roads and Bazar is very important aspect of landuse and takes 60 hectors of land in this Union. However, there are no Upazila roads but only Union road and village roads are servicing in this Union at 16% and 84% respectively. Only one Union road that is paved and village roads are totally earthen that are mostly used as a river barrier. The summary of roads of Hatsherpur Union is given in the following table:
m Two times production per year. Generally, paddy is produce twice in a year.
Explanation of how much recover of the damaged resources is the main concern in this part. Recovery consists of rebuild, reconstruction and renaissance of resources, that had damaged before. The amount of recovery is expresses by the term of recovery ratio that measures as;
To recover the damaged resources, various organizations of governmental program like CLP (Chars livelihoods project), TMSS (Thengamara Mahila Sabus Sangha), NGO’s like world Vision, ASA are activate. Where there is a necessity of basic needs like food and shelter people try their best to recover such needs. Generally, what people can afford to recover, they try to do but what they cannot afford, it goes its own principle.
The resources that have damaged, it requires time to be recovered. Time consideration is an important factor for recovery analysis. In this part, an assessment of recovery on damage conditions that occurred in 2001 has done. But, there are some damages that are occurring every year. Therefore, this chapter describes the existing conditions of the recovery results of damage that had occurred in 2001and also including damage occurrence in later. Damage analyses have made on the household, agriculture land and crop production and roads. Thus, their recovery analysis also made on such damage criteria.
Most cases, the recovery has done for the necessity for additional population. Villages that are nearly to the riverside and affected by the river erosion, have lost its resources, which are households, roads and land. But it causes development of houses, roads in other villages that are not nearly to the river and not affected by the river erosion. Thus, considering all these factors recovery analysis has done.
Recovery analysis of Fulbari Union:
Fulbari Union has relatively less disaster effects. It has a little change which disaster is responsible. Most of the changes in this Union are happened for the requirement of the additional population. As some damage is happening every year from 2001, its rate of recovery should be implicit.
Household recovery analysis:
From the year 2001 to 2008, overall household growth rate is 16.55%, where 9.39% was developed in between 2001-2004 and 7.16% has developed in 2004-2008 (BBS, TMSS). The results of development whether it is growth and decayed (in each village from the previous condition) in 2004 from 2001 and 2008 from 2004 are vividly shown in the following figure:
The above figure shows that the mentionable development takes place in Fulbari, chawkibari, Amtali, Baluatair and Goalbatan village and negative development in Domkandi, Char Domkandi, Ramnagar, and Char Ramnagar village. In fact, those villages are nearly to the river and affected by riverbank erosion have this negative development. The number of new households in 2004 and 2008 are 804 and 559 respectively (TMSS). Thus, the total recovery ratio is 22.47% in which 10.05% in 2004 and 12.42% in 2008. Thus, the household recovery table is:
Table 4-1: Household recovery condition in Fulbari Union
|No of damage houses||No of new houses||Recovery ratio|
|2001||2004||2004 (2004-2001)||2008 (2008-2004)||2004||2008|
Data: BBS-2001, TMSS-2004, 2008
A field survey has made on each village of the existing condition in 2008 (damage and recovery condition only in 2008) which data presented the recovery condition of household as follows:
Recovery analysis of agricultural land and crop production:
In the sense of agricultural land and crop production, recovery analysis includes renewal of agricultural lands that are enhanced productivity through river protective measures, flood controlling treatment and other necessary tools. In the Fulbari Union, no mentionable initiative has taken for significant changes in the agricultural sector yet. Thus, recovery analysis has made only on the land that is given by the river accretion. Furthermore, as crop production is related to the amount of agricultural land and its productivity, its analysis includes in the analyzing of the recovery of agricultural land. Following table shows the recovery of agricultural land in the Fulbari Union:
Table 4-2: Recovery condition of agricultural land in Fulbari Union
|Year of damage||damage of land (in acre)||Renewal of Land (in acre)||Recovery ratio|
Data: Field survey
Recovery analysis of road:
Recovery of roads until 2008 that was damaged in 2001 is the basis of its analysis. In this part, it can be mention the road development program taken by the government, which is named “100 Days Package” (SPIO). Under this program, 22 km length of 16 no of roads is included for development. However, it does not include all those entire roads, which are totally damaged. Following table shows the recovery of damaged road in Fulbari Union.
Table 4-3: Recovery condition of road in Fulbari Union
|Year||Damaged Length (km)||Recovery length (km)||Recovery ratio|
Data: UP, UED
Recovery analysis of Hatsherpur Union:
People of this Union have to conscientious against disaster for recovery as it has a great damage effects on resources. Though, the people do hard work for the recovery of damage, they do not get release from the sufferings of disaster. As around 100 percent of agricultural land and most of their households, drown during flood.
Recovery analysis of household:
The numbers of recovered households have not the same proper and homestead land that previously exist before damage. Most of the households that are destroy by river erosion; resettle besides the both side of the river barrier road. Thus, though they recover their damage houses, it does not equivalent to the property as they had before.
In between the defined year of 2001 to 2008, total growth rate of household is 20.87%, of which 15.59% increase within 2004 and rest 5.28% are increase in between 2004-2008. The results of growth and decay of households within the range of 2001-2004 and 2004-2008 are shown in the following figure:
Though the villages of this union are affected heavily by flood as well as river erosion, few numbers of villages have the negative development and most of the village have growth trend. But, it was very slow in 2004-2008. The number of new households in 2004 and 2008 are 727 and 246 respectively (TMSS). Thus, the total recovery ratio is 10.66% in which 8.55% in 2004 and 2.10% in 2008. Thus, the household recovery table is:
|No of damage houses||No of new houses||Recovery ratio|
|2001||2004||2004 (2004-2001)||2008 (2008-2001)||2004||2008|
Table 4-4: Recovery condition of household in Hatsherpur Union
Recovery analysis of agricultural land and crop production:
A plenty amount of agricultural land have gone to the river basin every year. At the same time river, accretion provides a vast amount of alluvial land. Now a days, the amount of this alluvial land are increasingly expand. But it is not as suitable as it had before (when it was in a state of human settlement or agricultural land) in terms of infrastructure provision, utility and communication services and not all of lands are suitable to cultivate. Development of ‘Groyne Badh’ to control the river movement and its erosion, makes such changes of land. But, in the case of drowning agricultural land into floodwater, there is no considerable change through this development. Thus, the mentionable recovery trend in Hatsherpur union of renewal agricultural land is given in the following table
|Year of damage||damage of land (in acre)||Renewal of Land (in acre)||Recovery ratio|
Table 4-5: Recovery condition of agricultural land in Hatsherpur Union
Recovery analysis of road:
Union road characterized as paved road does not necessitate recovering but need further restructuring. The village roads, which are characterized as earthen road, need recovery initiatives. About 7 km of village road have been damaged in 2001. Until 2008, only 4 km of its length are recovered (UP). In addition, restructuring of roads through 100 days program initiate by the government, takes 15 km of 14 no of roads in Hatsherpur Union. The recovery condition of Hatsherpur Union is:
|Year||Damaged Length (km)||Recovery length (km)||Recovery ratio|
Table 4-6: Recovery condition of road in Hatsherpur Union
Data: UP, UED
 Under this program, 747 no of workers in Fulbari Union and 533 no of workers in Hatsherpur Union are involved in the development of road structure include all kinds of land filling and have taken 16 and 14 no of roads respectively in these unions. The working duration of this program is sep-Nov and March-April in 2008 and 2009, working days is 20 days per month-SPIO.
DEVELOPMENT OF NICHE INDEX:
This chapter aims at measurement of the niche overlaps values of different two age groups young and elderly population of the community to observe the community health against disaster in terms of the cohabitative communication level and risk potential. To analyze spatial overlapping between young and elderly people, it is assumed that people from 15 to 59 years old are of working age (W) or young and that people over 60 are of retired age (R) or elderly according to the BBS, or tradition demography. To serve this purpose several niche indices models have used which are Chi (Whittaker and Fairbanks, 1958); Chi (Levins, 1968); αhi (Pianka, 1973); LO (Helbert, 1978); and Ohi (proposed index). The changes of niche indices over 2001, 2004 and 2008 are consider for study, in order to make decision whether the communities of the study areas are improved or deteriorated.
The results of these models are depended on some variables and consisting of measurement of some ideology through which community is identified as strong or week that can be express in the following manner:
Table 5-1: Value result of niche index and measurement consideration
|Niche index||Value <1 or small||Value =1||Value >1 or large||Consideration for Measurement|
|Chi||More segregation, much week.||Level of no more week and strong||More concentrate, much strong|
Concentration and segregation from another type of population.
|Chi(Levins)||More segregation, much week.||Level of no more week and strong||More concentrate, much strong|
Intending probability to be concentrate and segregate from the same and other type of population.
|αhi||More segregation, much week.||Level of no more week and strong||More concentrate, much strong|
Spatial correlation and association of types of populations.
|LO||More segregation, much week.||Level of no more weeks and strong, as a uniform distribution of populations.||More concentrate, much strong|
Ecological factor, resource distribution, implies degree of different types of populations.
|Ohi||Small value indicates the more concentration of elderly population and having week community health.||–||Large value indicates the less concentration of the elderly population and having strong community health.|
Represents an elderly people concentration property.
Niche Index Development of Fulbari Union
Relative features of elderly -young populations:
Young and elderly population changes have impact on the result of niche overlaps. Increasing and decreasing number of two types of populations bring the different niche results which the subject matter of this part to analyze whether it become healthier or worse. The trends of these populations along with total population are shown in the following table with detail:
Table 5-2: Population changing condition in Fulbari Union
|Type of population|
% of Increase
% of Increase
% of increase from 2001Total population597846543056469.446888934595.7915.23Young (15-59)Population317163451728018.833651019936.2815.11Elderly(60+) Population394041091694.2944653569.0413.32
Data: BBS-2001; TMSS-2004, 2008
The proportion percentages of young and elderly population in total population in each village measure the comparative suitability of the villages. The following figure shows, distribution of young and elderly populations in each village in a varied rate. This distribution both in high disaster affected village and less disaster affected village and their respective resources i.e. living area size, are used for establishment the niche indices of the Union.
According to the above figure (fig. 5-1), young population trends have much fluctuated than the trends of elderly population. It is shown that, at ‘Char Ramnagar’ the number of young population is low and its elderly population is high in respect of other locations.
Elderly-young overlap degree can be measured by the ratio of these populations. This ratio is one of the ways to realize the quality of human community. The larger number of young population against elderly population means the healthier condition in terms of cohabitative communication level in such particular community. Thus, the smaller ratios of elderly-young population indicate the better cohabitative and its conversing situations express the lower cohabitative quality of the community. In the following figure (fig.5-2), graphical expansion shows the deterioration level and its contraction expresses the healthy level of the specified location.
Figure 5-2: Elderly-young ratio at each village in Fulbari Union over defined years.
On such consideration, Amtali, Baluartair and Harina locations have acquired better; and Paringapara and Bhitapara have acquired weak cohabitative condition. In 2001, the locations Dhapara, Golbatan and Ramnagar had bad condition but later in 2008, they recovered it. Some locations such as Majbari, Dhagatali, Chawkibari Char Domkandi and Katakhali were deteriorated in 2004 but they also improved their condition in 2008.
Density analysis of the elderly-young populations:
The density of young and elderly populations in a community that has a particular area size is an influencing factor of niche indices. Density of an area cannot directly means the concentration and segregation of its population. As, less population concentration is a big area size received low density i.e. less population per acre though they are concentrate. Again, high population segregation in a small area size received high density i.e. more population per acre though they are segregate. In spite of this matter, density can be a way of understanding the overlapping degrees of young and elderly populations in a community along with its area size. In order to make analysis of the occupation on land of young population or elder population, density is estimated in terms of area per young population or elderly population.
This amount is fluctuated over time such as, in 2001, 2004 and 2008; it gets the rate of 0.28, 0.26 and 0.43 acres respectively for young population and in the case of elderly population it take on 10.73, 7.12 and 6.12 acres respectively. However, the rates of ‘area per young or elderly population’ in each village are also differed over time; mostly it reduces (because population increase is the common features) without some exceptional cases. The features of changes for area occupational criteria of young population and elderly population of Fulbari Union are given in the following figures (figures on 2001 and 2008 to understand its initial and final stage) .
In the above figures, the area of circle means the area of respective village and its position along the vertical axis shows its density level i.e. ‘area per person’ in that village. In this sense, the more the village towards the zero position, the more they are overcrowded and the more the village far from the zero position, it indicates the little crowding of the respective population. Thus, movement towards zero shows the increase and far from the zero shows the decrease of that population in the respective village.
Thus, Villages such as Domkandi, Baluartair, Dhagatali take negative growth of populations in both case of young and elderly pollution. Among the big size villages (Fulbari, Chawkibari, Domkandi), Fulbari is shown the dense location in name of young and elderly population.
Measurements of the niche overlap:
Each model shows the different values and different changing trends. So, each expresses the different meanings of the overlap.
Table 5-3: Values of niche indices for elderly-young in Fulbari Union
Data: calculated values by author
In 2001, the value of Chi (Eq-1), Chi (Levins) (Eq-2), αhi (Eq-3)take on smaller values than its standard level of healthiness where as the value of LO (Eq-5), Ohi (Eq-6) have satisfactory level of community healthiness. Thus, in respect of Chi , Chi (Levins), αhiFulbari Union was much week, in 2001. In the period of 2004 and 2008, only Chi value has reached to the standard level and Chi (Levins), αhi values are improve towards healthiness but cannot reached to the standard level. By the consideration of LO, community become healthier in 2004 and 2008.
The values of, Ohi in 2004 and 2008 are fluctuated but within the limit of healthier condition. That is, in 2004 Ohi take on relatively large value than in 2001 and become healthier than before where in 2008, this level is fall.
The improving trends of Chi , Chi (Levins), αhi over 2001, 2004 and 2008 indicate increasingly healthier condition of this region. Though LO has downed in 2004, it has a very fast revolving towards improvement. Ohi has also improving features but fluctuating i.e. it falls from 2004.
Niche Index Development of Hatsherpur Union
Relative features of Elderly-Young populations:
The trends of the populations over time horizon are fluctuating but having increasing characteristics. Young population has continuously increased though total population and elder population were reduced in 2004. These changing features of young and elder population bring the different niche values. To have its detail, the table of population’s trend is shown in the following way:
Table 5-4: Populations changing trend in Hatsherpur Union
|Types of population|
% of Increase
% of Increase
% of increase from 2001Total population2757026851-719-2.6132899604821.9419.33Young (15-59)Population10639110063673.4512993198718.6822.13Elderly(60+) Population13181285-33-2.50143915411.689.18
Data: BBS-2001, TMSS-2004,2008
Because of riverbank erosion, human settlements are very much unstable. There is a probability to replace the settlement in a convenient place where there have safeties from riverbank erosion and flood. Considering these circumstances, the value of population assume varied rate in the village of Hatsherpur Union. Moreover, working-age people’s proportion rates in each village in total population are very fluctuating and elastic nature. Other side, the proportion rates of elderly population are to a certain extent and calm characteristics.
In figure (5-7), above lines show the elderly population and below lines show the elderly population proportion. Some villages have high proportion of both elderly and young population e.g. Khord balail and some bare only high proportion of elderly population but low proportion of young population e.g. Tajurpara. The causes of this population pattern can be demonstrated by the continuous shifting of the population’s inhabitants among the locations, because of disaster especially river erosion.
In this study, as cohabitation of young and elderly population is the basis of the niche indices to determine the level of quality, its ratios have to receive precedence for analysis. Over defined years, what the final condition of the community in 2008, in accordance to the others studied year is the main concern of this analysis. Following figure (5-8), shows the elderly-young ratio at each location in Hatsherpur Union.
In the figure, graphical expansion indicates larger value of this ratio and community deterioration level as well. Thus, by seeing the figure, it is obtained ‘Tajurpara’ and ‘Dhegapara’ are the more detrimental location; and ‘Karajapara’ and Khord ‘Balail’ are the healthier location as having large elderly-young ratio and small elderly-young ratio respectively. Again, ‘Simulbari’; ‘Shahanbandha’ and Nij Balail express healthy condition in 2008 that were deteriorated in 2001 and 2004.
In the above figure, there are several locations that have improving trends over time horizon. But it is not indicate the locations that were good in past, somewhat indicate good or bad in present.
Density analysis of the elderly-young populations:
There is a high variation among the rates of ‘area per population’ in Hatsherpur Union and existed a significant number of both low dense and high dense villages. As a disaster affected region, it is physically deteriorate and creates less employment opportunities and there is no much job variations to be employed. This is why; the trend of becoming more concentration of people is slow and in some cases, it is segregated. Following figures (5-9), (5-10), (5-11) and (5-12) show the trend of changes whether it increase or decrease the inhabitation of young and elderly population in each village, by means of ‘area per population’ (young or elder) assessment in 2001 as the initial year of study and 2008 as a last and final year of study. In these figures, each location is prescribed by the serial number and they are located according to this series.
[There is a little change by increasing dense in all entire locations except Chak Ratinath (4) and Hatsherpur (6) which are identified as a big size location. Again, a significant downward movement i.e. increasing density, is being seen at Karnibari (10)]
[Elderly population is seen relatively increasing density at karnibari (10) and Dhanarpara and decreasing density at Shimulbari (14) and others are considered to be more or less relatively unchanged.]
The size of the circle shows the area of the respective village and it’s up and down position express the value of ‘area per population’ or density of that village. Upper position of the circle means the less density of the respective population in that particular village and below position means high density of the respective population. In the case of young or working age population, it assumes very slow movement to have its increase in the village where the elderly population is assumed fast movement at some locations in such case and others are remain still. It is a matter of note that Chak Ratinath has large area size, but contains small number of young and elderly population.
Measurements of the niche overlap:
Niche index is easily interpreted in provisos of geometry and different in overlap and correlation. Overlap values of niche indices in the following table interpreted the condition of the community through its level of standardization.
Table 5-5: Values of Niche Overlap Indices for Elderly-Young in Hatsherpur Union
Data: Calculated values by author
Only the value of Ohishows the increasing trend and of other models expresses- fluctuating increasing character LO; decreasing trend Chi (Levins) and αhi, and standing still after little decrease, Chi .
In 2001, Hatsherpur Union has received well off condition by the value observing in Chi , LO and Ohi as it is much more than the level of their standardization (standard level=1). Thus, they represent better condition in sense of spatial temporal age group distribution. But in the case of Ch (Levins) and αhi, it does not reach to its standard level but nearly stay. Again, in 2004, though the value of Chi, Chi (Levins),and αhihas reduced, it is increased in LO and Ohi that are consider ecological factor and resources distribution; and properties of elderly population respectively. Herlbert meeting ratio (LO) is the expansion of the niche index to identify the healthier location sharply. And proposed model (Ohi) by Kanjitani,Y et al (2005) also have a much reliability to determine better community in terms of cohabitative communication level. Thus, in 2004, though Hatsherpur Union falls from the previous healthy condition stated in Chi and intending healthy condition stated in Chi (Levins) and αhi , it gains much strength and better cohabitative condition according to the LO and Ohi. In the last year, 2008, the cohabitative communication level has a much increase in Ohi and remains stable in Chi and a little bit decrease in other niche models from its immediately previous year, 2004. This condition is not means deteriorated condition rather fluctuating character.
Some are parts: