Climate Change Vulnerability of Urban Development in the PhanrangThapcham (Ninh Thuan, Vietnam)45215

Climate Change Vulnerability of Urban Development in the Phanrang-Thapcham Ninh Thuan, Vietnam Tuy Bao Van 1* , Tho Tran Quang 2, Kien Nguyen The 3 1 HCM City University of Natural R

Climate Change Vulnerability of Urban

Development in the Phanrang-Thapcham (Ninh

Thuan, Vietnam)

Tuy Bao Van (1)* , Tho Tran Quang (2), Kien Nguyen The (3)

(1) HCM City University of Natural Resources and Environment, HCM City, Vietnam

(2) Southern Institute of Water Resources Research, HCM City, Vietnam

(3) VNU University of Economics and Business, Vietnam National University, Hanoi, Vietnam

(*) Correspondence email: bvtuy@hcmunre.edu.vn

Abstract: The impacts of climate changes and extreme weather events in recent years have destructive impacts on urban development Climate change increases in the frequency and severity of floods, and as well aware, the impacts of flooding include loss of human life, damage to property, destruction

of roads, schools, hospitals, markets, irrigation channels, dams, destruction of crops, loss of livestock and deterioration of health conditions due to waterborne diseases As the consequence, all these effects will have severe damage to urban development This paper recognized key aspects of urban that could be adversely affected by climate change, develop measures and standards for assessing the vulnerability to urban, develop an urban database of the sensitive variables consistent with the vulnerable assessment measures, and applied the criteria in a study of the vulnerability to Phanrang-Thapcham urban Key findings highlight approximately 50% of the area has a medium vulnerability, 10% of the area has a high vulnerability Areas along the Dinh river and the center area of the urban have a low vulnerability

Keywords: Climate change; vulnerable assessment; impacts; urban; Phanrang-Thapcham; Vietnam

1 Introduction

All human activities such as land use change, fossil fuel burning are increase of greenhouse gases into atmosphere, which result climate change The main characteristics

of climate change are changes precipitation particularly over places; increases in average temperature in global scale (global warming); melting of ice and glaciers insulting sea level rise (UNFCCC 2007) According to The Fourth Assessment Report of the IPCC, over the last century, the average global temperature rose by 0.74° C and is predicted by 2100 range from 1.8° C to as much as 4° C During the 20th century, sea levels rose by 0.17 meters and by

2100, projected to rise between from 0.18 to 0.59 meters (IPCC 2007) Because of climate change, there are many negative impacts such as water resources for human use will be exhausted from ice and glaciers melting such as Greenland in recent years (UNEP 2007) Moreover, the type, frequency and intensity of extreme events, such as hurricanes, typhoons, heavy precipitation events, floods, and droughts are also expected to rise (Greenough et al 2001) If average global temperature rise around2°C, approximately 59%

of population in the world would be exposed to water shortage (Rockstrom et al 2009)

Vietnam is the countries predicted the most affected severely by climate change due

to its long coastlines, the high concentration of population and economic activity in coastal areas, and a heavy reliance on agriculture, natural resources and forestry (Adger 1999) The impacts of climate change such as typhoons, floods, prolonged droughts and sea level rise,

would increase risks to properties, livelihood and urban infrastructure assets (MONRE 2012)

Phanrang-Thapcham is the coastal urban of the Ninhthuan province which is often affected by natural disasters and predicted severely affected by climate change in the coming decades Recently, droughts and water resources depletion have frequently occurred which severely affected in agriculture, aquaculture, urban water supply, environment Moreover, the frequent heavy rains and floods are greatly damaged the urban and its surroundings Salinity intrusion, bank erosion, and coastal erosion are also severely impacts on these areas All consequences have negatively affected on urban development (NinhThuan PPC 2012)

Vulnerability is a term commonly used to describe a weakness in a system; its susceptibility to a specific threat and harmful event This concept is used across different fields which are often location or sector specific A variety of definitions of vulnerability have been proposed in the climate change literature (Ribot 1995) The most common use is that vulnerability is a function of the exposure and sensitivity of a system to a hazard, and the ability to adapt to the impacts of the hazard (Brooks et al 2005) From a social point of view, vulnerability can be considered as the exposure of people to livelihood stress causes

by impacts of environmental change or climate extremes (Kelly 2004) As such, vulnerability can be the combination of social factors and environmental risk (Adger 2006) Vulnerability in the context of climate change is basically known as a function of biophysical and socioeconomic factors (O’Brien et al 2007) Vulnerability is also a function of the character, magnitude, rate of climate variation and variation to which a system is exposed, sensitivity, and adaptive capacity to climate change (McCarthy 2001) According to the IPCC, vulnerability to climate change is defined as the degree to which a system is susceptible to, and unable to cope with negative effects of climate change, including climate variability and extremes (Adger 2007) The definition of the IPCC is criticized too vague and the resulting difficulty in making it operational (Hinkel 2011) But the definition could

be considered as an integrative concept that can link the social and biophysical dimensions

of environmental change (Turner 2003)

The general aim of this study is to calculate the vulnerability index of urban development to climate changes, to establish to what extent the urban assets are vulnerable and identify the major risks and levels of stress it faces with regard to resource stress, development pressure, and management capacity These are essential components for computing vulnerability index in the region The results should provide decision-makers with options to evaluate the current situation, modify existing policies, and implement adaptation and mitigation measures for sustainable water resources management in the study area

Figure 1 Map of Phan Rang - Thap Cham city and surroundings

2 Methodology

Vulnerability is the degree to which a system is susceptible to and adverse effects of climate change, including climate variability and extreme events The vulnerability is a function of the character, magnitude, and rate of climate change and variation to which a system is exposed, its sensitivity, and its adaptive capacity

V = f (E, S, AC)

Of which

Exposure (E): Exposure is the extent to

which a system is exposed to the climate

change E depends on the threats (threat

intensity, frequency, duration) and

location of the system with respect to the

threat (how far from systems to threats)

Sensitivity (S): Sensitivity is the degree to

which exposure to a threat arising from CC

will negatively affect the operation of the

system S may be influenced by the

integrity of assets under threats and

related factors

Figure 2 Framework for vulnerability assessment

(IPCC.2007)

Adaptive capacity (AC): is a measure of the potential, ability, or opportunities available to decrease exposure or sensitivity of a system to a climate-induced stress

2.1 Set up indicator set

Table 1 The indicator set of the exposure (E), sensitivity (S) and adaptive capacity (AC)

1 Flood depth It is flood depth (m) It is classified into five categories

from Very Low to Very High

2 Frequency It reflects the number of flood events in a year

3 Percentage of

affected areas

It is the percentage of affected areas in a commune/ward

It is classified into five categories: Very High (>30%), High (10-30%), Medium (5-10%), Low (2-5%) and Very

Low (<2%)

density It is the population density (person/km2)

1 Percentage of

resident area

It is the percentage of area per capita, allowed to build

houses (%)

3 Percentage of

park/tree areas

It is the percentage of park/planting tree areas per capita

(%)

4

Percentage of surface water areas

It is the percentage of surface water areas per capita (%)

5

Percentage of ethnic minority group

It is the percentage of the ethnic minority groups among

the groups (%)

6 Percentage of

permanent house

It is the percentage of households having the semi-permanent and semi-permanent houses (%)

7 Percentage of

houses before 2000 It is the percentage of houses built before 2000 (%)

8 Percentage of

threatening areas

It is the percentage of households living in natural

disasters-prone areas (%)

1 Life expectancy High life expectancy is high AC to extreme climate events

2 Percentage of

female It is the percentage of female population (%)

3

Percentage of working population

It reflects the percentage of population in working age

(%)

4 Percentage of the

poor

It is the percentage of the poor in the total population

(%)

5 Percentage of

health insurance

It is the percentage of people having health insurance in

the total population (%)

6 Percentage of

medical staff Number of medical staff per 10.000 inhabitants

7 Percentage of

literate people

It is the percentage of literate people over 15 years old

(%)

8 Percentage of

internet It is the percentage of the household having internet (%)

9 Percentage of TV It is the percentage of households having TV (%)

10 Percentage of

radio broadcasting

It is the percentage of wards/commune having radio

broadcasting system (%)

12 Percentage of

trained employees

It is the percentage of trained employee in the total

population (%)

13 Financial support It is the percentage of the household supported credit

loan (%)

2.2 Determine vulnerable index

2.2.2 Determine indicators (E), (S) and (AC)

Table 2 Determine indicators of (E), (S) and (AC)

Exposure

(E)

Ei is the standardized value of the exposure of the i

n number of (E) sub-indicators Sensitivit

y (S)

Si is the standardized value of the sensitivity of the i

n number of (S) sub-indicators Adaptive

capacity

(AC)

ACi is the standardized value of the adaptive capacity of

the i

n number of (AC) sub-indicators

The value of indicators is classified into five categories as below:

2.2.3 Determine Vulnerable indices

As figure 1, the potential impact is calculated from (E) and (S), based on the follow assessment matrix

Table 3 The assessment matrix of (I)

Very High Average Average High Very High Very High

Vulnerability (V) is calculated based on the Potential Impact (I) and Adaptive

Table 4 The assessment matrix of (AC)

2.3 Climate change scenarios

Vulnerable indices are an important element to develop the adaptive plan to climate change Therefore, average and high climate change scenarios in the short future are suitable It is the reason the scenarios baseline, RCP 4.5 and RCP 8.5 in 2030 are chosen

3 Results

3.1 Vulnerability Indices under the baseline scenario

The result of vulnerable assessment points out that the vulnerability of several communes is average (15/32 ward/commune) Only three communes including Phuoc Dan, An Hai, and Phuoc Hai have a high vulnerability because these communes have high exposure and low adaptation The low vulnerability is identified in communes along the Dinh River due to low exposure and high adaptation These communes are located in the urban center (Table 6 and Figure 3)

Table 6 The vulnerable index of each ward/commune under the baseline scenario

Ward/Commune Vulnerability Ward/Commune Vulnerability

Note: VL = very low, L = low, M = medium, H = high, VH = very high

3.2 Vulnerability Indices under the RCP 4.5 scenario in 2030

In 2030, the vulnerable index of the most communes shows an upward trend There are five communes with a high vulnerable index including Nhon Son, Phuoc Thuan, Phuoc Huu, Phuoc Hai, and Phuoc Dan and An Hai communes while the most in the urban are suffered from low to average only This can be explained by the fact that the urban has the lowest to average impact level and the highest adaptation compared to other areas (Table 7 and Figure 4)

Table 7 The vulnerable index of each ward/commune under the RCP 4.5 scenario

Note: VL = very low, L = low, M = medium, H = high, VH = very high

Figure 3 The Vulnerable index map under the

baseline

Figure 4 The Vulnerable index map under the

RCP 4.5

3.3 Vulnerability Indices under the RCP 8.5 scenario in 2030

Vulnerability in the RCP8.5 scenario tends to be higher than the RCP4.5 Two communes (Phuoc Dan and An Hai) have a very high level of vulnerability and 5 communes reach a high vulnerability (Nhon Son, Phuoc Thuan, Phuoc Huu, Phuoc Hai, and Phuoc Nam) The vulnerability of the urban's wards is in the range of low to an average level Unlike the RCP 4.5 scenario, the vulnerability in some areas is higher one level in the RCP 8.5 scenario In detail, the vulnerable index of Phuoc Dan town and An Hai communes rise from high to a very high level and Phuoc Nam commune will be from medium to high level (Table 8 and Figure 5)

Table 8 The vulnerable index of each ward/commune under the RCP 8.5 scenario

Van Hai Ward M Phuoc Vinh Commune M

Figure 5 The Vulnerable index map under the

RCP 8.5

Figure 6 The map of flooding risk

4 Discussion and conclusions

4.1 Discussion

Due to the steep topography at the upstream, floodings in the downstream hapeen quickly (about 4-5 hours) Flood risk map (Figure 6) shows that the flooding occurs almost

in the urban, mainly along the banks of the Dinh river The districts of Ninh Hai, Ninh Son, Thuan Nam and PR-TC, especially Ninh Phuoc district, are the areas often serverly flooded (accounting for nearly 50% of the district area) The high flooding risk areas are mainly located in Nhon Son (Ninh Son District); Phuoc Vinh; neighboring areas of Phuoc Hau, Phuoc Huu and Phuoc Thai; and Phuoc Dan and An Hai of Ninh Phuoc district The urban

is not affected heavily because of the banks surrounded, but if the extreme floodings in the upstream occur, the urban is effected more severely than other areas surroundings

The exposure assessment shows that the high exposure occurs in Phuoc Dan, Phuoc Hai and An Hai communes (Ninh Phuoc district) and Bao An ward, Thanh Hai commune (the urban) Other communes and wards of the urban have different exposure levels from very low to low

The sensitivity assessment indicates that the sensitivity varies from low to high In particular, My Son (Ninh Son) and Phuoc Ninh (Thuan Nam) are highly sensitive The urban has low sensitivity to the flood risk The other communes in the flood-affected area have an average level

In contrast to the sensitivity, the adaptive capacity of most wards of the urban is high, except Dong Hai, My Dong and My Binh wards (average level), located near in the coatal areas The adaptive capacity is low in communes located in surroundings

Based on the indicators of exposure, sensitivity and adaptation of ward/commune

in the urban and surroundings, the vulnerability of several communes is average (15/32 ward/commune) Only three communes namely Phuoc Dan, An Hai and Phuoc Hai have a high vulnerability because these communes have high exposure and the low adaptation The low vulnerability is identified in communes along the Dinh River due to their low exposure and high adaptation These communes are located in the urban center

Along the time to 2030, the climate change scenarios in Ninhthuan show the extreme weather events happen frequently and intensity Therefore, the exposure and sensitivity indicators will be higher, leading to high vulnerability The high vulnerable areas almost are located in the surroundings, especially in the southern bank of Dinh river, in the areas near the coastal areas due to high flooding and low adaptive capacity

4.2 Conclusions

Recently, extreme weather events such as drought, water depletion, and floods have negatively impact the Phan Rang-Thap Cham urban are Therefore, the vulnerability of this area is very high Along the time, the vulnerability tends to be higher from the baseline to the RCP8.5 scenarios If in the baseline scenarios, there are only 3 communes high vulnerability then in the RCP 8.5, there are 2 communes very high vulnerability and 5 communes high vulnerability Generally, approximately 10% of the area has very high vulnerability, 15% of the area has high vulnerability, mostly in the surrounding areas 30%

is low vulnerability, located mainly in the urban center The remains are average vulnerability, located near the urban or a part of the urban One of the reasons that the urban has low vulnerability is high adaptive capacity although the exposure is almost the same with other areas

Acknowledgments

The research described in this article is the result of the Cooperation Program between the Kingdom of Belgium and the Government of Vietnam The intended target of Program is to contribute the sustainable development through integrated water resources and urban development in relation to climate change at three provinces: Ha Tinh, Ninh Thuan, and Binh Thuan We appreciate the support and assistance on this research from the Vietnam and Belgium’s experts We also thank the experts from Ninhthuan province, who contributed to this research

References

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Adger, W.N (2006) Vulnerability Glob Environ Chang, 16, 268-281