Scoring and methodology for prioritization Comparative assessment of Air and Water Quality in Five cities

16 Similarly, precipitation data were also recorded and scrutinized for variations over average annual rain fall, heavy and very heavy rain fall intensities during monsoon seasons.

3.8 Scoring and methodology for prioritization

Natural hazards occurrence and their past impacts within target urban areas were evaluated against several sectors taking in to consideration the natural hazard exposure levels. A matrix was created to evaluate and assign a score as per the degree of impact from respective hazard types. This approach has helped to identify and prioritize the cities in terms of impact from extreme events. The appraisal was on qualitative terms based on a comparative subjective assessment. .For easy reference, a score of five 5 was assigned for a worst case and one 1 was for the least case. When data is not available, the score of zero was allocated. Similar approach was used for presentation of the results of Climate scenario study as well as sector based vulnerability assessment and study of data availability and to prioritize the cities for detail study under Phase 2. 17 4 Brief introduction to 5 selected cities

4.1 Chiang Rai

Population : 141,291 Economy : Agriculture, Trade Role in the province : Administrative, Commercial and Educational Center Major Climate hazards and impacts : Floods, Landslide, Tropical storm; River erosion; : Water pollution

4.1.1 Location

Chiang Rai province is Thailand’s northernmost province. Clipped to the north by the Mae Kok River, Chiang Rai city is 60 kilometers far from Thailand’s northern border where the Mekong River skirts the boundaries of Thailand, Lao PDR and Myanmar. Muang Chiang Rai, the district capital of the province of the same name, approximately 785 km north of the nation’s capital, Bangkok and located at 19 55 ’ N, Longitude-99 50 ’ E and with an elevation of 395m is included in the Lower Mekong basin with its boundary stretching to Lampang in the south, Phayao in the east and Chiang Mai in the west. The watershed area of the Mae Kok River is 7,895 square kilometers with an annual run-off of 5,119 million cubic meters. The general landscape consists of a large fertile plain, set within a midst of crisp and scenic mountain ranges. These form into a pan shape with elevations at approximately 580 m above sea level. Figure 4.1. Map of Chiang Rai district Source: GISTDA 18

4.1.2 Resources

Formerly part of the Golden Triangle, the substitution program to replace opium production with tea, coffee and rice cropping has led to the increase of border trade and commerce. Thus the economy of the city relies mostly on agricultural resources, small business owners, especially with the extension of tourism. Although over 30 of the land area is officially classed as farmland, only about 19 is really considered suitable for cultivation – and most of the cultivatable area is located along the Phaholyothin highway, which runs through the districts of Phan, Muang and Mae Chan and ends in Mae Sai. Moreover through the development of tourism and its associated increasing transport facilities, the city is gradually becoming a privileged gateway to reach China, Myanmar, Lao PDR, Vietnam and Cambodia. The city currently plays the role of a major transport hub in the whole region, using also the river as a transportation channel. These dynamics contribute to the urban extension of Muang Chiang Rai over the past years.

4.1.3 Climate

Because of its higher elevations, the climate in Chiang Rai province is generally somewhat cooler when compared to the rest of the country. However, there are still three distinct seasons; the hot season, the rainy season and the cool season. Throughout the winter months, nighttime temperatures can drop considerably from the average daytime figures. At other times during the year, day and night temperatures do not vary significantly. The Cool Season lasts from late October until the end of February with temperatures ranging from 13°C to 28°C. The coldest months are December and January. The Hot Season begins at the end of March and lasts until the end of May, with temperatures ranging between 17° C and 36° C. The hottest month is April. In Chiang Rai, the monsoon or rainy season starts around May and ends in October - earlier than in Central Thailand. The average rainfall in Chiang Rai is considerably higher than its neighbor, Chiang Mai province. So much so that during the months of August and September, when rainfall is heaviest, many of the streets throughout the province will flood. At most other times the rain will normally fall sporadically The hot season lasts from March to May with a daytime average temperature of 26 °C. The rainy season actually presents two peaks: one in May-June 200mm average in one day and one in August-September up to 380mm average in one day. The average precipitation amount in a year is around 150 millimeters. The refreshing season starts in October and continues until the month of January. The average daytime temperature drops to 21 °C during this period. The monthly mean data of temperature and rainfall over Chiang Rai during the period 1980- 2008 is used in the present analysis. The monthly mean data of maximum temperature Tmax, minimum temperature Tmin, mean temperature mean T, total rain, number of rainy days and maximum rain in 1 day is analyzed for 29 years from 1980 to 2009 to prepare the monthly normal. In addition, the highest Tmax and lowest Tmin in a given month are also considered to calculate the normal of these two parameters during the 29 years period 19 mentioned here. The normal of temperature parameters are shown in Figure 4.2 and normal rainfall parameters during this period is discussed in Figure 4.3 . It is seen from Figure 4.2 that the peak summer is in April about 35°C with March to May as the hot weather season. The extreme Tmax normal is about 4 to 5 degree higher than that of normal Tmax during whole season Figure 4.2a. Similarly extreme cold temperature reported during Dec to Feb Figure 4.2b. There is not much variation in the mean temperature from April to October, 2009 Figure 4.2c The peak rainfall months and the observation of highest rainfall in a day of the order to 6 cmday are reported mainly during July to September Figure 4.3ac. The number of rainy days is also highest in August followed by July, June, May, September and October Figure 4.3b. 20 Figure 4.2. Normal monthly mean temperature over Chiang Rai from 1980 to 2008. a maximum temperatureTmax and highest Tmax Ext. Tmax, b same as a but for minimum temperature and c mean temperature Source: Thailand Meteorological Dept. 21 Figure 4.3. Normal monthly mean rain parameters over Chiang Rai from 1980 to 2008. a total rain b number of rainy days and c maximum rain in 1 day Source: Thailand Meteorological Dept. 22

4.1.4 Climate hazard and extreme events

During the monsoon period, heavy rainfall trigger every year flooding of various intensity. The carriage way of the main river and associated drainage network is not sufficient to cope with the sudden amount of water. The water level thereby rises rapidly, leading to flooding and further erosion. Recently, in July 2000 massive floods, destroying the surrounding fields, affecting livelihood and leading to business interruption, overwhelmed the city. In 2006, flash floods occurred and affected the built-up environment as well as the utility and facility networks within the city. Transportation system was blocked and tourist activities ceased for various days. Loss of crop and economic breakdown led to migration wave to Bangkok. Water run-off is constantly increasing due to inadequate land-use planning coupled with increasing climate variability. Landslide and mudslide are substantial issues Chiang Rai has to face over the past decade. The topography of the zone associated with heavy rainfalls and unplanned human settlements, leads to increase the landslide risk and therefore the correlated damages on livelihoods, infrastructures and property. In fact, each year landslide occurs in the zone. For instance, in 2005, seven events have been reported in Chiang Rai province, affecting a total area of 800 square meters; and in 2007, four landslide events occurred, affecting 300 square meters. Tropical storms are highly frequent in Chiang Rai. Since the beginning of the eighties, the cyclone frequency tends to be accelerated. Strong winds, comprised between 63 kmh and 118 kmh and heavy rainfalls are associated to cyclone period. In recent times several ice rains and gale has been common phenomena. Drought is also of main concern in the province. In April 2008, a period of extreme drought hit the province. The Mekong River was very shallow, impeding the boat tour to work. According to TNA, 314,000 families in 18 districts have been hardly affected by water shortages. The lack of irrigation facilities for agriculture has led to the lost of the crops. In fact, more than 68,000 rai 27,700 acres of agricultural lands have been damaged. The provincial authorities have declared the 18 districts of Chiang Rai as a drought ravaged area.

4.2 Udon Thani

Population : 174,531 Economy : Agriculture, Trade, Industry Role in the province : Administrative, Commercial, Industrial and Educational Center Major Climate change issues : Flooding; Soil acidity and salinity; Tropical storms erosion, water shortage 23

4.2.1 Location

In the northern part of the Isan region, Udon Thani is the capital Amphoe Muang of Udon Thani province latitude 17°2427N and longitude 102°4735E with its boundary stretching to Nong Khai in the north, Khon Kaen in the south, Sakon Nakhon in the east and Nong Bua Lamphu in the west. Located 60 kilometers away, from the Lao PDR border and the Nong Khai checkpoint, Muang Udon Thani forms a plateau, 187 meters above sea level. Muang Udon Thani is part of the Lower Mekong Basin. Three affluents of the Songkhram River, which is the third largest tributary of the Mekong, run through the city. The riverbanks are currently and increasingly endangered by human population growth and it’s correlated increasingly with urbanization trends and associated activities. The erosion process is thus accelerated, with the risk of riverbank slope destabilization and river widening. Increasing human settlements nearby the canals amplify the potentiality of these areas to be badly affected in case of heavy rainfalls coupled with insufficient water retaining capacity. In fact, the river flows within concrete channels, which reduce the drainage. Figure 4.4. Map of Udon Thani district Source: GISTDA

4.2.2 Resources

The city plays a major role as a regional and international transport hub as the gateway to Laos, North Vietnam and Southern China. Muang Udon Thani is thereby easily accessible from Bangkok by train or by plane or even by route. Furthermore the main agricultural productions of the region, such as sugarcane, rice straw, cassava, corns, converge to Muang 24 Udon Thani. The city is thus well known for being a primary resources market hub for neighboring provinces. Muang Udon Thani relies on agriculture as income generating primarily derives from local communities by rice farming, rising in wholesale and retail trading activities. Nevertheless most of the soils are sandy loams and loamy sands, which are very low in fertility, very low in water holding capacity, often highly acidic and low in their organic matter content. No efficient irrigation system has been so far developed in the zone. Weather forecast is thereby of primary importance for crop production and the necessary potential adaptation towards possible changes. Large-scale industries include sugar, jute, cassava and rice mills are located in Udon Thani. Small-scale industries such as cotton, silk and mat weaving have also brought revenue to the city. Meanwhile, Udon Thani is part of the northeast region of Thailand, which is the most deprived region economically, with per capita average income less than 40 of the national average. The trend of Udon Thani’s urbanization is rapid and mostly unplanned. The city encompasses four reservoirs, two of them in the direct urban environment. These reservoirs are of important use for the whole region as they provide water supply for public, cattle and agriculture purposes. Meanwhile the gravity of the July 2000 flooding was increased by the overflow of two reservoirs. In fact, water shortage has become a pressing issue as the water supply encounters difficulties to meet the increasing demand. This might have some negative repercussions over agricultural business and could trigger food shortage within the city but also at the regional scale.

4.2.3 Climate

Udon Thani climate is tropical savanna and can be divided into three main seasons. The hot season is running from March to May with temperatures comprised between 24 °C and 36°C. Rainfalls start to me more frequent as the hot season moves forward, leading to a very high humidity rate in May. The monsoon then starts in June and lasts until October, characterized with two peaks, one in June 230mm for the highest average record and the other one in August 280 mm for the highest average record. Then the cool season runs from November to February with a 15 °C to 30°C temperature range. Therefore temperatures range from 16 °C to 36°C with January as the coldest month; and precipitation varies from 6.0 to 978.0 mm per month with the heaviest rainfalls during the month of August. The monthly mean data of maximum temperature Tmax, minimum temperature Tmin, mean temperature mean T, total rain, number of rainy days and maximum rain in 1 day is alalysed for 29 years from 1980 to 2009 to prepare the monthly normal. In addition, the highest Tmax and lowest Tmin in a given month is also considered to calculate the normal of these two parameters during the 29 years period mentioned here. The 29 years normal of temperature parameters are shown in Figure 4.5 and normal rainfall parameters during this period is discussed in Figure 4.6 . 25 It is seen from Figure 4.5 that the peak summer is in April about 36 C with March to May as the hot weather season. The extreme Tmax normal is about 4 to 5 degree higher than that of normal Tmax during whole season Figure 4.5a and the peak values in hot weather season is about 2 C higher that the corresponding values of Chiang Rai as shown in Figure 4.2a. Similarly extreme cold temperature reported during Dec to Feb Figure 4.5b. The extreme Tmin during winter is slightly higher compared to that of Chiang Rai values as shown in Fig. 2b. There is not much variation in the mean temperature from April to October, 2009 Figure 4.5c. The peak rainfall months and the observation of highest rainfall in a day of the order to 6 to 7 cmday are reported mainly during May to September with peak during August Figure 4.6ac. Number of rainy days is also highest in August followed by July, June, May, September and October Figure 4.6. 26 Figure 4.5. Normal monthly mean temperature over Udon Thani from 1980 to 2008. a maximum temperatureTmax and highest Tmax Ext. Tmax, b same as a but for minimum temperature and c Mean temperature Source: Thailand Meteorological Dept. 27 Figure 4.6. Normal monthly mean rain parameters over Udon Thani from 1980 to 2008. a total rain b number of rainy days and c maximum rain in 1 day Source: Thailand Meteorological Dept.

4.2.4 Climate hazard and extreme events

Muang Udon Thani is no exception concerning climate change effects. The city has to cope with climate unpredictability comprising unseasonable and intense weather events. In July 2000, the highest record of rain for the whole province fell over the city and led to massive floods, causing two fatalities and interruption of all activities for several days. In August, 2001 torrential monsoon rainfalls for more than two weeks, triggered many fatalities and 28 displaced thousands. These massive climatic events meant to occur more frequently, unhinge the normal course of activities on the middle term and can foster new type of vulnerabilities and increase the existing one, if adaptation initiatives are not developed. Every one to two years, Udon Thani is issuing tropical storm warning, which originates over South China Sea during the months of May to October see Table 1. Cyclones in the area trigger wind comprised between 63kmh and 118 kmh and high levels of rainfall. Large- scale industries of the region include sugar mills are affected. Between January and July 2009, 2 tropical storms were reported by the Department of Disaster Preparedness and Mitigation DDPM of Udon Thani. 1,404 people and an overall of 434 households have been affected, leading to an economic loss of 4,236,290 Bahts.

4.3 Hat Yai

Population : 53,638 Economy : Trade, tourism Role in the province : Commercial and Tourism Center Major Climate hazards : Flash floods; Droughts; Water shortage; Pollution during floods; Slope destabilization

4.3.1 Location

Located 50 kilometers from the Malaysian border at longitude 100° 23 55 E and latitude 06° 55 46 N, 92 feet 28 m above sea level, Hat Yai Municipality is the second most important city of Songkhla Province, forming the urban corridor known as the Greater Hat Yai- Songkhla Metropolitan Area. It has become a very popular tourist centre for Malaysian and Singaporean visitors. Songkhla Province shares its western boundary with Satun Province; Phatthalung lies north; Pattani and Yala south. Hat Yai Municipality is low-lying, sitting at the base of a roughly circular valley. Located in the downstream area of the Khong U-Taphao Basin, the Utaphao River flows through the heart of the city, often in concrete channels that provide limited drainage. The Utaphao River rises at Sadao, on the border with Malaysia and flows to Songkhla lake, a coastal lagoon just downstream of Hat Yai that is hydraulically connected to the Gulf of Thailand. 29 Figure 4.7. Map of Hat Yai district Source: GISTDA

4.3.2 Resources

As the centre of commercial trade and administration in Southern Thailand, Hat Yai is a bustling modern city, which concentrates increasing commercial and touristic activities. The city is also a major transportation hub with an international airport located in the suburbs of the city and other inner city transportation facilities as its geographical location makes it a gateway to the major neighboring countries of Malaysia and Singapore, and is thus a city with high tourism potential for domestic and foreign tourists who visit year-round.

4.3.3 Climate

Hat Yai benefits from an equatorial climate. Temperatures range from 17 °C to 39°C over the year, with a daily average of 26.8 °C. The number of rainy days per month in a year is 161.2 with an annual rainfall amount of 2 meters, with a peak during the months of May 161.7mm in a month and November 318.1mm. Hat Yai only has two seasons; wet and dry. The wet season, influenced by monsoon and rainstorms, starts in May and ends in the month of December. Usually in November, heavy rainfall beat down on the city with sometimes twenty-two days of continuous rain leading to more than 500 mm of precipitation. The dry season lasts four months, January to April with average highest temperature of 33 °C. 30 The monthly mean data of maximum temperature Tmax and minimum temperature Tmin obtained from Thai Met Department is shown in Figure 4.8. Similarly the normal monthly total rain obtained from 29 years 1980 to 2009 is shown in Figure 4.9. As seen from these figures the hottest month is April and the coldest month is January and is slightly similar to the condition over Phuket as shown in Figure 4.11. But with respect to normal rainfall the pattern is slightly different over Phuket with peak rainfall varies from September to December Figure 4.9 with highest in the month of November. Another peak is in the month of May. Figure 4.8. Normal monthly mean temperature over Hat Yai from 1980 to 2008 Source: Thailand Meteorological Dept. Figure 4.9. Monthly normal rainfall over Hat Yai mm from 1980 to 2008 Source: Thailand Meteorological Dept. 31

4.3.4 Climate hazard and extreme events

Due to its geographical characteristics and to unplanned urbanization and deforestation in upstream areas, Hat Yai Municipality has become extremely vulnerable to flood disasters. With its population density and as a commercial center, the municipality has characteristics that can magnify the impact of flooding to which it is prone. Hat Yai Municipality is thus prone to inundation due to its hydraulic system combined with heavy annual rainfalls and rapid unplanned urbanization. In fact the river suffers from regular flash flooding during the monsoon season. Serious flooding events occurred in 1988 and again in 2000. Triggered by torrential rains, the flooding of November 2000 has been described as one of the worst natural disasters in the history of urban Thailand Charlchai et. al., 2004. Flood depths of two to three meters height caused 40 fatalities, thousands of injuries and severe damages to property, livelihood, and lifelines, affecting drastically the economy of the city. More recently, in 2006 flooding also affected more than 200,000 people and paralyzed the city for various days. During the period 2005- 2008 the total amount of loss reached 23,194,466 Bahts with 290 transportation infrastructures affected and 3,792 Rai of agricultural lands damaged. Drought is also a substantial problem in the zone. This issue affected 2,137 people i.e. 613 households between 2005 and 2008.

4.4 Phuket

Population : 29,227 Muang Phuket, 18,547 Patong Economy : Tourism, Service Role in the province : Touristic Center Major Climate change issues: Flood, Landslide, Sea level rise, Storm surge, Tsunami, Water shortage

4.4.1 Location

Phuket covers a total area of 543 km2, which comprises of Phuket Island and 32 nearby islands. Located 862 kilometers south of Bangkok, in the Andaman Sea, the main island is connected to the mainland by the older Sarasin Bridge and the newer Thep Krasattri Bridge. The two bridges running side-by-side spans over the Pak Prah strait. On the north of Phuket province lies Phang Nga Province, and on the Eastern side, Krabi Province lies on the other side of Phang Nga’s sea. Phuket island is constituted at 70 of mountainous areas and 30 of plain areas mostly located in the central and eastern parts of the island. Phuket city is spreading from the coastline to the upper hill, with an elevation from 0 to 10 meters. The municipality covers the 32 subdistricts of Talad Yai and Talad Nuea. Patong city is on the Andaman coastline, characterized by a massive tourist industry attracted by its seashore and the development of numerous and unplanned human settlements in the toe of the mountains. Figure 4.10. Map of Phuket Province Source: GISTDA

4.4.2 Resources

Phuket formerly derived its wealth from tin and rubber. The island was on one of the major trading routes between India and China, and was frequently mentioned in foreign trader’s ship logs. The region now derives much of its income from tourism. The tourism service industries, such as lodging, restaurant, transportation and tourism commerce are clearly the most important sources of income in Phuket. In 2003 4.2 million tourists came to the island, generating revenue of 72,599 million Bahts. Patong area attracts the highest number of visitors. In fact Phuket accounts for 30 of the national tourism revenue. Following the service sector, the commercial and agricultural activities are also important economic sectors Table 4.1. 33 Table 4.1. Income of Phuket Department of Provincial Administration 2004 2005 2006 2007 Agriculture 4,886 4,945 5,529 5,788 Agriculture, Hunting and Forestry 1,642 1,947 2,402 2,537 Fishing 3,244 2,998 3,127 3,251 Non-Agriculture 50,076 45,427 51,599 56,268 Mining and Quarrying 8 Manufacturing 2,037 2,271 2,394 2,556 Electricity, Gas and Water Supply 1,355 1,296 1,460 1,574 Construction 2,457 2,925 2,927 2,999 Wholesale and Retail Trade; Repair of Motor Vehicles, Motorcycles and Personal and Household Goods 4,603 5,089 6,043 6,275 Hotels and Restaurants 25,785 20,766 22,000 23,880 Transport, Storage and Communications 6,614 5,174 7,887 9,173 Financial Intermediation 1,459 1,660 1,924 2,176 Real Estate, Renting and Business Activities 1,424 1,516 1,713 1,923 Public Administration and Defence; Compulsory Social Security 1,155 1,227 1,306 1,432 Education 993 1,172 1,519 1,673 Health and Social Work 821 923 990 1,127 Other Community, Social and Personal Services Activities 1,318 1,359 1,388 1,430 Private Households with Employed Persons 48 49 49 51 Gross Provincial Product GPP 54,962 50,371 57,128 62,055 GPP Per capita Baht 201,339 180,439 200,765 214,621 Population 1,000 persons 273 279 285 289

4.4.3 Climate

Phuket climate is characterized by two seasons. The hot season starts in December and ends in March, with a daily mean temperature average of 28.4 °C and 40mm monthly average of rainfall amount. The rainy season begins in April and lasts until November, with rainfall peaks in May up to 320mm and September up to 400mm. During this season the temperature is comprised between 32 °C for the highest and 23.8°C for the minimum. The daily average temperature during the year is comprised between 23 °C and 34°C. 34 The monthly normal as calculated from the monthly mean of different temperatures during the period from 1980 to 2008 is given in Figure 4.11. Being a coastal station the minimum temperature is slightly higher compared to that of northern stations particularly in winter. Figure 4.11 . Monthly mean normal of temperature; Tmax, Tmin, mean Temperature, Ext. Tmax and Ext. Tmin obtained from the data 1980 to 2008 over Phuket Source: Thailand Meteorological Dept. With respect to monthly normal rainfall it is found that September and October are the peak months followed by August, May, July and June Figure 4.12a. The peak no. of rainy days and the observation of highest rainfall in a day more than 7 cmday is reported mainly during September and October Figure 4.12ac. 35 Figure 4.12. Normal monthly mean rain parameters over Phuket from 1980 to 2008. a total rain b number of rainy days and c maximum rain in 1 day Source: Thailand Meteorological Dept. 36

4.4.4 Climate hazard and extreme events

The coastline of the island is continuously exposed to sea erosion and has to cope with sudden and disastrous events, such as tsunami tidal wave. The 26 December 2004 the earthquake in the Sumatra Island created a massive tsunami tidal wave, which devastated the Andaman Coast. Phuket suffered from disastrous loss of lives, assets and natural resources. 13,065 people died or disappeared during the event; 402 residences were totally destroyed; 550 partially. The utility and facility systems of the island were heavily damaged. In total the overall damages cost more than 13,000.54 million Bahts Strategy for Provincial Development Unit, Phuket Governor’s Office and National Economic and Social Development Board. Strategic plan has been developed to curb the potential impacts of such disasters. Phuket is also very much exposed to irreversible damages on its coral reefs due to high concentration of carbon dioxide emissions in the atmosphere that tends to increase the sea temperature. Reef-building corals are a part of a rich ecosystem that provides resources for the coastal populations. They also serve as buffer against strong waves that erode coastlines during storms. Currently the coral cover is declining at the rate of one to two per cent annually due to destructive fishing, tourism, sedimentation caused by coastal development, eutrophication due to untreated water run-off, dredging and climate change. According to Phuket Marine Biological Centre PMBC, Phuket coastline is seriously endangered by all these interlinked dynamics. According to the Thailand Meteorological Department, the southern part of Thailand is relatively exposed to high risk of tropical storms and typhoon. On top of high-speed winds that can damage the infrastructure, heavy rainfall due to the topography of the area can lead to flooding and contribute to destabilize the slopes. In fact one of the disasters Phuket has to increasingly cope with is landslide occurrence. Uncontrolled human settlements help weaken the slopes and heavy rainfalls help trigger landslides in the zone. The tropical climate participates thereby to the instability of the slopes and as climate change interacts with rainfall events, triggering more intense and more frequent rain amount, landslides are meant to occur and affect more people more frequently. Surrounded by mountains Patong area is especially prone to landslide as about 20 of the area has high to moderate susceptibility to landslide. The area is heavily prone to risk; first the populations living in the toe of the mountain are located within the landslide prone area, while the populations living in the plain area are exposed to flood risk. Adaptation project towards landslide risk mitigation has started to be implemented in the zone.

4.5 Samut Sakhon

Population : 176,423 Economy : Fishery, Industry Role in the province : Trade, fishery and agricultural center 37 Major Climate change issues : Flood, Land subsidence, Salt intrusion, Air pollution, Water shortage, Coastal erosion

4.5.1 Location

Muang Samut Sakhon is located at latitude 13 °31 ƍ59ƎN and l ongitude 100°16 ƍ59ƎE at the mouth of the Tha Chin River, which flows into the Gulf of Thailand as one of the distributaries of the Chao Praya River. The municipality is situated 30 kilometers from Bangkok and shares its western provincial border with Samut Songkhram; its northern one with Nakhon Pathom; and Eastern one with Bangkok. Muang Samut Sakhon covers three subdistricts, namely Tha Calom, Krokkrak and Maha Chai, with respectively 9,865 5,262 and 40,250inhabitants. Figure 4.13. Map of Samut Sakhon Provice Source: GISTDA

4.5.2 Resources

The economy of Samut Sakhon mostly relies on fishery, as the city is one of the major fishing ports in the zone. The production of brine salt also provides substantial incomes to the region, thanks to the coastal location of the municipality. Industrial development has increased drastically for the past decade. Currently 4,000 industries are settled in the zone. The associated pumping of groundwater resources has led to land subsidence and the constant degradation of the aquifer. 38

4.5.3 Climate

With respect to the climate of Samut Sakhorn, it is situated in the central Thailand. The Central regions climate is influenced by the southwest monsoon winds and sea breezes. The mountains of the north and the northern part of the Central region reduce the northeast monsoon winds influence. Similarly the annual average temperature is 28 C, the average highest temperature being 330C, and the average lowest temperature being 20 C. Muang Samut Sakhon has 3 seasons, the rainy season, from June to October, when the southwest monsoon winds and depression storms exert their influence, winter, from November to January, when the northeast monsoon winds exert their reduced influence and thus is not as cold as the winter of the North or Northeast , and summer, from February to May, which is less hot than the summer of the North or Northeast due to the influence of the ocean and the trade winds from the ocean between February and April. The average rainfall of the city is 1,120 mmyear.

4.5.4 Climate hazard and extreme events

The city lies only 1 to 2 meters above the mean sea level. Flood is thus a frequent issue the municipality has to cope with, even if the municipal record doesn’t reveal much on the topic. Nevertheless coastlines are facing more and more recurrently coastal erosion and rising sea levels causing land subsidence and human migration. The causes are mostly man-made, such as sand mining, construction of industrial estates along the coastline, sedimentation coming from coastal development and groundwater drainage. During the last decade, the erosion process is faster than forecasted. Bangkok, Samut Songkhram, Samut Sakhon, Samut Prakan and Chachoengsao provinces are suffering severe erosion according to Master Plan on Coastal Erosion Management for the Upper Gulf of Thailand, published in September by the Thammasat University Research and Consultancy Institute, which studied the coastline covering 100km of shoreline from the mouth of the Mae Klong river in Samut Songkhram to the mouth of the Bang Pakong river in Chachoengsao. Some 2,667 hectares of this coastline was washed away in the 54 years from 1952 to 2006. The problem is severe and the rate of erosion is increasing. Local communities are suffering economic damage estimated at more than 100 million baht a year, according to the institutes report. Another simulation indicates that without intervention, in 20 years coastlines will retreat inland by 1.3 km as they are eroded away DMRC report. The intrusion of salt water into productive land areas and drinking water supply is a substantial risk in the area as the agricultural production such as rice straw and coconut would be destroyed, affecting then durably the local livelihood. 39

4.6 Comparative assessment of Air and Water Quality in Five cities

Environmental degradation is a serious issue to be addressed as it is observed to be deteriorating over time. Air pollution and water pollution are directly affected the human beings causing prolonged illnesses in the reciprocating system and vector borne diseases such as dengue fever and malaria. The air quality is progressively worsening in the urban areas. The concentration of ozone has particularly increased since the year 2000. Although the Particulate Matter PM10 concentration is varying a lot, some days have been recorded above standards over the past 10 years. In Chiang Rai, the number of days with exceeding standards for ozone indicator is increasing, in spite that the measurement stations were established only a few years ago. The direct consequence of high rate of low-level ozone is the formation of smog. Furthermore, the number of days with PM10 exceeding standard is also increasing, deepening the risk of respiratory diseases such as lung cancer. See Figure 4.14 - Figure 4.16. Figure 4.14. Particulate matters .PM10 concentration in urban areas from 1997 to 2008 Source: Thailand Pollution Control Dept. 40 Figure 4.15. O3 Low-Ozone concentration in urban areas from 1997 to 2009 Source: Thailand Pollution Control Dept. Figure 4.16. SO2- Sulfur Dioxide concentration in urban areas from 1997 to 2009 Source: Thailand Pollution Control Dept. The urbanization trend of Hat Yai is rapid since the past decades. Due to the increasing demand on development and settlement, urban areas have encroached into hazard prone areas. In the direct surroundings of the municipality, the constant human settlement expansion in four township municipalities is quite noticeable. The environmental degradation characterized by high peak of air and water pollution is deepening. The high concentration of Particulate matters PM10, from man-made origin such as the burning of fossil fuels, power plants and industrial process, deteriorates the quality of air in the city, increasing health hazards. In July 2002 and in February 2003 several consecutive days were categorized as unhealthful air quality period, with some days considered as very unhealthful. 41 For Samut Sakhon, in relation to industrial development, the pollution rate concerning water and air quality has been in the increase. Several days per year the air quality index shows high values, highlighting the unhealthful state of the air. The year 2003 especially the month of November recorded more than a week with unhealthful air quality. Industries also generate wastewater, around 68,000 m 3 per day, which highly contribute to pollute the water and groundwater bodies. Furthermore Samut Sakhon generates 700 tones of solid waste per day, of which 400 tones comes from within the municipality and the other 300 from the outside. 42 5 Climate scenario and observed trends in 5 cities Climate change is manifested by a rapid rise in temperatures all over the world. Only 30 years ago scientists were warning that global warming would change precipitation patterns significantly, with heavy rainfall in some areas while others would be very dry. Extreme weather conditions such as storms, floods, droughts and heat waves would become more intense and more frequent, and sea levels would rise, the scientists warned. These changes can already be observed, according to the report East Asia Environment Monitor 2007: Adapting to Climate Change, published by the World Bank. In the last few years there have been widespread changes in extreme temperatures, droughts have become longer and more intense, the frequency of heavy precipitation has increased over most land areas, and arctic sea ice has shrunk by 2.7 per cent per decade, resulting in a rise in sea level that is now beginning to submerge small island countries like Kiribati and Nauru in the South Pacific, the report said. Thailand has 2,880km of coastline along 136 districts in 23 provinces, thus it is extremely vulnerable to sea level rises due to climate change. A one-meter rise will not only sink Bangkok and low-lying areas, resulting in destruction of infrastructure, loss of beaches and irreversible damage to coastal ecosystems like mangrove forests and coral reefs, but also cause land subsidence and coastal erosion. In recent times due to increase of urban population in Thailand in conjunction with the impact of climate change, the cities are becoming more vulnerable towards disasters. Now, the cities are responsible for managing their growth and prepare the community for consequences of climate change and vulnerabilities. As the five sites of Thailand chosen for this project are under the influence of various disasters such as flooding, heavy rainfall spell, drought, storm surge, tsunami, sea level rise etc., it will be essential to analyze the past data over these five sites of Thailand. This will facilitate to identify options for integrating climate change adaptations in the governance process considering pre identified indicators for modifications to built environment. These urban areas experience frequent occurrences of hydro-meteorological disaster events with direct and indirect losses of social and economic nature. Preliminary studies in the Phase 1 concerning the changes in climate trends will be useful for city governing bodies and provincial authorities to initiate productive actions leading to long term solutions, local level adaptation options and identifying gaps. Under the study, the following activities were carried out. • Assessment of the status of impacts of climate change in five selected cities • Evaluation of data availability for study on previous events and trends as well as for study of potential exposures to future climate change scenarios • Identification of source agencies and data providers, availability of essential data • Search for information gaps, outlining the areas for further qualitative and quantitative assessment 43 • Identification of the sources of most useful information for developing strategy for facing future challenges on climate change impacts • Collect information on relevant studies carried out previously by national or international agencies

5.1 Change of precipitation pattern