An Environmental Zoning for Sustainable Development in Thua Thien Hue Province, Vietnam45218

An Environmental Zoning for Sustainable Development in Thua Thien Hue Province, Vietnam Hang Anh Phan 1 , Thang Van Le 1 , Tuan Anh Tran 1 , Son Hoang Nguyen 2* 1 University of Science,

An Environmental Zoning for Sustainable

Development in Thua Thien Hue Province, Vietnam Hang Anh Phan (1) , Thang Van Le (1) , Tuan Anh Tran (1) , Son Hoang Nguyen (2)*

(1) University of Science, Hue University, Hue, Vietnam

(2) University of Education, Hue University, Hue, Vietnam

* Correspondence: nguyenhoangson@dhsphue.edu.vn

Abstract: Based on the natural, socio-economic and environmental characteristics, Thua Thien Hue

province is divided into 6 environmental regions They included of the environmental region of O Lau river basin, environmental areas of A Sap river basin and upstream of Dakrong river, the environmental region of Bo river basin, the environmental region of Huong river basin, and the environmental region of Truoi river basin and the environmental region of Bu Lu river basin Each region was divided into 3 sub-regions corresponding to upstream, middle, and downstream river basins The study results are considered scientific bases to propose solutions for socio-economic sustainable development for each sub region in Thua Thien Hue province

Keywords: Environmental zoning; sustainable development; environmental functions; GIS; Thua

Thien Hue

1 Introduction

Environmental zoning was the division of territory into regions and sub-regions based on spatial division of natural, socio-economic characteristics and environmental status according to the objectives of protection and preservation, development and adaptation to climate change Environmental partitioning is one of the bases of spatial development plans such as environmental protection planning, land use planning, urban planning, etc (Lindsey 1997; Taylor 1998) and the ultimate goal is to ensure sustainable development socio-economic sustainability of the territory (Elizabeth 1992; McGregor et al 1999; Montgomery 2004)

In the world, functional zoning has been used in urban planning and land use adjustment In Europe, since the late 19th century there has been a division of areas in cities

to control development In the US, in 1916, New York City implemented the first partition (Edington 1977; Buckingham 1996) Environmental zoning has been conducted and according to various methods such as functional zoning in Europe, USA , eco-approach zoning in China, Australia, Brazil, Peru (Minaya, et al 2012), Ecuador, Venezuela, and others (PRHCCSLA 2002), or environmentally sensitive partitions in Malaysia, India (Choo 1997) In 2016, Leman et al conducted an environmental-sensitive area assessment for land use planning in Langkawi, Malaysia The study to assess the environmental sensitivity of Langkawi also uses a multi-criteria evaluation model The set of indicators used in the study include indicators on disaster risks (slope, vegetation, rainfall, seismic ), heritage values and life support indicators The study classified environmental sensitivity into four levels: high, medium, low and non-sensitive (ADB 1991; Fang, et al 2008; Hall 2002)

In Vietnam, there have been many studies on the theoretical basis and methodology

of environmental planning or environmental protection planning, confirming the role of environmental zoning At the provincial scale, our country has about 20 localities studying and developing environmental planning or environmental protection planning At the regional scale, we have environmental planning for the basin of Cau, Nhue - Day and Dong Nai river systems by 2015 and orientations to 2020, the Hong River Delta environmental planning Most of these plans have adopted an integrated, systematic approach and are aimed at sustainable development

Thua Thien Hue is the southernmost province in the North Central Coast region, on the North-South road transport axis and the East-West corridor axis linking Thailand - Laos

- Vietnam along the 9th road The province's economy is growing well, the average annual economic growth rate in the period 2000 - 2018 reached 8.8% The economic structure has been shifted towards increasing the proportion of the service sector, reducing the proportion

of agriculture GDP in the province per capita in 2018 reached US $ 1,793 / person Total state budget revenue is 7,236 billion Dong (TTHO 2019) In addition to economic achievements, resource degradation and environmental pollution are taking place particularly in production areas and urban areas One of the causes of the above problem is that Thua Thien Hue has not implemented the planning of economic development spaces associated with environmental protection To elaborate on an environmental protection plan which contains contents of environmental partitioning necessary to delimit territorial space into areas for natural and environmental conservation and restoration; give priority to development ensure the sustainable development of the economy and society

2 Methodology

2.1 Principles and criteria of zoning

- Principles of environmental zoning: Environmental zoning in Thua Thien Hue follows

the principles: (1) Respect the objectivity of the region, (2) Accept the relative homogeneity

of the region, (3) In accordance with the nature of the region, (4) In accordance with the management method (Dang 2017)

- Criteria of environmental zoning: Environmental zoning is based on natural factors,

people's livelihood and environmental status Natural factors include geographical location, geology, topography, land cover, hydrology, and creatures Group of livelihood factors including living, production activities (agriculture, industry, services), urbanization process, etc

2.2 Data collection and processing

- Method of collecting, analyzing, synthesizing documents: Collecting,

systematizing, analyzing and comparing documents on environmental zoning, including theoretical documents on environmental zoning, figures and data on natural, socio-economic characteristics, environmental status, climate change, development plans of Thua Thien Hue Province provided by some offices and departments

- Field word study: The work of field survey aims to verify information related to

environmental zoning; in addition, it also aims to collect and supplement new documents and data from province and districts departments Field routes include: Batch 1: Along the coast from Phong Dien to Lang Co; Batch 2: From downstream to upstream of Huong River; Batch 3: Follow the Ho Chi Minh road; Batch 4: From Hue city along National Highway 1A

to Bach Ma The subjects of survey include natural characteristics, natural resources, current status of natural resource exploitation and current protection of natural resources and environment Socio-economic characteristics which are studied include the status of development of economic sectors (agriculture, industry and services), population distribution, population, settlement, local socio-economic development plan Besides, it also studies problems of resource degradation, environmental pollution, environmental protection, climate change adaptation, and consults experts, management agencies and local people about problems related to environmental zoning

- Map and GWAS methods: The map method was used to analyze the component

maps (maps of topography, soil, vegetation), and edit the environmental zoning map of Thua Thien Hue province The map method gives visual results about objects according to territorial space (Hall 2002)

- Survey of experts: Environmental zoning needs to have comprehensive information

on various fields, it was necessary to consult experts, professional staff of departments’ opinions in order to get the result of zoning and orient reasonable use of resources, protect the environment, and develop economic suitably for each environmental zoning unit

3 Selected study area

3.1 Natural, socio-economic, and environmental characteristics

3.1.1 Natural characteristics

a Geology, minerals: The geological structure of the territory was very diverse,

including 16 stratigraphic units and 7 intrusive magma complexes There are various kinds

of magmatic, metamorphic and sedimentary rocks, accounting for ¾ of the natural area, distributing in the western, southwest and southern mountains of the province Unconsolidated sediments making up 1/4 of the territory areas distribute in the coastal plain

in the East There are 120 mines, mineral spots with 25 different types of minerals discovered

in the territory (PCTTH 2005)

b Topography: Thua Thien Hue has all kinds of terrain from mountains, hills, plains

and coastal areas The mountainous terrain ranges from 250 to 1,800 m, accounting for ¼ of the province's area, and distributing in the west of the territory Hill topography ranges from 10 - 250 m, accounting for ½ of the territory The plain was an abrasive, agglomerated, sandy and lagoon plain with a total area of about 1,400 km2 (PCTTH 2005)

c Climate: The climate was tropical monsoon climate The annual average

temperature was from 23.70C The temperature decreases from the plain to the mountains, the annual average temperature was 24 - 250C in the plains and mounds lower than 100 m;

the temperature drops to 20 - 220C when it rises to 500 - 800 m and to 180C in mountainous areas over 1,000 m Average rainfall over 2,600 mm, some places up to 4,000 mm (Bach Ma, Thua Luu) Average annual rainfall increases gradually from East to West and from North

to South The coastal plain has an average annual rainfall of 2,700 - 2,900 mm; the hilly areas

in the west and the plain from Phu Bai to Truoi have an average annual rainfall of 2,800 - 3,200 mm; in the West of A Luoi - Ngai cave, the average annual rainfall was over 3,400 mm;

In Nam Dong - Bach Ma - Phu Loc, the average annual rainfall was 3,400 - 4,000 mm The rainy season was from September to February of the following year, the rainiest months last from September to December has the highest rainfall (accounting for 30% of the annual rainfall) The average humidity was from 85 to 86% This province was affected by 2 types

of monsoon, the southwest monsoon and the northeast monsoon (Le 2018)

d The river system: The total area of the river basin of the whole province was about

4,200 km2 The density of rivers and streams was from 0.3 - 1 km / km2, in some places 1.5 - 2.5 km / km2 IN the territory of Thua Thien Hue from the North to the South, the main rivers are O Lau, A Sap, Bo, Huong, Nong, Truoi, Cau Hai and Bu Lu Rivers

e Tam Giang - Cau Hai lagoon: Tam Giang - Cau Hai lagoon system has length of 68

km, with the water surface area about 22,000 ha, belonging to 4 districts and 1 town including Phong Dien, Quang Dien, Phu Vang and Phu Loc, and Huong Tra town The lagoon system consists of 4 lagoons connecting with each other, including Tam Giang, Sam,

Ha Trung - Thuy Tu and Cau Hai lagoon Tam Giang Lagoon has a water area of 5,200 ha,

27 km long from O Lau estuary to Huong river estuary, which was open to the sea via Thuan

An estuary Sam lagoon which was a closed lagoon, has an area of 1,520 ha Ha Trung - Thuy

Tu lagoon which was also a closed lagoon, has a water surface of 3,600 ha The Cau Hai Lagoon was the largest one with a water surface of about 11,200 ha, connecting to the sea through Tu Hien estuary Lap An Lagoon (also known as An Cu Lagoon or Lang Co Lagoon) has an area of 1,500 ha, connecting to the sea through Lang Co estuary (PCTTH 2005)

g Soil: There are many types of soils in the plain including sea sandy soil (accounting

for 10% of the natural land area of the whole province), saline soil (accounting for 2.7%), and alluvial soil (accounting for 8.9%) Types of soils in the midlands and mountainous areas include yellow-red feralite (accounting for 66.3%), yellow-brown feralite on ancient alluvium, alluvial soils in the valleys, infertile soils, and inert eroded feralites rocky gravel, and humus feralite soil on mountains… (PCTTH 2005)

h Creature: The vegetation of the rainforest was various with native plants such as

ironwood tree, sindoer, white meranti, etc (Northern legume); Migratory trees such as chestnut, cypress, pines, pines, and southern oil crops the forest cover was about 57.3%, (2018) Due to war and indiscriminate exploitation, forest area was decreasing Rich forests are mainly distributed in the high mountains of the West, Southwest, and Southern territories; the rest are medium and poor forests Besides, newly planted forests are being promoted The natural animals of Thua Thien Hue are plentiful and have high economic value In addition to the common animals in the forest such as monkeys, deers, peacocks,

wild chickens many rare animals have been discovered in Nam Dong, Phu Loc, A Luoi such as elephants, tigers, pheasants, pheasants, flying ferrets, bear dogs

3.1.2 Socio-economic characteristics

a Residential: According to the Statistical Yearbook of Thua Thien Hue Province in

2018, the province's population was about 1,163,608 thousand people, the urban population was 568,552 thousand people, accounting for 48.86% of the population, the rural population was 595,056 thousand people Natural population growth rate was 10.8 ‰ The average population density was 230.23 people/km2 The population was not equally distributed, mainly concentrated in Hue city, towns and townships, in plains and sparsely in rural and mountainous areas In Hue city, the population density was 5,040 people/km2, whereas in

A Luoi district, the population density was 41 people/km2 In terms of ethnic composition, the Kinh majority accounts for the majority of the population Ethnic minorities in Thua Thien Hue include Bru - Van Kieu, Co Tu, Ta Oi, Pa Koh living in the western mountainous region of the province

b Economy

Regarding the size of the economy, the gross domestic product per capita in 2018 reached $ 1,793 In terms of economic structure, the agriculture, forestry and fishery accounted for 11.6%, the service industry accounted for 31.2%, the service accounted for 50.2%, the product taxes minus product subsidies accounts for 7.0%

Regarding agriculture, the area of annual crops was 66,268.4 ha, of which rice area was 54,731.7 ha, accounting for 82.6% of the annual crop area; 4,680.3 ha of vegetable area; 3,269.4 ha of peanut area; 1,943.5 ha of sweet potatoes; 1,643.5 ha of maize The area of perennial crops was 11,523.3 ha, including 8,875.1 ha of perennial industrial trees; fruit trees area was 2,648.2 ha For animal husbandry, in 2018, there were 178,811 pigs; 24,339 cows; buffalo 20,847 children; 9,442 goats; 2,969 thousand poultry; 2,459 beehives; 372 thousand quails; 16 thousand doves (TTHGSO 2019)

In terms of forestry, the forest cover in 2018 was 57.3%, the newly concentrated planted forest area was 6.14 thousand ha; production forest area was 5.84 thousand ha, protective forest area was 0.22 thousand ha, special-use forest area was 0.09 thousand ha The exploited wood output was 585.6 thousand m3; firewood production was 316.65 thousand ster

Regarding industry, the main production sectors include food, beverages and apparel Industrial production index in 2018 reached 108%, ranked 44th out of 63 cities and provinces in the country (the highest position was Ha Tinh at 188.5%, ranked 5th out of 6 regional provinces) The main industrial products are construction materials, beverages and consumer goods, in particular limestone and other calcium Regarding the distribution of points, industrial zones (IPs), the North has Phong Dien, Tu Ha industrial zones, Dong Lam cement; in the South, there is Phu Bai Industrial Zone, Chan May - Lang Co urban economic zone; the West has built Ta Trach, Huong Dien, Binh Dien, A Luoi hydroelectric factories and Nam Dong cement factory

In terms of service activities, total retail sales of goods and consumer services at actual prices in 2018 reached 38,230.7 billion VND, ranked 36th out of 63 provinces and cities

in all over the country (ranked first was Hanoi with 469,502 billion VND); ranked 4th among

6 provinces in the North Central region (Thanh Hoa ranked first with VND 93,734.8 billion)

In 2018, revenue from travel services reached 175 billion VND, from accommodation services 1,606.4 billion VND, from dining 4,765.8 billion VND, from other consumer services 2,000.9 billion VND The tourism sector has outstanding strengths and brings large revenue

to the province

3.1.3 Environmental quality

a The current state of the water environment

- The monitoring points of power of hydrogen parameter of rivers in the whole province are valid to meet the permitted standard according to QCVN 08-MT: 2015/ BTNMT column A1 (6 - 8.5) The pH of the monitoring points on the Huong River system ranges from 6.6 to 6.9; on O Lau, Bo, Truoi and Bu Lu rivers 6.6 - 7.8; in Tam Giang - Cau Hai lagoon from 6.5 - 8.1

- The concentration of Biochemical Oxygen Demand 5 (BOD5) is mostly in the allowed standard of column A1 (4 mg/l) BOD5 concentration of the monitoring points on the Huong River system is from 1.1 to 2.5 mg/l; on O Lau, Bo, Truoi and Bu Lu rivers 1.1 - 3.7, the slot area receives the water source of the frozen factory CP - Phong Dien Industrial Park (symbol NSOL6) with BOD5 content up to 11 mg/l; In the downstream area of Phu Bai river, the Biochemical Oxygen Demand content exceeds the standard (values from 4.8 to 6.6 mg/l)

- COD (Chemical Oxygen Demand) content is mostly in the allowed standard in column A1 (10 mg/l) On Huong River, O Lau River, Bo River, Truoi River, Bu Lu River COD from 90 - 91, some points are beyond the standard such as the location is 1 km Tuan three-way crossroad in the upstream (95 mg/l), NSOL6 (30 mg/l), 1 km downstream of Truoi market (14.4 mg/l), area at the end of Truoi river (at Truoi sluice) (10.4 mg/l), lower area Phu Bai river basin (15.4 mg/l), Phu Tu bridge of Dai Giang river (19.2 mg/l) In Tam Giang - Cau Hai lagoon area, COD ranges from 7.6 to 9.3 mg/l, within the permitted standard limit

- Turbidity in rivers in Thua Thien Hue has many points that exceed the permitted level in column A1, the average turbidity in rivers in Thua Thien Hue is 5.8 mg/l

- The content of TSS (turbidity and suspendid solids) at the monitoring points is within the permitted limit according to the water quality standard in column A1 (20 mg/l) Turbidity and suspendid solids on Huong River is from 4.1 to 11.4 mg/l; on O Lau, Bo, Truoi and Bu Lu rivers, from 2.7 to 11.9 mg/l At the point NSOL6, the TSS content is up to 118.2 mg/l

- Coliform rivers within permissible limit at column A1 (2,500 MPN / 100 ml) such

as Huong River (63 - 830 MPN / 100 ml), O Lau River, Bo River, Truoi and Bu Lu Rivers (10

- 673 MPN)/100 ml), Tam Giang - Cau Hai lagoon (15 - 1,100 MPN/ 100 ml) Some spots with

higher levels of Coliforms are NSOL6 (10,333 MPN/100 ml), Phu Bai River, 500 upstream from the receiving point of Phu Bai Industrial Area (11,000 MPN/100 ml)

b The current state of the air environment

Total of hanging dust (TSP) in urban areas and industrial parks and production facilities exceeds QCVN 05: 2013/BTNMT (national technical regulation on ambient air quality) The level of dust pollution at the points in Hue City includes the Northern Bus Station Area - symbol K1 (482 μg/m3), the South Bus Station - K2 (350 μg/m3), the Pham Van T-junction area Dong and Tung Thien Vuong - K3 (899 μg/m3), Dan Nam Giao - K4 area (192 μg/m3), around Tinh Tam lake - K5 (119 μg/ m3) Phong Dien District: At the junction of National Highway 1A and Provincial Highway 6 of Phong Dien Town - K7 (170.6 μg/m3), around Dong Lam Cement Plant - K23 (154.5 μg/m3), residential area residing on provincial road No 6 north of Phong Dien industrial area - K24 (163.6 μg/m3) Phu Vang District: Residential area of Thuan An town - K9 (132.6 μg/m3) Huong Thuy district: Cultural area

of Huong Thuy town - K10 (138.88 μg/m3), the intersection of Da Le street and Hue bypass

- K21 (1,689 μg/m3), area near Phu Bai industrial area and Phu Ba Airport - K26 (103 μg/m3) Nam Dong District: Residential area of Khe Tre Town - K14 (972 μg/m3) Quang Dien district: Residential area of Sia town - K15 (136 μg/m3) Huong Tra District: Tu Ha Town Residential Area - K8 (166.7 μg / m3), Tu Ha Industrial area - K19 (471.8 μg / m3), Oxi - Nito

Tu Ha Factory, conveyor area Luks - K20 cement limestone (483 μg / m3), Phu Loc District: Chan May Lang Co area - K11 (116 μg / m3), Lang Co town residential area - K12 (221 μg /

m3), area around La Son industrial area - K18 (225.6 μg / m3) (CNNREM 2018)

Content of Nitro dioxide and Sulfur dioxide at monitoring locations in Thua Thien Hue is within the limit of QCVN 05: 2013 / BTNMT

c The environment in industrial area and industrial clusters

The environmental components around industrial area and clusters tend to be polluted When the wastewater of industrial area and clusters have not yet been treated or processing not yet achieved, it is discharged directly into receiving sources, thus polluting the surface water The amount of solid waste is increasing, but the problem of collection and treatment of solid waste is still inadequate The management, transportation and registration of hazardous waste generators in facilities has not been focused Boilers and incinerators have almost no treatment system to discharge smoke and dust to pollute the air environment

4 Results

In Thua Thien Hue province, the hydrological system, which is the dominant factor, divides the territory into 6 environmental regions corresponding to 6 major river basins of the province The regions are divided into sub-regions based on the dominant element of typographic hierarchy (mountainous areas with elevations from 250 to 1,800 m, hilly areas with elevations between 10 and 250 m, and low plains of under 10 m) The system of environmental zones and sub-regions is divided into (figure 1, 2)

I Environmental region of O Lau river basin

I.A Environmental sub-region in the upstream of O Lau river

- Characteristics of the sub region

Environmental sub region covers an area of 120.54 km2 The low mountainous terrain has height of 250 - 750 m, there are some places in the West above 750 m high, with

a slope of more than 25 The main soil types of the sub-region including pale yellow soil on sandy rock with 101.73 km2, accounting for 84.4% of the sub-region's land, red-yellow loam

on metamorphic rocks (10.21 km2 area, accounting for 8.47% of the sub-region's land), yellow red soil on shale (7.17 km2, accounting for 5.95% of the area) There is also yellow red soil on metamorphic clay (accounting for 1.14% of the area), alluvial soil in streams (0.03%), alluvial soil deposited annually (0.01%) Mechanical components from light meat to heavy meat This area has a small population (population density of 60 people / km2) This area is watershed protection forest, mainly special-use forest land (area of 120.17 km2, accounting for 99.69% of the total area); protective forest land (0.21 km2, accounting for 0.17% of the area); production forest land (0.16 km2, accounting for 0.13%)

- Environmental functions of the sub-region

The main environmental functions of the sub-region include biodiversity conservation in Phong Dien Nature Preservation zone; watershed protection function; water regulation in Hoa My irrigation lake

- Environmental problems of the sub-region can be listed as the decrease of forest area;

risk of soil erosion and degradation

- Socio-economic sustainable development solutions for the sub-region

Strictly protect Phong Dien natural preservation zone; planting and protecting special-use and protection forests; development of production forests; erosion control

I.B Environmental sub-region in the middle hill of O Lau river

- Characteristics of the sub region

Environmental sub region covers an area of 288.44 km2 The hill has the shape of a bowl face down, flat top, gentle slopes (5 - 150) Soils occupying the largest area of the sub-region include light yellow soil on sandy rocks (area of 181.94 km2, accounting for 63.08%

of the total area of the sub-region), yellow red soil on clay shale (82.47 km2, accounting for 28.59% of the area) In addition, there also have alluvial soil without accretion (accounting for 2.16% of the area), alluvial soil deposited annually (1.78%), white sand dune (1.57%), water surface (1.07%), alluvial soil with red-yellow variegated soil (0.94%), alluvial soil in streams (0.39%), sea sandy soil (0.25%), alluvial soil covered with sea sand (0.18%) Soil composition is from light to medium meat, sand, mixed sand The population density of this area is 90 people/km2 The main economic activity is agricultural and forestry production with 128.72 km2 special-use forest land, accounting for 44.63% of the total land use area of the whole sub-region Production forest land is 75.13 km2, accounting for 26.05% of the area; protective forest land is 23.7 km2, accounting for 8.22% of the area; land for planting perennial trees is 20.8 km2, accounting for 7.21% of the area Other land use types include

water surface (occupying 4.36% of the area), unused land (3.24%), residential land (2.25%), another annual cropland (1.45%), rice cultivation land (1.39%), special purpose land (1.06%), aquaculture land (0.11%), another agricultural land (0.03%)

- The environmental functions of the sub-region are to conserve the biodiversity of

Phong Dien nature conservation zone; provide space for developing forestry-agricultural production; rural accommodation; provide resources and space for industrial development (providing minerals for construction materials, mainly sand and gravel); solid waste container

- The environmental problems of the sub-region are the decrease of forest resources due

to over-exploitation Besides, due to loss of vegetation cover and unreasonable cultivation, the land is eroded and degraded

- Socio-economic sustainable development solutions for the sub-region: Protecting

biodiversity in Phong Dien Nature Preservation zone; planting and protecting protection forests; planting production forests; prevent soil erosion; solving the problem of centralized collection and treatment of domestic wastewater; building solid waste treatment facilities; developing tourism; developing agriculture, mainly focusing on crops with the advantage

of perennial crops and fruit trees; construction of industrial parks and industrial clusters

I.C Environmental sub-region in the lower delta of O Lau river

- Characteristics of the sub region

Environmental sub region covers an area of 186.55 km2 The delta has the height less than 15 m Types of land occupying the largest area of the sub-region includes white sand dune 105.83 km2, accounting for 56.73% of the land area of the whole sub-region; alluvial soil covered with sea sand 17.94 km2, accounting for 9.62%, sea sandy soil 15.36 km2, accounting for 8.23% There are also other types of soil such as gleyic fluvisols (accounting for 7.82%), water surface (6.48%), alluvial soil without accretion (5.06%), acid sulphate soil operating deep, medium salinity (4.04%), alluvial soils with red and yellow variegated layers (1.15%), average saline soils (0.84%), high saline soils (0.03%) Mechanical components include sand, sand mixed, and light to medium meat Population density of 99 people/km2 Economic activities are mainly agricultural and aquatic production Regarding the current land use status of the sub-region, production forest land is 41.89 km2, accounting for 22.46% of the total land use area; rice cultivation land is 33.51 km2, accounting for 17.96%; special purpose land is 25.73 km2, accounting for 13.79%; water surface is 20.55 km2, accounting for 11.02%; unused land is 17.2 km2, accounting for 9.22% Other land use types include residential land (occupying 8.16% of the area), protective forest land (7.89%), another annual cropland (5.23%), aquaculture land (2.32%), land for planting perennial trees (1.73%), special-use forest land (0.21%), another agricultural land (0.02%)

- Environmental function of the sub-region: Rural residence; providing space for agricultural development (wet rice, vegetables, aquaculture)

- Environmental issues of the sub-region: Flood risk; pollution risk from living and production activities

- Socio-economic sustainable development solutions for the sub-region: Priority in aquaculture development; developing small handicraft production places

II Environmental areas of A Sap river basin and upstream of Dakrong river II.A The mountainous environmental sub-region of the upstream A Sap river

- Characteristics of the sub region

Environmental sub region covers an area of 389.35 km2 Average mountain terrain has height between 500 and 1,800 m Types of soil occupying the largest area of the sub-region include reddish yellow soil on metamorphic clay is 288.18 km2, accounting for 74.02%

of the sub-region's land area, red yellow humus on acid magma rocks is 33.6 km2, accounting for 8.63% There is also red yellow soil on acid magma rock (accounting for 6.12% of the sub region’s area), red yellow loam on metamorphic rocks (accounting for 5.76%), yellow-red soil on shale (3.18%), yellow-brown soil on ancient alluvial (2.04%), water surface (0.26%) The population is sparsely distributed with a population density of 30 people/km2 The main economic activity is forestry Regarding the current land use status of the sub-region, production forest land is 172.22 km2, accounting for 44.23% of the total land use area of the sub-region, protective forest land 116.25 km2, accounting for 29.86%; special-use forest land 46.52 km2, accounting for 11.95% of the area Other land use types include unused land (accounting for 7.25% of the area), land for planting perennial trees (2.06%), special purpose land (1.74%), rocky mountains without trees (1.15%), rice cultivation land (0.55%), residential land (0.49%), another annual cropland (0.45%), water surface (0.25%), aquaculture land (0.02%)

- The environmental function of the sub-region is to conserve biodiversity; regulate the flow; rural mountainous areas; providing mineral resources, timber, firewood, and forestry products

- The environmental problems of the sub-region are the risk of declining watershed areas due to unreasonable exploitation of human beings

- Socio-economic sustainable development solutions for the sub-region: Planting, protecting and restorating special-use forests and protection forests; developing production forests; improving the material and spiritual life of rural people; developing ecotourism

II.B Environmental sub-region of A Sap river valley

- Characteristics of the sub region: Environmental sub region covers an area of 97.26

km2 The topography has height from 250 - 750 m Types of soil occupying the largest area

of the sub-region include yellow-brown soil on ancient alluvial soil is 52.93 km2, accounting for 54.42% of the sub-region land area; yellow red soil on metamorphic clay is 38.98 km2, accounting for 40.08% There is also red yellow soil on acid magma rock (accounting for 2.69% of the sub-region land area), yellow-red soil on shale (1.95%), water surface (0.82%), red yellow humus on acid magma rocks (0.03%) The population density is 50 people/km2,

and A Luoi town is the urban area of the sub-region Main economic activities are agriculture and forestry production Regarding the current land use status of the sub-region, production forest land is 39.22 km2, accounting for 40.32% of the total land use area of the sub-region; residential land is 16.43 km2, accounting for 16.89%; special purpose land is 12.05

km2, accounting for 12.39%; rice cultivation land is 10.49 km2, accounting for 10.79% Other land use types include another annual cropland (accounting for 6.63% of the whole sub-region), land for planting perennial trees (6.32%), unused land (2.49%), water surface (2.27%), protective forest land (1.58%), aquaculture land (0.29%), special-use forest land (0.01%), another agricultural land (0.01%)

- Environmental functions of the sub-region include: Conservation biodiversity; rural

accommodation; providing resources and space for agricultural production and handicraft; providing mineral resources, timber, firewood, and forestry products; regulating water for reservoir

- Environmental problems of the sub-region can be mentioned are landslides, especially

along the Ho Chi Minh road corridor passing through A Luoi district, flash floods along rivers and streams threaten the safety of mountainous residential areas The problem of dioxin toxins left behind after the war in A Luoi airport area so far has not completely solved all the dangers

- Socio-economic sustainable development solutions for the sub-region: Planting and

protecting special-use forests and protection forests; conservation biodiversity; developing production forests; preventing soil erosion; protecting and renovating population roads and spots at risk of landslides and flash floods; developing A Luoi town to become an economic, political and cultural center of the region; implementing new rural construction; developing eco-tourism; developing agriculture with models of long-term industrial crops and fruit trees along the direction of commodity production and rice cultivation to meet local needs

II.C Environmental sub-region in the upstream of Dakrong river

- Characteristics of the sub region:

Environmental sub region covers an area of 115.85 km2 The mountainous terrain has height from 250 to 750 m Types of soil occupying the largest area of the sub-region include yellow red soil on metamorphic clay is 68.05 km2, accounting for 58.74% of the sub-region land area; yellow-red soil on shale is 39.39 km2, accounting for 34% There is also red-yellow loam on metamorphic rocks (accounting for 4.57% of the sub-region land area), red yellow humus on acid magma rocks (2.01 red yellow soil on acid magma rock (0.65%), light yellow soil on sandstone (0.03%) The population density is 38 people/km2 Main economic activities are forestry production and agriculture Regarding the current land use status of the sub-region, special-use forest land is 38.72 km2, accounting for 33.42% % of the total land use area of the sub-region; production forest land is 38.14 km2, accounting for 32.92%; unused land is 29.61 km2, accounting for 25.56% Other land use types include protective forest land (accounting for 3.96%), another annual cropland (1.79%), land for planting

perennial trees (1.11%), residential land (0.69%), rice cultivation land (0.35%), water surface (0.17%), special purpose land (0.02%)

- Environmental function of the sub-region: Preserving biodiversity

- Environmental issues of the sub-region: The risk of deforestation due to overexploitation activities of human beings

- Socio-economic sustainable development solutions for the sub-region: Watershed protection

III The environmental region of Bo river’s basin

III.A Mountain environment sub-region of Bo river’s upstream

- Characteristics of the subregion

Environmental sub region covers an area of 400.35 km2 The topography of the region is from 250 to 900 m in height The soils occupying the largest area of the sub-region include red-yellow soil on metamorphic clay 211.18 km2, accounting for 52.75% of the total area of the sub-region; red yellow soil on acid magma rock is 69.94 km2, accounting for 17.47%; yellow-red soil on shale 56.83 km2, accounting for 14.2%; light yellow soil on sandstone is 37.16 km2, accounting for 9.28% Besides, there are also other soils including red yellow humus on acid magma rocks (accounting for 4.02% of the sub-region land area), yellow-brown soil on ancient alluvial (1.3%), red yellow humus on metamorphic rocks (0.9%), water surface (0.08%) Population density is 90 - 95 people/km2 Economic activities

sub-of the resident are mainly agriculture and forestry About status sub-of using the current land sub-of the sub-region, special-use forest land 188.38 km2, accounting for 47.05% of the total land-use area of the sub-region, protective forest land is 96.02 km2, accounting for 23.98%; production forest land is 77.58 km2, accounting for 19.38% In addition, the sub-region also has other annual cropland (accounting for 5.08% of the area), unused land (1.55%), special purpose land (0.83%), rice cultivation land (0.77%), land for planting perennial trees (0.7%), water surface (0.33), residential land (0.32%)

- Environmental functions of the sub-region: Biodiversity conservation; supplying wood, firewood and other forest products; rural accommodation

- Environmental issues of the sub-region: Forest area degradation due to unreasonable exploitation

- Socio-economic sustainable development solutions for the sub-region: Protection and restoration of special-using forests and protection forests; planting production forests; biodiversity conservation; erosion control; building a new countryside; eco-tourism development

III.B The environmental sub-region of Bo river’s middle hill

- Characteristics of the sub-region

Environmental sub region covers an area of 427.98 km2 The terrain has an altitude

of 15 to 250m The soils occupying the largest area of the sub-region include yellow-red soil