Diversity in ecological, climatic, topographical and land features
Vietnam is located in the Indochinese peninsula, borders China to the north, Laos to the northwest, Cambodia to the southwest and Southeast Asia Sea to the east. The country’s total area is over 330,000 km2, of which 3/4 are mountains and hilly lands. Spanning over 15° parallel, from 8°30´N to 23°22´N, Vietnam has highly diverse topographical and climatic features. In general, the country has a tropical monsoon climate, with the annual average temperature of c.23oC, the sunshine time of around 2.300 h/year, the rainfall ranging between 1500-2000 mm/year, solar radiation varying among 100 – 130 Kcal/cm2/year and humidity between 75-90%. However these figures vary greatly from regions to regions and depend much on both the parallel and altitude.
Figure 1: Ecological regions of Vietnam inland territory Administratively the country’s inland area is divided into 59 provinces and 5 cities under the Central Government, but ecologically its inlands can be divided into 8 different regions: Northeast, Northwest, Red River Delta, North Central Coast, South Central Coast, Central Highlands, Southeast and Mekong River Delta (Figure 1). Each of these regions is characterized with specific natural conditions and cultural conditions.
Both North East and North West regions are characterized with complicated topography created by high and rugged mountains with the country's highest peak of Fan Si Pan of 3,142 meters. Over 85% of the land areas in these regions are sloping, of which 62% are with slope of over 25o, 16% with slopes of 15 – 25o. The climate is subtropical with 4 distinct seasons (spring, summer, autumn and winter). In the higher mountainous areas of these regions (Dien Bien, Lao Cai, Yen Bai, Son La, Ha Giang, Bac Kan, Lai Chau, Son La, Cao Bang, Tuyen Quang and part of Hoa Binh provinces), the winter can be very cold, and the climate is suitable for both temperate and subtropical plants (fruits, vegetables, flowers, timbers). In these regions, on hilly sides annual food crops (maize, cassava, upland rice) are produced while in flat lands scattered in valleys or small plains wet-rice are cultivated intensively. There are also large land areas allocated for planting forests where different timber species are produced.
The Red River delta is with subtropical monsoon climate with rather cold and dry winter. The entire delta region is less than three meters, and much of it one meter or less, above the sea level. The land here is fertile with much alluvial deposits brought by various rivers over a period of millennia, and is mainly planted to double-crop of wet-rice. Upland field crops are produced in the 3rd cropping season (in winter, after harvesting of the 2nd rice crop) or in gardens or in warps along rivers. Fruits, mostly subtropical and others (citrus, longan, litchi, banana, papaya, guava...) are planted mainly in home gardens.
The Annamite Range (Truong Son) originates in the Tibetan and Yunnan regions of southwest China, runs North-South along Vietnam's border with Laos and Cambodia. This makes the climatic, soil and topographical features of the North Central Coast specific with very dry and hot summer with foehn wins often blowing through. Both tropical and subtropical plants can be produced in this region; however the drought problem is really problematic. There is a long and big coastal area where crop production faces problems of winds, sands and saline pollution. There are also fertile plains suitable for intensive production of wet rice, vegetables, fruits and tuber/root crops. In the upland and highland areas upland crops, fruits and forest trees are produced.
The South Central Coast is almost hot all the year around, with 2 clearly distinguished seasons, dry and wet, which however do not coincide with the dry and wet seasons in other regions of the country. While in both South and North the summer (or the hot season) is wet, in the Central part summer is very dry. The costal areas face great problems of drought in the dry season and severe flood problems in the wet season. Wet rice, upland crops, fruits, industrial trees and forest plants of different kinds are produced at small scale.
The Central Highlands (Tay Nguyen) is with rugged mountains, extensive forests, and rich soils. Comprising 5 relatively flat plateaus of basalt soil spreading over the provinces of Dak Lak, Gia Lai, and Kon Tom, the highlands account for around 16% of the country's arable land and 22% of its total forested land. The climate here is typically monsoon tropical with 2 distinct seasons: dry and wet. Farming households in these regions are larger-scale compared to those in the above mentioned regions. Industrial trees (rubber, coffee, cotton, pepper, sugarcane) are mainly produced here. Natural forests still exist with rather good quality.
The Southeast region is on average at 100 – 200 m above the sea level and with tropical monsoon climate. Main crops are industrial perennials and annuals (rubber, cacao, pepper, cashew, coconut, sugarcane, soybean, peanut...). There are also orchards with large scale of different tropical fruits. There are also large land areas for planting forests.
The Mekong delta is a low-level plain, less than three meters above the sea level on the average, with many areas lower than 1 m. There are a maze of canals and rivers criss-crossing through. With about 10,000 km2 of rice production area, the delta is one of the major rice-growing regions of the world. The southern tip, known as the Ca Mau Peninsula, or Mui Bai Bung, is covered by dense jungle and mangrove swamps. There are also large areas which are often flooded (for many months or many days in a month) where melaleuca is widely growing. The region also has a typical tropical climate. Farming households in these regions are also larger-scale compared to those in the northern and central part. Main products from this region are rice, aquaculture, and tropical fruits. Commercial orchards in this region are with the largest scale compared to all other regions in the country.
Agriculture, including crop production, agro-forestry, forestry, animal husbandry and aquaculture, according to the Ministry of Agriculture and Rural Development of Vietnam (MARD), has been a mainstay of the economy (MARD, 2009).
Population, ethnicity and farming cultures
The population of Vietnam is currently over 90 mil., and is predicted to reach over 100 mil. in 2015 and 104 mil. people in 2050 (Nguyen Van Tuan, 2013). Population of Vietnam comprises people from 54 ethnic groups. Viet people, also called Kinh, form the largest group representing over 80% of the whole nation’s population. Kinh, Hoa (ethnic Chinese) and Khmer Krom people reside mainly in the country’s alluvial deltas and coastal plains. Other 51 ethnic minorities live mostly in mid- and high- lands. Each of these 54 ethnicities has distinct culture and language, making Vietnam highly diverse in culture and indigenous knowledge.
The country had 450,300 households that suffered from food shortage and the poor household ratio around 11.3-11.5% in 2013 (World Bank, 2013). Poverty is more concentrated in rural areas, where 18% of the population remains poor. Among the poor rural areas of the country, the north-western mountain region has the highest poverty incidence, at 28.55% (MOLISA, 2013). Poverty also remains substantially higher among ethnic minorities (50%) than those of the majority groups (8.5 %). Among the ethnic minority population, food insecurity and hunger are widespread, with nearly 30 percent considered “food poor”.
Thus, Vietnam in highly diverse in terms of ecological, climatic, topographical, land, ethnicity and cultural conditions. In general, farming households in the central and northern regions are with small scale, crops and trees are produced in small plots with area often ranging from some tens to some hundreds of meters square. Further to the south, the scale of households are bigger, plots can be as big as some hectares to some tens of hectares.
In the high mountainous areas: upland annual crops (maize, cassava mainly) and trees (forests, fruits and industrials) are produced in slopping lands, and wet rice in terraces and flat lands scattered in valleys or in small plains. There are also large land areas allocated for planted forests or for forest regeneration. Fruits, subtropical and temperate, are produced in home gardens or slopes near to people houses.
In the midland areas: mostly upland crops (cassava, maize, legumes) and industrial trees (coffee, tea, cashew, pepper, sugarcane...) are produced in plateaus or slopping lands, while rice in plain lands. Planting forests are aimed at the tops of the hills for water resources and soil protection. Fruits are produced in home gardens or field/slopes near people houses.
In the deltas: rice is intensively produced in 2 or 3 cropping seasons. Upland field crops are produced in the 3rd cropping season (after harvesting of the 2nd rice crop) or in gardens or in warps along rivers. Fruits, mostly subtropical and others (citrus, longan, litchi, banana, papaya, guava...) are planted mainly in home gardens. Nowadays, increasing rice land areas are planted to upland crops or fruits due to their higher economic benefits compared to rice. Big orchards and vegetable farms have been formed.
In the costal areas and low-lands frequently flooded with saline water: mangrove or melaleuca are popularly growing and aquaculture or rice production are integrated.
Picture 13: Typical farm landscapes in mountainous regions (a &b), small plains in midland regions (c), Central Highlands (d), costal plains(e), main deltas (f), often flooded areas in the southwest (g), and mangrove forests (h)
Climate change impacts and the needs for transition in agriculture and agro-forestry
Vietnam is among the countries most vulnerable to climate change (IPCC, 2007). According to MONRE (2011), during the past 50 years the sea level rose about 20 cm; and the Mekong Delta is one of the world’s most vulnerable deltas to the sea level rise. Also, as predicted in the climate change scenarios (MONRE, 2011), by the end of this century the sea level in Vietnam can rise 75 cm - 1 m compared to the 1980 -1999 period, and then, about 40% of the Mekong Delta area, 11% of the Red River Delta and 3% of the coastal provinces will be inundated (over 20% of Ho Chi Minh City will be flooded); about 10 - 12% of Vietnam’s total population will be directly impacted and the country will lose around 10% of GDP. Impacts vary widely depending on crops and agroecological regions. The predicted impacts of climate change on crop yields are summarized in Table 1 (World banks, 2010).
Table 1: Potential impacts of climate change on crop yields in Vietnam
Potential impacts of climate change without adaptation
Rice yield declines by 11.1-28.2%; yields of other crops decline by 5.9-23.5 %
Rice yield declines by 4.4-39.%; yields of other crops decline by 2.7-38.3%
Red River Delta
Rice yield declines by 7.2-32.%; yields of other crops decline by 4.1-32.9%
Rice yield declines by 7.2-32.6%; yields of other crops decline by 4.1-32.9%
Rice yield declines by 8.4-27.0%; yields of other crops decline by 4.0-20.9%
Rice yield declines by 11.1-42.0%; yields of other crops decline by 7.5-45.8%
Rice yield increase by 4.3-8.8%; yields of other crops decline by 3.0-22.7%
Mekong River Delta
Rice yield declines by 6.3-12.0%; yields of other crops decline by 3.4-26.5%