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Terraced Fields and Natural Disasters in Nepal -- An Fuyusawa

Terraced Fields and Natural Disasters in Nepal


The Himalayas are the dreams of climbers and trekkers the world over. Nepal is a gateway to the Himalayas. The mountains in Nepal are covered with terraced fields that appear to reach the sky.

Though Nepal has only a fourth the area of Japan, it has various climates because of its wide range of altitudes. Thus, the Nepalese people's lifestyles are also diverse.

However, a big change has been taking place in Nepal since the middle of the 20th century: extensive deforestation.

The Scheme of the Himalayas

In the Himalayas, deforestation became increasingly severe as the population grew, causing a higher frequency of natural disasters such as landslides. Consequently, earth and sand flowed into the Ganges, raising the riverbed in Bangladesh in the lower Ganges, and hence floods became more frequent in Bangladesh. This is the outline of "The scheme of the Himalayas." I first heard this more than 20 years ago.

You can see an instance of this hypothesis if you fly from Bangkok to Katmandu. On one such flight, as we passed above Bangladesh, I spotted many large sandbanks along the Ganges. In addition, around the border between India and Nepal, I saw that mud had flooded and covered the valleys. As the aircraft descended in its approach to the airport, I could see terraced fields on the mountains around Katmandu Valley, whose several sides were collapsed because of landslides.

In this way, the hypothesis that deforestation in the Himalayas caused floods in Bangladesh was proved. It is natural that many journalists and the mass media, such as NHK (Japan Broadcasting Corporation), have informed people about what has been going on in the Himalayas as a good example of environmental destruction in developing countries. Prof. Yugo Ono of Hokkaido University well explains this hypothesis in Fig. 1.

However, Jack D. Ives of the University of California and Bruno Messerli of Switzerland opposed this common sense in a 1989 book entitled The Himalayan Dilemma: Reconciling Development and Conservation. In this book, they insisted that: 1. Population growth is remarkable in urban areas like Katmandu or in the lowlands, while it is not very notable in the Himalayas. 2. Most of the terraced fields were cultivated by Tibetans who emigrated from the north in the 13th century, so the number of terraced fields hasn't increased drastically in these several centuries. 3. Those who live in the mountains use the forests sustainably, so the extent of the deforestation is not very serious. Rather, campfires by trekkers are more likely to damage the environment than is deforestation.

Well, how can we explain what I saw on the way from Bangkok to Katmandu? We have seen deforestation and natural disasters on TV and in print. Were they just illusions? Our group investigated in the field four times from 1998 to 2000.

Climate in Nepal

Though Japan's land mass is small, its span from north to south is vast. This span gives it a range of climates, from the cold-temperature zone of Hokkaido in the north to the subtropical zone of Okinawa in the south. Nepal is just one-fourth the size Japan, but the climate is as varied as Japan's because of its range of altitudes. Terai Plain, which is near India, is about 100 m above sea level and belongs to the tropical zone. But a mere 150 km north of Terai Plain, the Great Himalayas rise to about 8000 m above sea level. The Great Himalayas belong to the alpine zone, and their climate is similar to that of the Arctic or Antarctica. The climate in the areas between the Great Himalayas and Terai Plain, such as the Siwalik and Mahabharat ranges, also varies according to elevation.

Climatic diversity is related to where certain tribes live. Indians dominate the plain, while both Indo-Aryan Hindus and Tibeto-Burman Buddhists prevail in the Siwalik and Mahabharat ranges. However, most of those who live in the upper mountains are Tibetans. I think Hindus, who are originally from hot areas, can't bear the cold mountainous climate. Jiro Kawakita, who has worked in Nepal as his research field, indicates that Hindus, for whom bathing is a religious custom, can't bear to live in mountains where it is cold and water is not easily obtained, while Tibetans, who are used to cold weather and don't place a similar emphasis on bathing, find themselves well suited to life in the Himalayas (Fig. 2).

Flying to Pokhara

Pokhara, which lies at the foot of Mt. Annapurna, is Nepal's second-largest city. Many Japanese visit Pokhara to see the Himalayas. Old, small airplanes carry people from Katmandu to Pokhara. Signs inside the aircraft are written in different languages--I think the Nepalese must have collected used airplanes from all over the world.

On sunny days, you can see Mt. Himalchuri and Mt. Manaslu on your right side. The series of mountains known as the Great Himalayas stands from Mt. Everest in the northeast of Katmandu, to Mt. Manaslu, Mt. Annapurna, Mt. Dhaulagiri in Nepal, and then to Mt. Nanda Devi in India and K2 in Karakorum (Photo 2).

There is another series of mountains, standing 2000-4000 m above sea level, to the south of the Great Himalayas. This series is called the Lesser Himalayas, or the Mahabharat Range. The Lesser Himalayas seem to be just bare, reddish-brown mountains, but if you look carefully, you'll see narrow terraced fields running from the bottom of the valley to the top of the mountains. Several villages, each with some dozens of farmhouses, are scattered round the mountainsides. There are no water sources at the tops of the mountains. Moreover, underground water can't be saved because there are no forests. Therefore, people have only rainwater with which to cultivate the fields.

Rice terraces can be found on mountains in countries that are hit by monsoons, including Japan, southern China, the Philippines and Indonesia. But most rice terraces are irrigated. On the other hand, terraced fields in Nepal are cultivated only with rainwater, since a lot of rain falls there. Warm and humid wind from the Indian Ocean strikes the mountains around Pokhara and changes to rain. As a consequence, the annual precipitation of this area is about 4000 mm, which is two to three times that of Japan. Precipitation is especially high in the rainy season, which is from May to September.

Terraced Fields in Pokhara

Pokhara Valley has the same latitude as Okinawa. The altitude is as low as 800 m, so it is warm even in winter. A lot of trekkers visit the Pokhara Plain. One of the popular and easy trekking routes starts from Phedi Village in the north side of Pokhara. Hikers walk along the ridge, reach Dhampus Village, whose altitude is 1800 m, and come back to Phedi. This is a two-day route. When you look up the mountain from the valley in the east of Dhampus, you'll see terraced fields that stretch for about 800 m from the bottom of the valley to the ridge.

In the lower part of the mountain, there are rice fields called 'khet.' The khets include rice fields in the lowlands around rivers and rice terraces on the upper slopes. In winter, corn, wheat and rapes are cultivated as secondary crops in khets. Many other rice fields are not used during the winter. Rapes are cultivated in higher-altitude rice fields rather than in fields in the lower valley. This is probably because the middle of the mountainside is warmer than the bottom of the valley is.

There are contradicting opinions about secondary crops. Some say, "Because of the increase in secondary crop cultivation, livestock (water buffalo and sheep) cannot be pastured, so the amount of excretion has decreased. Consequently, the soil became poor." Others say, "Secondary crop cultivation has decreased because of a lack of workers." For as long as we were there to observe, secondary crop cultivation seemed to decrease.

There are villages on the upper sides of khets. Villages were built in the middle of a side to avoid flooding and malaria infection. Old villages are found on mountaintops also in Italy and Spain for the same reason. On the other hand, most of the new villages built as the population grew are in the lowlands. I saw such new villages damaged by mud floods. I remembered that when I once observed the influence of mud floods that had occurred in Nagano Prefecture, central Japan, I found new villages severely damaged while old villages were less damaged. I learned that referring to past natural disasters is important in preventing calamities.

On the upper sides of the villages, there is a type of terraced field called a 'pakho.' Corn and millet are cultivated in pakhos. In areas higher than 2000 m above sea level, corn cultivation has given way to millet and potato farming. People conduct single cropping in most of the pakhos, but double cropping is also conducted in some of these fields.

On the upper sides of the pakhos, there are fields of a type called 'khoriya,' in which crops are rotated. In one khoriya, millet is cultivated once every 3-5 years, and the field is fallow in the other years. This is said to be a relic of slash-and-burn agriculture from olden times. I also found khoriyas in the sides far from villages. Since khoriyas are not very productive, most of them were abandoned during the First World War because of a lack of workers. Few khoriyas remain today (Adhikari, 1996). However, according to Minami (2000), large-scale slash-and-burn agriculture is done every year by the Magar and Chepang tribes in areas of 500-1500 m altitude in the Mahabharat Range.

Since most of the farmhouses are in the middle of the mountains, farmers have to climb several hundred meters to cultivate their fields. We sometimes saw farmers climbing in rubber flip-flops sandals, with large baskets strapped to their backs, while heavily equipped trekkers walked on the same route. Many trekkers hire porters to carry their baggage and most of the porters also walk in rubber flip-flops. When I talked with a girl who had walked from a part of Mt. Everest, she said she could easily walk to Tibet through a pass at 6000 m altitude wearing the rubber flip-flops, so walking up for several hundred meters doesn't constitute a 'climb' to the residents of these mountains.


The forest area in Nepal continues to decrease. It was 45% of the total area of Nepal in the 1960s, but this ratio decreased to 37.4% by 1980 and is now only 29%. This compares with 66.2% in Japan and 66% in Bhutan, a neighbor of Nepal.

Most of the fuel used in Nepal-in fact, an estimated 75% of it--is wood. Propane is also used in Katmandu, but wood alone fuels most farm villages. Charcoal, on the other hand, is hardly used.

When we compare the ratios of forest area lumbered per unit of forest area among Asian countries, we see that Nepal has the fourth-highest deforestation rate, after Bangladesh, Pakistan and India. Moreover, the ratio of the amount of wood used as fuel to the total amount of wood lumbered is second-highest in Nepal, lower only than Bangladesh. These facts indicate that excessive deforestation is done to obtain fuel in Nepal (Fig. 3).

Wood is used mostly for cooking. Nepalese barely use wood for heat, even on severely cold days. I think people in villages in the higher mountains use fireplaces, but I haven't confirmed this yet.

Raksi is a typical Nepalese liqueur. Especially people in the higher mountains seem to drink raksi often, because of the cold climate. Raksi is made from millet such as barnyard grasses. Large amounts of wood are used to produce raksi: Almost 500 kg of firewood is needed in order to turn 100 kg of millets into raksi. Raksi provides important revenue for the Gurung and Sherpa tribes who live in the mountains. However, I have heard that some Hindus have negative feelings against such Tibetan tribes who sell raksi.

The rate of decrease of forest areas depends on the area. The forest area decreased 5.7% between 1964 and 1978 in Nepal as a whole. However, it decreased 15.5% in the Siwalik Range during the same period, and was 24.4% in the Terai Plain. On the other hand, the forest area increased 1.8% in the Mahabharat Range.

The forest area is said to have decreased at an even faster rate in the 1980s. In Terai Plain, 60% of forests was lost. According to Jiro Kawakita, the concept of forests differs between Indo-Aryans and Tibeto-Burmans. While Indo-Aryans regard forests as an object of exploitation, Tibeto-Burmans have a tradition of using forests sustainably. Such a difference seems to be reflected in the varying degrees of forest destruction depending on the area. When the natural regeneration rate and lumbering rate are compared, we see that the lumbering rate is higher than the regeneration rate in the Terai Plain and Katmandu, indicating that deforestation in these areas is severe (Fig. 4). In the Terai Plain, agricultural development was conducted to eradicate malaria. Moreover, population growth has been remarkable in this area. Indians and poor farmers have immigrated here. In addition, many Nepalese, who had lived in Bhutan for a long time, escaped from Bhutan and came back to Nepal as refugees because of political conflicts. Muslims persecuted in India have also emigrated to this area.

Many immigrants live illegally in places other than settlements established by the government. I found many huts built on dry riverbeds near Bhairawa. Moreover, these illegal settlers pioneer the destruction of the forests to make fields. This is another major cause of deforestation.

(This report is continued in the next issue.)

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