Republica: Monsoon rain patterns in South Asia including Nepal are fast changing. There are many examples of longer dry spells and shorter sudden heavy showers, replacing the three month continuous rain which has characterized Nepali monsoon. The rainfall pattern is inconsistent with higher intensities of rain and less number of rainy days creating long drought for some time and heavy rain in some other periods. This is a challenge for policymakers and for the farmers to cope with.
Intensive farming in lands reclaimed from all types of forests, industrialization and other man-made factors, such as settlement and road construction, have affected the monsoon patterns. As of now, the monsoon rain for this season has already delayed by 15 days and this will certainly have a negative effect on crop production, particularly rice. Last year, the monsoon rain was timely, well distributed and adequate and as a result rice yield was good.
The southwest summer monsoon is attracted to Nepal by a low pressure area that is caused by the extreme heat of the Thar Desert in Rajasthan, India and adjoining areas, during summer. Moisture-laden winds from the Indian Ocean come to fill up the void, but because they can’t pass through the Himalayan region, they are forced to rise. The gain in altitude of the clouds results in a drop in temperature, bringing about rain.
When the southwest monsoon reaches India, it splits into two parts around the mountainous region of the Western Ghats in south-central India. One part moves northwards over the Arabian Sea and up the coastal side of the Western Ghats. The other flows over the Bay of Bengal, up through Assam hitting the Eastern Himalayan range including Nepal.
The average annual rainfall in Nepal is 1800 mm. The monsoon rain is more in east and declines as it moves west. Nepal is vulnerable to climate change given the complex topography and low level of development of protection mechanism. The ongoing climate change and alterations projected to occur are likely to have impacts on different sectors, some more severe than others. The sensitive sectors are agriculture, forestry, water and energy, health, infrastructure, tourism, industry and overall livelihoods and economy.
Monsoon rains affect Nepali agriculture in many ways. Since only limited land has all-year-round irrigation facilities, the first effect is on crop production. A late or erratic monsoon causes losses of crops and ultimately results in food insecurity. The production of cereal, pulses, vegetables, and fruits is reduced due to changes in the climate particularly due to longer drought and erratic rain. This situation makes the agriculture sector one of the most vulnerable to climate change in Nepal. Farmers are witnessing heavier and more erratic rainfall during the monsoon period, flooding their rice fields as a result. These extreme weather changes put a lot of stress on farmers’ already fragile livelihoods.
Furthermore, erratic rainfall in the recent years has resulted in more landslides and erosions in the hills and mountains. Top soils, which are considered very fertile because farmers treat these soils every year with compost manure, are lost due to erosion. Therefore, soil loss is a major cause of decline in agriculture production in the hills and its effects is negative particularly in crop yield.
Incessant rains in the eastern parts of Nepal in 2008 led to rise in water level of Koshi River early in the monsoon season. Water level had reached 167,000 cusec in August 18, 2008 leading to breaking of embankments and heavy flooding in many villages of eastern Nepal and neighboring Bihar in India. At least 60,000 people lost their homes and fertile lands in the flood. Not to this extent, but many houses, standing crops and fertilizer lands are lost every year due to flooding and landslides in other parts of the country.
The increasing failure of the monsoon has been attributed to a number of factors including temperatures rising by an average 0.5 degrees Celsius over the last 100 years, receding Himalayan glaciers and rising sea levels. Changes in hydrological cycles have taken place and the depletion of water resources are the top challenges Nepal faces in context of climate change. Flood-induced river cutting and deposition of sand and gravel in agricultural field have become a severe problem in many districts of Tarai.
Coping strategies and adaptation mechanism are essential to address this challenging issue. Short term, mid-term and long term measures need to be taken. Use of alternative crops and varieties, rain water harvesting, conservation of water resources, changing cropping patterns, and shift from agriculture to forestry and animal husbandry are some of the short term measures. Changing rainfall patterns have forced farmers to adopt short-ripen rice varieties instead of local long season varieties like: Samamansuli, Mansuli, Basmati and Kala nimak, Aanadi etc. In some areas, farmers have adopted vegetable farming, fruit growing, agro-forestry and bagar farming of groundnut/peanut as an alternative to cereals.
The mid-term measures are capacity building at the government and community level, continuous development of new technologies and crop varieties suitable for changing conditions and income diversification. The long term measures can be reforestation, soil erosion control, soil fertility maintenance, and landslide and flood control.
Started in year 2010, ‘Climate Himalaya’ initiative has been working on Mountains and Climate linked issues in the Himalayan region of South Asia. In the last five years this knowledge sharing portal has become one of the important references for the governments, research institutions, civil society groups and international agencies, those have work and interest in the Himalayas. The Climate Himalaya team innovates on knowledge sharing, capacity building and climatic adaptation aspects in its focus countries like Bhutan, India, Nepal and Pakistan. Climate Himalaya’s thematic areas of work are mountain ecosystem, water, forest and livelihood. Read>>