Scientific Research

monsoon in Nepal

Monsoon in Nepal

Rocky Talchabhadel
Researcher, Kyoto University
Board Member, S4W-Nepal

The word “Monsoon” comes from the Arabic word “mausim” which translates directly to ‘season’ in English. The monsoon season in Nepal and other parts of Central and Southeast Asia is characterized by a large seasonal shift in wind flow and direction accompanied by a dramatic increase in precipitation. Monsoon can be both boon and bane for inhabitants of this region. Extreme (heavy) precipitation during the monsoon season often results in major water-induced hazards such as floods, landslides, and debris flow. However, the monsoon season is equally important for agriculture and the economy. Lower than average monsoon precipitation, or even simply a later than average start date to the monsoon season, can have a disastrous impact on the nearly 3/4th of the population in Nepal that is dependent on agriculture. The nature of the monsoon precipitation – its amount, temporal variability, intensity, frequency of occurrence, and spatial variation is a major factor affecting agricultural potential. In Nepal between 1968 and the present, the average start and end dates for the summer monsoon are June 10th and September 23rd, respectively. Figure 1 shows the start and end dates, and average duration, during this period.

Figure 1: Monsoon onset (blue squares) and withdrawal (orange circles) and average onset and withdrawal (gray shaded area).

The country receives more than 80% of its annual precipitation during the monsoon season (Shrestha, 2000). Rice is a major food staple in Nepal. The planting of rice normally begins in early May in the hills and in June in the Tarai, the country’s food basket. The monsoon precipitation is directly linked with the growth of this rice crop and the country’s agriculture and in turn, the economy. This year (A.D. 2020) monsoon began in Nepal on the 12th of June. The monsoon season is characterized by not continuous but continual rain for a few days separated by rainless intervals. The long term temporal record of monsoon onset and withdrawal (Figure 1) shows a delayed monsoon withdrawal coupled with either altered or unchanged monsoon onset. The monsoon season is, in general, found to be longer in recent times. On average, six or seven monsoon depressions* (twice per month) move in every year, each corresponding to a period of about 17 days (Nayava, 1980). When the monsoon trough (a large depression) moves closer towards the foothills of Nepal (which we call active break-monsoon), heavy precipitation-related extreme events usually occur in parts, or across the whole, of Nepal. During such extreme precipitation events, floods (river floods, flash floods, urban floods) are likely to occur. The timing of flood/inundation and early warning mechanisms are crucial for effective mitigation of flood risks, along with mapping and understanding of flood-prone areas, which are, to some extent, predictable.

However, landslides and debris flow can sometimes even occur in unexpected areas. A recent example of a landslide followed by a debris flow at Kushma municipality, Parbat on June 13, 2020 highlights this point. The terrain, which never experienced a landslide before, experienced this, followed by a debris flow that was a devastating event affecting lives and property. Figure 2 shows a preliminary assessment of cumulative precipitation derived from hourly precipitation data of a satellite-based product, PERSIANN CCS (spatial resolution, 4 km) and the spatial location of landslide/debris flow before and after the event using Planet Imagery (spatial resolution, 3 m). 

Even a single event with intense precipitation for a short period can bring urban inundation, land/mudslides, or flash flooding. Therefore, it is high time to map potential hazards and prepare for worst-case scenarios. You can’t manage what you don’t measure.  Citizen-science based precipitation measurements can be used as a reference to calibrate and correct satellite-based precipitation estimates. Let’s measure.

                       Figure 2: Kushma municipality, Parbat landslide, and resulting debris flow.


Nayava JL. 1980. Rainfall in Nepal. The Himalayan Review. Nepal Geological Society, 12.

Shrestha ML. 2000. Interannual variation of summer monsoon rainfall over Nepal and its relation to Southern Oscillation Index. Meteorology and Atmospheric Physics, 75: 21–28.

*Note: Monsoon depression: a depression that forms within the locations of relatively minimum sea level pressure in a monsoon region.

Sagar Gosai

Meet Sagar Gosai and the Young Researchers’ Circle (YRC)

Young Researchers’ Circle Announcement & Activities

The Young Researchers’ Circle (YRC) is a voluntary, independent, collaborative, non-profit circle of young researchers/students that was founded in Spring 2020 by S4W-Nepal with an aim to promote and support citizen science-based water resource monitoring and management in the Kathmandu Valley and other parts of Nepal. The motto and objective of YRC is “Rejuvenating research among young aspiring minds” and YRC seeks to accomplish this via events, outreach programs, involvement in S4W-Nepal’s activities, and various networking opportunities.

The current ongoing activities of YRC include participation in S4W-Nepal’s  Monsoon Expedition 2020, publication of a bi-monthly newsletter and a weekly Environmental News Refresher[1], and analysis of S4W-Nepal’s data. YRC plays a crucial role in the Monsoon Expedition in building a strong network of Citizen Scientists throughout the Kathmandu Valley (and other parts of Nepal) and motivates them to get involved in water-related research activities. YRC intends to build a good relationship between different colleges of Nepal, mobilize graduate-level students in water-related research, and help develop their skillset for the design, implementation, completion, and communication of research projects.

To date, YRC has published its first issue of the bimonthly newsletter ‘Young Researchers’ and six issues of the weekly Environment News Refresher. YRC has also conducted two online trainings, one on Open Data Kit (ODK) and one on ArcGIS, for the interested members of Young Researchers’ Circle for building their research skillset. Furthermore, YRC celebrated World Environment Day on June 5th by organizing an article writing competition among YRC members on the topic “Water as a whole to sustain biodiversity”. Finally, YRC has also conducted a video campaign in order to promote and conserve biodiversity.

In the near future, YRC plans to conduct webinars, facilitate managing and supporting conferences/events conducted by water-related organizations, become involved in various research activities and publications,  and more. The YRC initiative has thus far been successful, and these new ideas will hopefully allow for its continued success and growth!

You can find out more about the Young Researchers’ Circle through the S4W-Nepal Facebook page, by contacting S4W-Nepal at:  or by contacting YRC directly at .

Sagar Gosai

Meet Sagar Gosai

Sagar Gosai has been an active citizen scientist with S4W-Nepal for a long time and recently became vice-secretary of the Young Researchers’ Circle. Let’s hear a little bit from him about his experience as a citizen scientist and with S4W-Nepal.

Citizen Scientist’s Story

Namaste, I am Sagar Gosai. I am a third-year bachelor’s student studying Environmental Science at Khwopa College, Bhaktapur. I am an enthusiastic youth with a keen interest in the field of drinking water quality and its management. I was motivated and inspired to be a citizen scientist and got involved with S4W-Nepal through an outreach program conducted at my college. I have been actively collecting daily precipitation data for more than two years now, and have also been collecting daily evaporation data for the past six months.

S4W-Nepal has developed a low-cost gauge (each costs about $1.50 for materials and construction) to record these measurements, and these gauges are initially made available to citizen scientists by the organization for free. Considering the plastic pollution issues happening both locally and globally, I really appreciate the idea of reusing and repurposing plastic water bottles for measurement as well as the cost-effective data transmission methods through mobile application Open Data Kit (ODK) Collect.  S4W-Nepal has made me aware of the importance of data collection and also helped me develop the capability to easily communicate with other fellow citizen scientists and local people about the data collection procedures and the importance of the data. I am very happy to be a part of S4W-Nepal and excited and eager to know how the data collected are being used in making wise water resource management decisions.

[1] The weekly Environmental News Refresher provides an overview of local, national, and international environmental news stories with some commentary.

Yurisha Duwal

Meet Yurisha Duwal

Water is one of our most precious and indispensable commodities. Smartphones4Water (S4W)-Nepal generates the data necessary to support both water users and policymakers in making wise water management decisions. In the Kathmandu valley of Nepal, extreme population growth has led to stress on water resources; the project initiated by S4W-Nepal has the objective of collecting the data necessary to quantify these stresses so that effective solutions can be identified, developed and implemented. S4W-Nepal leverages “citizen scientists” for the measurement of different components of water (precipitation, evaporation, water level, etc.) through use of an Android smartphone application called Open Data Kit (ODK) Collect. For the measurement of precipitation and evaporation, S4W-Nepal provides a local rain gauge to the citizen scientists. This approach is rapidly scalable and cost effective in a developing country like Nepal.

We have 60+ citizen scientists taking daily precipitation measurements in different parts of the Kathmandu Valley, covering the Valley spatially. Included below is an interview with Yurisha Duwal, one of our citizen scientists taking daily precipitation and evaporation measurements. Each citizen scientist has their own story and unique perspective to share. Keep reading to learn about her experiences working as a citizen scientist with S4W-Nepal, some of her personal interests, and some of her other thoughts.


Yurisha Duwal is a bachelor’s student studying to become a pharmacist at Little Angels College of Health Science. Since she is in her final year, her daily activities are very concentrated on academics, however, she has a keen interest in and really enjoys dancing and singing. Besides that, she loves travelling to new places and has so far explored the central and eastern parts of Nepal (Janakpur, Sauraha and Chitwan) and Darjeeling and Sikkim of India. She got involved in S4W-Nepal through one of her friends and learned more about our work through our website and social media (Facebook and Instagram).

In her interview, Duwal said ‘Data is an important aspect for management of any resource! Here, in this case, it’s water!’. She believes the water-related data collected by S4W-Nepal and citizen scientists will ultimately help in sustainable water resource management in the near future. She further added, ‘I had no idea about the citizen science concept. I thought citizen scientists should come from a scientific background with good academics at first. However, being a part of S4W-Nepal, I came to understand this modern concept of citizen science and became fascinated by it.’ Being a medical student, she was not related to the water resources field academically, however, as a responsible citizen, she believes it’s her duty to be aware and take care of the environment she lives in. She added, ‘I will always be happy to contribute to the environment from my side, whether that be a small contribution like data collection or any other contribution. This is one of the key factors that drove me to become a part of S4W-Nepal’. She further encouraged her friends to become citizen scientists and become aware of the importance of data collection. Additionally, Duwal is one of only a few citizen scientists taking evaporation measurements, which we think is fantastic and really appreciate.

She believes that to accomplish or achieve any goal (in this case, sustainable water resource management), huge actions are not mandatory; small actions by many can help achieve and contribute to a better change. A lot of little things added together can turn out to be a pretty big thing. Adding this idea to the message she shares with others, she tells her fellow citizen scientists and friends that even a single measurement and data point can make a huge difference and can bring a significant change in the field of research and implementation of more sustainable management strategies. She further encourages everyone to continually collect and send data.

Nepal is a developing country where expensive technologies and environmental monitoring equipment and methods are not affordable. In such an instance, Duwal appreciates the cost-effective initiative taken by S4W-Nepal in mobilizing citizen scientists, mobile technologies and young researchers in data collection. However, she also suggests that measures to enhance the data collection techniques looking forward into the implementation of sustainable management strategies will be an interesting project and thing to think of. Since thus far, S4W-Nepal has mostly focused on the Kathmandu Valley, she added that this interesting and fascinating concept should be introduced all over the rest of Nepal too.

Each day, Yurisha Duwal uses an Android application called Open Data Kit (ODK) collect to record rainfall and evaporation. These measurements are recorded using a locally made inexpensive gauge (each gauge costs about $1.50 USD, learn how to make your own here). Each gauge is provided to citizen scientists by S4W-Nepal for free.

S4W = young researchers + citizen scientists + mobile technology. Citizen science refers to collaborations between scientists and general people to fill important scientific data gaps and expand the horizon of scientific data collection. S4W-Nepal uses an Android application called Open Data Kit (ODK) for data collection with the help of citizen scientists. The advanced mobile technology with good GPS and camera have improved the reliability and accuracy of citizen science observations. The citizen science approach is cost effective and rapidly scalable.

Citizen Scientist

Citizen Science: Enabling normal people to contribute in scientific research and resource management!

Water is one of our most precious and indispensable commodities. Putting our favorite Lord Kelvin phrase into action (‘You can’t manage a resource you don’t measure’), SmartPhones4Water (S4W)-Nepal generates data to support students, researchers and policymakers in making wise water management decisions. Extreme population growth has led to stress on the water resources of the Kathmandu Valley, and the project initiated by S4W-Nepal has the objective of collecting the data necessary to quantify these stresses and inform sustainable water management, so that effective solutions can be developed and implemented. Although we began in the Kathmandu Valley, S4W-Nepal has recently been expanding efforts and data collection into other regions of Nepal as well.

Included below is an interview with Sadam Bala, one of our citizen scientists taking daily precipitation measurements. Each citizen scientist has their own story and unique perspective to share. Let’s see what some of his personal interests, experiences working as a citizen scientist in S4W-Nepal and other thoughts are.

Fig: Citizen Scientist

Currently working at Nepal Electrical Authority (NEA) in Pokhara as an Electrical Engineer, Sadam Bala was born and raised in Bhaktapur. He completed his Bachelor’s in Electrical Engineering at the Institute of Engineering (IOE), Pulchowk Campus, which is one of the most prestigious engineering colleges in Nepal. Along with his work, he is currently enrolled in Western Regional Campus in Pokhara, pursuing his Master’s in Distributed Generation. Besides academics and work, his personal interests are travelling to new places and up to now, he has travelled several districts of Bagmati, Gandaki, Dhaulagiri and some parts of the mid and far-western regions of Nepal. He looks forward to continuing to travel and explore new places! He loves exploring and learning about new things and the modern concept of ‘citizen science’ fascinated him and drew him into being a part of S4W-Nepal.

It has been a year since Bala became involved in S4W-Nepal as a citizen scientist taking daily precipitation measurements. He is one of only a few citizen scientists from Pokhara. In his interview, Bala said, ‘Data collection is the basis for scientific research.’ He believes effective and informative research is an outcome of good data, and good data is also the basis for appropriate management of natural resources (including water!) both in the present and looking to the future. He further added, ‘It is not a tough job to take a picture and send data through a mobile application. It only takes a few minutes a day, not at all time consuming’.  He feels happy to be able to participate in scientific research with minimal effort.  Bala was aware of the importance of the citizen science concept as in his interview he highlighted citizen scientists as a critical part of research. Through S4W-Nepal, he has learned about existing problems and data gaps in the water resources field and how citizen scientists can reduce or eliminate those data gaps.

To his fellow citizen scientists, he conveys a message that these types of projects help an individual learn new and interesting things and can make them aware of existing problems that need to be addressed. Besides, citizen science projects can help built a network among individuals with different experience and backgrounds, which can be crucial in their personal development as well as for overall community or nation-building in the long run. From his personal experience, he suggests that his fellow citizen scientists be dedicated, self-motivated and work selflessly as the work is important and only requires a few minutes each day.

Each day, Sadam Bala uses an Android application called Open Data Kit (ODK) to record rainfall collected by an inexpensive locally made rain gauge (each gauge costs about $1.50 USD). Bala is motivated to participate in the project because he is fascinated by the citizen science concept, and he understands that data collection is a very important part of scientific research. Because of this, he is also eager to participate in large scale data collection in the near future if any opportunities are available.

Citizen science helps ordinary people increase their scientific understanding. All it takes is a smartphone with good GPS, a camera and access to the Internet to deinstitutionalize science and help the inner scientist in all of us grow, learn, and participate in scientific work on a broader scale. It gives every one of us opportunities for better understanding of a variety of subject matters, from water resources to backyard birds to the time of year that flowers are in bloom.


S4W = citizen science + mobile technology + young researchers. Citizen science refers to collaborations between scientists and general people to fill important scientific data gaps and expand the horizon of scientific data collection. S4W-Nepal uses an Android application called Open Data Kit (ODK) for data collection with the help of citizen scientists. The advanced mobile technology with good GPS and camera have improved the reliability and accuracy of citizen science observations. The citizen science approach is very cost effective and rapidly scalable.

Citizen Scientist Story

Meet Sabina Tamang (Citizen Scientist Story)

Happy Boxing Day Everyone!

This is our fourth interview with one of our citizen scientists who are collecting the data and doing the day-to-day work that makes our project in the Kathmandu Valley possible. We’re excited to introduce you to Sabina Tamang!

Figure 1. Sabina with her daughter Aifa.

Q: What is your name?  A: My name is Sabina Tamang. 

Q: How old are you?  A: I’m 25 years old.

Q: Where were you born?  A: I was born in Okhreni, Sundarijal in the Kathmandu Valley.

Q: Where do you live in the Kathmandu Valley?  A: I live in Okhreni, Kathmandu.

Interviewer’s Note: Okhreni is located about 15 kilometers northeast of Nepal’s capital, Kathmandu, within Shivapuri National Park. Since it is located within a National Park, it still lacks basic infrastructure such as concrete houses, proper roads, shops, etc. Okhreni is a very important cultural site since it is near natural (i.e. still undeveloped) and located in the headwaters of the Bagmati River.

Q: Can you walk us through a typical day of life? What are the activities you’re doing?  A: In addition to being a mother and keeping a household, I am involved in S4W as a citizen scientist, and I have been taking precipitation and water level measurements for the past two years.

Interviewer’s Note: S4W-Nepal is thankful for the opportunity to provide part-time employment opportunities to people like Sabina in a way that provides supplemental income and adds value to their lives, as well as improving our understanding of Nepal’s water resources. It’s a win-win!

Q: Can you tell us a little bit about your family?  A: I have one daughter, Aifa, who is three and a half years old.  I live with her and my mother.

Q: What is (or was) your favorite subject in school?  A: Nepali was my favorite subject.

Q: Can you tell us about a favorite moment of yours?  A: My favorite moments of my life are from my school days…

Q: How did you hear about the S4W-Nepal project?  A: I heard about S4W-Nepal through another citizen scientist named Sumina Tamang. She who lives in Mulkharka, on the other side of Shivapuri National Park.

Figure 2. Spring at Okhreni.

Q: What has been your experience as a citizen scientist with S4W so far?  A: As I mentioned before, I have been collecting precipitation and water level data for about two years. I have started noticing changes in the measurements I take throughout the year. I can now explain to people about base flow and runoff of rivers in my area. I have also started to understand the importance of the monsoon. I am also getting a stipend which motivates me in continuing to participate in the project. This project has helped me in boosting my knowledge about local resources as well as my economic condition.

Sabina is playing a critical role in S4W-Nepal as a citizen scientist and is one of the longest standing CS involved in our team.  Each day,  she uses an Android application called Open Data Kit (ODK) to record rainfall collected by an inexpensive locally made rain gauge (each costs about $1.50) and to record water level as seen on a gauge installed  near her house. Sabina is one of the citizen scientists who sends data regularly and is very dedicated in her work. She is motivated to participate in the project both because she feels a sense of responsibility and because she is financially compensated for her participation.  

S4W-Nepal is a collaboration between S4W-USA, Himalayan Biodiversity and Climate Change Center (HimBioCliCC), Tribhuvan University Institute of Engineering (TU IoE), Kathmandu Institute of Applied Sciences (KIAS), Delft University of Technology, the Swedish International Development Agency, and Stockholm University.  Water is our most precious resource.  Lord Kelvin, a famous Scottish mathematician, once said, “you can’t manage a resource you don’t measure.”  S4W-Nepal’s goal is to generate the data necessary to support wise water management decisions. S4W aims to accomplish this with a three-pronged approach of Research, Education, and Employment. This project in the Kathmandu Valley is our first project.

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