S4W

Every month we will be posting a story about the work we are currently doing in Nepal. We will be alternating between science-focused and citizen scientist-focused stories. The citizen scientist stories will be interviews with some of the wonderful citizen scientists that we are privileged to be partnering with to collect this important data. This is our first one; we hope you find it interesting and enjoy 🙂

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

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

Q: Where were you born? A: I was born in Sindupalchowk.

Interviewer’s Note: This was one of the areas greatly affected by the earthquake in 2015, especially the second main shock centered to the northeast of Kathmandu.

Q: When did you move to the Kathmandu Valley? A: I moved to the Kathmandu Valley after getting married 8 years ago.

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

Interviewer’s Note: Chovar is on the south side of the Kathmandu Valley, right where the Bagmati River leaves the Valley and heads south towards the Tarai (the plains on the border with India).

Q: Can you walk us through a typical day of life? What are the activities you’re doing? A: I help to run a small store near the entrance of a Hindu Temple, and I raise two children.

Q: Can you tell us a little bit about your family (Spouse, Children, Brothers, Sisters, Cousins, etc.)? A: I have a husband named Roshan, my first son named Abusan who is 7, and another son named Asirbad who is 14 months. We live in the home that my husband’s mother (Iswari) was born in 64 years ago.

Interviewer’s Note: it is quite common for 3 or 4 generations of families to live together in one household in Nepal (and much of Asia for that matter).

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

Q: Can you tell us about a favorite memory of yours? A: My favorite memories are of my two sons being born.

Q: How did you hear about the S4W-Nepal project? A: The S4W-Nepal team was looking for a place to store some extra equipment while they were taking measurements in the Bagmati River a few months ago. We let them keep the equipment in our courtyard, and we have been friends since then.

Q: What has been your experience as a citizen scientist with S4W so far? A: It has been fun to learn about something new!

Sabina is playing a critical role in S4W-Nepal as a citizen scientist. Each day, Sabina uses an Android application called Open Data Kit (which you’ll have the opportunity to learn more about next month if you keep checking back!) to record rainfall collected by an inexpensive locally made rain gauge (each costs about $1.50 to construct) and the water level in the Bagmati River just below her house. Sabina is motivated to participate in the project because she feels a sense of responsibility to care for the river, and because each observation she makes earns her an extra 25 rupees (roughly $0.25).

S4W-Nepal is a collaboration between S4W, Himalayan Bio-Diversity and Climate Change Center (HimBioCliCC), 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.

Posted on April 22, 2017

The location of the first SmartPhones4Water (S4W) project is the Kathmandu Valley in Nepal, which is an area of approximately 587 square kilometers or 227 square miles. It is also home to somewhere between 1.3 and 5 million people. Assuming a 2.5 million person population, and assuming that the population is evenly spread out over the entire watershed (which it isn’t), that’s nearly 4,300 people per square kilometer or 11,000 people per square mile. It’s a lot of people in a little space!

Much of this population growth has occurred over the last 50 years or so, as people have moved to the Kathmandu Valley to escape from political unrest and civil war, or to seek economic opportunities in the big city that weren’t available in more rural areas. This rapid population growth has placed a great deal of stress on the water resources of the Kathmandu Valley. However, how population pressures have impacted water resources have not been fully quantified, and as our favorite Scottish mathematician Lord Kelvin once said, ‘You can’t manage a resource you don’t measure.’ S4W is working to collect the hydrologic data necessary to characterize over time and space the quantity and quality of water in the Kathmandu Valley, all of which will be required to make informed water management decisions in this important water basin.

With such a huge undertaking, where do you begin?

With a map of course! We needed to define the area of interest and better understand the spatial extent and characteristics of the Kathmandu Valley and its water resources. In order to successfully design and implement a successful hydrologic monitoring network, we need to understand where the water is in the Kathmandu Valley.

Our initial dataset was produced by NASA as part of the Shuttle Radar Topography Mission (SRTM) mission and is publically available for free. DEM stands for Digital Elevation Model, and it is essentially a very detailed digital topographic map with elevation for every 30 meter by 30 meter area of land (or “pixel”). This is shown in Figure 1.  To get a sense of scale, each pixel in a SRTM DEM takes up roughly the same amount of area as the infield of a Major League Baseball diamond field.  Within the Kathmandu Watershed (KTM_Watershed) there are over 652,000 pixels, and each pixel has a value corresponding to the average elevation above mean sea level in meters (colors ranging from 1298 to 2700).  Using Quantum GIS (QGIS), an open-source GIS software platform, a GRASS module was run on the DEM to develop a coverage of stream networks. The operation analyzes drainage directions from adjacent cells within the DEM, and the user defines the minimum number of cells that need to accumulate (i.e. have upstream cells) before the drainage area is classified as a stream. This was completed, and the results have since been verified through hiking expeditions and exploring the Kathmandu Valley, which is something we’d love to do anyways, so it’s a win-win. The resulting stream network for the Kathmandu Valley can be seen below in Figure 2.

The Kathmandu Valley is in the shape of a giant bowl, with all of the major rivers flowing down to the valley floor, joining together, and then exiting through one outlet. There are nine perennial (flowing year round) tributaries to the Bagmati River within the Valley. Beginning from the furthest south and working our way around the rim of the bowl in a counterclockwise direction, they are the Nakkhu, Kodkhu, Godawari, Hanumante, Manohara, Bagmati, Dhobi, Bishnumati, Manamati, and Balkhu. The Bagmati river starts up in the northern most portion of the Valley on the south slopes of Shivapuri peak, and flows southward all the way through and out of the valley, and the others are tributaries to it.

Once the map has been developed and the spatial extent of the study area is understood, the monitoring network can be designed. The objective of a monitoring network is to accurately characterize existing conditions through the data that are collected. Over time, this data record will demonstrate seasonal and annual variations and changes, trends (such as decreasing stream flows or lowering groundwater levels, which are symptoms of an over-exerted water basin) can be seen, and these results can guide leaders to make informed water management decisions. S4W is currently in the process of installing data collection sites and hiring citizen scientists as part of the monitoring network in the Kathmandu Valley. To date, approximately 50 stations have been installed and nearly 1,500 measurements have been taken by a diverse team of 25 citizen scientists, science students, and researchers, and we are continuing to grow. One year from now we aim to have 10 to 20 fixed stream flow monitoring points, 120+ total monitoring locations, 100 citizen scientists, and 4 to 6 full time staff working hard to develop the data necessary to make good water management decisions. Finally, the measurements that have been taken to date can be seen in Figure 4 below.

We could keep going on for a long time on this stuff (we think it’s pretty fascinating), but we’ll wrap this one up here for now. That’s just a little taste of what we’re up to in Nepal; we hope you found it interesting!

As you read this, we are continuing to expand our monitoring network with the installation of new data collection points, our team of citizen scientists with new additions that are also quickly becoming friends, and our dataset with new measurements that will provide the baseline data necessary for wise stewardship of the Kathmandu Valley’s water resources. Thanks for your interest and your support!

Check back next month for our first story on one of our wonderful citizen scientists!