South Asia Drought Monitor

A Streams of Thought contribution by Swamini Khurana (she/her), in conversation with Toma Rani Saha (she/her) and Pallav Kumar Shrestha (he/him)

The South Asia Drought Monitor (SADM) is a portal where people can monitor the condition of soil moisture in the South Asian subcontinent using time varying maps. SADM focuses on monitoring agricultural drought at a high-resolution (~27 km) (Saha et al., 2021). The portal transfers information from science to practice; scientific jargons are bypassed and the soil condition is presented as six categories of dryness, varying from no dryness through to exceptional drought. It is well known that drought is a creeping phenomenon that expresses itself through soil moisture which moves slowly. Therefore, in addition to monitoring, SADM also provides the opportunity to look into the near future based on current soil moisture conditions.

Caption: South Asia Drought Monitor displaying the 2009-2010 drought in the region.

The target audience

Toma intended SADM to be used by a variety of stakeholders including agriculturalists, policy makers, private sector (e.g. insurance) organisations and the scientific community. The entire dataset (going back to 1982) is available for download and can be viewed as interactive plots directly on the portal. The monitor is updated in real time with five days of latency.

The inspiration behind an agricultural drought monitor for South Asia

Toma was the idea generator and approached the team at Helmholtz Centre for Environmental Research (or UFZ in German abbreviation) to create an agricultural drought monitor specifically for Bangladesh, much along the lines of the already established German (Zink et al., 2016) and US drought monitors. Bangladesh is an agriculture dependent country, and while there was already information available using meteorological drought indices such as SPI and SPEI, there was no information that included soil moisture indices to assess agricultural droughts. Through discussions with Luis Samaniego, Pallav Shrestha, Oldrich Rakovec and Stephan Thober, Toma developed a plan to model the Indian peninsula (including Sri Lanka) as well as the three Himalayan basins Ganges, Brahmaputra and Indus. Thus, the SADM covers seven countries in the region (Afghanistan, Bangladesh, Bhutan, India, Nepal, Pakistan and Sri Lanka), giving the picture of the whole South Asia.

Secondly, existing drought monitoring tools didn’t offer the historical data to users. SADM overcomes this limitation by providing the data for various purposes, including exploring historical trends, defining initial conditions for forecasting and so on. Another aspect was to explore a relatively new hydrological model (mesoscale hydrological model, mHM) (Samaniego et al., 2010, Kumar et al., 2013) for simulating agricultural drought in South Asia. The existing drought monitoring tools for South Asia use other hydrological models. mHM has proven its applicability in Europe (Thober et al., 2015) and North America (Rakovec et al., 2019), but it was yet to be tested over South Asia.

Use of SADM by the target audience

SADM has a wide variety of potential applications. Agriculturalists can look into the historical data and explore patterns between historical droughts and corresponding agricultural yields, along with deriving information on the impact of these droughts. For example, Bangladesh experienced a big drought in 1982. This can assist agriculturalists with management strategies to enhance and protect crop yield.

Policymakers and local government agencies are the second biggest stakeholders for SADM. Historical trends available in SADM can assist with policy support for farmers, for example when claiming insurance in case of crop failure or setting policy around mandatory insurance coverage. This is important as currently, farmers are not compensated by the government if crops are lost due to natural disasters. So, governments can use information presented by SADM to understand risk and propose measures to mitigate the impacts.

Agrochemical companies in the private sector might also be impacted by decreased land productivity and so they are potential users of SADM as well. Water and energy professionals can use the monitor to estimate the potential impact of upcoming or recent droughts on water supply. SADM can be used to confirm prevailing drought conditions and to then issue public health advisories with respect to wildfires for example, as well as to disseminate information through the media. Lastly, economists may want to use the tool to understand the potential impacts of drought on the economy.

Challenges along the way

SADM was developed over a period of one and a half years. This is a really short time horizon to develop such a tool, and there was not enough time to consult with potential stakeholders on how they would like the data to be presented. The team believes that this feedback would have improved the tool if it had been available.

One might imagine that data collation and harmonisation would have been the primary challenge. But it was made easy by Oldrich Rakovec (from UFZ) who was already working on creating a global database of mHM-ready preprocessed data  encompassing land use and cover, topography, climatic conditions, soil and geology. Toma was also supported by Stephan Thober (also from UFZ) in using a post-processor program for mHM called SMI (Soil Moisture Index) (Samaniego et al, 2013). The soil moisture simulated by mHM is input into the SMI program, which in turn generates maps of SMI that are used to define drought in the portal. 

What next for SADM?

From the technical and modelling perspective, Pallav and Toma would like to decrease uncertainty from two different sources: external forcing and the method. Incorporating a variety of meteorological forcing sources (currently only ERA5) will aid in understanding the related uncertainty in the final result. Methodologically, the model only uses mHM as the hydrological model but SADM would benefit if it incorporated more models. This will better characterize uncertainty, and thereby increase the tool’s applicability. This multi-model paradigm in hydrology is exactly what the team is currently working on in the ULYSSES project where four hydrological models produce global seasonal hydrological forecasts alongside monitoring, at a finer resolution (~10 km). The next big step is to connect the current portal downstream of ULYSSES and take it global.

Most importantly though, Pallav and Toma would like the SADM to reach more users, which will enable them to improve the feedback loop. Currently, SADM doesn’t track its users, so they have no means of assessing if the stakeholders find it useful or what could improve the tool from their perspective. Along similar lines, they would also like to issue a monthly or quarterly bulletin, based on the outputs of SADM, that can be used to disseminate information to a variety of stakeholders.

Hydrologists and society

Hydrologists are already an important part of water resources management. They contribute a great deal to planning and overseeing water supply for municipal and industrial use, as well as for energy needs. But we are yet to adapt to a changing climate regime, wherein extreme events are rising in both frequency and intensity. Hydrologists should be doing more to provide information about the current and potential future state of water resources. For instance, in South Asia, there is massive property, livelihood and life loss associated with extreme events every year. The SADM aims to monitor the current state of drought risk so that stakeholders can adapt and hopefully mitigate the worst impacts.

Hydrologists must also communicate with end users more. We often come up with terrific technical solutions (such as SADM), but lack the feedback to ensure these tools are applied in practice. So, science communication must be taken up by every professional so that they can reach the people for whom they aim to work.


  1. Saha, T. R., Samaniego, L., Shrestha, P. K., Thober, S., and Rakovec, O. (2021) A Drought Monitoring Tool for South Asia, Environmental. Research Letter, 16, 054014, DOI: 10.1088/1748-9326/abf525.
  2. Zink, M., Samaniego, L., Kumar, R., Thober, S., Mai, J., Schäfer, D., and Marx, A. (2016) The German drought monitor, Environmental. Research Letter, 11, 074002.
  3. Samaniego, L., Kumar, R. and Attinger, S. (2010) Multiscale parameter regionalization of a grid-based hydrologic model at the mesoscale, Water Resour. Res., 46, 5.
  4. Kumar, R., Samaniego, L. and Attinger, S. (2013) Implications of distributed hydrologic model parameterization on water fluxes at multiple scales and locations, Water Resour. Res., 49, 360–79.
  5. Thober, S., Kumar, R., Sheffield, J., Mai, J., Schäfer, D., & Samaniego, L. (2015). Seasonal soil moisture drought prediction over Europe using the North American Multi-Model Ensemble (NMME). Journal of Hydrometeorology, 16(6), 2329–2344.
  6. Rakovec, O., Mizukami, N., Kumar, R., Newman, A. J., Thober, S., Wood, A. W., … Samaniego, L. (2019). Diagnostic Evaluation of Large-Domain Hydrologic Models Calibrated Across the Contiguous United States. Journal of Geophysical Research: Atmospheres, 124(24), 13991–14007.
  7. Samaniego, L., Kumar, R., & Zink, M. (2013). Implications of Parameter Uncertainty on Soil Moisture Drought Analysis in Germany, Journal of Hydrometeorology14(1), 47-68.

Further resources

  1. mHM website (download, documentation, discussions, news)
  2. mHM-users mailing list – send an email with some information about yourself to 
  3. Stochastic and Land Surface Hydrology group at UFZ

About Pallav and Toma

Toma is a researcher and development professional, working in research organisations and the development sector throughout her career. For 7 years, Toma has been working on the environment, water, climate change, youth, social development, agriculture, and ICT. Recently, she has completed the International Climate Protection (ICP) fellowship from the Alexander von Humboldt Foundation to develop a drought monitoring tool for South Asia. She can be reached via e-mail (

Pallav is a PhD researcher and works in Luis Samaniego’s team at UFZ since late 2017. Trained as a Civil and Water Resources Engineer, Pallav’s passion for programming turned into his profession (developer) at UFZ where he is currently on a quest of developing a lake/reservoir module for mHM in hopes of improving the state-of-the-art in global hydrological modelling. In parallel, Pallav provides development and technical support to ongoing projects in the group (SADM being one) and is currently supporting operationalization of global multi-model seasonal hydrological forecasting in the ULYSSES project funded by ECMWF. He can be reached via e-mail [] and twitter handle [@Pallav_Shrestha].

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