This dataset provides stream networks for three river basins in eastern Sri Lanka (Mundeni Aru, Maduru Oya and Miyangolla Ela). The stream networks were developed for use in hydrologic modelling and are provided as shapefiles. The work was supported by the Natural Environment Research Council (Grant NE/S005838/1). Full details about this dataset can be found at https://doi.org/10.5285/0537af26-5cab-4381-aca0-d997db421111

This dataset includes measurements of groundwater levels (2019–2021) and rainfall data (2020–2021), collected through citizen participation on the Indian Ocean island of Karainagar, Sri Lanka. Karainagar, the study area, is one of seven islands located off the coast of Jaffna in northern Sri Lanka. This rectangular island is bounded on three sides by the Palk Strait, while the fourth side faces the Jaffna Lagoon and is connected to the mainland by a causeway. Karainagar covers an area of approximately 22 km², including inland water bodies. Seven dug wells used for domestic purposes were inventoried and monitored to track groundwater levels. Rainfall data were collected from six locations, including two schools, three households, and one village government office (Grama Niladhari Office). Full details about this dataset can be found at https://doi.org/10.5285/bce114d8-8f3b-49e0-90c6-f0788c1e9a0d

This dataset contains information about meteorological conditions, ammonia concentration and deposition rates resulting from an experimental ammonia (NH3) enhancement setup in a tropical forest in central Sri Lanka. The experiment is designed for controlled enhancement of ambient NH3 concentration within the study plot under natural field conditions so that effects of NH3 on tropical vegetation can be studied. This will help identify tolerance thresholds of vegetation to NH3 as an air pollutant and determine critical levels that can be incorporated into regional environmental policy. Meteorological measurements were recorded at multiple heights on a meteorological tower. Under suitable wind conditions, NH3 was released towards two vegetation monitoring transects replicating pollution from a point source, and NH3 concentrations in the air were measured using monthly passive samplers. Continuous meteorological data, NH3 release, and NH3 concentration data are provided in 15-minute intervals and this dataset relates to measurements taken in 2023 – 2024. Deposition rates were modelled using a bi-directional resistance model on a monthly timescale based on measured NH3 concentrations in the air, micrometeorology and plant physiology. This dataset provides an extension of the 2022 dataset to enable longer term analysis of NH3 deposition and its effects in a tropical forest. The work was supported by UKRI GCRF South Asian Nitrogen Hub (Grant NE/S009019/1). Full details about this dataset can be found at https://doi.org/10.5285/449e746d-6291-4653-a3e0-b18f897abc3e

This dataset contains information about meteorological conditions and ammonia concentration and deposition rates resulting from an experimental setup. An NH3 enhancement experiment along with a full suite of multi-height meteorological measurements was established in a tropical forest in central Sri Lanka. Under suitable wind conditions measured at the meteorological tower, NH3 is released towards two monitoring transects. Along the downwind monitoring transects, NH3 concentrations in the air are measured using monthly passive samplers. Deposition rates are modelled using a bi-directional resistance model based on measured NH3 concentrations in the air, micrometeorology and plant physiology. Additionally, NH3 concentrations were measured at high temporal resolution at a fixed downwind distance from the source to achieve the target enhancement concentrations. The work was supported by UKRI GCRF South Asian Nitrogen Hub (Grant NE/S009019/1). Full details about this dataset can be found at https://doi.org/10.5285/998c2b2b-7470-42b0-81e7-409b91752377

This dataset contains Leptospirosis case numbers for a number of place studies in Brazil, Malaysia, Philippines, Argentina, China and Sri Lanka. Leptospirosis case numbers are provided as weekly or monthly case numbers and cover the period 1978 to 2020, although timelines vary within place studies. Area-weighted daily average hydrometeorological variables are also included: precipitation, river discharge and soil moisture. The data have been collected and collated for a global analysis of the effect of hydrometeorological extremes on leptospirosis infection risk. Also included are the spatial polygons for each of the place studies. Full details about this dataset can be found at https://doi.org/10.5285/56f42170-3678-4586-b8c8-9b05f03125e1

The database includes the classification of 966 active nitrogen-relevant policies from South Asia (including Afghanistan, Pakistan, India, Nepal, Bhutan, Bangladesh, the Maldives and Sri Lanka). The collection during 2020 and 2021 focuses on national level policies; some subnational policies were also collected. Data collection involved building on an existing open access global database developed by Kanter et al., 2020 that contained 51 policies for South Asia established to 2017 sourced by the environmental law ECOLEX database. Further policies were collected mostly from online sources: such as international policy databases: FAOLEX and national government and ministry websites. A protocol for policy collection and classification was established and followed to ensure consistent and thorough collections across the eight countries. Policies were classified according to a variety of parameters including the sink (air, water etc.) and sector (agriculture, industry etc.) they address and by type of policy. Policies were clustered if they had a central node policy in place and if a ‘subordinate policy’ (including amendments) did not offer anything new in terms of content related to Nitrogen management. This data was collected as part of a collective partnership that brings together leading organisations from across South Asia and the UK to reduce the adverse global impacts of nitrogen pollution on the environment, health, and wellbeing. More specifically providing a resource for both SANH partners and the wider scientific and policy community to understand the nitrogen policy landscape in the south Asian region. Furthermore, this research contributes to efforts in building a nitrogen policy arena promoting sustainable management of nitrogen, mitigating adverse effects. The dataset provides a thorough overview of available nitrogen related policies in South Asia but does not provide a complete set of all the nitrogen relevant policies available in each country. In some cases, this was due to our dependency on policy availability online, and some websites were not maintained. In addition, we excluded policies established post 2020 to avoid policy responses to COVID19 and to align more closely with the original global study. Repealed policies were omitted from the database. Full details about this dataset can be found at https://doi.org/10.5285/e2f248d5-79a1-4af9-bdd4-f739fb12ce9a

[This dataset is embargoed until August 31, 2026]. This dataset includes measurements of groundwater levels, salinity, and pH collected from 36 dug wells, along with rainfall data, on the Indian Ocean island of Karainagar, Sri Lanka, spanning the period from 2019 to 2024. Karainagar, the study area, is one of seven islands located off the coast of Jaffna in northern Sri Lanka. This rectangular island is bounded on three sides by the Palk Strait, while the fourth side faces the Jaffna Lagoon and is connected to the mainland by a causeway. Karainagar covers an area of approximately 22 km², including inland water bodies. Thirty-six dug wells—used for agricultural, domestic, Kovil (Temple), and public purposes—were inventoried. These wells were monitored to track groundwater levels and key physicochemical parameters, specifically salinity (measured as electrical conductivity, EC) and pH, on Karainagar Island. Full details about this dataset can be found at https://doi.org/10.5285/ba22d53b-4eee-48a1-b6f3-653d252c0358