Data Report 2020

The Data Report 2020 of the Acid Deposition Monitoring Network in East Asia (EANET) provides a comprehensive analysis of acid deposition and air concentration data collected across 13 participating countries. The report presents findings from five key environmental monitoring activities: wet deposition, dry deposition (air concentration), soil and vegetation, inland aquatic environments, and catchment-scale monitoring. It details methodologies, site classifications, and data management processes, ensuring the consistency and reliability of monitoring efforts. The results offer insights into regional air pollution trends, deposition rates, and ecosystem impacts, contributing to scientific understanding and policy-making on acid deposition. The report also includes statistical summaries, quality assurance measures, and historical data comparisons to track long-term environmental changes. This information serves as a valuable resource for researchers, policymakers, and stakeholders working towards mitigating acid deposition effects in East Asia.

The Data Report 2020 of the Acid Deposition Monitoring Network in East Asia (EANET) compiles harmonized monitoring results from 13 participating countries and describes the network’s purpose, design, methods, QA/QC procedures and 2020 findings across five items: wet deposition, dry deposition (air concentration), soil & vegetation, inland aquatic environment, and catchment-scale monitoring. The network exists to build a common regional understanding of acid deposition and provide inputs to policy makers at multiple levels.

Network & scope

EANET monitoring began in 2001; by 2020 it included Cambodia, China, Indonesia, Japan, Lao PDR, Malaysia, Mongolia, Myanmar, Philippines, Republic of Korea, Russia, Thailand, and Vietnam. In 2020, 64 sites were nominated for acid deposition monitoring, classified as 26 urban, 17 rural, and 21 remote; a regional map and full site list (with coordinates/altitude) are provided.

Site typology underpins the assessment: urban sites address impacts in built/industrial settings (including effects on buildings and health), rural sites capture agricultural/forest exposure, and remote sites represent background areas and long-range transport. Ecological modules use basic survey and ecosystem analysis sites near deposition stations to link atmospheric inputs with ecosystem effects.

Wet deposition: methods, QA/QC, and statistics

All parties follow the Technical Manual for Wet Deposition Monitoring (2010) to ensure comparable, high-quality data. The report reproduces the sampling and analysis flow chart, with measurement priority: SO₄²⁻, NO₃⁻, Cl⁻ by ion chromatography, then NH₄⁺ (spectrophotometry if IC is not available) and Na⁺, K⁺, Ca²⁺, Mg²⁺ (IC or AAS). Wet-only samplers are recommended; samples should be refrigerated (or preserved with thymol in tropical conditions) to avoid degradation.

The manual defines Data Quality Objectives (DQOs) for detection limits (e.g., SO₄²⁻ 0.3 μmol L⁻¹, NO₃⁻ 0.5, NH₄⁺ 0.8). Mandatory checks include ion balance (R1) and conductivity agreement (R2), with explicit formulae and allowable ranges by concentration/conductivity. Meteorological measurements (wind, temperature, humidity, precipitation, solar radiation) are recommended on-site or from nearby stations to interpret unusual events.

The 2020 chapter includes monthly and annual summaries of precipitation-weighted concentrations, wet deposition amounts, data completeness (%PCL, %TP), and results of R1/R2 for each site; multi-year tables (2006–2020) and plots visualize QA/QC performance.

Dry deposition (air concentration) & methods

Chapter 4 describes dry deposition (air concentration) monitoring, with separate subsections for automatic monitoring and manual methods, reflecting EANET’s dual approach to continuous and integrated sampling. (The methods sections are explicitly titled “4.1.1 Automatic Monitoring Method” and **“4.1.2 Manual Monitoring Method.”)

Although the 2020 report focuses on results tables/figures per site, the network’s standard practice (consistent with other EANET years) involves automatic monitors for gases/particles (e.g., SO₂, O₃, NO/NO₂, PM₁₀/PM₂.₅) and manual filter-pack sampling for reactive gases (SO₂, HNO₃, HCl, NH₃) and particulate ions—methods aligned with the 2013 Air Concentration Technical Manual referenced across EANET Data Reports (see chapter headings here for 2020).

Ecological effects: soil & vegetation; inland aquatic environment

Chapters 5 and 6 outline field/lab protocols, site networks and 2020 results for the soil & vegetation and inland aquatic environment modules, which track indicators such as soil pH, exchangeable base cations, stream/lake chemistry, and ANC/EC in lakes and rivers proximate to deposition sites—enabling interpretation of ecosystem responses to atmospheric inputs.

A consolidated table lists 31 plots in 10 countries (soil/vegetation) and 19 lakes/rivers in 11 countries (inland waters), typically paired with a nearby deposition station to integrate cause–effect analysis.

Catchment-scale monitoring

The catchment-scale module quantifies input–output budgets (linking deposition, stream discharge, and water balance) for materials such as nitrogen and sulfur. In 2020, sites included Lake Ijira catchment (Japan) and the La Mesa Watershed (Philippines), with standardized site codes and data structures.

Data submission & governance

Participating countries submit their validated datasets to the Network Center (NC) by end-June each year. Drafts are reviewed with QA/QC managers at STM22, then verified by SAC21 before adoption; the Data Report 2020 compiles results obtained during calendar year 2020.

Keywords (from the report)

EANET, acid deposition, wet deposition, dry deposition, air concentration, ion chromatography, wet-only sampler, Data Quality Objectives (DQO), detection limits, ion balance (R1), conductivity agreement (R2), meteorological measurements, site classification (urban/rural/remote), basic survey/ecosystem analysis, soil and vegetation, inland aquatic environment, catchment-scale monitoring, input–output budget, Network Center (NC), SAC/STM review.