Analyzing Long-Term Freshwater Pollution Trends Under Land-Use and Climate Pressure: A Global Water-Quality Assessment Using Real Monitoring Data

Abstract

Freshwater pollution is increasing in many river, lake, and groundwater systems. The problem is linked with land-use change, wastewater discharge, agricultural runoff, and climate stress. This paper analyzes long-term freshwater pollution trends using real public monitoring data. The main dataset is SDG Indicator 6.3.2, reported by countries in 2017, 2020, and 2023. The paper also reviews open archives, including GEMStat, GRQA, GLORICH, and HydroWASTE. The analysis compares global, regional, and selected country scores for good ambient water quality. It also evaluates monitoring capacity and climate-related water-quality evidence. The global share of monitored water bodies with good quality changed from 57.0% in 2017 to 56.0% in 2023. River water bodies showed a larger fall, from 53.7% to 49.7%. Groundwater scores stayed higher than river scores, but small changes can still hide local risks. Regional results show uneven change across Africa, Asia, Europe, Oceania, and Latin America. The results also show a large monitoring gap. High-income countries reported far more water bodies than low-income countries. Climate evidence shows that droughts, heatwaves, floods, and long-term warming often worsen river quality. The paper proposes an integrated monitoring framework. It combines routine field data, open databases, land-use control, wastewater treatment, and climate early warning. The study shows that pollution control must be linked with land and climate policy