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Asia-Pacific Network for Global Change Research

Asia-Pacific Network for Global Change Research

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Project • CRRP2019-09MY-Onodera

Future Water Resources, its Quality Management and Nutrient Flux in Asian Coastal Megacities

The megacities (MCs) with > 10 million population are counted 35 in the world. More than 60% of MCs are located in Asia and 70% of them are situated in coastal areas. Nutrients flux (NF) plays a significant role in maintaining ecosystem services and biodiversity in the coastal area. Quality management (QM) for water resources (WR) is important for the ecosystem as well as water use. In this project, coastal Asian MCs (AMCs) and associated cities are categorized based on their location (continent with a large river or island) and urbanization stage (US). The 1st US has a growing population, high dependence on groundwater for WR, and degradation of surface water quality; the 2nd US has a stable population, improvement of surface water quality by sewage treatment systems, but diverse groundwater pollution appears, and the 3rd US has population decline, growing dependence on surface water for WR, but expansion of groundwater pollution. Based on these criteria, coastal cities in Indonesia are as typical examples for island-1st US type, China as continental-2nd US type, Japan as island-3rd US type, are selected for study sites. For sustainable water use in AMCs and coastal ecosystem conservation, four specific subjects are proposed as A) Assessment of current WR and NF statuses considering vulnerability and resilience to water pollution; B) Reconstruction of NF history; C) Future scenario of WR and NF under climate extreme and human impacts; and D) Framework of QM for WR and NF.

Project publications

Peer-reviewed publication • 2022

Nitrate contamination in groundwater: Evaluating the effects of demographic aging and depopulation in an island with intensive citrus cultivation

Peer-reviewed publication • 2022

Assessment of long-term phosphorus budget changes influenced by anthropogenic factors in a coastal catchment of Osaka Bay

Peer-reviewed publication • 2022

Effects of forest growth in different vegetation communities on forest catchment water balance

Peer-reviewed publication • 2022

Heavy metals and Pb isotopes in a marine sediment core record environmental changes and anthropogenic activities in the Pearl River Delta over a century

Peer-reviewed publication • 2021

Evaluation of nitrogen loading in the last 80 years in an urbanized Asian coastal catchment through the reconstruction of severe contamination period

Peer-reviewed publication • 2021

Long-term variations in water balance by increase in percent imperviousness of urban regions

Peer-reviewed publication • 2021

Effects of forest growth in different vegetation communities on forest catchment water balance

Peer-reviewed publication • 2021

Vulnerability of groundwater to iron and manganese contamination in the coastal alluvial plain of a developing Indonesian city

Peer-reviewed publication • 2021

Release characteristics and mechanisms of sediment phosphorus in contaminated and uncontaminated rivers: A case study in South China

Peer-reviewed publication • 2020

Potential sources of ammonium-nitrogen in the coastal groundwater determined from a combined analysis of nitrogen isotope, biological and geological parameters, and land use

Peer-reviewed publication • 2020

Quantifying the impacts of anthropogenic activity on chemical weathering based on source identification of hydrochemistry: the Liuxi river basin, southern China

Peer-reviewed publication • 2019

210Pb dating to investigate the historical variations and identification of different sources of heavy metal pollution in sediments of the Pearl River Estuary, Southern China