Groundwater and environmental challenges in Asia

Asia stands out as the most populous and geographically diverse region globally.The pressing issues of water resource development and the resulting ecological impacts are exacerbated by the region's rapid population growth and economic expansion.Groundwater,a vital source of water in Asia,faces significant disparities in distribution and suffers from unsustainable exploitation practices.This study applies groundwater system theory and categorizes Asia into 11 primary groundwater systems and 36 secondary ones,based on intercontinental geological structures,climate,terrain,and hydrogeological characteristics.As of the end of 2010,Asia's assessed groundwater resources totalled 4.677×10^(9) m^(3)/a,with exploitable resources amounting to 3.274×10^(9) m^(3)/a.By considering the geological environmental impacts of groundwater development and the distinctive characteristics of terrain and landforms,six categories of effect zones with varying distribution patterns are identified.The current research on Asia's groundwater resources,environmental dynamics,and human impacts aims to provide a theoretical foundation for sustainable groundwater management and environmental conservation in the region.

Development,hotspots and trend directions of groundwater numerical simulation:A bibliometric and visualization analysis

Groundwater is a vital component of the hydrological cycle and essential for the sustainable development of ecosystems.Numerical simulation methods are key tools for addressing scientific challenges in groundwater research.This study uses bibliometric visualization analysis to examine the progress and trends in groundwater numerical simulation methods.By analyzing literature indexed in the Web of Science database from January 1990 to February 2023,and employing tools such as Citespace and VOSviewer,we assessed publication volume,research institutions and their collaborations,prolific scholars,keyword clustering,and emerging trends.The findings indicate an overall upward trend in both the number of publications and citations concerning groundwater numerical simulations.Since 2010,the number of publications has tripled compared to the total before 2010,underscoring the increasing significance and potential of numerical simulation methods in groundwater science.China,in particular,has shown remarkable growth in this field over the past decade,surpassing the United States,Canada,and Germany.This progress is closely linked to strong national support and active participation from research institutions,especially the contributions from teams at Hohai University,China University of Geosciences,and the University of Science and Technology of China.Collaboration between research teams is primarily seen between China and the United States,with less noticeable cooperation among other countries,resulting in a diverse and dispersed development pattern.Keyword analysis highlights that international research hotspots include groundwater recharge,karst water,geothermal water migration,seawater intrusion,variable density flow,contaminant and solute transport,pollution remediation,and land subsidence.Looking ahead,groundwater numerical simulations are expected to play a more prominent role in areas such as climate change,surface water-groundwater interactions,the impact of groundwater nitrates on the environment and health,submarine groundwater discharge,ecological water use,groundwater management,and risk prevention.

Research on groundwater ecological environment mapping based on ecological service function:A case study of five Central Asian countries and neighboring regions of China

The groundwater system is a unique ecosystem that serves both resource and ecological functions.Hydrogeologists have conducted extensive theoretical research and practical work on groundwater ecological mapping.This paper,based on the study of groundwater resources and surface ecology in the five Central Asian countries and adjacent areas of China,introduces the concept of ecosystem service functions.It establishes a groundwater ecological zoning index system and conducts research of ecological mapping using the five Central Asian countries and adjacent areas of China as examples.Through this process,the ecosystem service functions of groundwater can be more comprehensively reflected,which can better guide regional geological environment protection and industrial planning.This approach helps coordinate the relationship between socio-economic development and water resource protection,maintain the health of the groundwater ecological environment,enhance the value of groundwater ecological services,and promote the sustainable development of regional economies and societies.

Research hotspots and trends of groundwater and ecology studies:Based on a bibliometric approach

Groundwater,as a critical component of the hydrological cycle,is essential for sustainable ecosystem development.To clarify the current status of domestic and overseas research,and to identify hotspots,frontier and future trends of groundwater and ecology research,this study utilizes bibliometric methods and CiteSpace software to examine relevant published articles in the Web of Science(WOS)and CNKI databases from 1978 to 2022.Specifically,this study analyzes(1)the annual number of published papers;(2)research institutions;(3)keywords;and(4)evolution of research hotspots.The findings reveal that the United States,China,and Germany are the top three countries in groundwater and ecology research.International research hotspots mainly focus on microbial ecology,climate change,groundwater-surface water interactions in the hyporheic zone,biodiversity,and submarine groundwater discharge,while domestic research hotspots mainly focus on ecological water conveyance,ecological flow,groundwater development and utilization,groundwater pollution,and groundwater and ecological protection.Both domestic and international research hotspots exhibit interdisciplinary features with diverse research objects and assessment methods.Future research in this area is expected to focus on topics such as contamination,groundwater quality,framework,mechanism,spatial distribution,and dissolved organic matter.Additionally,the study of ecological recharge,ecological flow,ecological protection,water intake and use will continue to be the hot topics domestically.

Ecological function zoning and protection of groundwater in Asia

The natural groundwater recharge in Asia is estimated to be 4677.74×10^(9)m^(3)/a.However,it features extremely uneven spatial-temporal distribution.Groundwater is distributed in various natural and geological environments,and it is liable to be affected by numerous factors and possesses different properties.Moreover,groundwater faces complex ecological problems.This paper gains a complete understanding of groundwater in Asia in terms of the structure of aquifer systems,the processes of groundwater cycle,and the spatial variation laws of surface ecosystems.Based on this,it proposes the ecological function zoning scheme of groundwater in Asia,aiming to provide guidance for the utilization of regional water resources and the planning for economic and social development,coordinate the relationship between social and economic development and water resource protection,and improve the ecological functions of groundwater.Furthermore,this paper analyzes the problems with regional groundwater management in Asia and puts forward countermeasures and suggestions,thus providing a theoretical basis for the sustainable development and utilization of regional groundwater and environmental protection.