Managing climate change impacts on groundwater in China's Hebei Province
|A shorter version of this lesson has been featured on the booklet produced by the MDG-F Environment and Climate Change window "Seeds of Knowledge - Contributing to Climate Change Solutions". - Read more about the booklet or download it in English / Spanish / French / Arabic.|
Groundwater is an essential water resource, making up 20 percent of the world’s freshwater supply, and is naturally recharged by precipitation, streams and rivers. At 760 billion cubic metres, groundwater resources account for 26.8 percent of China’s total water resources. However, in many parts of China, especially in the North, long-term overexploitation of groundwater has resulted in a continuous fall in the groundwater table and a series of geological and environmental problems, such as ground sedimentation, karst collapse, seawater intrusion and desertification. Pollution from agriculture and industry has also contributed to the decline of groundwater quality. Climate change is further compounding these problems. For example, more frequent extreme droughts, floods and other natural disasters cause variations in groundwater recharge rates and changes in groundwater circulation.
In response to these challenges, the JP conducted pilot work in management of climate change effects on ground water resources. The results of the pilot work showed that more active measures need to be taken to protect groundwater resources including adopting water saving practices, using alternative water resources and strictly adhering to total extraction limits. Groundwater recharge could be increased during the wet season using field canals and low lands to retain more runoff. Results also revealed that a greater understanding is still needed of the interaction between the direct and indirect influences of climate change on groundwater and that an integrated and comprehensive approach is needed to surface and groundwater management.
In sum, the lesson learned from our work with water in the China JP is that greater efforts should be made to make existing data available to all relevant stakeholders while also enhancing groundwater related research and training, while also enhancing advocacy and education of groundwater knowledge. All of these efforts should be done within a framework that emphasizes an integrated and comprehensive approach to water management, which includes both surface and groundwater.
Purpose of the activity
To help manage the effects of climate change on their groundwater resources in three pilot provinces in China: Hebei, Shaanxi and Shandong. This lesson learnt refers to the results of the pilot work conducted in Cangzhou City, Hebei.
The team first built up the necessary local capacities, updating monitoring systems and installing portable water quality meters. The programme also provided technical assistance and on-site training to technicians on groundwater monitoring, well maintenance, water sampling, and data storage and analysis. With the improved capacity for groundwater monitoring, relevant data necessary for modelling and developing adaptation measures was then collected from the pilot site.
Original issue addressed by the activity
Cangzhou City is located in a region that has suffered from severe water shortages. Following a long-term decrease in river flows, groundwater has become the major source of the local water supply. Over-exploitation and contamination by industrial and domestic sources have all contributed to its depletion. Therefore, the city had an urgent need to monitor its groundwater resources with the aim of maintaining a safe water supply and sustainable groundwater use.
Strategy / approach chosen to address the issue
Local capacities to monitor groundwater, well maintenance, water sampling, and data storage and analysis were built up, monitoring systems updated, and portable water quality meters provided. The programme also provided technical assistance and on-site training to technicians on groundwater monitoring, well maintenance, water sampling, and data storage and analysis. With the improved capacity for groundwater monitoring, relevant data necessary for modelling and developing adaptation measures was then collected from the pilot site.
Implementation of the strategy / chosen approach
Based on the data collected and through a statistical analysis of long-term historical meteorological data, the team were able to model the future impacts of climate change on groundwater. Furthermore, the team explored the effects of climate change and human activity on changes in precipitation, temperature, evaporation and groundwater table over the past 30-40 years.
Challenges and Innovations
Little understanding lack of related knowledge, similar methodologies or projects for reference purposes which was in effect the motivation between such interventions in the first place.
Based on the results of field work, technical regulations on groundwater monitoring were revised and recommended for nation-wide adoption.
Results and Impacts
The major findings from this vulnerability study are as follows:
- The temperature in Cangzhou has increased by 0.045°C per year while precipitation has gradually decreased since the 1950’s;
- Changes in evaporation and temperature have had a slight impact on the groundwater table, but have affected water use significantly and so have had a significant indirect impact on the groundwater table;
- The groundwater table in Cangzhou has fallen continuously. Water consumption from human activities has been a principal cause of this but climate change has also played a part. The groundwater table is influenced by human activities with a weighting of 70-90 percent and precipitation with a weighting of 10-30 percent;
- The fall in the groundwater table could be effectively lessened through improved water conservation, which would reduce consumption by 10 percent;
- Techniques such as low-quality water use and rainwater harvesting could decrease groundwater extraction and effectively reduce the fall in the groundwater table. A 10 percent decrease in groundwater exploitation would mean a reduction in the water table of only 1.06 m by 2050;
- Deep groundwater extraction could intensify the rate at which the groundwater table falls.
Moreover, a conceptual model for groundwater simulation and management was built, scenarios identified, and groundwater responses to climate change tested and technical regulations on groundwater monitoring were revised and recommended for nation-wide adoption.
Results have been shared at “Impact of Climate Change on Groundwater” on the 4th International Yellow River Forum was held in Zhengzhou, October 2009 and at High Level Roundtable Conference on Climate Change and Water Security 2010 by by Global Water Partnership.
A greater understanding is still needed of the interaction between the direct and indirect influences of climate change on groundwater. For example, the direct effects of droughts on recharge rates are exacerbated by the indirect influences of human activities such as more intensive extraction of groundwater brought about by droughts. Groundwater modelling needs to take into account both these influences.
It was deemed that the Government should develop more comprehensive and integrated policies for management of both surface and groundwater. Such policies should provide for proper management of water abstraction licenses, water metering and emergency responses to natural disasters. In particular, they should address the systemic integrity of the circulation of groundwater to better protect water resources and ensure prioritization in water resource allocations, with the aim of balancing water abstractions and recharges. The Government has developed some polices on groundwater management already; however they are still very rudimentary and do not fully take into account the impacts of climate change. In turn, policy development needs to be supported by accurate data collected from monitoring systems and research work. River basin-level and regional level groundwater management is particularly important in this context.
Awareness of the climate change impacts on groundwater should be promoted, as should the interaction between climate change and human activities that both had received little attention in China prior to the CCPF.
Potential replication / application
The results of our pilot work revealed that monitoring alone is not sufficient to fully understand and develop policies/actions to address the complex effects of climate change on groundwater resources. We recognized that a greater understanding is still needed of the interaction between the direct and indirect influences of climate change on groundwater and that an integrated and comprehensive approach is needed to surface and groundwater management.
If others are to implement similar activities with respect to groundwater monitoring/management, our major lessons learned are as follows:
- Capacity building to improve groundwater monitoring and to allow for better data analysis, modelling and scenario development is of great importance in the identification of effective adaptation measures in countries with scarce water resources and/or at risk from the effects of climate change.
- Greater efforts should be made to make existing data available to all relevant stakeholders while also enhancing groundwater related research and training, while also enhancing advocacy and education of groundwater knowledge.
- All monitoring/management efforts should be done within a framework that emphasizes an integrated and comprehensive approach to water management, which includes both surface and groundwater.
This lesson learnt has been adapted from “The China Climate Change Partnership Framework Occasional Paper”.