Saltwater intrusion and agriculture: a comparative study between the Netherlands and China.

Abstract: Saltwater intrusion, which can be facilitated by natural conditions, human activities and climate change, is a big threat to mankind from social-economic, environmental and ecological perspective. Agriculture, the largest consumer of water, is identified as both contributor and most vulnerable sector to saltwater intrusion, especially in coastal low-lying areas, with the increasing demands and competition of water owing to economic bloom, population growth and climate fluctuations. Sustainable water resource management is urgently needed owing to its essential in solving this issue. Hence this study is to deliver the understanding of linkage between saltwater ingress and agriculture and seek appropriate water resource management strategies in coastal low-lying areas to address saltwater intrusion and reduce its impacts on agriculture.   This study conducts a comparative case study between Texel, the Netherlands and Shouguang, China to specify the linkages between saltwater intrusion and agriculture with local features. The reasons, impacts and associated mitigations and/or adaptations of the issue, together with the legislation of each region have been investigated and compared.   The results show that for combating the saltwater intrusion and reducing the losses from agriculture, both study areas have adapted specific approaches. Among them similar approaches, despite different legislations and policies, such as developing alternative water resource (treated wastewater and rainwater) and saline agriculture are implemented by both of the regions. Through the comparison, each can learn the lessons from the other. The integrated water legislation together with its effective implementation, the strong involvements of different stakeholders and ecological approach to post-treat effluent of Texel can no doubt inspire Shouguang. While the highlights of counteract measures taken by Shouguang such separating rainwater from wastewater during collection and treatment, water diversion and development of special market to achieve high profit for saline products can obviously inspire Texel as well.   The analysis and comparison between these two case studies can reflect the general problems regarding to water management on saltwater intrusion and agriculture in all the regions that suffer from this problem. Hence, it is concluded that 1) integrated water legislation and management (with climate change considered and integrated as well) are the foundations, while water conservation should be core idea that always kept in mind; 2) strong involvements of different stakeholders and necessary supervision systems can guarantee the effectiveness of implementation; 3) all actions should be based on both technical knowledge and local-cultural knowledge; 4) self-sufficient approaches should be promoted at micro level to reduce the dependency on external water intrusion; 5) economic means should be carefully combined with environmental and ecological ways as well to achieve the goal of development of sustainability; 6) monitoring systems are of great significance.