Search

Groundwater is generally stored in pore spaces and fractures within rocks and the proportion of void space is known as the porosity. The rate of groundwater flow is governed by the permeability of the rocks: a measure of how connected the void spaces are. Evaluation of contemporary aquifer recharge rates is fundamental to considering the sustainability of groundwater resource development. A catchment-scale vision of managing groundwater systems includes the requirements for acceptable river baseflow and adequate aquifer levels to sustain Groundwater-Dependent Ecosystems. The complexity of groundwater management increases as more linkages are considered, and a pragmatic decision taken on which are most relevant to maintain a reasonable balance between the costs and benefits of management interventions. Groundwater management must deal with balancing the exploitation of a complex resource with the increasing demands of water and land users, who can pose a threat to resource availability and quality, and the aquatic environment.

There are high aspirations for environmental water quality targets in the UK, but requirements for significant growth in agricultural production to meet both food security objectives and provide viable livelihoods for farmers make these hard to achieve. Significant water quality challenges are related to nutrients, pesticides, pharmaceuticals, pathogens, sediments and habitat alteration. To facilitate the challenges posed, there is a need for predictive, spatially distributed models to be developed that encompass the key aspects of agriculture and water management in order to inform future policy and organizations with an interest in land management. Additionally, there needs to be recognition from policy makers that different solutions are needed in different agri-water systems and that it often takes many years or decades for policies to have a sustained water quality impact. Long-term support for research infrastructure and the scientific skills base is required to enable measurement and data analysis necessary to inform decision making. Farmers need clearly articulated information on the issues and potential solutions on which to make informed management decisions regarding water. There are existing solutions to some problems and this knowledge needs to be effectively disseminated with appropriate incentives for implementation to have maximum impact. Greater collaboration between researchers, industry, and policy makers, with the necessary framework to deliver effective joint working, is urgently needed. There is also a need for a wider societal understanding of the land–water system and the various ways in which society pays (and might pay in the future) for the real value of water

The multiple, complex and systemic problems of the agriculture–food–water–environment nexus (“Nexus”) are among the most significant challenges of the 21st century. China is a key site for Nexus research amidst profound socio-environmental problems. The policy implications of these problems have been authoritatively summarized elsewhere. This study presents discussions at an international workshop in Guangzhou that asked instead “What science is needed to deliver the growing policy commitments regarding these challenges? And, What changes are needed to the science itself?” Understanding and effective intervention regarding the Nexus calls for a paradigm shift: to a new kind of science of (capacity for) international, interdisciplinary, and impactful research working with and within complex socio-natural systems. We here argue that science must become proactive in approach, striving only for “minimal harm” not “silver bullet” solutions, and adopting an explicitly long-term strategic perspective. Together, these arguments lead to calls for reorienting science and science policy in three ways: from short-term remediation to longer-term optimization; from a focus on environmental threats to one on the opportunities for international collaborative learning; and toward supporting new forms of scientific career. We bring these points together by recommending a new form of scientific institution: a global network of collaborative Nexus Centres, under the umbrella of a global Food Nexus Organization akin to those of the human genome and proteome.