| 英文摘要: | The various supply chains that deliver the services society needs are often managed in silos. Research now shows the advantages of integrated management. Living in the beautiful cities of Stockholm and Vienna we note, with some irritation, occasional interruptions to their scenic walkways. Striving to provide services, a street might get torn up several times within a few months. First to do sewage repairs, then to lay new high-capacity data cables and finally to increase the capacity of the gas mains — efforts that might cost three times more tax money than if these activities were coordinated. And this is just an example at local level — globally it can be worse. Our societies are simply not organized to undertake integrated planning and action1. We spend far more than we need to deliver the services societies demand. Writing in Environmental Science and Technology, Bartos and Chester2 show the missed opportunities from the lack of integrated water-energy management in the state of Arizona, USA. The delivery systems of society's services consist of a chain of activity. They originate from natural resources and ecosystems. These are extracted, processed and transported to provide products and services. Those chains are shaped by economics, technology and policies — notably to ensure secure supplies. Society's 'delivery chains' have traditionally been managed individually. Initially, interactions between many chains were largely inconsequential — their supplies were abundant and our demand was small. For practical reasons, separate management also allows for delineated responsibility and focused planning. Hence, at all governmental levels, we find authorities for energy, water, agriculture and so on, each tasked with their own sectoral mandates. Such mandates often do not include any assessments of the impacts of action in one sector on others. A notable exception is the European Commission's Strategic Environmental Assessments. These assessments are required for certain types of public plans and programmes (for example, on land use, transport, waste and water management, energy and agriculture)3. Although practical, delineation generally discourages coordination. At best, it misses synergies; at worst it creates conflict. Sectoral interdependencies are increasing. We require staggering amounts of water to provide food and energy. Water systems require (and can produce) large quantities of energy. At the same time, these sectors affect and are vulnerable to a changing climate. Moving towards more integrated governance is not trivial. It requires new skills, tools and motivation. It is here that the study by Bartos and Chester2 makes an addition. Using a recently completed integrated water-energy model, they illustrate how the water and energy systems are intertwined in Arizona. Yet the state policies are not. The researchers show that measures to reduce water use can indirectly reduce energy supply needs. Water lifting, distribution pumping and treatment are electricity intensive. Any programme that lowers water use immediately reduces electricity demand — as well as the fuels required to generate electricity. In fact, Bartos and Chester show that through introducing water-efficiency measures alone, Arizona could reach 16% of its mandated energy-efficiency target. Similarly, by introducing renewable and energy-efficiency measures, indirect water savings can reduce non-agricultural water withdrawals by 1.9−15.0%. When including rough economic estimates, the analysis concludes that the cost reductions, including these indirect savings, are significant. This results in savings not only on state-wide water bills, but also (indirectly) on energy bills — and vice versa. For the socio-economy, this could translate into cheaper services and more efficient resource use. Figure 1 indicates how much energy is embodied in, or used for, irrigation, public supply and electricity generation, as well as how the embedded energy is returned to the environment as waste water or evaporation.
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