Environmental water incentive policy and return flows
Environmental water incentive policy and return flows
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DOI：
10.1029/2008wr007445
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发表时间：
2010-04
影响因子：
5.4
通讯作者：
M. Qureshi;K. Schwabe;J. Connor;M. Kirby
中科院分区：
文献类型：
--
作者：
M. Qureshi;K. Schwabe;J. Connor;M. Kirby
随着城市、工业和农业用水需求的增加以及预计在气候变化下供应的减少，在许多干旱和半干旱流域，对环境的分配非常低。因此，许多政府正在努力增加环境流量，通常是通过以市场为导向的机制，包括补偿灌溉农业（大多数流域中最大的用水户），以减少改道。由于减少部分调水可以构成下游消费水权或环境流量的基础，因此在恢复环境用水的政策方面出现了广泛记录的挑战。本文对澳大利亚墨累—达令盆地（MDB）部分地区为环境流动获取水的两种激励政策进行了实证比较。一项政策包括向灌溉公司和输水公司支付资金和管理投资，以改善农田灌溉和输水；另一项政策是让政府在活跃的MDB水市场上从灌溉商那里购买水。结果表明：第一种方案的回流减少幅度较大，而第二种方案往往会导致显著的灌溉土地退耕，耗用减少幅度较大，而回流减少幅度较小。在灌溉损失导致很少有用回报流的情况下（例如，在某些情况下，蒸发损失减少或干旱期间），提高效率的投资可能提供一些具有成本效益的机会。如果损失的很大一部分形成了有价值的回报流，就很难证明涉及灌溉和运输系统升级投资支付的政策的成本效益。
With increasing urban, industrial, and agricultural water demand and projected reduced supply under climate change, allocations to the environment are critically low in many arid and semiarid basins. Consequently, many governments are striving to augment environmental flows, often through market‐oriented mechanisms that involve compensating irrigated agriculture, the largest water user in most basins, for reducing diversions. A widely documented challenge with policies to recover water for the environment arises because part of the water diversion reduction can form the basis for downstream consumptive water rights or environmental flows. This article gives an empirical comparison of two incentive policies to acquire water for environmental flows for a part of the Murray‐Darling Basin (MDB), Australia. One policy consists of paying irrigators and water delivery firms to make capital and management investments that improve on‐farm irrigation and water‐conveyance; the other policy consists of having the government buy water from irrigators on the active MDB water market. The results show that the first option results in relatively larger return flow reduction, while the second option tends to induce significant irrigated land retirement with relatively large reductions in consumptive use and small reductions in return flow. In cases where irrigation losses result in little useful return flow (e.g., evaporative loss reduction or during drought in some instances), efficiency‐improving investments may provide some cost‐effective opportunities. Where a large portion of loss forms valuable return flow, it is difficult to make a case for the cost‐effectiveness of policies involving payments for investments in irrigation and conveyance system upgrades.