Estimating the impact of rural land management changes on catchment runoff generation in England and Wales
Estimating the impact of rural land management changes on catchment runoff generation in England and Wales
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估计英格兰和威尔士农村土地管理变化对流域径流产生的影响
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Parrott
中科院分区：
文献类型：
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作者：
T. Hess;I. Holman;S. Rose;Z. Rosolova;A. Parrott
尽管对科学文献的审查未能证明农村土地管理对洪峰径流量的影响的确凿证据，但政策制定者越来越重视农村土地管理在流域范围洪水风险管理中的作用。恶劣的土壤和田间条件会导致极端降雨事件产生更高的径流率；然而，土地条件的改善将导致不同的土地利用、土壤类型和气候条件下的径流响应。这项研究评估了田野和土壤条件的改善对英格兰和威尔士一系列土壤和植被覆盖类型的日径流量峰值的相对影响。这表明，农村土地管理的变化可望对可持续的洪水风险管理作出积极贡献，特别是对于更频繁的事件。在干旱地区治理草地下，通过改良退化的渗透土壤，可以实现最大的相对径流减少量。以耕地和草地系统土地管理改善的合理情景为例，估计了环境署集水区洪水管理计划中定义的518个政策单位的峰值径流相对减少量。对于百年一遇的事件，只有少数几个政策单位的径流预期减少量超过5%。可能有利于洪水风险管理的农村土地管理做法可能会为因成本效益原因而无法实施结构性措施的地区提供一些保护，并可能有助于抵消与气候变化有关的洪水风险预期增加的部分影响。版权所有©2010 John Wiley&Sons，Ltd.
Although reviews of the scientific literature have failed to demonstrate conclusive evidence for the impact of rural land management on peak runoff rates, increasing emphasis is being placed by policy makers on its role in catchment‐scale flood risk management. Poor soil and field conditions can lead to higher rates of runoff from extreme rainfall events; however, the improvement of land condition will lead to differing runoff responses depending on land use, soil type and climatic regime. This study has evaluated the relative impact of improvement of field and soil conditions on peak daily runoff rates for a range of soils and vegetation cover types across England and Wales. It has shown that rural land management changes could be expected to make a positive contribution to sustainable flood risk management, especially for more frequent events. The greatest relative reduction in runoff can be achieved through the improvement of degraded permeable soils under managed grassland in drier regions. Taking a plausible scenario of land management improvement in arable and grassland systems, the relative reduction in peak runoff was estimated for 518 policy units as defined in the Environment Agency's Catchment Flood Management Plans. For the 1 in 100 year event, there were only a few policy units where the expected reduction in runoff exceeded 5%. Rural land management practices which are likely to be beneficial to flood risk management may afford some protection to areas where structural measures may not be implemented for cost–benefit reasons, and may help to offset some of the anticipated increases in flood risk associated with climate change. Copyright © 2010 John Wiley & Sons, Ltd.