Model analysis of forest thinning impacts on the water resources during hydrological drought periods
Model analysis of forest thinning impacts on the water resources during hydrological drought periods
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DOI：
10.1016/j.foreco.2021.119593
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发表时间：
2021-04
影响因子：
3.7
通讯作者：
H. Momiyama;T. Kumagai;T. Egusa
中科院分区：
文献类型：
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作者：
H. Momiyama;T. Kumagai;T. Egusa
在日本，最近越来越多的人呼吁间伐森林，以保护森林覆盖的山区集水区在一年中长期干旱期间的径流资源。通过8年的水文观测、利用随机模型产生的100年气象数据输出和半过程降雨-径流模型的组合，研究了森林稀疏是如何改变它们的水量平衡和产生的径流的。降雨-径流模型是在TOPMODEL模型的基础上发展起来的，该模型假设森林间伐主要通过林冠截留的变化来影响径流。这一分析的主要创新之处在于，利用所生成的100年气象数据，可以调查在最严重的干旱条件下森林稀疏对山区集水区水资源的影响。该模型通过2010-2017年在日本关东地区森林山地集水区进行的径流观测得到验证。结果表明，该模型能较好地再现径流和蒸散量在年际和年内的时间变化，并能较好地再现径流历时曲线。根据预测的100年径流历时曲线，尽管年总径流量随着间伐的增加而增加，但枯水年和正常年(枯水最少的年份和最低的50年)的低流量(在>；70%时间超越范围内的流量)都受到森林疏伐的影响较小。模拟还表明，低流量会增加更多的集水保水能力，而较高的集水保水能力会增强森林间伐对增加可用水资源的作用。这项研究将有助于规划考虑森林集水区径流的更好的森林管理。
In Japan, there has recently been an increasing call for forest thinning to conserve water resources from forested mountain catchments in terms of runoff during prolonged drought periods of the year. How their water balance and the resultant runoff are altered by forest thinning is examined using a combination of 8-year hydrological observations, 100-year meteorological data output that is generated using a stochastic model, and a semi-process-based rainfall-runoff model. The rainfall-runoff model is developed based on TOPMODEL assuming that forest thinning has an impact on runoff primarily through an alteration in canopy interception. The main novelty in this analysis is that the availability of the generated 100-year meteorological data allows the investigations of the forest thinning impacts on mountain catchment water resources under the most severe drought conditions. The model is validated against runoff observations conducted at a forested mountain catchment in the Kanto region of Japan for the period 2010–2017. It is demonstrated that the model reproduces temporal variations in runoff and evapotranspiration at inter- and intra-annual time scales, and the flow duration curves were well reproduced. On the basis of projected flow duration curves for the 100-year, despite the increase in an annual total runoff with thinning, low flow rates (the flows within the range of >70% time exceedance) in both dry and normal years (the years in which low flow are the lowest and 50th the lowest) were impacted by the forest thinning to a lesser extent. Simulations also showed that low flows would increase more with higher catchment water retention capacity, and higher catchment water retention capacity would enhance the forest thinning effect on increasing available water resources. This study would be helpful in planning for better forest management considering runoff from forested catchments.