Distinguishing streamflow trends caused by changes in climate, forest cover, and permafrost in a large watershed in northeastern China
Distinguishing streamflow trends caused by changes in climate, forest cover, and permafrost in a large watershed in northeastern China
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DOI：
10.1002/hyp.11160
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发表时间：
2017-05
影响因子：
3.2
通讯作者：
L. Duan;Xiu-ling Man;B. Kurylyk;Tijiu Cai;Qiang Li
中科院分区：
文献类型：
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作者：
L. Duan;Xiu-ling Man;B. Kurylyk;Tijiu Cai;Qiang Li
了解河流如何应对土地覆盖、气候和地下条件的变化，对于可持续地管理水资源和生态系统至关重要。在这项研究中，长期的水文，气候，和卫星数据（1973-2012）从塔河上游流域对大兴安岭2359 km ~ 2的100个样地进行了气候变率的相对水文效应分析（系统输入）以及森林覆盖变化和冻土融化的综合影响（系统特性）对年平均径流量（系统响应）的影响，采用2种方法：基于灵敏度的方法和Kendall-Theil稳健线方法。研究期间分为森林采伐期（1973-1987）、森林稳定期（1988-2001）和森林恢复期（2002-2012）。结果表明，森林采伐和多年冻土融化对森林采伐期至森林稳定期径流量（+47.0 mm）的综合影响约为与气候变率（+20.2 mm）相关的影响的两倍。同样，从森林稳定期到森林恢复期，森林恢复和冻土融化的综合影响导致的年平均径流量减少（-38.0 mm）远大于气候变率导致的减少（-22.2 mm）。一个简单的方法被用来区分森林覆盖变化和冻土融化的不同影响，但区分这些影响是困难的，由于与冻土融化相关的地表和地下水文连通性的变化。结果强调，需要考虑多个径流驱动程序在未来的流域和水生生态系统管理。由于大兴安岭生态和水文对干扰的敏感性，森林采伐可能会对该地区的生态水文过程产生负面影响，森林物种转换在森林恢复过程中的作用有待进一步研究。
Understanding how rivers respond to changes in land cover, climate, and subsurface conditions is critical for sustainably managing water resources and ecosystems. In this study, long‐term hydrologic, climate, and satellite data (1973–2012) from the Upper Tahe River watershed (2359 km2) in the Da Hinggan Mountains of northeast China were analysed to quantify the relative hydrologic effects of climate variability (system input) and the combined influences of forest cover change and permafrost thaw (system characteristics) on average annual streamflow (system response) using 2 methods: the sensitivity‐based method and the Kendall–Theil robust line method. The study period was subdivided into a forest harvesting period (1973–1987), a forest stability period (1988–2001), and a forest recovery period (2002–2012). The results indicated that the combined effects of forest harvesting and permafrost thaw on streamflow (+ 47.0 mm) from the forest harvesting period to the forest stability period was approximately twice as large as the effect associated with climate variability (+20.2 mm). Similarly, from the forest stability period to the forest recovery period, the decrease in average annual streamflow attributed to the combined effects of forest recovery and permafrost thaw (−38.0 mm) was much greater than the decrease due to climate variability (−22.2 mm). A simple method was used to separate the distinct impacts of forest cover change and permafrost thaw, but distinguishing these influences is difficult due to changes in surface and subsurface hydrologic connectivity associated with permafrost thaw. The results highlight the need to consider multiple streamflow drivers in future watershed and aquatic ecosystem management. Due to the ecological and hydrological susceptibility to disturbances in the Da Hinggan Mountains, forest harvesting will likely negatively impact ecohydrological processes in this region, and the effects of forest species transition in the forest recovery process should be further investigated.