Sediment yield response to large storm events and forest harvesting, Motueka River, New Zealand
Sediment yield response to large storm events and forest harvesting, Motueka River, New Zealand
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新西兰莫图伊卡河沉积物产量对大型风暴事件和森林采伐的响应
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
T. Hewitt
中科院分区：
文献类型：
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作者：
LR Basher;D. Hicks;B. Clapp;T. Hewitt
在Motueka流域的七个地点测量了悬浮泥沙产量（SY），以表征对产沙量变化的主要影响，并估计向塔斯曼湾输送的泥沙。利用暴雨事件与峰值流量的关系，结合长期的流量记录来计算暴雨事件的SY。在大流域尺度上，与地质和降雨相关的SY存在明显差异，但对SY的主要影响是50年一遇风暴的影响，导致源头SY增加10-20倍，海岸SY增加2-3倍。森林采伐是小流域的重要影响因素，使事件SY增加了5倍。SY的增加幅度、恢复时间和受影响的总面积均小于大风暴的影响。沿海地区的年产量变化很大，从4.9万吨到1.7万吨不等。
Suspended sediment yields (SY) were measured at seven sites in the Motueka catchment to characterise major influences on sediment yield variation and estimate sediment delivery to Tasman Bay. Relationships between storm event SY and peak flow were used with long-term flow records to calculate SY. At large catchment scale, there were clear differences in SY related to geology and rainfall, but the major influence on SY was the impact of a >50-year return period storm that caused an increase in event SY ranging from 10–20 times in the headwaters to 2–3 times at the coast. Forest harvesting was an important influence at small catchment scale, producing a five-fold increase in event SY. The magnitude of the SY increase, the time to recover and the total area affected were all smaller than the impact of large storms. Annual SY at the coast was extremely variable, ranging from 49,000 t to 1.7 Mt.