Effects of Forest Clear‐Felling on the Storm Hydrograph
Effects of Forest Clear‐Felling on the Storm Hydrograph
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DOI：
10.1029/wr006i003p00768
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发表时间：
1970-06
影响因子：
5.4
通讯作者：
J. Hewlett;J. D. Helvey
中科院分区：
文献类型：
--
作者：
J. Hewlett;J. D. Helvey
早期的猜测认为，森林蒸散量和随之而来的森林下土壤水分赤字是洪水产生的因素，这一猜测得到了配对流域实验的证实。成熟的硬木森林在阿巴拉契亚山脉南部的108英亩的集水区，经过18年的校准期后被清除。没有森林物质被移走，也没有发生地表径流。对清理前（77）和清理后（30）的所有主要风暴过程线进行的统计分析显示，砍伐后，风暴流量（快速流量）总体上显著增加了11%（0.001水平），或在平均快速流量为2.1英寸时增加了0.23英寸。砍伐后峰值流量略有增加（约6 cfsm或7%，平均峰值流量为92 cfsm），但测试结果不像快速流量那样具有决定性。对达峰时间（上升时间）、消退时间和快速流动持续时间进行了检测，准确度在其各自平均值的10%范围内（0.05水平），但未检测到治疗效应。在创纪录的7天洪水序列中，由于砍伐导致的快速流量增加从0英寸的小洪水到1.9英寸。后一个值比该地区创纪录的洪水期间预计的总快速流量（8.7英寸）增加了22%。森林蒸散对深层土壤斜坡释放的洪水的影响全年持续存在，这一结果可以用径流的可变源区概念来解释。
Earlier speculation that evapotranspiration from forests and the consequent soil water deficits under forests are factors in the production of floodwaters was verified by a paired watershed experiment. Mature hardwood forest on a 108-acre catchment in the southern Appalachians was clear-felled after an 18-year calibration period. No forest material was removed, and no overland flow (surface runoff) occurred. A statistical analysis of all major storm hydrographs before (77) and after (30) clearing revealed that after felling stormflow volume (quick flow) was significantly (0.001 level) increased 11% overall, or 0.23 inch at the mean quick flow volume of 2.1 inches. Peak discharge increased slightly after felling (about 6 cfsm or 7% at the mean peak flow of 92 cfsm), but the test was not as conclusive as in the case of quick flow volumes. Time to peak (time of rise), recession time, and quick flow duration were tested to an accuracy within 10% of their respective mean values (0.05 level), but no treatment effect was detected. Quick flow increases due to felling ranged from 0 in small floods to 1.9 inches during a record 7-day flood sequence. The latter value represented a 22% increase over the total quick flow (8.7 inches) expected during that regional record flood. The effect of forest evapotranspiration on floodwater released by deep-soil slopes persists throughout the year, a result explainable by the variable source area concept of runoff.