Vegetation changes in recent large-scale ecological restoration projects and subsequent impact on water resources in China's Loess Plateau
Vegetation changes in recent large-scale ecological restoration projects and subsequent impact on water resources in China's Loess Plateau
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DOI：
10.1016/j.scitotenv.2016.06.141
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发表时间：
2016-11-01
影响因子：
9.8
通讯作者：
Su, Huimin
中科院分区：
文献类型：
--
作者：
Li, Shuai;Liang, Wei;Su, Huimin
近年来，植被活动与气温变率的关系在我国受到了广泛的关注。然而，植被通过改变地表能量平衡（例如，干旱）引起的水资源变化尚未得到充分记录。以北方黄土高原为例，研究了植被变化的内在原因及其对径流的影响。结果表明，卫星植被指数在过去三十年中经历了显著的增长趋势，特别是在2000-2012年。大规模的生态重建，天然林保护工程和退耕还林（草）绿色工程是植被增加的主要驱动力。植被覆盖度的增加导致地表温度的降低，导致温度的升高。这种积极的影响可以抵消较高的蒸散量和净效应是白天的地表温度下降。植被恢复后蒸散量增加是径流系数降低的主要原因。降水偏少、城镇及工农业用水量增加等因素也是径流量减少的重要原因。这两个生态恢复工程对整个生态系统服务功能的影响既有积极的一面，也有消极的一面。因此，需要长期持续监测。(C)2016爱思唯尔B. V.保留所有权利。
Recently, relationship between vegetation activity and temperature variability has received much attention in China. However, vegetation-induced changes in water resources through changing land surface energy balance (e.g. albedo), has not been well documented. This study investigates the underlying causes of vegetation change and subsequent impacts on runoff for the Northern Shaanxi Loess Plateau. Results show that satellite-derived vegetation index has experienced a significantly increasing trend during the past three decades, especially during 2000-2012. Large-scale ecological restorations, i.e., the Natural Forest Conservation project and the Grain for Green project, are found to be the primary driving factors for vegetation increase. The increased vegetation coverage induces decrease in surface albedo and results in an increase in temperature. This positive effect can be counteracted by higher evapotranspiration and the net effect is a decrease in daytime land surface temperature. A higher evapotranspiration rate from restored vegetation is the primary reason for the reduced runoff coefficient. Other factors including less heavy precipitation, increased water consumption from town, industry and agriculture also appear to be the important causes for the reduction of runoff. These two ecological restoration projects produce both positive and negative effects on the overall ecosystem services. Thus, long-term continuous monitoring is needed. (C) 2016 Elsevier B.V. All rights reserved.