Attributing the hydrological impact of different land use types and their long-term dynamics through combining parsimonious hydrological modelling, alteration analysis and PLSR analysis
Attributing the hydrological impact of different land use types and their long-term dynamics through combining parsimonious hydrological modelling, alteration analysis and PLSR analysis
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DOI：
10.1016/j.scitotenv.2019.01.085
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发表时间：
2019-04-10
影响因子：
9.8
通讯作者：
Van der Zaag, P.
中科院分区：
文献类型：
--
作者：
Gebremicael, T. G.;Mohamed, Y. A.;Van der Zaag, P.
了解水文过程与环境变化之间的关系对于改善水管理非常重要。埃塞俄比亚的盖巴流域是特克泽-阿特巴拉盆地的源头，在最近的流域综合管理取得成功之前，该流域以其严重的土地退化而闻名。本研究采用综合方法分析土地管理变化造成的水文响应，包括 (i) 模拟土地利用/覆盖 (LULC) 变化的水文响应； (ii) 使用水文指标改变 (IHA) 评估水流的改变； (iii) 使用偏最小二乘回归模型 (PLSR) 量化各个 LULC 类型对水文的贡献。结果表明，与 1970 年代相比，以牺牲自然植被为代价的农业和牧场扩张使 1990 年代地表径流增加了 77%，旱季流量减少了 30%。然而，自 20 世纪 90 年代末以来，自然植被开始恢复，旱季流量增加了 16%，而地表径流量则下降了 19%。在子流域层面，径流变化更为明显，这主要与土地退化和恢复的空间分布不均匀有关。然而，低流量的增长速度在 2010 年代停止，很可能是由于灌溉取水量的增加。水文变化参数的波动与观测到的土地利用和覆盖变化一致。 PLSR 分析表明，大多数 LULC 类型与所有水文成分都有很强的相关性。这些发现表明，水条件的变化归因于观察到的 LULC 变化动态。降雨径流模型、蚀变指标和 PLSR 的综合分析能够评估环境变化对复杂流域水文的影响。 IHA 工具可以稳健地评估从水文模型获得的水流变化的幅度，而 PLSR 方法则可用于放大确定造成这种变化的 LULC。 (C) 2019 年作者。由 Elsevier B.V. 出版
Understanding the relationship between hydrological processes and environmental changes is important for improved water management. The Geba catchment in Ethiopia, forming the headwaters of Tekeze-Atbara basin, was known for its severe land degradation before the recent success in integrated watershed management. This study analyses the hydrological response attributed to land management change using an integrated approach composed of (i) simulating the hydrological response of Land Use/Cover (LULC) changes; (ii) assessing the alteration of streamflow using Alteration of Hydrological Indicators (IHA); and (iii) quantifying the contribution of individual LULC types to the hydrology using Partial Least Square Regression model (PLSR).The results show that the expansion of agricultural and grazing land at the expense of natural vegetation has increased the surface runoff 77% and decreased dry season flow by 30% in the 1990s compared to 1970s. However, natural vegetation started to recover from the late 1990s and dry season flows increased by 16%, while surface runoff declined by 19%. More pronounced changes of the streamflow were noticed at sub-catchment level, mainly associated with the uneven spatial distribution of land degradation and rehabilitation. However, the rate of increase of low-flow halted in the 2010s, most probably due to an increase of water withdrawals for irrigation. Fluctuations in hydrological alteration parameters are in agreement with the observed LULC change. The PLSR analysis demonstrates that most LULC types showed a strong association with all hydrological components. These findings demonstrate that changing water conditions are attributed to the observed LULC change dynamics. The combined analysis of rainfall-runoff modelling, alteration indicators and PLSR is able to assess the impact of environmental change on the hydrology of complex catchments. The IHA tool is robust to assess the magnitude of streamflow alterations obtained from the hydrological model while the PLSR method is useful to zoom into which LULC is responsible for this alteration. (C) 2019 The Authors. Published by Elsevier B.V.