The impact of land-use/land cover changes on water balance of the heterogeneous Buzi sub-catchment, Zimbabwe
The impact of land-use/land cover changes on water balance of the heterogeneous Buzi sub-catchment, Zimbabwe
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DOI：
10.1016/j.rsase.2020.100292
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发表时间：
2020-04-01
影响因子：
4.7
通讯作者：
Mushore, Terence
中科院分区：
文献类型：
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作者：
Chemura, Abel;Rwasoka, Donald;Mushore, Terence
在自然和受干扰的环境中，生态、物理和水文特征之间相互作用的性质决定了土地覆盖变化对地表和次地表水文的影响，但这些相互作用的性质尚未得到很好的理解。对2009 - 2017年津巴布韦布齐流域水通量的时空动态及其与土地覆盖变化的关系进行了评价。为了实现这一目标，使用极端梯度增强（XGBoost）算法，从30米Landsat数据中描述了所研究地区的土地覆盖动态。经过土地覆被分类，关键水分平衡成分为；估算了2009年和2017年各类别的截留、蒸腾和蒸散（ET）贡献。两个时期Landsat数据的图像分类总体精度在80%以上。结果表明：2009年（25.4%）至2017年（22.5%），人工林土地覆被类型占比略有下降；根据土地覆盖类型划分年度截留、蒸腾和ET，流域内最高的ET来自种植，而种植茶叶的土地覆盖类型在流域内截留、蒸腾和ET最高。流域东部蒸散量、截留量和蒸腾量较高。在流域水平上，2017年的水分平衡高于2009年，部分原因是人工林覆盖类型的减少。
The nature of interactions between ecological, physical and hydrological characteristics that determine the effects of land cover change on surface and sub-surface hydrology is not well understood in both natural and disturbed environments. The spatiotemporal dynamics of water fluxes and their relationship with land cover changes between 2009 and 2017 in the headwater Buzi sub-catchment in Zimbabwe is evaluated. To achieve this, land cover dynamics for the area under study were characterised from the 30 m Landsat data, using the eXtreme Gradient Boosting (XGBoost) algorithm. After the land cover classification, the key water balance components namely; interception, transpiration and evapotranspiration (ET) contributions for each class in 2009 and 2017 were estimated. Image classification of Landsat data achieved good overall accuracies above 80% for the two periods. Results showed that the percentage of the plantation land cover types decreased slightly between 2009 (25.4%) and 2017 (22.5%). Partitioning the annual interception, transpiration and ET according to land cover classes showed that the highest amounts of ET in the basin were from plantation where land cover types with tea had the highest interception, transpiration and ET in the catchment. Higher ET, interception and transpiration were observed in the eastern parts of the catchment. At catchment level, results show that 2017 had a higher water balance than 2009, which was partly explained by the decrease in plantation cover type.