干旱区生态环境知识资源中心(Arid): Predicting gully densities at sub-continental scales: a case study for the Horn of Africa

Arid

DOI	10.1002/esp.4999
	Predicting gully densities at sub-continental scales: a case study for the Horn of Africa
	Vanmaercke, Matthias; Chen, Yixian; Haregeweyn, Nigussie; De Geeter, Sofie; Campforts, Benjamin; Heyndrickx, Wouter; Tsunekawa, Atsushi; Poesen, Jean
通讯作者	Vanmaercke, M
来源期刊	EARTH SURFACE PROCESSES AND LANDFORMS
ISSN	0197-9337
EISSN	1096-9837
出版年	2020
卷号	45 期号:15 页码:3763-3779
英文摘要	Despite its environmental and scientific significance, predicting gully erosion remains problematic. This is especially so in strongly contrasting and degraded regions such as the Horn of Africa. Machine learning algorithms such as random forests (RF) offer great potential to deal with the complex, often non-linear, nature of factors controlling gully erosion. Nonetheless, their applicability at regional to continental scales remains largely untested. Moreover, such algorithms require large amounts of observations for model training and testing. Collecting such data remains an important bottleneck. Here we help to address these gaps by developing and testing a methodology to simulate gully densities across Ethiopia, Eritrea and Djibouti (total area: 1.2 million km(2)). We propose a methodology to quickly assess the gully head density (GHD) for representative 1 km(2)study sites by visually scoring the presence of gullies in Google Earth and then converting these scores to realistic estimates of GHD. Based on this approach, we compiled GHD observations for 1,700 sites. We used these data to train sets of RF regression models that simulate GHD at a 1 km(2)resolution, based on topographic/geomorphic, land cover, soil and rainfall conditions. Our approach also accounts for uncertainties in GHD observations. Independent validations showed generally acceptable simulations of regional GHD patterns. We further show that: (i) model performance strongly depends on the amount of training data used, (ii) large prediction errors mainly occur in areas where also the predicted uncertainty is large and (iii) collecting additional training data for these areas results in more drastic model performance improvements. Analyses of the feature importance of predictor variables further showed that patterns of GHD across the Horn of Africa strongly depend on NDVI and annual rainfall, but also on normalized steepness index (k(sn)) and distance to rivers. Overall, our work opens promising perspectives to assess gully densities at continental scales. (c) 2020 John Wiley & Sons, Ltd.
英文关键词	Gully erosion Ethiopia Eritrea Djibouti Google Earth Land degradation Random forests Arid region
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000572947400001
WOS关键词	CONCENTRATED FLOW EROSION ; SEDIMENT YIELD ; SOIL-EROSION ; LAND-USE ; TOPOGRAPHIC THRESHOLD ; TEMPORAL VARIABILITY ; NORTHERN ETHIOPIA ; HEAD DEVELOPMENT ; REGIONAL SCALES ; STONE BUNDS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
来源机构	西北农林科技大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/328276
作者单位	[Vanmaercke, Matthias; Chen, Yixian; De Geeter, Sofie] Univ Liege, Dept Geog, Liege, Belgium; [Chen, Yixian] Chinese Acad Sci, Inst Soil & Water Conservat, Yangling, Shaanxi, Peoples R China; [Chen, Yixian] Minist Water Resources, Yangling, Shaanxi, Peoples R China; [Haregeweyn, Nigussie] Tottori Univ, Int Platform Dryland Res & Educ, Tottori 6800001, Japan; [De Geeter, Sofie; Poesen, Jean] Univ Leuven, Dept Earth & Environm Sci, Div Geog & Tourism, Leuven, Belgium; [Campforts, Benjamin] Univ Colorado, Inst Arctic & Alpine Res, CSDMS, Boulder, CO 80309 USA; [Tsunekawa, Atsushi] Tottori Univ, Arid Land Res Ctr, 1390 Hamasaka, Tottori 6800001, Japan; [Poesen, Jean] UMCS, Fac Earth Sci & Spatial Management, Lublin, Poland
推荐引用方式 GB/T 7714	Vanmaercke, Matthias,Chen, Yixian,Haregeweyn, Nigussie,et al. Predicting gully densities at sub-continental scales: a case study for the Horn of Africa[J]. 西北农林科技大学,2020,45(15):3763-3779.
APA	Vanmaercke, Matthias.,Chen, Yixian.,Haregeweyn, Nigussie.,De Geeter, Sofie.,Campforts, Benjamin.,...&Poesen, Jean.(2020).Predicting gully densities at sub-continental scales: a case study for the Horn of Africa.EARTH SURFACE PROCESSES AND LANDFORMS,45(15),3763-3779.
MLA	Vanmaercke, Matthias,et al."Predicting gully densities at sub-continental scales: a case study for the Horn of Africa".EARTH SURFACE PROCESSES AND LANDFORMS 45.15(2020):3763-3779.