Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1002/ldr.2424 |
Sediment in Alluvial and Lacustrine Debris Fans as an Indicator for Land Degradation Around Lake Ashenge (Ethiopia) | |
Lanckriet, Sil1; Asfaha, Tesfaalem1,2; Frankl, Amaury1; Zenebe, Amanuel3; Nyssen, Jan1 | |
通讯作者 | Lanckriet, Sil |
来源期刊 | LAND DEGRADATION & DEVELOPMENT |
ISSN | 1085-3278 |
EISSN | 1099-145X |
出版年 | 2016 |
卷号 | 27期号:2页码:258-269 |
英文摘要 | Sediments deposited by (paleo) flash floods can hold valuable information on processes of environmental change, land degradation or desertification. In order to assess the suitability of flash flood deposits as proxies for land degradation, we monitored a representative gully segment in North Ethiopia (Ashenge catchment), investigated a sequence of alluvial debris fans downstream of this segment and dated a neighbouring subaquatic debris fan using short-lived Pb-210 isotope counting. During one rainy season (July-September 2014), we measured daily rainfall, peak discharge, bedload transport, suspended sediment load and sediment deposition rates. The data show that sediment deposition in the debris fans is significantly dependent on micro-topography (net incision in micro-channels) (p<01) and position within the sequence (net incision farther away from the lake) (p<005). As sediment transfer to the lake significantly depends on the balance between available water and sediment (ratio rainfall depth/bedload transport) (p<005), we could reconstruct the hydro-sedimentary evolution of the gully over the past half century and validate it with aerial photographs and semi-structured interviews. The findings are consistent with the short-lived isotope count results, indicating increased sediment supply from the 1970s onwards, when little amounts of clay were deposited in the lake (<5%), and a subrecent clear water effect that resulted in increased deposition rates of clay in the lacustrine debris fan. Overall, our analysis indicates that debris fan sediments can be used to estimate past environmental degradation rates, if the contemporary water and sediment behaviour is well understood. Copyright (c) 2015 John Wiley & Sons, Ltd. |
英文关键词 | sediment gully hydrogeomorphology Pb-210 short-lived isotopes |
类型 | Article |
语种 | 英语 |
国家 | Belgium ; Ethiopia |
收录类别 | SCI-E |
WOS记录号 | WOS:000370151700016 |
WOS关键词 | NORTHERN ETHIOPIA ; GULLY EROSION ; DEATH-VALLEY ; HIGHLANDS ; TRANSPORT ; CALIFORNIA ; DYNAMICS ; STREAMS ; RATES |
WOS类目 | Environmental Sciences ; Soil Science |
WOS研究方向 | Environmental Sciences & Ecology ; Agriculture |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/194924 |
作者单位 | 1.Univ Ghent, Dept Geog, Krijgslaan 281,S8, B-9000 Ghent, Belgium; 2.Mekelle Univ, Dept Geog, Mekelle, Ethiopia; 3.Mekelle Univ, Dept Land Resources Management Environm Protect, Mekelle, Ethiopia |
推荐引用方式 GB/T 7714 | Lanckriet, Sil,Asfaha, Tesfaalem,Frankl, Amaury,et al. Sediment in Alluvial and Lacustrine Debris Fans as an Indicator for Land Degradation Around Lake Ashenge (Ethiopia)[J],2016,27(2):258-269. |
APA | Lanckriet, Sil,Asfaha, Tesfaalem,Frankl, Amaury,Zenebe, Amanuel,&Nyssen, Jan.(2016).Sediment in Alluvial and Lacustrine Debris Fans as an Indicator for Land Degradation Around Lake Ashenge (Ethiopia).LAND DEGRADATION & DEVELOPMENT,27(2),258-269. |
MLA | Lanckriet, Sil,et al."Sediment in Alluvial and Lacustrine Debris Fans as an Indicator for Land Degradation Around Lake Ashenge (Ethiopia)".LAND DEGRADATION & DEVELOPMENT 27.2(2016):258-269. |
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