Modeling of Gully Erosion in Ethiopia as Influenced by Changes in Rainfall and Land Use Management Practices

被引：2

作者：

Setargie, Tadesual Asamin ^{[1
,2
]}

Tsunekawa, Atsushi ^{[3
]}

Haregeweyn, Nigussie ^{[4
]}

Tsubo, Mitsuru ^{[3
]}

Rossi, Mauro ^{[5
]}

Ardizzone, Francesca ^{[5
]}

Vanmaercke, Matthias ^{[6
]}

De Geeter, Sofie ^{[6
]}

Fenta, Ayele Almaw ^{[4
]}

Ebabu, Kindiye ^{[3
,7
]}

Yibeltal, Mesenbet ^{[2
]}

Berihun, Mulatu Liyew ^{[2
,8
]}

Sultan, Dagnenet ^{[2
]}

Nzioki, Benedict ^{[1
]}

Meshesha, Taye Minichil ^{[1
,9
]}

机构：

[1] Tottori Univ, United Grad Sch Agr Sci, 4-101 Koyama Minami, Tottori 6808553, Japan

[2] Bahir Dar Univ, Bahir Dar Inst Technol, Fac Civil & Water Resources Engn, POB 26, Bahir Dar, Ethiopia

[3] Tottori Univ, Arid Land Res Ctr, 1390 Hamasaka, Tottori 6800001, Japan

[4] Tottori Univ, Int Platform Dryland Res & Educ, 1390 Hamasaka, Tottori 6800001, Japan

[5] CNR, Res Inst Geohydrol Protect, Via Madonna Alta126, I-06128 Perugia, Italy

[6] Katholieke Univ Leuven, Dept Earth & Environm Sci, Celestijnenlaan 200E, B-3001 Heverlee, Belgium

[7] Bahir Dar Univ, Coll Agr & Environm Sci, POB 1289, Bahir Dar, Ethiopia

[8] Univ Florida, Trop Res & Educ Ctr, Homestead, FL 33031 USA

[9] Debre Markos Univ, Inst Technol, Dept Hydraul & Water Resources Engn, POB 269, Debre Markos, Ethiopia

来源：

LAND | 2023年 / 12卷 / 05期

基金：

日本科学技术振兴机构; 日本学术振兴会;

关键词：

LANDPLANER; topographic threshold; GIS and RS; sustainable land management; land use/land cover; runoff curve number; dryland; CONSERVATION PRACTICES; SOIL; HIGHLANDS; SUSCEPTIBILITY; INITIATION; DYNAMICS; IMPACTS; SURFACE;

D O I：

10.3390/land12050947

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Gully erosion is one of the most extreme land degradation processes that exhibit spatial and temporal variation depending on topography, soil, climate, and land use and management characteristics. This study investigated the impact of changes in rainfall, land use/land cover (LULC), and land use management (LUM) practices on gully erosion in two midland watersheds (treated Kecha and untreated Laguna) in the Upper Blue Nile basin of Ethiopia by using the LANDPLANER model in combination with intensive field measurements and remote sensing products. We simulated gully erosion under past (in 2005), present (in 2021), and three potential future curve number conditions, each time under four rainfall scenarios (10, 30, 60, and 100 mm) using the dynamic erosion index (e), static topographic (esp), and erosion channel (esp_channel) thresholds. Density plot analyses showed that gullies frequently occur in low-lying gentle slope areas with relatively higher curve number values. The best predictions of gullies identified through true positive rates (TPR) and true negative rates (TNR) were achieved considering the static esp_channel > 1 for Kecha (TPR = 0.667 and TNR = 0.544) and the dynamic e > 0.1 for 60 mm of rainfall in Laguna (TPR = 0.769 and TNR = 0.516). Despite the 10 mm rainfall having negligible erosion-triggering potential in both watersheds, the 60 and 100 mm rainfall scenarios were 4-5 and 10-17 times, respectively, higher than the 30 mm rainfall scenario. While the LULC change in the untreated Laguna watershed increased the impact of rainfall on gully initiation by only 0-2% between 2005 and 2021, the combination of LULC and LUM significantly reduced the impact of rainfall in the treated Kecha watershed by 64-79%. Similarly, the gully initiation area in Kecha was reduced by 28% (from 33% in 2005 to 5% in 2021) due to changes in LULC and LUM practices, whereas Laguna showed little increment by only 1% (from 42% in 2005 to 43% in 2021) due to LULC change. In addition, the future predicted alternative land use planning options showed that gully initiation areas in Laguna could be reduced by 1% with only LULC conversion; 39% when only LUM practices were implemented; and 37% when both were combined. These results indicate that LUM practices outweigh the impact of LULC on gully erosion in the studied paired watersheds. Overall, LANDPLANER successfully simulated the spatio-temporal variation of gully erosion with scenario-based analyses and hence can be used to predict gullies in the study area and other data-scarce regions with similar agro-ecological settings.

引用

页数：23

共 60 条

[11] Reduced runoff and sediment loss under alternative land capability-based land use and management options in a sub-humid watershed of Ethiopia [J].