[en] Agricultural terraces are a commonly applied soil and water conservation strategy on steep and intensely cultivated hillslopes. Yet agricultural terraces can lead to an increased incidence of landslides. Nevertheless, their effects on hillslope stability remain poorly studied, especially in the tropical Global South, where terraces are increasingly implemented. Here we investigate to what extent the presence of such terraces may increase the incidence of landslides in the densely-populated northwestern Rwanda. For this, we mapped three important landslide events that were triggered by distinct and intense rainfall events in the region and analyzed the relation of these landslides to the presence of terraces and other controlling factors. Based on an inventory of >4,600 mostly shallow landslides in these three events, we show that landslides are about three times more likely to occur on terraced hillslopes as compared to non-terraced hillslopes. However, our results also demonstrate important variability between the events. While the effect was most pronounced for the largest 2020-event, the other two events, 2016 and 2018, showed a less clear or even negative impact of terracing on landslide occurrence. Furthermore, we observed this effect mainly on moderately to highly susceptible hillslopes and less so in areas with a very high landslide susceptibility. Landslides on terraces also tend to be slightly smaller than their counterparts in non-terraced areas. These findings have important implications for both landslide susceptibility assessment and land management.
Landslide and flood hazards and vulnerability in NW Rwanda: towards applicable land management and disaster risk reduction (LAFHAZAV)
Funders :
ARES CCD - Académie de Recherche et d'Enseignement Supérieur. Coopération au Développement
Funding number :
COOP-CONV-20-015
Funding text :
The Académie de Recherche et d'Enseignement Supérieur (ARES), in collaboration with the University of Liège (ULiège), the Royal Museum for Central Africa (RMCA), the University of Namur (UNamur), the University of Rwanda, Rwanda Polytechnics, and INES-Ruhengeri, financially supported this work through the research and development project "Landslide and flood hazards and vulnerability in NW Rwanda: towards applicable land management and disaster risk reduction" (LAFHAZAV).
Commentary :
This paper is in the AGU spotlight (https://eos.org/thelandslideblog/rwanda-terraces-1?utm_campaign=ealert)
Agnoletti, M., Errico, A., Santoro, A., Dani, A., Preti, F., Terraced landscapes and hydrogeological risk. Effects of land abandonment in Cinque Terre (Italy) during Severe rainfall events. Sustainability, 11, 2019, 235, 10.3390/su11010235.
Al Qudah, K., Abdelal, Q., Hamarneh, C., Abu-Jaber, N., Taming the torrents: the hydrological impacts of ancient terracing practices in Jordan. J. Hydrol. 542 (2016), 913–922, 10.1016/j.jhydrol.2016.09.061.
Amsalu, A., de Graaff, J., Farmers’ views of soil erosion problems and their conservation knowledge at Beressa watershed, central highlands of Ethiopia. Agric. Hum. Values 23:1 (2006), 99–108, 10.1007/s10460-005-5872-4.
Arnáez, J., Lana-Renault, N., Lasanta, T., Ruiz-Flaño, P., Castroviejo, J., Effects of farming terraces on hydrological and geomorphological processes. A review. Catena 128 (2015), 122–134, 10.1016/j.catena.2015.01.021.
Bartelletti, C., Giannecchini, R., D'Amato Avanzi, G., Galanti, Y., Mazzali, A., The influence of geological-morphological and land use settings on shallow landslides in the Pogliaschina T. Basin (northern apennines, Italy). J. Maps 13:2 (2017), 142–152, 10.1080/17445647.2017.1279082.
Bizoza, A. R., 2011. Farmers, institutions and land conservation: institutional economic analysis of bench terraces in the highlands of Rwanda. (Unpublished doctoral thesis) at Wageningen University, Netherlands.
Broeckx, J., Vanmaercke, M., Duchateau, R., Poesen, J., A data-based landslide susceptibility map of Africa. Earth Sci. Rev. 185:2017 (2018), 102–121, 10.1016/j.earscirev.2018.05.002.
Brown, A.G., Fallu, D., Walsh, K., Cucchiaro, S., Tarolli, P., Zhao, P., Pears, B.R., van Oost, K., Snape, L., Lang, A., Albert, R.M., Alsos, I.G., Waddington, C., Ending the Cinderella status of terraces and lynchets in Europe: the geomorphology of agricultural terraces and implications for ecosystem services and climate adaptation. Geomorphology, 379, 2021, 107579, 10.1016/j.geomorph.2020.107579.
Cammeraat, E.L.H., Scale dependent thresholds in hydrological and erosion response of a semi-arid catchment in southeast Spain. Agr. Ecosyst. Environ. 104:2 (2004), 317–332, 10.1016/j.agee.2004.01.032.
Casagli, N., Intrieri, E., Tofani, V., Gigli, G., Raspini, F., Landslide detection, monitoring and prediction with remote-sensing techniques. Nat. Rev. Earth Environ. 4:1 (2023), 51–64, 10.1038/s43017-022-00373-x.
Cevasco, A., Brandolini, P., Scopesi, C., Rellini, I., Relationships between geo-hydrological processes induced by heavy rainfall and land-use: the case of 25 October 2011 in the Vernazza catchment (Cinque Terre, NW Italy). J. Maps 9:2 (2013), 289–298, 10.1080/17445647.2013.780188.
Chen, C., Huang, W., Land use change and landslide characteristics analysis for community-based disaster mitigation. Environ. Monit. Assess. 185:5 (2013), 4125–4139, 10.1007/s10661-012-2855-y.
Chen, Y., Vanmaercke, M., Jiao, J., Bai, L., Tang, B., Wang, N., Zhang, Y., Wang, H., Quantifying the importance of different erosion processes and soil and water conservation measure collapses following an extreme rainstorm in the Chinese Loess Plateau. Land Degrad. Dev. 34:2 (2023), 403–422, 10.1002/ldr.4468.
Corominas, J., van Westen, C., Frattini, P., Cascini, L., Malet, J.P., Fotopoulou, S., Catani, F., Van Den Eeckhaut, M., Mavrouli, O., Agliardi, F., Pitilakis, K., Winter, M.G., Pastor, M., Ferlisi, S., Tofani, V., Hervás, J., Smith, J.T., Recommendations for the quantitative analysis of landslide risk. Bull. Eng. Geol. Environ. 73:2 (2014), 209–263, 10.1007/s10064-013-0538-8.
Critchley, W., Bruijnzeel, L., 1995. Terrace risers: Erosion control or sediment source. In: Sustainable Reconstruction of Highland and Headwater Regions; Singh, R.B.A., Haigh, M.J., Eds.; Oxford and IBH Publishing: New Delhi, India; pp. 529–541.
Crosta, G.B., Dal Negro, P., Frattini, P., Soil slips and debris flows on terraced slopes. Nat. Hazards Earth Syst. Sci. 3:1/2 (2003), 31–42, 10.5194/nhess-3-31-2003.
Crozier, M.J., Glade, T., 2005. Landslide hazard and risk: issues, concepts and approach. In: Landslide Hazard and Risk. doi: 10.1002/9780470012659.ch1.
de Graaff, J., Amsalu, A., Bodnár, F., Kessler, A., Posthumus, H., Tenge, A., Factors influencing adoption and continued use of long-term soil and water conservation measures in five developing countries. Appl. Geogr. 28:4 (2008), 271–280, 10.1016/j.apgeog.2008.05.001.
Deijns, A.A.J., Dewitte, O., Thiery, W., d'Oreye, N., Malet, J.-P., Kervyn, F., Timing landslide and flash flood events from SAR satellite: a regionally applicable methodology illustrated in African cloud-covered tropical environments. Nat. Hazards Earth Syst. Sci. 22:11 (2022), 3679–3700, 10.5194/nhess-22-3679-2022.
Deijns, A.A.J., Michéa, D., Déprez, A., Malet, J.-P., Kervyn, F., Thiery, W., Dewitte, O., A semi-supervised multi-temporal landslide and flash flood event detection methodology for unexplored regions using massive satellite image time series. ISPRS J. Photogramm. Remote Sens. 215 (2024), 400–418, 10.1016/j.isprsjprs.2024.07.010.
Deng, C., Zhang, G., Liu, Y., Nie, X., Li, Z., Liu, J., Zhu, D., Advantages and disadvantages of terracing: a comprehensive review. Int. Soil Water Conserv. Res. 9:3 (2021), 344–359.
Depicker, A., Jacobs, L., Delvaux, D., Havenith, H.-B., Maki Mateso, J.-C., Govers, G., Dewitte, O., The added value of a regional landslide susceptibility assessment: the western branch of the East African Rift. Geomorphology, 353, 2020, 106886, 10.1016/j.geomorph.2019.106886.
Depicker, A., Govers, G., Jacobs, L., Campforts, B., Uwihirwe, J., Dewitte, O., Interactions between deforestation, landscape rejuvenation, and shallow landslides in the North Tanganyika-Kivu rift region. Africa. Earth Surface Dynamics 9:3 (2021), 445–462, 10.5194/esurf-9-445-2021.
Depicker, A., Jacobs, L., Mboga, N., Smets, B., Van Rompaey, A., Lennert, M., Wolff, E., Kervyn, F., Michellier, C., Dewitte, O., Govers, G., Historical dynamics of landslide risk from population and forest-cover changes in the Kivu Rift. Nat. Sustainability 4:11 (2021), 965–974, 10.1038/s41893-021-00757-9.
Dewitte, O., Dille, A., Depicker, A., Kubwimana, D., Maki Mateso, J.-C., Mugaruka Bibentyo, T., Uwihirwe, J., Monsieurs, E., Constraining landslide timing in a data-scarce context: from recent to very old processes in the tropical environment of the North Tanganyika-Kivu Rift region. Landslides 18:1 (2021), 161–177, 10.1007/s10346-020-01452-0.
Dewitte, O., Depicker, A., Moeyersons, J., Dille, A., 2022. Mass movements in tropical climates. In: Shroder, J.J.F. (Ed.), Treatise on Geomorphology, vol. 5. Elsevier, Academic Press, pp. 338–349. doi: 10.1016/B978-0-12-818234-5.00118-8, ISBN: 9780128182345.
Dille, A., Dewitte, O., Handwerger, A.L., d'Oreye, N., Derauw, D., Ganza Bamulezi, G., Ilombe Mawe, G., Michellier, C., Moeyersons, J., Monsieurs, E., Mugaruka Bibentyo, T., Samsonov, S., Smets, B., Kervyn, M., Kervyn, F., Acceleration of a large deep-seated tropical landslide due to urbanization feedbacks. Nat. Geosci. 15 (2022), 1048–1055, 10.1038/s41561-022-01073-3.
Dorren, L., Rey, F., A review of the effect of terracing on erosion. Soil Conserv. Protect. Europe, 2004, 97–108 http://139.191.1.96/projects/scape/transf/Dorren_Rey.pdf.
Dotterweich, M., The history of human-induced soil erosion: geomorphic legacies, early descriptions and research, and the development of soil conservation-A global synopsis. Geomorphology 201 (2013), 1–34, 10.1016/j.geomorph.2013.07.021.
Ebabu, K., Tsunekawa, A., Haregeweyn, N., Tsubo, M., Adgo, E., Fenta, A.A., Poesen, J., Global analysis of cover management and support practice factors that control soil erosion and conservation. Int. Soil Water Conserv. Res. 10:2 (2022), 161–176.
Fashaho, A., Ndegwa, G.M., Lelei, J.J., Musandu, A.O., Mwonga, S.M., Effect of land terracing on soil physical properties across slope positions and profile depths in medium and high altitude regions of Rwanda. S. Afr. J. Plant Soil 37:2 (2020), 91–100, 10.1080/02571862.2019.1665722.
Food and Agriculture Organization (FAO), 2000. Manual on Integrated Soil Management and Conservation Practices. FAO Land and Water Bulletin, 8(ISBN 92-5-104417-1), pp. 15–214.
Gabet, E., Dunne, T., Landslides on coastal sage-scrub and grassland hillslopes in a severe El Niño winter: the effects of vegetation conversion on sediment delivery. Bull. Geol. Soc. Am. 114:8 (2002), 983–990, 10.1130/0016-7606(2002)114<0983:LOCSSA>2.0.CO;2.
García-Ruiz, J.M., Nadal-Romero, E., Lana-Renault, N., Beguería, S., Erosion in Mediterranean landscapes: changes and future challenges. Geomorphology 198 (2013), 20–36, 10.1016/j.geomorph.2013.05.023.
Garden, R.A.M., Gerard, A.J., 2003. Runoff and soil erosion on cultivated rainfed terraces in the Middle Hills of Nepal.
Gariano, S.L., Guzzetti, F., Landslides in a changing climate. Earth Sci. Rev. 162 (2016), 227–252, 10.1016/j.earscirev.2016.08.011.
Glade, T., Landslide occurrence as a response to land use change: a review of evidence from New Zealand. Catena 51 (2003), 297–314, 10.1016/S0341-8162(02)00170.
Glade, T., Anderson, M., Crozier, M.J., 2012. Landslide Hazard and Risk. John Wiley & Sons Ltd.; 111 River Street, Hoboken, NJ 07030, USA. doi: 10.1002/9780470012659.
Guzzetti, F., Peruccacci, S., Rossi, M., Stark, C.P., Rainfall thresholds for the initiation of landslides in central and southern Europe. Meteorol. Atmos. Phys. 267 (2007), 239–267, 10.1007/s00703-007-0262-7.
Guzzetti, F., Mondini, A.C., Cardinali, M., Fiorucci, F., Santangelo, M., Chang, K.T., Landslide inventory maps: new tools for an old problem. Earth Sci. Rev. 112 (2012), 42–66, 10.1016/j.earscirev.2012.02.001.
Hungr, O., Leroueil, S., Picarelli, L., The Varnes classification of landslide types, an update. Landslides 11:2 (2014), 167–194, 10.1007/s10346-013-0436-y.
Jacobs, L., Dewitte, O., Poesen, J., Delvaux, D., Thiery, W., Kervyn, M., The Rwenzori Mountains, a landslide-prone region?. Landslides 13 (2016), 519–536, 10.1007/s10346-015-0582-5.
Jones, J.N., Boulton, S.J., Bennett, G.L., Stokes, M., Bennett, G.L., Whitworth, M.R.Z., 30-year record of Himalaya mass-wasting reveals landscape perturbations by extreme events. Nat. Commun., 12, 2021, 6701, 10.1038/s41467-021-26964-8.
Kagabo, D.M., Stroosnijder, L., Visser, S.M., Moore, D., Soil erosion, soil fertility and crop yield on slow-forming terraces in the highlands of Buberuka, Rwanda. Soil Tillage Res. 128 (2013), 23–29, 10.1016/j.still.2012.11.002.
Kitutu, M.G., Muwanga, A., Poesen, J., Deckers, J.A., Farmer's perception on landslide occurrences in Bududa District, Eastern Uganda. Afr. J. Agric. Res. 6:1 (2011), 7–18, 10.5897/AJAR09.158.
Koulouri, M., Giourga, C., Land abandonment and slope gradient as key factors of soil erosion in Mediterranean terraced lands. Catena 69:3 (2007), 274–281, 10.1016/j.catena.2006.07.001.
Kuria, A.W., Barrios, E., Pagella, T., Muthuri, C.W., Mukuralinda, A., Sinclair, F.L., Farmers’ knowledge of soil quality indicators along a land degradation gradient in Rwanda. Geoderma Reg., 16, 2019, e00199, 10.1016/j.geodrs.2018.e00199.
LaFevor, M.C., Restoration of degraded agricultural terraces: rebuilding landscape structure and process. J. Environ. Manage. 138 (2014), 32–42, 10.1016/j.jenvman.2013.11.019.
Lee, S., Pradhan, B., Landslide hazard mapping at Selangor, Malaysia using frequency ratio and logistic regression models. Landslides 4:1 (2007), 33–41, 10.1007/s10346-006-0047-y.
Lesschen, J.P., L. H., Cammeraat, T.N., 2008. Erosion and terrace failure due to agricultural land abandonment in a semi-arid environment. Earth Surf. Process. Landforms, 33(1676), 1574–1584. Doi: 10.1002/esp.1676.
Lewis, L.A., Terracing and accelerated soil loss on rwandian steeplands: a preliminary investigation of the implications of human activities affecting soil movement. Land Degrad. Dev. 3:4 (1992), 241–246, 10.1002/ldr.3400030405.
Lewis, S.L., Edwards, D.P., Galbraith, D., Increasing human dominance of tropical forests. Science 349:6250 (2015), 827–832.
Lewis, L.A., Nyamulinda, V., The critical role of human activities in land degradation in Rwanda. Land Degrad. Dev. 7:1 (1996), 47–55, 10.1002/(sici)1099-145x(199603)7:1<47::aid-ldr213>3.3.co;2-d.
Londoño, A.C., Pattern and rate of erosion inferred from Inca agricultural terraces in arid southern Peru. Geomorphology 99 (2008), 13–25, 10.1016/j.geomorph.2007.09.014.
Londoño, A.C., Williams, P.R., Hart, M.L., A change in landscape: lessons learned from abandonment of ancient Wari agricultural terraces in Southern Peru. J. Environ. Manage. 202 (2017), 532–542, 10.1016/j.jenvman.2017.01.012.
Maes, J., Kervyn, M., de Hontheim, A., Dewitte, O., Jacobs, L., Mertens, K., Vanmaercke, M., Vranken, L., Poesen, J., Landslide risk reduction measures: a review of practices and challenges for the tropics. Prog. Phys. Geogr. 41:2 (2017), 191–221, 10.1177/0309133316689344.
Maki Mateso, J.-C., Bielders, C.L., Monsieurs, E., Depicker, A., Smets, B., Tambala, T., Bagalwa Mateso, L., Dewitte, O., Characteristics and causes of natural and human-induced landslides in a tropical mountainous region: the rift flank west of Lake Kivu (Democratic Republic of the Congo). Nat. Hazards Earth Syst. Sci. 23:2 (2023), 643–666, 10.5194/nhess-23-643-2023.
Malamud, B.D., Turcotte, D.L., Guzzetti, F., Reichenbach, P., Landslide inventories and their statistical properties. Earth Surf. Proc. Land. 29:6 (2004), 687–711, 10.1002/esp.1064.
Mesfin, A., 2016. A Field Guideline on Bench Terrace Design and Construction. Ministry of Agriculture and Natural Resources Natural Resource Management Directorate, October, 44.
Meteo Rwanda, 2022. [dataset] Meteo Rwanda, 2022. Historical rainfall data for the northern-western provinces of Rwanda (obtained through the email).
Milledge, D.G., Bellugi, D., McKean, J.A., Densmore, A.L., Dietrich, W.E., A multidimensional stability model for predicting shallow landslide size and shape across landscapes. J. Geophys. Res. Earth 119:11 (2014), 2481–2504, 10.1002/2014JF003135.
MINEMA, 2018. National contingency plan for floods and landslides. 23. https://www.minema.gov.rw/publications.
Ministry of Environment, 2018. Upper Nyabarongo catchment management plan 2018-2024.[Technical report published by Rwanda Ministry of Environment]. https://waterportal.rwb.rw/node/3136.
Monsieurs, E., Kirschbaum, D., Thiery, W., van Lipzig, N., Kervyn, M., Demoulin, A., Jacobs, L., Kervyn, F., Dewitte, O., Constraints on landslide-climate research imposed by the reality of fieldwork in Central Africa. De Graff, Shakoor, A., (eds.) 3rd North American Symposium on Landslides: Landslides: Putting Experience, Knowledge, and Emerging Technologies into Practice, 2017, Association of Environmental & Engineering Geologists (AEG 978-0-9897253-7-8, 158–168.
Monsieurs, E., Jacobs, L., Michellier, C., Basimike Tchangaboba, J., Bamulezi Ganza, G., Kervyn, F., Maki Mateso, J.-C., Mugaruka Bibentyo, T., Kalikone Buzera, C., Nahimana, L., Ndayisenga, A., Nkurunziza, P., Thiery, W., Demoulin, A., Kervyn, M., Dewitte, O., Landslide inventory for hazard assessment in a data-poor context: a regional-scale approach in a tropical African environment. Landslides 15 (2018), 2195–2209, 10.1007/s10346-018-1008-y.
Monsieurs, E., Kirschbaum, D.B., Tan, J., Maki Mateso, J.-C., Jacobs, L., Plisnier, P.-D., Thiery, W., Augusta, U., Didace, M., Mugaruka Bibentyo, T., Bamulezi Ganza, G., Ilombe Mawe, G., Bagalwa, L., Kankurize, C., Michellier, C., Stanley, T., Kervyn, F., Kervyn, M., Demoulin, A., Dewitte, O., Evaluating TMPA rainfall over the sparsely gauged East African Rift. J. Hydrometeorol. 19:9 (2018), 1507–1528, 10.1175/JHM-D-18-0103.1.
Monsieurs, E., Dewitte, O., Demoulin, A., A susceptibility-based rainfall threshold approach for landslide occurrence. Nat. Hazards Earth Syst. Sci. 19 (4) (2019), 775–789, 10.5194/nhess-19-775-2019.
Mugaruka Bibentyo, T., Dille, A., Depicker, A., Smets, B., Vanmaercke, M., Nzolang, C., Dewaele, S., Dewitte, O., Landslides, bedrock incision and human-induced environmental changes in an extremely rapidly formed tropical river gorge. Geomorphology 109046 (2024), 7823–7830, 10.1016/j.geomorph.2023.109046.
Nakulopa, F., Vanderkelen, I., Van de Walle, J., van Lipzig, N.P.M., Tabari, H., Jacobs, L., Tweheyo, C., Dewitte, O., Thiery, W., Evaluation of high-resolution precipitation products over the Rwenzori Mountains (Uganda). J. Hydrometeorol. 23 (2022), 747–768, 10.1175/jhm-d-21-0106.1.
Nambajimana, J., He, X., Zhou, J., Justine, M.F., Li, J., Khurram, D., Mind'je, R., Nsabimana, G., Land use change impacts on water erosion in Rwanda. Sustainability 12:1 (2020), 1–23, 10.3390/SU12010050.
Niyokwiringirwa, P., Lombardo, L., Dewitte, O., Deijns, A.A.J., Wang, N., van Westen, C., Tanyas, H., Event-based rainfall-induced landslide inventories and rainfall thresholds for Malawi. Landslides 21 (2024), 1403–1424, 10.1007/s10346-023-02203-7.
Niyonzima, O., 2018. Grief and horror as landslide victims are buried in western Rwanda. Retrieved from https://www.ktpress.rw/2018/05/grief-and-horror-as-landslide-victims-are-buried-in-western-rwanda/.
Ozturk, U., Bozzolan, E., Holcombe, E.A., Shukla, R., Pianosi, F., Wagener, T., How climate change and unplanned urban sprawl bring more landslides. Nature 608:7922 (2022), 262–265, 10.1038/d41586-022-02141-9.
Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel, O., Duchesnay, É., Scikit-learn: machine learning in Python. the. J. Mach. Learn. Res. 12 (2011), 2825–2830.
Pepe, G., Mandarino, A., Raso, E., Scarpellini, P., Brandolini, P., Cevasco, A., Investigation on farmland abandonment of terraced slopes using multitemporal data sources comparison and its implication on hydro-geomorphological processes. Water, 11, 2019, 10.3390/w11081552.
Petley, D.N., Hearn, G.J., Hart, A., Rosser, N.J., Dunning, S.A., Oven, K., Mitchell, W.A., Trends in landslide occurrence in Nepal. Nat. Hazards 43:1 (2007), 23–44, 10.1007/s11069-006-9100-3.
Pijl, A., Quarella, E., Vogel, T.A., D'Agostino, V., Tarolli, P., Remote sensing vs. field-based monitoring of agricultural terrace degradation. Int. Soil Water Conserv. Res. 9:1 (2021), 1–10, 10.1016/j.iswcr.2020.09.001.
Posthumus, H., 2005. Adoption of terraces in the Peruvian Andes. In: Tropical Resource Management Papers (Vol. 72).
Regional Centre Mapping Resources and Development (RCMRD)., 2015. Map of land use of Rwanda. Retrieved from https://geoportal.rcmrd.org/layers/servir%3Arwanda_landcover_2015_scheme_ii.
Reichenbach, P., Rossi, M., Malamud, B.D., Mihir, M., Guzzetti, F., A review of statistically-based landslide susceptibility models. Earth Sci. Rev. 180 (2018), 60–91, 10.1016/j.earscirev.2018.03.001.
Rickli, C., Graf, F., Effects of forests on shallow landslides - Case studies in Switzerland. Forest Snow Landscape Res. 82:1 (2009), 33–44.
Romero Díaz, A., Marín Sanleandro, P., Sánchez Soriano, A., Belmonte Serrato, F., Faulkner, H., The causes of piping in a set of abandoned agricultural terraces in southeast Spain. Catena 69:3 (2007), 282–293, 10.1016/j.catena.2006.07.008.
Roose, E., Ndayizigiye, F., Agroforestry, water and soil fertility management to fight erosion in tropical mountains of Rwanda. Soil Technol. 11:1 (1997), 109–119, 10.1016/S0933-3630(96)00119-5.
Rossi, M., Guzzetti, F., Reichenbach, P., Mondini, A.C., Peruccacci, S., Optimal landslide susceptibility zonation based on multiple forecasts. Geomorphology 114 (2010), 129–142, 10.1016/j.geomorph.2009.06.020.
Rutebuka, J., Munyeshuli, A.U., Nkundwakazi, O., Mbarushimana, D.K., Mbonigaba, J.J.M., Vermeir, P., Verdoodt, A., Effectiveness of terracing techniques for controlling soil erosion by water in Rwanda. J. Environ. Manage., 277, 2021, 111369, 10.1016/j.jenvman.2020.111369.
Sasahara, K., Sakai, N., Development of shear deformation due to the increase of pore pressure in a sandy model slope during rainfall. Eng. Geol. 170 (2014), 43–51.
Schilirò, L., Cevasco, A., Esposito, C., Mugnozza, G.S., Shallow landslide initiation on terraced slopes: inferences from a physically based approach. Geomat. Nat. Haz. Risk 9:1 (2018), 295–324.
Schuster, R.L., Highland, L.M., 2001. Socioeconomic and environmental impacts of landslides in the Western Hemisphere. U.S. Geological Survey, pp47.
Sekajugo, J., Kagoro-Rugunda, G., Mutyebere, R., Kabaseke, C., Namara, E., Dewitte, O., Kervyn, M., Jacobs, L., Can citizen scientists provide a reliable geo-hydrological hazard inventory? An analysis of biases, sensitivity and precision for the Rwenzori Mountains, Uganda. Environ. Res. Lett., 17, 2022, 045011, 10.1088/1748-9326/ac5bb5.
Seto, K.C., Güneralp, B., Hutyra, L.R., Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. PNAS 109:40 (2012), 16083–16088, 10.1073/pnas.1211658109.
Sidle, R.C., Bogaard, T.A., Dynamic earth system and ecological controls of rainfall-initiated landslides. Earth Sci. Rev. 159 (2016), 275–291.
Sidle, R.C., Ziegler, A.D., Negishi, J.N., Nik, A.R., Siew, R., Turkelboom, F., Erosion processes in steep terrain - Truths, myths, and uncertainties related to forest management in Southeast Asia. For. Ecol. Manage. 224:1–2 (2006), 199–225, 10.1016/j.foreco.2005.12.019.
Tanyaş, H., Allstadt, K.E., van Westen, C.J., An updated method for estimating landslide‐event magnitude. Earth Surf. Proc. Land. 43:9 (2018), 1836–1847.
Tarolli, P., Preti, F., Romano, N., Terraced landscapes: from an old best practice to a potential hazard for soil degradation due to land abandonment. Anthropocene 6 (2014), 10–25, 10.1016/j.ancene.2014.03.002.
Terajima, T., Miyahira, E.I., Miyajima, H., Ochiai, H., Hattori, K., How hydrological factors initiate instability in a model sandy slope. Hydrol. Process. 28:23 (2014), 5711–5724.
Theunissen, K., Hanon, M., Fernandez, M., Carte Géologique du Rwanda-Scale: 1/250000. 1991, Royal Museum for Central Africa, Tervuren, Belgium.
Thomas, M.A., Collins, B.D., Mirus, B.B., Assessing the feasibility of satellite-based thresholds for hydrologically driven landsliding. Water Resour. Res., 2019, 10.1029/2019WR025577.
Thomas, M.A., Mirus, B.B., Smith, J.B., Hillslopes in humid‐tropical climates aren't always wet: implications for hydrologic response and landslide initiation in Puerto Rico. Hydrol. Process. 34 (2020), 4307–4318, 10.1002/hyp.13885.
Turkelboom, F., Poesen, J., Trébuil, G., The multiple land degradation effects caused by land-use intensification in tropical steeplands: a catchment study from northern Thailand. Catena 75 (2008), 102–116, 10.1016/j.catena.2008.04.012.
Uwacu, R.A., Habanabakize, E., Adamowski, J., Schwinghamer, T.D., Using radical terraces for erosion control and water quality improvement in Rwanda: a case study in Sebeya catchment. Environ. Develop., 39, 2021, 100649, 10.1016/j.envdev.2021.100649.
Uwihirwe, J., Hrachowitz, M., Bogaard, T.A., Landslide precipitation thresholds in Rwanda. Landslides 17 (2020), 2469–2481, 10.1007/s10346-020-01457-9.
Uwihirwe, J., Hrachowitz, M., Bogaard, T., Integration of observed and model-derived groundwater levels in landslide threshold models in Rwanda. Nat. Hazards Earth Syst. Sci. 22:5 (2022), 1723–1742.
Van Den Eeckhaut, M., Poesen, J., Govers, G., Verstraeten, G., Demoulin, A., Characteristics of the size distribution of recent and historical landslides in a populated hilly region. Earth Planet. Sci. Lett. 256:3–4 (2007), 588–603.
Van Dijk, A.I.J.M., Bruijnzeel, L.A., Runoff and soil loss from bench terraces.2. An event-based erosion process model. Eur. J. Soil Sci. 55 (2004), 317–334, 10.1111/j.1365-2389.2004.00605.x.
Water for Growth Rwanda, 2018. Integrated Water Resources Management Program Rwanda: Sebeya catchment plan 2018-2024 [Technical report published by the Rwanda Ministry of Environment]. https://waterportal.rwb.rw/sites/default/files/201904/Sebeya%20Catchment%20Plan_0.pdf.
Wei, W., Chen, D., Wang, L., Daryanto, S., Chen, L., Yu, Y., Lu, Y., Sun, G., Feng, T., Global synthesis of the classifications, distributions, benefits and issues of terracing. Earth Sci. Rev. 159:18 (2016), 388–403, 10.1016/j.earscirev.2016.06.010.
Wicki, A., Jansson, P.E., Lehmann, P., Hauck, C., Stähli, M., Simulated or measured soil moisture: which one is adding more value to regional landslide early warning?. Hydrol. Earth Syst. Sci. 25 (2021), 4585–4610, 10.5194/hess-25-4585-2021.
Williams, L.S., Agricultural terrace evolution in Latin America. Yearb. – Conf. Latin Am. Geogr. 16 (1990), 82–93.
Wolter, A., Ward, B., Millard, T., Instability in eight sub-basins of the Chilliwack River Valley, British Columbia, Canada: a comparison of natural and logging-related landslides. Geomorphology 120 (2010), 123–132, 10.1016/j.geomorph.2010.03.008.
Zhou, C.H., Lee, C.F., Li, J., Xu, Z.W., On the spatial relationship between landslides and causative factors on Lantau Island, Hong Kong. Geomorphology 43 (2002), 197–207, 10.1016/S0169-555X(01)00130-1.
