TY  - JOUR
TT  - Landslide Occurrences in The Hilly Areas of Rwanda, Their Causes and Protection Measures
AU  - Bizimana, Hussein
AU  - Sönmez, Osman
PY  - 2015
DA  - July
JF  - Disaster Science and Engineering
JO  - DSE
PB  - Emrah DOĞAN
WT  - DergiPark
SN  - 2149-7249
SP  - 1
EP  - 7
VL  - 1
IS  - 1
KW  - Landslides
KW  - Slope
KW  - Convex
KW  - Concave
KW  - Cohesion
KW  - Atterberg limits
KW  - Rainfall
N2  - Rwanda being a small country in central Africa, it is not well known for landslides, but recently especially in theyears with above normal rainfall and with high increase in population per kilometer square the loss of life and property fromlandslides and mud flows is increasing. This research assesses the factors that influence landslide occurrences in Rwanda, theirimpacts on the livelihood of the people, their causes and protection measures. For almost 10 years from 2000, heavy rains andlandslides left 108 people dead and ten thousand displaced and landless mostly in North and Western provinces. The volume ofdebris from landslides was 110 million m3 in and this was deposited into rivers and streams or in transportation roads. Twentynine of these landslides dammed rivers resulting in high losses of fertile soils and infection of fresh waters with used chemicals incultivating those lands. The main landslide types are debris flows which occur on concave slopes where water concentrates andwith the layer of clay downward water pushes the land to slides laterally. These landslides occur on steep slopes that are concaveand between slope angles of 140 to 550. Slopes facing north-west and West are most prone to landslides which coincide with thedominant rainfall in the areas. The soil types in this area are those conditioned by topography and tropical climate namely Nitisols,Ferralsols, Leptosols, Gleysols, and Acrisols. The soils contain medium to high plasticity clays and according to the Atterberglimits they approximately fall in the categories of kaolinite. The top soils also have a high infiltration rate which allows fast flowof water into the deeper clay rich horizons promoting water stagnation causing slope failure. The main triggering factor is rainfalland rainfall events of low intensity but prolonged for days are thought to be more disastrous however, this is an area that needsfurther investigation. İn order to reduce the occurrences of landslides terraces have started being constructed by the governmentand local people and afforestation is being promoted everywhere with the theme ‘’cut one tree plant three’’ in order to fight againstlandslides disasters with the construction of slope retaining walls, but still not yet a zoning map hasn’t being done, it is of highneed to implement a map of zones vulnerable to landslides in the whole country so that people will be able to avoid those placesin their daily works.
CR  - Ayalew, L., 1999. The effect of seasonal rainfall on landslides in the highlands of Rwanda. Bull. Eng. Geol. Env. 58: p. 9-19. Atterberg, A.M., 1846-1916. Geotechnique, 3(1), pp. 17 19
UR  - https://dergipark.org.tr/en/pub/dse/issue//381756
L1  - https://dergipark.org.tr/en/download/article-file/408168
ER  -