4.3.2.1. Slope analysis
Fig 4-2: Slope analysis
Source: Author, RNRA/CGIS-NUR
That slope map was created based on the DEM of Rusizi Town.
Using spatial analyst tools, the DEM was transformed into slope and after the
slope was classified into 2 classes using raster calculator as shown in Fig 3-2
in order to come up with the appropriate slope for constructing a landfill
which is about 8-12% because too steep of a slope would make it difficult to
construct and maintain while too flat of a slope would affect the runoff
drainage. Slopes above 12% created high runoff rates for precipitation. .
25
4.3.2.2. Constrained and permissible areas
Fig 4-3: Constrained and permissible areas
Source: Author, RNRA/CGIS-NUR
The constraint map was produced by merging each individual
theme within the study area. This procedure created a constraint map for each
theme containing only two classes (suitable land) and (unsuitable land). The 11
constraint maps (layers) namely, River, Lake, Wetland, forest, Roads, Airport,
Market, Primary schools, Secondary schools, District hospitals and Health
centers were used as shown by Fig 3-3.
26
4.3.2.3. Suitable sites in Rusizi Town
Fig 4-4: Distribution of Suitable sites in Rusizi Town
Source: Author, RNRA/CGIS-NUR
That map was created by combining the non restricted area map
and slope analysis map as shown in Fig3-4 in order to get the suitable landfill
sites in Rusizi town that would be located in the intersection of non
restricted area and suitable slope. 133 suitable landfill sites were identified
in the town of Rusizi. Their shape length area and shape area are shown in the
table 4-4 below.
27
Table 4-4: Suitable Sites and their areas (in Sqm)
|
OBJECT ID
|
Grid Cod
|
Shape
Length
|
Shape Area
|
|
OBJECT ID
|
Grid Cod
|
Shape
Length
|
Shape
Area
|
|
OBJECT ID
|
Grid Cod
|
Shape
Length
|
Shape Area
|
|
1
|
1
|
188.6
|
1711.6
|
45
|
1
|
355.0
|
5922.8
|
91
|
1
|
188.6
|
1711.6
|
|
2
|
1
|
200.0
|
2500.0
|
46
|
1
|
188.6
|
1711.6
|
92
|
1
|
187.5
|
1601.0
|
|
3
|
1
|
188.6
|
1711.6
|
47
|
1
|
283.7
|
3374.6
|
93
|
1
|
381.4
|
5010.8
|
|
4
|
1
|
200.0
|
2500.0
|
48
|
1
|
353.6
|
5867.0
|
94
|
1
|
188.6
|
1711.6
|
|
5
|
1
|
282.9
|
3413.5
|
49
|
1
|
188.6
|
1711.6
|
95
|
1
|
188.6
|
1711.6
|
|
6
|
1
|
188.6
|
1711.6
|
50
|
1
|
188.6
|
1711.6
|
96
|
1
|
355.0
|
5922.8
|
|
7
|
1
|
282.9
|
3413.5
|
51
|
1
|
188.6
|
1711.6
|
97
|
1
|
283.7
|
3374.6
|
|
8
|
1
|
188.6
|
1711.6
|
52
|
1
|
188.6
|
1711.6
|
98
|
1
|
188.6
|
1711.6
|
|
9
|
1
|
187.5
|
1601.0
|
53
|
1
|
188.6
|
1711.6
|
99
|
1
|
982.6
|
26915.3
|
|
10
|
1
|
282.9
|
3413.5
|
54
|
1
|
188.6
|
1711.6
|
100
|
1
|
188.6
|
1711.6
|
|
11
|
1
|
188.6
|
1711.6
|
55
|
1
|
188.6
|
1711.6
|
101
|
1
|
188.6
|
1711.6
|
|
12
|
1
|
841.2
|
29831.5
|
56
|
1
|
188.6
|
1711.6
|
102
|
1
|
433.8
|
11155.7
|
|
13
|
1
|
188.6
|
1711.6
|
57
|
1
|
188.6
|
1711.6
|
103
|
1
|
188.6
|
1711.6
|
|
14
|
1
|
282.9
|
3413.5
|
58
|
1
|
188.6
|
1711.6
|
104
|
1
|
188.6
|
1711.6
|
|
15
|
1
|
188.6
|
1711.6
|
59
|
1
|
188.6
|
1711.6
|
105
|
1
|
282.9
|
3413.5
|
|
16
|
1
|
188.6
|
1711.6
|
60
|
1
|
188.6
|
1711.6
|
106
|
1
|
188.6
|
1711.6
|
|
17
|
1
|
282.9
|
3413.5
|
61
|
1
|
188.6
|
1711.6
|
107
|
1
|
188.6
|
1711.6
|
|
18
|
1
|
379.4
|
5160.5
|
62
|
1
|
283.7
|
3374.6
|
108
|
1
|
188.6
|
1711.6
|
|
19
|
1
|
188.6
|
1711.6
|
63
|
1
|
188.6
|
1711.6
|
109
|
1
|
200.0
|
2500.0
|
|
20
|
1
|
353.6
|
5867.0
|
64
|
1
|
646.6
|
24024.8
|
110
|
1
|
282.9
|
3413.5
|
|
21
|
1
|
408.3
|
8280.5
|
65
|
1
|
282.9
|
3413.5
|
111
|
1
|
355.0
|
5922.8
|
|
22
|
1
|
282.9
|
3413.5
|
66
|
1
|
188.6
|
1711.6
|
112
|
1
|
400.0
|
7500.0
|
|
23
|
1
|
188.6
|
1711.6
|
67
|
1
|
188.6
|
1711.6
|
113
|
1
|
924.0
|
43540.0
|
|
24
|
1
|
188.6
|
1711.6
|
68
|
1
|
188.6
|
1711.6
|
114
|
1
|
187.5
|
1601.0
|
|
25
|
1
|
188.6
|
1711.6
|
69
|
1
|
282.9
|
3413.5
|
115
|
1
|
188.6
|
1711.7
|
|
26
|
1
|
188.6
|
1711.6
|
70
|
1
|
282.9
|
3413.5
|
116
|
1
|
200.0
|
2500.0
|
|
27
|
1
|
188.6
|
1711.6
|
71
|
1
|
188.6
|
1711.6
|
117
|
1
|
400.0
|
7500.0
|
|
28
|
1
|
188.6
|
1711.6
|
72
|
1
|
188.6
|
1711.6
|
118
|
1
|
200.0
|
2500.0
|
|
29
|
1
|
283.7
|
3374.6
|
73
|
1
|
188.6
|
1711.6
|
119
|
1
|
188.6
|
1711.7
|
|
30
|
1
|
188.6
|
1711.6
|
74
|
1
|
188.6
|
1711.6
|
120
|
1
|
188.6
|
1711.7
|
|
31
|
1
|
188.6
|
1711.6
|
75
|
1
|
188.6
|
1711.6
|
121
|
1
|
188.6
|
1711.7
|
|
32
|
1
|
188.6
|
1711.6
|
76
|
1
|
188.6
|
1711.6
|
122
|
1
|
200.0
|
2500.0
|
|
33
|
1
|
188.6
|
1711.6
|
77
|
1
|
188.6
|
1711.6
|
123
|
1
|
188.6
|
1711.7
|
|
34
|
1
|
188.6
|
1711.6
|
78
|
1
|
188.6
|
1711.6
|
124
|
1
|
282.9
|
3413.5
|
|
35
|
1
|
353.2
|
5791.9
|
79
|
1
|
188.6
|
1711.6
|
125
|
1
|
200.0
|
2500.0
|
|
36
|
1
|
188.6
|
1711.6
|
80
|
1
|
381.4
|
5010.8
|
126
|
1
|
188.6
|
1711.7
|
|
37
|
1
|
188.6
|
1711.6
|
81
|
1
|
282.9
|
3413.5
|
127
|
1
|
200.0
|
2500.0
|
|
38
|
1
|
188.6
|
1711.6
|
82
|
1
|
188.6
|
1711.6
|
128
|
1
|
271.7
|
3488.0
|
|
39
|
1
|
188.6
|
1711.6
|
83
|
1
|
188.6
|
1711.6
|
129
|
1
|
200.0
|
2500.0
|
|
40
|
1
|
188.6
|
1711.6
|
84
|
1
|
355.0
|
5922.8
|
130
|
1
|
1135.6
|
52633.1
|
|
41
|
1
|
282.9
|
3413.5
|
85
|
1
|
188.6
|
1711.6
|
131
|
1
|
188.6
|
1711.7
|
|
42
|
1
|
188.6
|
1711.6
|
86
|
1
|
188.6
|
1711.6
|
132
|
1
|
188.6
|
1711.7
|
|
43
|
1
|
188.6
|
1711.6
|
87
|
1
|
282.9
|
3413.5
|
133
|
1
|
379.4
|
5160.5
|
28
| 
