Spatial-Temporal Dynamics Land Use/Land Cover Change and Flood Hazard Mapping in the Upstream Citarum Watershed, West Java, Indonesia

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Fig. 10

Fig. 11

LULC descriptions used in this study (sourced and modified from Yulianto et al_ (2018, 2019)_

ID Class	LULC Type	Description
1	Urban/built-up area	Consists of all built-up area, residential, industrial, commercial area, villages, settlements, transportation infrastructure and others.
2	Primary forest	Consists of natural forests that have not been disrupted by human exploitation.
3	Secondary forest and mixed garden	Consists of industrial plantation forests and some garden planting, coconuts, fruits and others.
4	Plantation	Consists of conservation land, tea plantation, palm oil and others.
5	Wet agricultural land	Consists of land that requires much water for its planting patterns: irrigated rice fields, rice terraces and others.
6	Dry land farming	Consists of land that requires little water for its cropping patterns: fields, moorland and others.
7	Water body	Consists of all water sources, rivers, reservoirs, ponds and others.

Urban/built-up area size in the eight sub-watersheds in the study area_

Sub-Watershed	Area (ha)
	1990	1996	2000	2003	2009	2016
Cihaur	3,409.7	3,936.7	3,986.2	4,505.2	5,367.4	6,486.6
Cikapundung	8,414.6	8,965.7	9,222.3	9,702.7	10,451.0	12,311.6
Cikeruh	1,115.7	1,481.2	1,635.0	1,751.1	1,961.8	2,793.9
Ciminyak	207.1	210.3	218.8	292.9	422.2	435.3
Cirasea	1,019.8	1,022.3	1,194.9	1,257.6	1,373.7	1,788.1
Cisangkuy	808.3	858.7	944.5	1,111.6	1,318.9	1,692.9
Citarik	720.9	872.8	1,073.5	1,129.3	1,135.6	1,454.2
Ciwidey	391.9	392.8	405.1	459.9	586.6	753.9

Terrain surface classification (TSC) micro-landform characteristics related to flood conditions in the study area_

No	Micro-landform classification	Description	Flood hazard class
1	Plains, gentle slope, fine texture, high convexity	Plains area with the permissible range less than 9% gradient, dominant positive/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay. Depth of flooding in excess of 5 m	Very high flood hazard 1
2	Plains, gentle slope, fine texture, low convexity	Plains area with the permissible range less than 9% gradient, dominant negative/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay. Depth of flooding 4–5 m.	Very high flood hazard 2
3	Plains, gentle slope, coarse texture, high convexity	Plains area with the permissible range less than 9% gradient, dominant positive/concave convexity, coarse texture indicates a high proportion of sand. Depth of flooding 3–4 m.	High flood hazard 1
4	Plains, gentle slope, coarse texture, low convexity	Plains area with the permissible range less than 9% gradient, dominant negative/concave convexity, coarse texture indicates a high proportion of sand. Depth of flooding 2–3 m.	High flood hazard 2
5	Open slopes, moderate slope, coarse texture, high convexity	Open slope area with a gradient of slope between 10 and 15%, dominant positive/concave convexity, coarse texture indicates a high proportion of sand. Depth of flooding 1–2 m.	Moderate flood hazard 1
6	Open slopes, moderate slope, fine texture, low convexity	Open slope area with a gradient of slope between 10 and 15%, dominant negative/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay. Depth of flooding 1–2 m.	Moderate flood hazard 2
7	Upper slopes, steep slope, fine texture, high convexity	Upper slopes area with a gradient of slope between 16 and 30%, dominant positive/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay. Depth of flooding 0.5–1 m.	Low flood hazard 1
8	Upper slopes, steep slope, fine texture, low convexity	Upper slopes area with a gradient of slope between 16 and 30%, dominant negative/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay. Flood depth less than 0.5 m.	Low flood hazard 2
9	Upper slopes, very steep slope, fine texture, high convexity	Upper slopes area with a gradient of slope between 31 and 60%, and > 60%, dominant positive/concave convexity, fine texture indicates a high proportion of finer particles such as silt and clay.	No flood hazard 1
10	Upper slopes, very steep slope, coarse texture, low convexity	Upper slopes area with a gradient of slope between 31 and 60%, and > 60%, dominant negative/concave convexity, coarse texture indicates a high proportion of sand.	No flood hazard 2

The rate of urban/built-up area expansion in the eight sub-watersheds in the study area_

Sub-Watershed	UAER (ha a−1)
	1990–1996	1996–2000	2000–2003	2003–2009	2009–2016	1990–2016
Cihaur	87.8	12.4	173.0	143.7	159.9	118.3
Cikapundung	91.9	64.1	160.1	124.7	265.8	149.9
Cikeruh	60.9	38.4	38.7	35.1	118.9	64.5
Ciminyak	0.5	2.1	24.7	21.5	1.9	8.8
Cirasea	0.4	43.1	20.9	19.3	59.2	29.5
Cisangkuy	8.4	21.5	55.7	34.6	53.4	34.0
Citarik	25.3	50.2	18.6	1.1	45.5	28.2
Ciwidey	0.1	3.1	18.3	21.1	23.9	13.9