Remote sensing Application in Determination of Land Use Management Factors of the USLE

Remote sensing Application in Determination of Land Use Management Factors of the USLE

Dr.Roslan Zainal Abidin
Associate professor
Faculty of civil Engineering
MARA Institute of Technology
40450 Shah Alam
selangor, Malaysia
Tel: (603) 5563813
Fax: (603 ) 5592394
E-mail :drroslan@civil.engr.itm.edu.my
Dr .Amir Hashim Mohd. Kassim
Associate Professor, head of Dept.
dept. of Hydraulic & Hydrology
Faculty of Civil Engineering
Universiti Tecknologi Malaysia
Locked Bag 791
80990 Johar Bahru
Tel: 96070 5503087
Fax: (607) 5566157
E-mail :amir.fka@utm.my
Tew Kia Hui
Researcher
58, jalan Gangsa 2
81300 Skudai
Johor ,Malaysia
Tel: (6016) 223181
Fax: (607) 5542181
E-mail:valen@tm.net.my

Abstract
Cameron Highlands, an idyllic highland resort in Malaysia are mostly covered by thick tropical rainforest acquiring 59,153 hectares (6.22%). With he cool temperature averaging between 100c to 230C makes it an ideal retreat for holiday makers. The climate and soil encourages tea , vegetables, citrus fruits, coffee, strawberry and mushroom cultivation. However, the agricultural activities carried out in Cameron Highlands are at an alarming rate to meet the increasing demand of vegetable and cash crops form all over Peninsular Malaysia. This has led to indiscriminate clearing of new lands, no proper covering provided after harvesting of the crops that leaving the soil bare towards direct rainfall and making it venerable for landslides to occur. This has been supported by the fact the at recent developments has taken its tall in the highland itself with many on -gong and new proposed development project. As a result of human ignorance, a spate of landslips and flash floods since occurred in Cameron Highland lately to which incurred loss of lives.

Though, we cannot halt development that brings benefit to the country, it should however be environmentally sound and sustainable. In this regard, study on the land use management factors 9 cover Management factor, C and Support Practice Factor, P) of the Universal Soil Loss Equation (USLE) is certainly timely s this parameter emphasizes on the land covers in the study area and its effect on the amount of soil erosion loss. With the use of recent technologies, color infrared interpretative key is used to determine the combined land use management factor, C and P. coupled with the remoter sensing imagery using Landsat Thematic Mapper, the Ringlet location in Cameron Highlands has been determined as having the highest erosion risk/loss based on the CP factor justified by the highest erosion risk/loss based on the CP factor justified by the Conversely, the Sg. Ikan location shows the highest reduction in the amount of still erosion loss as well s erosion risk with most of the is area are still covered with forest t. results of this study highlights some of the important land use at various locations in Cameron Highlands as it would give some indication about the possibility of reducing any further erosion risk/loss that will occur in time to come so that development of any new projects can be well planned and decided in ensuring a quality environment.

Introduction
By definition, the cover Management Factor, C in the USLE is a factor that measures the combined effect of all the inter-related cover and management variables and is defined as the ration of soil loss form land cropped under specified conditions to the corresponding loss from clean-tilled continuous fallow land.

Generally, whenever sloping soil is to be cultivated and exposed to erosive rains, the protection offered by sod or close-growing crops in the system needs to be supported by practices that will slow the runoff water and thus reduce the amount of soil it can carry. The most important of these supporting cropland practice factor, P in the USLE is the ratio of soil loss with a specific support practice to the corresponding loss with up-and -down-slope culture. Improved tillage practices, sod-based rotation, fertility treatment and greater quantities of crop residues left on the field contribute materially to erosion control.

With the use of the remote sensing application, a color infrared interpretative key is used a determine the combined land use management factor, C and P of the USLE as shown in Table 1.

Table 1. Showing colour infrared interpretative key for land use management factor C and P of the USLE .

Land Use Management	Photo Characteristics	CP Factor Value
Grassland/hay	Pink tones, smooth texture	0.003
Residential	Pink tones, houses/streets	0.003
Forest	Red tones, cioarse texture	0.003
Rangeland (grass & Weeds )	Variable colours	0.007-0.450*
Cropland	Pink tones, cultivation	0.300-0.400**
Construction Areas	White tones, coarser texture	1.000
Impervious Areas	Bluish-white, smooth texture	0.005
* for Rangeland, the average CP factor is taken as 0.229
** for Cropland, the average CP factor is taken as 0.35

Methodology
11 Location have been identified in Cameron Highlands as indicated in Figure 1 and their respective zoning within a 5 km radius are shown in Table 2.

Figure 1. Map showing the 11 locations with their respective zoning within 5 km radius in Cameron Highlands
From the remote sensing image 9 Landsat Thematic Mapper dated 23.4.90) obtained from MACRES ( Malaysian Center for Remote sensing ), the data re processed and the overall image covering the catchments of Cameron Highlands is as shown in Figure 2.

Figure 2. Landsat Thematic Mapper image showing the overall picture of Cameron Highlands catchment
Table 2. The 11 locations in Cameron Highlands with their respective zoning within 5 km radius

Zone No.	Location
1	Ringlet
2	Ldg. Teh Boh
3	Tanah Rata
4	Brinchang
5	Tringkap
6	Ldg. Sg. Palas
7	Gunung Brinchang
8	Kuala Terla
9	Kg. Raja
10	Sg. Ikan
11	Blue Valley

Result Analysis
The "Landsat Thematic Mapper" image is processed according to he colour infrared interpretative key for the 11 locations Highlands with their respective zoning within a 5 km radius to acquire the CP factor will not be included in the calculation as for these areas either the types of land use could not identified or cropping or land management would not be done. The ringlet location with its respective zoning within a 5 km radius is shown in figure 3.

Figure 3. Map showing respective land use management for Ringlet location (Zone 1) within 5 km radius
With reference to the enclose Appendix , a ranking of the various land use management factors, C and P for the 11 locations is carried out and a typical results( Residential Image ) is shown in Table 3. Finally, the weighted CP factor is as shown in Table 4.

Comments and Discussions
The observation carried out using he remote sensing image has a resolution of 30 meters which means that each pixel inside the image will represent and area of 30 m x 30 m on site. Although this image will give a better accuracy compared to land use maps, the roads and other buildings with a width of less than 30 meters would not be identified. Further studies using a better resolution image could be carried out to give a better representation of the various CP factors in future. However , this study highlights some of the important land uses at various locations in Cameron highlands and gives some indication about the possibility of reducing any further erosion risk /loss that will occur in time to come based on the CP factor of the USLE.

Table 3. Ranking for land use management factor C an P ( Residential image for the respective 11 location in Cameron highlands

Rank	Location	Area (Hectares )	% image
1	Ringlet	0.46	5.39
2	Kuala Terla	0.46	0.34
3	Ldg.sg.Palas	0.44	0.15
4	Tringkap	0.42	4.87
5	Ldg.The Boh	0.26	3.00
6	Brinchang	0.26	3.00
7	Tanah Rata	0.25	2.90
8	Gunung Brinchang	0.24	2.78
9	Kg. Raja	0.24	2.76
10	Blue valley	0.18	2.13
11	Sg. Ikan	0.15	1.71

Table 4. Ranking of CP factor for 11 locations in Cameron Highlands with their respective zoning with in 5 km radius

Rank	Location	CP factor
1	Ringlet	0.0875
2	Kuala Terla	0.0830
3	Ldg.sg.Palas	0.0795
4	Tringkap	0.0763
5	Ldg.The Boh	0.0762
6	Gunung Brinchang	0.0543
7	Brinchang	0.0540
8	Tanah Rata	0.0504
9	Kg. Raja	0.0501
10	Blue valley	0.0471
11	Sg. Ikan	0.0355

Conclusion
From the analysis carried out, it has been found out that the Ringlet location has the highest erosion risk/loss based on the CP factor of the USLE with a value of 0.0875. this is well supported and justified by the fact that this location recorded the highest ranking for residential (5.39%) and construction (2.07%) area compared to the other locations.

Conversely, the location at Sg. Ikan has the highest reduction in the amount of soil erosion loss as well as the lowest erosion risk as the CP factor recorded a value of 0.0355. this is also well supported and justified by the fact that this location has the largest area covered with forest (84.21%0 which indicated that this area has yet to be developed and therefore the erosion risk/loss is less. For the other land uses, Sg. Ikan recorded the lowest value for residential (1.71%) and construction (0.73%) areas which justifies the results obtained.

With a knowledge of the ranking of the ranking of the CP factor at various locations in Caneron Highlands, development of any new projects can be well planned and decided in ensuring a quality environment.

Finally, further improvements by using a better resolution image should be carried out in order t give the best representation of the land uses in Cameron Highlands and liaison with the State Government to implement stricter laws in developing a particular area seen to be necessary so as the ensure sound and sustainable development in future.

References:

Roslan ,Z.A.(1993) Environmental Assw3ssment on Soil Erosion Using USLE model in technical Workshop on hydrological research in a changing environment in sub humid and humid tropical areas (15-18 June 1993),Bangi, Selangor, MALAYSIA
Roslan, Z.A. and Tew, K.H. 91995) Erosion study in Cameron Highlands in Malaysian science and technology Congress (22-25 August 1995), Perdanasiswa Universiti Malaya, Kuala Lumpur, MALAYSIA.
Soong, N.L.(1980) Soil Erosion and Conservation in Malaysia, Rubber Research Institute of Malaysia, kuala Lumpur, MALAYSIA .
Wischmeier, W.H., and Smith, D.D. (1978) Predicting rainfall erosion losses-a guide to conservation planning, UDSA, Agriculture Handbook No .537, USA.

Appendix

Sample Calculation of Land use Management Factor C and P of the USLE for Ringlet Location with its Respective Zoning Withing Within 5 Km Radius in Cameron Highlands

Location Ringlet (Zone 1)

No.	Land use management	% image (1)	CP factor from Table 1(2)	CP factor (1) X(2)
1	Water body	0.34	-	-
2	Forest	62.06	0.003	0.0019
3	Rangeland	9.43	0.229	0.0216
4	Cropland	12.27	0.350	0.0429
5	Grassland	5.10	0.003	0.0002
6	Impervious	2.37	0.005	0.0001
7	Residential	5.39	0.003	0.0001
8	Construction	2.07	1.000	0.0207
9	Unclassified	0.97	-	-
	TOTAL	100.00		0.0875

Weighted CP factor,
[(0.003)x62.06%]+[(0.229)x 9.43%]+[(0.350)x12.27%] +[(0.003)x 5.10%] + [(0.005)x2.37%] +[ (0.003)x 5.39%]+[(1.000)x 2.07%] = 0.0875