The use of Remote Sensing Data for
Identifying Development of Sugarcane in Buttala Area
4.0 Results
4.1 Area Estimation
The extent of sugarcane cultivation in different periods considered are shown in the table 1.0 given below.
Table 1.0 : Sugarcane cultivation and its changes in the study area for four different years
| Years |
Source |
Area (ha) |
Increase |
| 1983 |
Air photos |
Very small |
- |
| 1988/89 |
- do - |
5215 |
5000 (approx.) |
| 1991/92 |
IRS |
8925 |
3710 |
| 1994/95 |
Air photos |
9770 |
845 |
The distribution and expansion of sugarcane during these dour years is shown in a map of scale 1:275000 (figure. 3.0)
Figure 3.0
4.2 Yield Estimation
Yield estimation was done according to the following table
Table 2.0 : Yield estimation for three different years
| Years |
Cultivation area (ha) |
Estimated Yield(ton/ha) |
Estimated Production(m.ton) |
| 1988/89 |
5215 |
60 |
312,900 |
| 1991/92 |
8925 |
67 |
597,975 |
| 1994/95 |
9770 |
70 |
683,900 |
5. Discussion
The areas estimated in different years using aerial photographs and IRS data could not be compared with the available data from Pelwatte Sugar Industries Ltd., as the total extent of cultivation was not availabe.
The main aim of this study was to monitor the changes of sugarcane cultivated areas. It is quite evident that the sugarcane areas have increased very rapidly during last decade. For this reason it is separated from other crops as in earlier classification and considered as a separate category for present Land Use Mapping.
This exercise can also be utilized to predict harvest under normal irrigated conditions. In doing so one has to separate the vegetative stages of sugarcane from the mature stages. Combining this information with few field investigation it is possible to predict harvest within agreeable limits.
References
-
The National Atlas of Sri Lanka
- Agrometerological crop monitoring and forecasing by M.Frere and G.F.Popov, Food and Agriculture Organization of the United Nations, Rome.
