Application of GIS and Remote Sensing to Analyses Landscape Structures
3.2 Data for Analyses
Data used for analyses are listed below:
-
Digital Map 50m Grid (Geographical Survey Institute)
- Landsat TM data (14th April 1997)
- Urban Planning Map
- Actual Vegetation Map
- Surface Geology Map
3.3 Lanscape Types
The basic data were scrutinized and well examined before landscape analysis. The landscape types for use in the classi-cation were then de-ned, taking into consideration the topographic condtions and land use types in sakura. As discussed by Hara(2000), the following landscape types were chosen to describe the landcape, Rural landscape (Lowland rural landscape, Upland rural landscape, Yatsuda rural landscape), Urban landscape.
1) Marsh Landscape
Cover Lake Inbanuma and surrouding areas. This landscape, which consists of the open water area of the lake and its shore areas covered by reed (Phragmites communis) and other plant communities. This landscape maintains a high level of natural environment.
2) Rural Landsacpe
- Lowland rural landscape:
Mostly oat and marshy lowlands with an altitude of less than 10 meters. The scenery is mostly paddy-elds and there is no housing. Rice paddies are transformed to dry paddies in winter for cultivation of other crops. Some -elds are also laid abandoned.
- Upland rural landscape:
Typical upland farm village landscape on upland with altitudes of 10 to 40 meters. Mainly farmhouses and and dry farmlands, mixed with oak forests and other secondary forests.
- Yatsuda rural landscape:
At upstream of small rivers, paddy -elds with narrow widths spread along the streams, forming paddy shapes called yatsuda. In contrast with the paddy -elds around Lake lnbanuma, some paddy -elds in this region remain wet throughout the year. These Yatsuda paddy -elds and the slope forests surrounding these paddies are class-ed as the Yatsuda rural landscape.
3) Urban landscape
This landscape covers both those residential areas going back many years and the relatively newly developed housing areas. In terms of composition, the majority was developed in years after the mid-1960s.
3.4 Method of Classi-cation
Figure 1 shows the decision tree followed in executing the landscape classi-cation. In this classi-cation method, independent topographic elements were extracted and used for classi-cation. For the diŽerentiation of lowlands and uplands, the altitude of 20 meters from the sea level was used as threshold borderline.
4 Results and Discussions
4.1 Landscape Map
Figure 2 shows the results executed by the landscape classi-cation method described above. Digital data are treated automatically on the GIS system in accordance with the analyses algorithm, so whoever executes the classi?cation, the outcome should be the same. In this way, the standardization of the classi-cation is achieved. `Results for each landscape type were examined by using the units called ecotopes.
4.2 Extraction of Ecotopes
There are diŽerent views on what the minimum units of landscapes should be. For the purpose of our discussions, we will use the concept "ecotope" which is minimum unit combining topographic features and land use.
Remote sensed satellite data and DTM were used for the extraction of ecotopes. Based on the ISODATA method in accordance with procedures of Hara (1997), Landstat TM data covering the entire area of Sakura, detected on April 14th 1997 (referred to herein as TM970414), Marsh (marsh), paddy (paddy-eld), Grass(grassland), Scrub (scrub), Forest-b (broad-leaved froest), Forest-c (conifer forest), Urban-g (urban district with many trees), Urban-o (urban district), Urban-f (factory and industrial area), Field (-eld), Bare-o (bare land), and Bare-c (bare land covered concrete).
From DTM for Sakura, altitudes and inclination of slopes were calculated and land-scapes of the entie Sakura City area were classi-ed into four broad types including lowland, upland and slope areas by topographic features. From these two sets of information, a total of 52 ecotopes were de-ned. Table 1 shows extracted ecotopes.
