A Step-wise Landscape Segmentation for Determining the Field Sampling Sites in Land Resources Assessment
Junun Sartohadi et al Soil Geographer
Universitas Gadjah Mada
Big question!!! Is my sampling site representative? The essence of sustainable development
Learn the landscape pattern Could be natural Could be artificial
Could be combination
Learn the ecological processes To harmonize both of them through land resources map
Problems We have landform classification; example: by Verstappen, Buedell, Klimazewsky, … We have a theoretical background of those landform classification systems
But we have no technical guide in applying those classification systems in different scale of landscape mapping
Look at the Soil Taxonomy systems by USDA: It covers from global (theoretical based) upto detail (field application)
Problems One we misinterpret the relief / land surface morphology we are surely trapped in to the consecutive mistakes The sampling location for observation The sampling material for lab. Analysis The land resources evaluation The space allocation for development
We need a hierarchical relief classification that able to accommodate multi-scale mapping
Background Indonesia urgently require a principal land resources map The map that able to accommodate multi-user need The map that containing multi-information of land characteristics: Natural Resources Natural Hazard
The Mapping Unit shall be: consistently applied for general upto detail scale; recognizable easily both from topo-map and/or RSimageries, easily identified in the field
Background Climate mapping is tedious due to long period of weather record based Soil mapping is difficult due to internal soil morphological based Landcover mapping need to be regularly updated Relief/land surface morphology mapping is reliable in term of relatively permanent and directly discernable on topo-map and imageries, even in the field
In fact, relief is controlling the soil, near surface climate, and landcover characteristics It is the best compromise for principal land resources map
First think!
Started with the Global Theory
Understanding the earth formation and evolution by geomorphological processes -books
Understanding the lithological and tectonicalstructural arrangement – Geological Map Based on the basic knowledge: Different rocks have different resistivity to geomorphological processes expressed by different relief/earth surface morphology Different relief have different soil characteristics Different soils have different landcover and/or landuse Differences elevation express differences on climate (rainfall and temperature)
Case 1
Take a look on the zubduction zone and the chain of active volcanoes
Basic Concept of Geomorphology There are 3 object being studied in geomorphology: 1. Earth surface relief/morphology – 2. Materials embodied landform
3. geomorphological processes One we can delineate the relief on map and/or imageries, it means we already delineate the materials and geomorphological processes relief is an expression of complex interaction between geomorphological processes and materials
Basic Concept of Geomorphology EARTH SURFACE
R. ORDE I
CONTINENT
OCEAN
R. ORDE II
MOUNTAINOUS
PLAIN
Initial Landforms Structural Constructional Endogen
R. ORDE III
EROSIONAL LANDFORM
Sequential landforms processes of exogenic destructional
DEPOSITIONAL LANDFORM
RESIDUAL LANDFORM
Basic Concept of Geomorphology There are 10 genetic landforms: 1. Structural origin
2. Volcanic origin 3. Fluvial origin 4. Glacial origin 5. Solutional origin 6. Marin origin 7. Aeolin origin
8. Biological origin 9. Denudational origin 10. Anthropological origin
Basic principal in mapping Different map scale has some consequences:
Different level of generalization in term of delineation, the map will have different pictures
In term of data, the detail map scale will have more information Different level of information detail
Different level of classification Different level of application Detail map scale for field management Global map scale for regional planning
Basic principal in mapping Different map scale has some consequences: Different level of generalization
in term of delineation, the map will have different pictures In term of data, the detail map scale will have more information Different level of information detail Different level of classification
Different level of application Detail map scale for field management Global map scale for regional planning
Question
How to apply those concept of geomorphology into hierarchical landscape mapping?
First delineation
Landscape mapping processes Globally the continent is divided into two:
1. Mountainous – rough relief 2. Plain – smooth relief
The initial steps, those two landforms are divided by elevations: > 600 m mountain and plateau / high land plain < 600 m hills and low land plain
Second delineation
Landscape mapping processes There 10 global landform units based on single sequence of geomorphological processes:
1. Structural origin 2. Volcanic origin It is a constructional landforms important step of landform delineation! – separate your area in to two categories … structural and volcanic landforms! in fact the complex geomorphological processes is more common found in the field
Second delineation
Landscape mapping processes Together with the initial delineation of constructional landforms is elevation segmentation within the constructional landforms > 900 msl – above condensation elev.
< 900 msl – below condensation elev. The rainfall intensity in the area > 900 msl is decrease The rainfall intensity in the area 900 - 600 msl is the highest one The rainfall intensity in the area < 600 tends to have trend getting higher linear with the increasing of elevation
Third delineation
Landscape mapping processes There 10 global landform units based on single sequence of geomorphological processes: 3. Fluvial landforms
7. Glacial landforms
4. Marin landforms
8. Biological landforms
5. Aelolian landforms
9. Denudational landforms
6. Solutional landform
It is a destructional landforms furthure separation of the structural and volcanic landforms! All of those destructional landforms occupies a certain part of the structural or volcanic landforms
Fourth delineation
Landscape mapping processes There 10 global landform units based on single sequence of geomorphological processes:
10. Anthropological landforms It is a special destructional landforms The anthropological landforms might lay on any other destructional landform Keys of Geomorphology Nr. 5 ….. The complex geomorphological processes are more common than the simple processes Most of the areas in the earth surface have been created by more than two types of geomorphological processes
Fifth delineation
Landscape mapping processes Within the destructional landforms:
Delineate the zone of materials source (residual), zone of transport (erosional), and zone of deposition (depositional) slope form (compound slope)! It is further landform delineation after the delineation of destructional landforms combined with …
The intensity of erosion-deposition cycles may be influenced by the occurrence of biological action in the form of animal, vegetation, and human activities
Sixth delineation
Landscape mapping processes The next delineation would be based on slope inclination and slope length The slope inclination and slope length shows the potential of future landforms modification rate
The slope inclination should be the last step of landscape delineation – in a detail mapping only! Slope inclination and slope length depict as single slope!
Technical issues on stepwise landscape delineation First delineation constructional landforms + elevation
Second delineation constructional landforms + elevation Third delineation natural destructional landforms Fourth delineation artificial destructional landforms Fifth delineation erosion-deposition sequence Sixth delineation slope inclination and length
From the first to the sixth steps, the criteria applied for segmentation are different
Application of step-wise landscape delineation on land resources mapping First delineation < 1 : 250.000 Second delineation 1 : 100.000 Third delineation 1 : 50.000
Fourth delineation 1 : 25.000 Fifth delineation 1 : 10.000 Sixth delineation > 1 : 10.000
The common mistake is we apply the same level of landscape classification for all map scale!
The sequence of Subduction, Plateau, Active Volcanoes, and Folded Hills
Active volcanic zone is located in the central part of Jawa Other volcanic chain located not in the central part is belong to dormant volcanoes
The Plateau is located in the southern part of Jawa Island The chain of folded hills is located in the northern part of Jawa
The Fluvio-Volcanic Foot Plain of Bantul District is part of Southern Java Plateau
The Fluvio-volcanic foot plain is located in the Graben
Graben Bantul (cont.)
Lendah-Srandakan Hills
Alluvial Plain
What happen if we do not follow the rules of started from global to detail and having basic theory in Geomorphology in analyzing landscape? When we locate our sample in the alluvial plain in Srandakan-Bantul: We can not answer from where the soil parent material is coming from We do not know the basement rock of the alluvial plain May be we will consider the natural hazard in our sample area is only flood and other possible false interpretation!
Facts in our common situations We have slope classification and we apply it for all map scale without any modification
We have 1 : 250.00 Land System Map with very detail data base which usually applied for detail map The available systematic USDA soil classification is rarely apply properly in Indonesia… the Ordo – Subgroup – Great Group are very often apply for any scale of mapping
Concluding Remarks Logical thinking of classification hierarchy should match with the landscape mapping hierarchy We have to re-arrange the relief classification systems in order to fit with the mapping hierarchy
The proposed step-wise segmentation is only an example how to re-arrange the existing relief classification system for land resources mapping purpose
Concluding Remarks Heirarchical landscape segmentation will provide a guide to determine sampling site in land resources mapping
Lets we go to the correct direction in developing our nature!
