The Need and Prospect of Environmental Geomorphology

 

The background of the topic is the environmental problems occurring in Indonesia which tends to increase time by time, from mountainous until coastal area, from rural to urban area with various scale; natural hazard/disaster and anthropogenic hazard/disaster.  Most of the problems actually related to the land and water. The land and water are the most important natural resources for the human life; they are an object and also subject to geomorphology (Babar, 2005). Water is one of the most agents that forming and shaping the landform. The landform is the main object of geomorphology (Lobeck, 1939; Thornbury, 1959; Spark, 1960;  Cooke et al,, 1974; Van Zuidam et al., 1979 and Verstappen, 1983). Stallins (2006) wrote an article, Geomorphology and ecology  is unifying themes for complex system in biogeomorphology; he stated that  interaction of geomorphic and ecologic landscape components has been largely conceptualized as independent; in one direction geomorphic processes and landform shape the distribution of biota; conversely, in the direction, biota modify geomorphic processes and landforms. Thus, it can be interpreted  that the interaction between geomorphic component (geomorphic processes and landforms) and ecologic component (biota including human being) as sources for changing the land and water resources in the earth surface, partly initiate the environmental degradation as well natural resources depletion.

All of the problems are actually related to the man wishes to transform or use and change the surficial processes; according to Coates (1991 in Panizza, 1996), such practical use of geomorphology for solution of those problems is defined as environmental geomorphology. Some problems on environmental that related to the land and water always occur in Indonesia and tend to increase both in magnitude and frequency, it necessary to speed up the emerging of environmental geomorphology and its prospect scientifically as well as the practical use in Indonesia. By my small experience as lecturer in Geomorphology I have a strong feeling that environmental geomorphology will be well developed in Indonesia, even though not as fast as in developed countries.

Before I discuss in more detail about the need of the environmental geomorphology, let me remind the short history of my academic carrier in geomorphology. When I was a student in the Faculty of Geography Gadjah Mada University I got difficulty to decide which department I should choose. At that time, there was regulation that in the second years on the beginning of third semester the students must decided which department among eight departments they should attend. Until a day before the due date, I had not decided it yet; it was not essay to choose because I had not enough known about the content and the prospect of all geography’s branches.  At mid night of the last day, I dreamed that someone asked me to joint him to climb up a mountain, he was Prof. Kardono Darmoyuwono, but at that time I did not know what his field of study. Finally, I knew that Prof Kardono was a lecturer on geomorphologic department and than without any doubt I decided to take geomorphologic department. During that time (1964-1965),  geomorphologic department was not popular, among 80 students in the Faculty of Geography there were only 4 students in Geomorphologic Department, others were in hydrological, population geography and demography, economic geography and resources, agricultural geography, regional and politic geography, and cartography department.  The number of students increased year by year and some lecturers went abroad for post graduate master program and another duty as lecturer in Malaysia and also supported the works of governmental institute (National Survey and Mapping Coordination Agency), and there was a gap between number of students and available human resource in this department than I and my colleagues as lecturer’s assistance had to tackle the student’s practical works and partly gave an lecture especially on geological and geomorphologic subjects. For about 4 years, I gave practical works or exercises on: mineralogy and petrography, structural geology, field geology and basic geomorphology under Prof. Karmono Mangunsukardjo supervision.

Based on the lesson learned as assistance, I had enough time to read literatures on related subject to geomorphology. Based on academic requirement, a student who had passed all the theoretic subjects had to do research for undergraduate thesis (skripsi). I submitted a research proposal and the title was: The relation between geomorphologic and groundwater conditions of small river basin, in East Java Province. Prof. Kardono was pointed out as my supervisor together with Prof. Sugeng Martopo and I graduated in 1971. After graduation, I had opportunity to joint the Serayu Project, joint cooperation between Gadjah Mada University and Free University of Amsterdam, Amsterdam University and ITC which sponsored by NUFFIC, started in 1973 until 1979; and then continued with Earth Sciences Project until 1989. Scientific Board from Gadjah Mada University site was Prof. Kardono.and from ITC side was Prof. Herman Verstappen. The purpose of this joint cooperation was mainly on the curricula development, strengthening research capability and educational staff’s development. The focus of interest of the Serayu Valley Project as well as Earth Sciences Project was geomorphology, hydrology and pedology toward watershed management and environmental management. On the operation plan of the project, I was a candidate for the doctoral  program supervised by Prof. Kardono and Prof, Dr. G. B. Engelen (from Free University of Amsterdam). In 1974, I studied at ITC and FUA, 1975-1976 did field work in Serayu River Basin, and in 1977 I came to FUA for consultation and thesis writing and graduated in 1981. My dream to climb up a mountain accompanying Prof. Kardono became reality in my academic carrier.

I’m truly agree with what have stated by Luna B. Leopold (2004) that no successful scientist who does not point to one or several teachers, advisors, or supervisor whose influence crucial to his development. There were some persons who lifted up my academic carrier in geomorphology and it related subject, among others were: Prof. Kardono Darmoyuwono (geomorphologist); Prof. Surastopo Hadisumarno (physical geographer); Prof, Karmono Mangunsukardjo (geomorphologist); and Prof Sugeng Martopo (hydrologist) from Indonesia site, all of them had passed away before retired; while from foreign country among others were: Prof. Dr. G.B. Engelen ( hydrogeologist from FUA); Prof. Dr. H. Th. Verstappen (geomorphologist from ITC); Prof. Dr. A. M  Meijering ( hydrogeomorphologist and remote sensing, from ITC); Dr. R.A van Zuidam (geomorphologist  from ITC), Mr. R. Vouskuil (geomorphologist from ITC); Prof. Terwind (coastal geomorphologist from Utrecth University); and Prof. Dr. Masahiko Oya (geomorphologist, from Waseda University Japan).  In this good occasion I would like to remember, to thanks and to appreciate for their kindness in guiding and giving geomorphologic perspective to me; for them who are still with us now, I do hope they always have a good health, and who were passed away I do hope Allah SWT accept for their good works and forgive all of the mistakes.

After shortly I remind my journey to be a gemorphologist, even though not really geomorphologist. I will discuss on why we need environmental geomorphology. The term of environmental geomorphology was introduced by Coates in 1971 (Panizza, 1996), the definition: environmental geomorphology is the practical use of geomorphology for the solution of  problems where man wishes to transform or to use and change surficial processes. The discipline involves the following issues and themes:

a)       the study of geomorphic processes and terrain that affect man, including hazard phenomena, such as flood and landslides;

b)       the analysis of problems where man plan to disturb or has already degraded the land-water ecosystem;

c)       man’s utilization of geomorphic agents or products as resources, such as water or sand and gravel;

d)       how the science of geomorphology can be used in environmental planning and management. 

 

Panizza (1996) formulated environmental geomorphology as the area of Earth Sciences which examines the relationships between man and environment, the later being considered from the geomorphological point of view. According to Panizza environment is defined as the range of physical and biological components that have an effect on life and on the development and activities of living organism. Man, as living organism interact with environment, man influence the environment and on the other hand man are also influenced by the environment (Soemarwoto, 1996). There are three components of the environment  that are abiotic, biotic and cultural, which is known as A,B,C of  environmental  components (Tanjung, et al., 2005); those components interrelated each other to composed  natural system or ecosystem. Without any disturbance by man the natural systems are in balance condition.

Based on the fact  very scar area in the Earth surface still in virgin without any disturbance by man; it means that most of the area in the Earth surface have modified by man to fulfill the basic human need as settlement as well as for crop cultivation and other human facilities. As population increases and the pressure on  Earth resources grows, the competition for water, timber, open space, fuel, and environmental desires will bring a need for more knowledge and more data on the process and the factors in geomorphology. Geomorphology is importance to both science and to daily life (Leopold, 2004).  The daily life that related to the importance of geomorphology directly as well as indirectly involve to the environmental components, it means in daily life we need environmental geomorphology as stated by Coates and Panizza (1996).

In the daily life we need natural resources and always face with natural hazard. In relation to environmental problems, environmental geomorphology divides into geomorphological resources and geomorphological hazard.  Geomorphological resources include both raw material and landform is useful to man or may become useful depending on economic, social and technological circumstances. While geomorphological hazard is defined as the probability that a certain phenomenon of geomorphological instability and of a given magnitude may occur in a certain territory in a given period of time.(Panizza, 1996).

     Natural resources and natural hazard actually could be studied by various disciplines. The difference between environmental geomorphology and other disciplines to study on natural resources and natural hazard is the approach.  Landform approach is usually used for evaluation of natural resources and natural hazard. Landform is very useful to evaluate the natural resources for certain purposes and can be used as framework for mapping and evaluation unit as well. The landform characteristics that consist of relief, materials (lithology and structure) and geomorphic processes are very relevance to the natural resources and natural hazard factors. Relief is the product of interaction  between lithology and structure and geomorphic processes, it mean that relief reflected lithology and structure, and  geomorphic processes ( van Zuidam, 1983). Landform unit approach has been used widely for assessment of natural resources potential  and  natural hazard zoning for mitigation purposes. To apply geomorphology for natural resources and natural hazard must be founded by basic theory and principles in geomorphology (Thornbury,1959; Summerfield,1991), geomorphological survey and mapping (van Zuidam, 1985; Verstappen, 1983), and should be supported by related subject such as geology, climatology and hydrology. Remote sensing technique and GIS has importance contribution and tools for geomorphological surveys and mapping.

            After discussing on ontology and a little bit on epistemology of environmental geomorphology as above, then I will  propose  environmental problems in Indonesia that need solving from environmental geomorphology point of view; it relates to the axiology of the environmental geomorphology. The main environmental problems in Indonesia are related to it’s geographical condition. Indonesia consist of more than seventeen thousand islands, the coast line for about eighty one thousand kilometers, is located in tropical climate, active tectonic, active volcanic, more than two hundred twenty five million inhabitants with uneven distribution, and composed of more than 300 ethnics; and situated  between two ocean (Hindia and Pasific) and two continents (Australia and Asia). The territory for about 1,900,000 km², and roughly two-third is submerged (sea), the distance from west to east 5100 km and from north to south is 2000 km, the relief range between 5030 m above sea level to more than 9000 m below sea level (Verstappen, 2000). Such geographical condition influences the type, distribution, potency of the natural resources as well as the natural hazard and human hazard.

Indonesia very rich in various natural resources, such as oil, gas, hydrothermal, coal, mineral, rock, water, land, timber, biota, crop, etc.,. The actual data of the natural resources was unavailable precisely. Not all of the natural resources can be evaluated using geomorphological approach; it is applicable if the objects are located on the surface or near surface of Earth (Strahler and Strahler, 1996). As far as the landform unit is related to the natural resources and natural hazard, the out line  of  the Indonesia Geomorphological Map of  Indonesia by Verstappen (2000) is applicable for identification the natural resources, at least the site and the spatial distribution. The geomorphological map can be used as basic framework for multi level survey. In general the landform unit of Indonesia morphogenetically consist of denudational, volcanic, structural and depositional landform, each of them composed several landform units. The uneven distribution of the landform in Indonesia followed by uneven distribution of the natural resources too. The natural resources that directly related to landform unit is the land resources. Landform approach is useful for land resources evaluation. Sutikno, et al., 2003 used landform approach to evaluate the natural resources of the Merapi Volcano, including land capability, show that the land capability classes is more or less coincide to the landform unit.  The landform approach is also applicable for groundwater resources evaluation, especially for unconfined aquifer (Sutikno,1988, 1989). The results of the environmental geomorphology using landform unit approach for natural resources studies are the site location, spatial distribution, and the potency of the resources (the quantity and the quality). Such quantitative data has high values for natural resources management. The real contribution of the geomorphological resources is to support data for natural resources and environmental management and give recommendation how ought to conserve and to use continually for the future generation.

Beside rich on natural resources, Indonesia also rich on various types of natural hazard and natural disaster, such as earthquake, tsunami, volcanic eruption and the associated hazards, landslides, flood, drought, fire, biological and  human conflict. The earthquake, tsunami, volcanic disaster are related to the position of Indonesia that located on collision between India-Australia and Eurasia plate, between Pacific and Eurasia plate. Historically, Indonesia has stricken by earthquake and tsunami several times. The relatively new of earthquake (the magnitude: 8.9 RS) and tsunami occurred at Aceh  in  26 December 2004, and recent earthquake (the magnitude: 5.9 RS) at  Bantul, Yogyakarta  and Klaten , Central Java in 27 May 2006. The casualties of the earthquake and tsunami at Aceh: 165,708, while the earthquake at Yogyakarta and Central Java: 5,760 (National Technical Team, 2007). Both areas are high risk in nature to disaster because of the location at collision zone and subduction zone of India-Australia and Eurasia plate. Based on the field observation, the damage area in Aceh geomorphologically are located on alluvial plain, ancient beach ridges, delta plain, back swamp and partly on foot slope. The susceptible area to tsunami can be approached by landform unit, while the susceptible area to earthquake can be analyzed the position to subduction zone and geological structures. Contribution of environmental geomorphology to earthquake and tsunami hazard is the spatial distribution map of the susceptible class area toward earth quake which include the safe area for refugees; beside that also for recommendation of the spatial planning or land use planning with take care of the hazards.

Historically,  Bantul, Yogyakarta  at least had seven earthquakes happened above 6 RS since 1867, that were: 1867, 1937, 1943, 1981, 1992, 2001 and 2004 ((National Technical Team, 2007). The strings of quakes, however, did not cause any disaster of the 27 May 2006 scale because the epicenter was at the Indian Ocean. Geomorphologically, the Bantul area compose of fluvio volcanic foot plain, alluvial plain, river terraces, foot slope, sand dunes, karsts topography and denudational hill. The transition between the lowland area and the hilly area is marked by Opak fault that partly coincide to Opak River. Based on the landform unit, the most damage areas are located on fluvio volcanic foot plain, alluvial plain, and foot slope; while on karst topography and denudational unit were less damage. Unconsolidated material and shallow depth of groundwater on fluvio volcanic foot plain and alluvial plain were factors that higher amplified the earthquake motion. The casualties of Bantul earthquake was too much if compare with the magnitude: 5,9 RS, because the area is dense populated area. What is the contribution of the environmental geomorphology to the case of Bantul earthquake? It is suggested to have geomorphological map in detail and make microzonation of the susceptible area for earthquake hazard, and risk map. The land use planning should be revised and earthquake hazard should use as input data. Based on the lesson learned from the 27 May earthquake, people should be aware with the location where life always faces with disaster either natural or human made. People must believe and aware with the principle that: the present is the key to the past. education seems effective to make people become aware.

The next hazard is volcanic hazard, Indonesia crowned by 129 active volcanoes; distribution of the volcanoes is located on volcanic arc from Sumatra, Java until Banda, and in the north part is North Sulawesi and North Maluku. Most of the volcanos in Indonesia  are strato volcano. Geomorphologically the strato volcano can be differentiated into volcanic cone, volcanic slope, volcanic foot, volcanic foot plain, and fluvio volcanic foot plain unit. Each unit has difference on the slope, the material composition and geomorphic processes even though the boundary is not too sharp. The different of the each unit will follow by natural resources and the hazard as well. The natural resources of the strato volcano: scenery, weather, landscape, land resources, soil, sand and stones, water and biota (flora and fauna). Due to high potential of the natural resources the volcanic area is dense populated, in contrary that area is danger. The volcanic hazards consist of:

1)       direct hazard: eruption, ash, bomb, pumice, pyroclastic rain, lava flow, glowing cloud, lahars flow and mud flow;

2)       indirect hazard: earthquake, tsunami, lahar, landslide, topographic changes;

3)       volcanic gas hazard: H₂S, SO₂, CO and HCN;

4)       physical environment changes;

5)       air poluttion (Nott ,2006; Muzil Alzwar, dkk., 1988 ).

In relation to the natural hazard of the volcano what is the contribution of the environmental geomorphology? The main contribution is the spatial distribution of the susceptible area to various type of the volcanic hazard. The landform of the strato volcano can be identified easily from air photographs and remote sensing images; landform unit is not enough to determine the area distribution of every hazard in the volcanic area because of the various energy and agent of the hazard, it should be supplemented by field measurement, such as the morphometry of the valley.

Flood and drought is another type of that occurring in the earth surface, and also in Indonesia. The flood and drought hazard is not fully caused by natural factor, but human factor has important contribution. Land use changes, land conversion, forest cutting, public facilities construction, urbanization, housing, mining, groundwater withdrawal are human activities causing the flood and drought disaster. From geomorphological point of view the spatial distribution of the flood and drought can be determined successfully. Flood hazard map and drought hazard map is important data for mitigation and can be used for risk assessment. Mostly flood occur on flood plain, alluvial plain, delta plain, river terraces, natural levee, and coastal alluvial plain.

Landslide is the most disaster occurring in the sloping and upland area. Classification of landslide is based on the material that involve and movement types. Based on movement processes we know: fall, topple, rotational, translational, planar, lateral spreading, flow and complex; the material of the landslide consist of rocks, debris and earth. Factors that influence the landslide: lithology, soils, slope, geological structure, stratigraphy, land use, land cover, drainage, rainfall  and human activities.

Contribution of environmental geomorphology related to landslide hazard is to determine the area distribution and classify the hazard, identify the causal factors and recommend how to manage the susceptible area. Land use planning is important to consider the landslide hazard.

Based on the above description, the environmental geomorphology is needed to cope the natural resources and natural hazard problem that tend to increase by time. To apply the environmental geomorphology, it must be supported by strengthening the basic theory in geomorphology, geomorphological survey and mapping. Geomorphological it self is not sufficient to solve the problems related to the natural resources and natural hazard, it should be integrated with related fields. It is true what has stated by Leopold (2004) that even though geomorphology is merely a sliver off corpus of science, it has both intellectual and practical value; in this case related to natural resources and natural hazards. Due to the problems on natural resources and natural hazards in Indonesia tend to increase and need to solve scientifically, the environmental geomorphology is promising and perspective to be developed in Indonesia.

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