GeoJournal 4.1.

31

31-44/1980

@ Akademische Verlagsgesellschafl • Wiesbaden

M a n a n d T r o p i c a l K a r s t in S o u t h e a s t A s i a Geo-ecological Differentiation, Land Use and Rural Development Potentials in Indonesia and other Regions Uhlig, H., Dr., Professor of Geography, I ustus Liebig-University, D-6300 Giessen, FR Germany.

Abstract: Some karst regions of Indonesia (lava, Sulawesi, Bali, Madura), on closer examination geomorphologically and hydro-geologically quite distinct from each other, are checked

with regard to land-use, settlement and other economic and cultural significance. Brief comparisons are made to similar regions from the Philippines (Bohol), Thailand etc. An amazingly strong differentiation, especially of the rice-cultivation systems, is determined by the varying access to water. Some densely populated limestone regions are suffering even from critical water supply for human consumption, cattle etc. Proposals for improvement and rural development are given. The comparison of agricultural landscape types under changing geo-ecological conditions yield fine examples of closely interwoven man-earth eco-systems.

Appropriate rural development should be based, on an intimate knowledge of the many differentiations of the Man-Earth Ecosystem. In this paper, the special potentialities offered by tropical karst regions for agricultural landuse and rural development shall be examined with some examples from Java, Sulawesi, Bali, Bohol (Philippines) and Thailand. These micro-regions already show a fascinating differentiation of the geo-ecological base for human occupance as well as of the existing rural structure and the possible means of its improvement. Tropical karst regions usually represent a domaine of geomorphology. The idea of this representation is, however, to demonstrate the surprisingly strong differentiations of agricultural landscapes resulting from man's attempts most dramatically in overpopulated Java - to carve out a living even under the severe conditions of such regions. It was initially the work of the late Herbert Lehmann and the IGU Karst Commission, created by his initiative, which stressed the differences between the "classical" karst-types of Yugoslavia I) and the other temperate climatical regions and those of the tropics. It is not the relief caused by solution hollows, like dolines, poljes etc. without

surface drainage ("abflul~lose Hohlformen"), but the "Vollformen', cones of limestone characterizing the tropical karst, named "Kegelkarst" by Otto Lehmann already in 1927. Tropical karst had to be distinghuished soon into one type consisting of bold, nearly vertical and sometimes overhanging limestone towers, frequently rising from a corrosion plain ("Karstrandebene" - karst border plain - K. Kayser, 1934), which was named "Turmkarst" (tower karst) by H.v. Wissmann (1954) in SW China, while H. Lehmann (1955, 1956) preferred the term " M o g o t e " - karst taken from examples in Cuba. In contrast to this type, a second one consists of beehivelike half cupolas bearing a number of terms, e.g. "Kegelkarst", "Halbkugelkarst', half-ball karst, Haymok karst (Philippines), "Sinuskarst" (sinoid karst) Flathe and Pfeiffer, (1965) or "Gunung Sewu-type karst", referring to that "classical area", where H. Lehmann (1936) carried out his research which later became the fundament of modern tropical karst geomorphology. It might be appropriate, therefore, to begin with the investigation of tropical karst regions under the aspects of agricultural geography at that entire place.

32

Gee Journal 4.1/1980

Agriculture and Settlement in Gunung Sewu (Java) Gunung Sewu ("Thousand Mountains") on the S coast of central Java, has been known in scientific literature since Junghuhn (1845). The limestones are stretching for about 85 km along the coast and about 10-25 km from S to N. The entire karst region covers an area of about 1,400 km 2. The highest elevations rise to more than 600 m. At the coast, the limestone rocks rise from the sea forming a 2 5 100 m high cliff. Given the uniform "gipfelflur" of the karst domes, the "Thousand Moutains" have more the character of a plateau carved out of the karst than that of a real mountain range (relative hights of the domes: approx. 75 m, with an average of 30 domes/km2). There are thousands of beehive-like cupolas.

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Fig 2 GunungSewu (Java) Ricefields (on impounded rainfall) in a karst dry-valley; fallow during dry season. Half-cupola of the "Kegelkarst" with cultivation terraces in the background; boys carrying drinking water from a "telaga". (phot.: H. Uhlig, August 1975)

waterlevel of perched groundwatersloreys ~

telaga,waterbearing

~

telaga,dry

Fig 1 Types of surface- and groundwater in Gunung Sewu (schematical) (from: Flathe and Pfeiffer, 1965)

The basic components were described by F. Junghuhn (1845): "Think of rounded, hemispherical mountains 100 to 200 feet high which rise up in their hundreds one beside the other in all directions, and which are separated from each other by narrow, labyrinthic, interconnected valleys" . . . "on a small-scale the mountain mass of Goenoeng Sewoe might be compared with a low ridge of earth on which moles have thrown up a densely spaced system of hills." H. Lehmann (1936, p. 18) continues: "The relief of Goenoeng Sewoe gives the impression of being the reverse of a normal mature doline landscape. Instead of the dolines which in the Dinaric Karst puncture the karst plateau like a sieve with a series of more or less circular bases, and instead of the narrow crests and angular residual pillars between the merging dolines in a maturing karst landscape, the hollow shapes here are angular with concave - inwards indented - boundary lines". The hollows and flat surfaces are filled or covered with brown terra rossa. The weathering products of the limestone were, in places overlain by allochthonous, fine-grained tufts, deposited from volcanic activity in Central Java,

formerly covering probably the entire region, but now washed into the karst basins. The filling of the hollows and the covering of the shallow slopes with these nutrient-rich and fine-grained soils is one of the few favourable factors on which the agricultural use can be based. At the bottom of some karst basins, the deposition of the clayey "Terra Rossa" reaches a depth of nearly 30 m and becomes fairly impermeable. Thus, little lakes without drainage are filled by the heavy downpours during the rainy season (Fig I). Moreover, many of these lakes, called "telaga", have been improved by dams to secure that main source of water supply. Additionally, some wells have been dug into the terra rossa fillings of the basins. There are some 450 telaga throughout the entire karst region, but still human beings and cattle have to make daily treks over distances up to several kilometres to obtain a meagre supply of water. Many of these open basins dry up completely during the dry season. H. Lehmann would like to avoid the term "dolines" to describe the hollows, which in size are similar to the dolines and uvalas of the Dinaric karst, because they are rarely round, bowl-shaped or funnel-shaped, while poljes are largely lacking; he therefore proposes the more neutral term "karst basins" ("Karstwannen"). There slopes are converted into terraced agricultural land. In order to maintain soil moisture, to prevent soil erosion, to create flat surfaces and to get rid of the rock fragments lying on the ground, a network of (drystone) terraces was gradually superimposed on the natural relief, composed of steps and walls built of rough limestone. Thus, a tremendous system of rising and falling terraced fields throughout the entire karst region was created. All of them, however, can be used only in dry cultivation. A few valleyfloors have been converted into bounded fields for "rice on impounded rainfall" (Fig 2). But the vast majority of the

GeoJournal 4.1/1980

slopes and terraces supports permanent dry fields without any irrigation. This allowed to establish scattered rural settlement throughout the many karst basins; on the other hand, irrigated land - which is normally the basis for permanent rural settlements in SE Asia - is rarely available. Instead of this, every soil-containing joint is cultivated (Fig 3). The unfavourable conditions of permeable substrate and the monsoonal rhythm of a pronounced dry season with only minimal precipiation from May/June to September/October (during 4.3 months of the year the average precipitation is less than 60 ram) contrasts with a more favourable rainy season (precipitation peaks occurring in December/January, rain lasting till April; 6.8 months with more than 100 mm of precipitation); altogether, the mean annual amount of precipitation is between 2.100 and 2.360 ram. Bearing in mind the fact that the soil moisture and nutrients apparently rise again to the surface during the dry season2), this permits intensive, continuous dry-field cultivation ("tegalan") of the nutrient-rich and waterretentive soils during each rainy season, but full fallow periods following in dry summers. In older descriptions, cassava (manioc), which is undemanding to grow but low in nutritional value, is given as the main crop. However, under the influence of the growing population pressure and also of initial development measures (for some years now modest amounts of artificial fertilizer have been used) this situation has changed. Nowadays the cultivation of dry rice 3) ("padi gogo") on large permanently ploughed areas, on the narrow terraces and between the karren using hoes or dibbles (sowing in September/October, harvesting in January), constitutes the dominant form of land-use during the rainy season (Fig 4 + 5). Soy-beans, groundnuts, maize, mung-beans, some sorghum, chillies and cassava (seedlings planted between the dry rice, then allowed to grow for 8 - 9 months in the

Fig 4 Gunung Sewu (Java) Smallholders, preparing their fields by hoe during the dry season. Limestone-boulders collected from the field and piled up on terracewalls. (phot.: H. Uhlig, August 1975)

33

~

Permanent(tegalan) dry fields (terraced) on flat areas and shallow slopes or in karst basins

~Dry

(permanent) agricultural terraces with crops planted between the karrsn and the slopes

cl a Residual secondaryforest, alang-alang and karren on topsef domes

Fig 3 "Kegel"-Karst at Gunung Sewu (Java) (Diagram adapted from H. Lehmann [19361, land-use supplemented by the author) field) are rotated. Dry rice - tobacco occurs where slightly more favourable amounts of soil moisture are retained. Tobacco, which remains in the fields until summer, is one of the few cash crops grown in this karst region otherwise carrying only subsistence farming. Groves of trees and the vegetable gardens around the settlements permit some yearround use. The near reversal of the ratio of wet-field (sawah) to dry-field (tegalan), which is normally typical for Java, is shown by the data for some kecamatan (rural districts) of Gunung Sewu 4) (1972) in %: Tab 1

Kecamatan Paliyan Semanu Tepus Rongkop Panggang

sawah 0,4 0,2 0,5 0,1 1,2

tegaLan 67 67 89 90 75

Fig5 GunungSewu(Java) Dry upland rice cultivation on terraced fields during the rainy season. The "telaga"-pond (enforced by a weir) servesfor householdwater supply only; it is not used as an irrigation-tank. (phot.: H. Uhlig, Dec. 1974)

34

GeoJoumal 4.1/1980

Tab 2 Kecarnatan Paliyan Sernanu Tepus Rongkop Panggang

km2

::: :Jnhabitants ::3 ]1 :::]i:': : , ....1

149.60 :) 106,86 :

961

53,065

: :

,: :i n h !ikm:~ ,'::::: ,: ::3 ::1961

:::::

:J'::'

:I

,',i:n 1 ': ' : 1971

I

]: :42,933 : : 3::34:02 : J:::: : : 177 12 : : ::5O,385: ::::~8:3: ]:: :i:': / 173.36 48,175 : :' ]3::::27'S: ::::t 168.58 4S,O09 : : ::267 ::3:::':::: :::t

Due to growing population pressure, more and more attempts are made to produce two crops during each rainy season. To achieve this, groundnuts, soybeans, maize etc. are intercropped by sowing them under the rice; they are harvested a few weeks after the rice. One alternative is to sow maize after the first rains in September/October and to harvest after about four months while the intercropped cassava remains for further five months in the field. The increasing shortage of land is even more strikingly demonstrated by the laborious efforts made during the fallow periods to improve the land and to renew or extend the stone walls and terraces. New terraces are continually being constructed to preserve the soil and the soil moisture even in relatively gently dipping fields and, apart from the rock fragments cleared up from the ground, more and more stones are quarried away from the karren. The small-farmers work ceaselessly using hammers to break off pieces of the walls and corners of the karren in order - often only square centimetres at a time - to win additional cultivatable areas from the stony land in these spaces that are farmed between the karren (Fig 4). Building of terraces, and refurnishing of walls and the construction of platforms on which houses are built, is one of the main activities of this "karst population"; during the dry season, the appearance of the slopes is dominated by the white colour of the poi'nts from which the stone has been freshly quarried. While a few peasants have large fields of relatively good and also fiat-lying agricultural land at their disposal, the majority are owners or tenants of extremely small and difficult to work fields on the steep slopes (average size of the holdings: I - 2 ha, but in many cases less than 0.2 ha). This is a general problem throughout Java, but it becomes particularly serious in the karst. Compared with the agrarian population densities in the well irrigated plains of Central Java with their rich cover of volcanic ash soils - e.g. 9 0 0 1,100 inh./km 2 in the plain around Yogjakarta - t h e densities in Gunung Sewu, which are around 240-400 inh./km 2, may at first seem low. But, compared to a supraregional level, these figures are also extremely high, and despite the unfavourable natural conditions, overpopulation is the dominant problem in the development of the karst region of Gunung Sewu. The rapid growth becomes even more evident when a comparison is made with the census of 1930 according to

Population and density for

[ five Kecamatan, which cover most of :

:::::55;950':"

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i971

:

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the karst region:

374

]:: g5~177 423 ':154,/30 ::3 309 ::::]:52;008 ::: 30i : 3::~7077 ' ::3:3279

:: ::: ::::3 ,: 3:"

which (Pelzer, 1963) the figures for Semanu were 253 inh./ km 2 (as against 432 inh./km 2 now) and for Panggang 212 inh./km 2 (as against the present figures of 279 inh./km2). This growth is reflected not only in the extreme expansion of the settled areas compared with the I : 50,000 scale map prepared in 1920 by the Netherlands Indies Topographical Survey (reprinted without change in 1943 as an AMS map), but it also effects the soil cover. The constant, wearisome expansion of new cultivated terraces and the creation of more and more, even extremely tiny, cultivatable plots between the karren on steep slopes, causes progressive deforestation and increasing exposure of karren as a result of the erosion of soil following the heavy agricultural activity. While ]unghuhn (1845) still found "high virgin forest stands" (including teak), H. Lehmann (I 936, p. 24) reported that typical karren-fields were existing only locally "because the karst crops out relatively rarely at the surface, even though the coherent soil cover of a 'covered karst' ('bedeckter Karst') is lacking. The hollows between the karren are filled with varying quantities of terra rosa so that a relatively lush vegetation can establish itself". The photographs published by Lehmann show that the secondary bush and alang-alang grass covering the hill-tops an slopes was at that time more dense and extended further down, whereas the terrace agriculture was restricted more to valley floors and gentle slopes. In contrast to this, large karren slopes are exposed nowadays; the area under cultivation often extends right up to the top of the karst domes, of which only the uppermost dry sections are left to pasture and bush. The explanation is that as the population pressure continued to increase, greater and less favourable areas were put under cultivation; larger soil surfaces have been exposed by agriculture and are subject to increasing erosion which is steadily uncovering the karren. In some places, farmers are forced to re-apply the earth washed down to the fields. On the other hand, the forestry authorities have banned agriculture and grazing in some less densely populated areas and have initiated re-afforestation experiments (in many places teak trees have been re-planted along the roads as well). Where this action has been taken place, we see that the secondary forest has grown up quickly and is starting to cover the karren slopes again. The harshness of the environment is determined even

GeoJournal 4.1/1980

more by the serious lack of water and by the increasing depletion and erosion of the soil. Even during the rainy season, when all the "telaga" ponds are filled with water, the inhabitants of many settlements must travel several kilometres each day to bring back the drinking, cooking and washing water in buckets on carrying rods (originally sections of bamboo trunk were used as natural buckets; nowadays mostly tins are used; similarly, the cattle must be driven to the same places to drink and wallow in the water, while the people also bath and wash their clothes there. The telagas are also used for fishing. This multiple use also effects the hygienic condition of the water; during the dry season the left over water consists of nothing more than a dirty sludge. Other telaga disappear completely during the dry season, and they are then planted with cabbage, tobacco, etc.; most wells dug into deep layers of terra rossa dry up. Certain large telaga holding water all the year round have to supply the needs of many villages - surveys conducted in September 1975 at the Telaga Sorsaga near Kemiri, which extends more than 1 km in a karst basin and presumably receives some inflow from karst springs, revealed that the "catchment area" was 1 5 20 villages and hamlets within a radius of up to 8 km; at that time, human beings and cattle were forced to make the arduous trek to the surviving source of water via the stony paths through the karst. Apart from the constant battle against the sharp-edged stones, these pathways are a further unfavourable factor effecting the fetching of water in the heat of the tropical dry season. Therefore, when considering development measures for Gunung Sewu - which, like the entire S mountains of Gunung Kidul (including also its non-karst sections) is regarded as a particularly critical development area in overpopulated Java - prime consideration had to be given to improving the water supply. There are, in contrast to Bali (see below), no cisterns available of the type which make life easier in the Mediterranean karst regions (even using just eaves-troughing and rain-butts, it would be possible to store a certain amount of water here). In addition, more funds should be made available for the drilling of deep wells down to the underground karst watercourses, which (as the vegetation in the dry valleys indicates) are in places not too far below the surface - at the moment only a few badly maintained winddriven pumps are available. Another project would be to tap the strong coastal karst springs (which discharge large quantities of subterranean karst water into the sea, where it flows off without being used, in various bays along the cliff coast) and to pump it back (by "hydraulic ram" or, more expensive, by motor pumps, as this is done for instance in the Argolis of Greece) for general use and irrigation purposes. Only very minimal use is being made of this opportunity at the present time; for example, a small pumping station is operating at the strong spring in the Bay of Baron, and this supplies water to an irrigation project of limited extent in the adjoining valley floor, thereby enabling cultivation of rice and vegetables all

35

~--= ~Jy.;]

Fig 6 Cisternfor a singlesettlement(NusaPenida) (from: Flathe and Pfeiffer, 1963)

the year round and also providing the population with a better water supply. Proposals have been made by a hydrogeological survey (see below), but much remains still to be done. "Bukit" Peninsula and Nusa Penida, Bali

Geologically a continuation of S Java's tertiary limestone belt, which still comprises some more karst regions (e.g. the Kendeng (K. Helbig, 1935) or the Blembangan peninsula etc.), the Bukit Pecatu peninsula (briefly called "Bukit" ("bukit ' ' = hill) or in Dutch the "Tafelhuk"), is connected by a 6 km long sand-bar to Bali, and the island of Nusa Penida, some 12 km off its S coast, are similarly poor endowed karst regions. Nusa Penida might have the worst conditions as it is extremely isolated from nearby Bali, being settled by the descendents of former exiles, who where displaced to that barren island by the rajas of the former small Balinese kingdoms. Still the 200 km 2 of the island were already settled in 1930 by 22 333 inh. (112/km2), the smaller Lembongan island by 4200 (457/km2). K. Helbig has given a detailed account of that karst island already in 1941, which shows many similarities to Gunung Sewu. Geomorphologically, the numerous domes of the Kegelkarst and the re-emergence of the water (quickly disappearing into the karst after the rains) in a series of strongly flowing springs at the foot of the steep limestone cliffs of the coast, appear to be more or less identical to that region in Java. Helbig mentions, however, one significant difference: there are no terra rossa soils, but a black soil of a regur type. This lack of the clayey terry rossa-filling of the karst basins may explain that there are no telaga lakes. This additional disadvantage has been counterbalanced by a very careful system to collect the rainwater from the roofs (into clay-pots imported from Bali) and to cut cisterns (jumbang) into the rock, with an artificial catchment area, formerly covered with grass, now with corrugated iron or concrete (Fig 6).

GeoJoumal 4.1/1980

36

Fig 7 Bukit-peninsula (Bali) Small-farmer's reservoir ("waduk") dried up during the dry season. Thorn-scrub and succulent trees between dry-fields in the background. (phot.: H. Uhlig, July 197"/)

More dramatical was the water-supply across some of the cliffs of the S coast, where a specialized social group, the "sekehe toja", emerged. Its members had to climb primitive ladders fixed into the solution-hollows of the karstic rocks, over the steep cliffs (up to 200 mJ) to carry up the water in buckets from the karst springs on the shoreline. K. Helbig, describing this desparate struggle for an agricultural existence (1941, p. 404--407), points rightly to the fact that it needed the tough industriousness of Balinese farmers to convert such land into permanently cropped tegalan terraces, whereas more extensively working ladangfarmers (shifting cultivators) would have depleted the vegetation cover and soil from this karst island fairly soon. He indicated a similar cultivation of dry-rice (padi gogo) on the slightly better and moisture-preserving soils of the karst basins and of maize intercropped with beans, chillies and cassava on the slopes. The karst geomorphology of Bukitpeninsula (85 km 2, rising to 210 m) is less spectacular. The lack of water on its ondulating plateaus on partly pure and massive, otherwise porous limestones, is nevertheless equally detrimental to settlement and land-use. The sheer cliffs rising from the sea - most spectacular 80 m above the roaring surf of the sea at Uluwatu temple - prevent again access to the sweetwater springs along the coastline. Cactaceae, Euphorbia sp. and Pandanus are prevailing in a dry savannah vegetation, interrupted by white limestone rocks, contrasting sharply to the lush green of the main island of Bali. The few fields, terraced with stone walls, are utilized mainly from single farmsteads with cattle raising and dry-field cultivation during the rainy season only (peanuts, soybeans, maize, cassava, sweet potatoes, capoc trees=ceiba etc.). Dry rice (padi gogo) is grown only in small quantities; it can hardly compete with the much cheaper rice from the markets of nearby Bali, which in con-

~, =

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Fig 8 Arrangement of Cisterns in Pecatu (Bali, Bukit Peninsula) From: Flathe and Pfeiffer, 1963, 35"/. trast to Nusa Penida is easily accessible by road. Small stonequarries for building-material, sometimes amidst a farmer's fields, are worked for some extra income, similarly matweaving (from Pandanus leaves), collecting of brush-wood for sale etc. The poor looking huts of the peasants, lacking the typical wall-enclosure and richly ornamented array of small temples, rice-barns etc. of the Balinese home, are another expression of the harshness of life on the karstpeninsula. However, Balinese spirit for hard and communal work was not lost and led to the construction of some "waduk" (artificial open reservoirs). These have been carved out partly from the rock or were dug, plastered with drystone walls (Fig 7) and leak-proofed with clay, when available in natural depressions, shaded by a dense growth of trees and bushes around. Cut about 5 m deep into the rock and measuring up to 40 by 20 m in an irregular shape, the waduk can store water for about three months after the rainy season. The remaining 2 - 3 months until the new rains, they fall dry, similar to some wells dug by individual farmers. This meant that water had to be carried during these months up to 10 kin, usually from groundwater wells on the sand-bar connecting with the main island, which is underlain by marine clays.

GeoJoumal

4.1/1980

This situation has been improved by the innovation of cisterns, as described and proposed for further extension by Flathe and Pfeiffer (1963) (Fig 8)i Similar to the Mediterranean type, they consist of walled catchment areas plastered with concrete, from which the water flows into underground storage shafts. A large cistern has improved considerably the living conditions of Pecatu, the only compact village of that peninsula. Finally, by Inpres-programmes (instant development programmes on local basis from the president's fund), some more modern cisterns have been constructed at several places of the peninsula. Bukit peninsula remains still the poor neighbour of Bali's sawahs, but compared to other karst regions, like Gunung Sewu, it demonstrates that something can be done to improve the calamities of lacking water supply.

North-Bone (Sulawesi) - a more Favourable "Kegelkarst"Region Parts of the old territory of Bone (E coast of S Sulawesi) again consist of a Kegelkarst, which in its geomorphological aspects reminds of the karst landscape of the well-known 'Gunung Sewu karst type' on Java (Achsan and Lehmann, 1960, p. 59). Examination of the agricultural landscape shows, however, that despite the many similarities in the relief, settlement and cultivation have quite different conditions compared to Gunung Sewu. A geological variation - which was not readily detectable in the aerial photographs interpreted by Achsan Sunartadirdja (1959) - between this region and Gunung Sewu, is of great significance with regard to the cultivation (and many also play a role in the morphogenesis, and might help to explain the large flat areas between certain regions of the cupola relief in Bone, described by Achsan and Lehmann). This difference derives from the fact that in the basic layers of the limestone of Bone - not very deep beneath the soil of the karst basins and of the flat areas - impermeable, water-bearing strata are found, so that a relatively large number of karst springs or wells are available (sometimes these strata are tapped by artificially enlarged "Jama"like shafts). In addition, some more clay-containing marllayers are interbedded, and where these intersect with slopes, small but perennial springs may emerge; some ponds are also available. This water supply, which is incomparably better than that at Gunung Sewu or in the Balinese karst (pen-) insulas, favours settlement and agriculture. Fairly regular street villages, a typical feature throughout Bone and other areas settled by Bugis, prevail (Fig 9). The floors of the karst basins are to some extent irrigable and support small " s a wahs", some even with double-cropping of rice! Otherwise, they retain at least greater amounts of soil moisture, favour-

37

Fig 9 N.-Bone (Sulawesi) Typical street-village of the Bugis, occupying a small karst-basin. Well covered "Kegelkarst" (cultivated in land rotation -"ladang") in the background; good soil- and water-conditions on the floor of the karst-basins.(phot.: H. Uhlig, Sept. 1975)

-.

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.-

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.

...:-:"

...=~:"

Irrigation, or areas with sufficient soil moisture, in the karst basins (2 x rice/annum or alternative rotalions) Terraces - permanen| dry-field cultivation ~ "t' Lsdang (shifting cultivation) r~ c~a

Residual secondaryforesl, alang-alang,karren

....... " Sawahs on impounded rainfall or simple ditch :t.. i.---! ~ irrigation (1 x rice during the rainy season)

Fig 10 "KegeI-Karst" in northern Bone (SW Celebes) favoured by water-bearing strata in shallow depth (H. Uhlig; cartogr. L. Dreher) ing crop rotations of rice (on impounded rainfall or by simple irrigation during the rainy season) with tobacco, beans, sweet potatoes, groundnuts, soybeans, millets, etc. Maize is also producing good yields. Above the karst basins, some of the slopes are additionally cropped with permanent dry-field cultivation similar to the type found in Gunung Sewu, but (in view of the good yield from the irrigated fields in the karst basins)

38

GeoJournal 4.1/1980

=,:~:,, Rice fields

Highway ..... .......

Field lane

Fig 11 Karst-Morphology of Bahai (Philippines). Section of a map by F. Voss (1970), based on aerial photogramrnetry

Foot path

Contours, distance 2(] m

Additional contours, distance 10 m x2w

Elevation in m

_-_-_-_ Hollows and flat - - - ground with high

groundwater-table -~.~,~,~(- Karst-basin,

karut-hallow Fault, direction of

movement indefioed Oblique fautt in m ......

the area is smaller and the terracing and cultivating activity remains less intense. Instead, unlike in Gunung Sewu, "ladang" cultivation (in form of a supplementary shifting cultivation) is practised on these slopes. It is mainly tobacco, which is the main crop of these "ladang" (although maize, cassava, spices etc. are also grown; upland rice is quite rare because the "sawahs" provide most of the rice supply). Compared with the other areas discussed here, the tobacco (of good quality) helps the population of the karst region of Bone to achieve a higher cash income and thus to enjoy a higher standard of living 5) (Fig 10). After just one year of cultivation, the "ladang" areas are again returned to bush fallow for three to five years (or finally imperata-grassland); under this more dense plant cover there is less soil erosion and exposure of karren fields. Higher yields from the irrigated floors of the karst below reduce the need to make excessive use of the dry fields on the slopes. A pedological study would be needed to examine whether, in addition, the presence of the clay-containing beds and of slightly more calcareous-porous "soft" sections of the limestones 6) favours better formation and retention of soil on the slopes and also leads to less exposure of karren-fields. Finally, the different distribution of the precipitation - although the total annual amounts are similar - is a further factor in favour of the karst in Bone. Given the location on the E side of the SW peninsula of Sulawesi, the SE monsoon is the main source of rain in that area, with three "wet" months from April to June. But since offshoots of the SW monsoon extend to this area as well, almost ten months receive an average of + 100 mm or more rain per annum and only two months (August and September) constitute the actual dry season. The more advantageous natural endowment of the "Kegelkarst"-region of Bone is also evident from the statistical data for the administrative district (Kecamatan) of Ulaweng, which is almost entirely located in the karst

Boundary of strata

•

Hipping of the strata

•~"

Striking of the strata

region7). In this district, 5 % of the total area is occupied by sawahs (in Gunung Sewu the percentage is only 0 . 2 1.2); and only 34% is used for "tegalan"-permanent dryfield cultivation (in Gunung Sewu the figures were 67 % to 89%). (The "ladang" areas were not statistically determined.) At 323 inh./km 2 the density of population is approximately equal to the average density population in Gunung Sewu; thus, lower population pressure is not a reason that can be given to explain the better preservation of the soils (and of a thickly vegetation-"covered" karst) in Bone. The "Kegelkarst" Island of Bahai / Philippines On the Phil/ppines, the bee-hive like "Halbkugelkarst" of Boho/ has been explored geomorphologically by F. Voss (1970). He is comparing its outward appearance with that of the "Gunung Sewu" type of Java. However, his paper and photographs make it clear that water-bearing strata are underlying a relatively "shallow" karst. This means that water for agriculture, even for irrigated rice-fields, is readily availal~le in the karst basins between the dome-like cupolas and his aerial mapping (from which a section is reproduced in Fig 11) reveals a structure so strikingly similar to the conditions of North-Bone (Fig 10) that this map could be taken easily as a section from that region, was it not for the different forms of settlements and the place-names. The Contrast: a "Karst Border Plain" of the "Tower Karst" - Maros / S Sulawesi In SW Sulawesi, about 35 km to the N of Ujung Pandang (Makassar), a magnificant karst region rises like a wall from the coastal plain near Maros; isolated towers stand amidst sawah-rice fields in front of steep limestone walls. This type

GeoJournal 4.1/1980

of tropical karst is called "Turmkarst" ("tower karst") according to H. v. Wissmann, or "Mogote-Karst" (applying a Latin-American name for these limestone towers) by H. Lehmann. Achsan Sunartadirdja and H. Lehmann (1960) have described the relief and genesis of this region and published instructive aerial photographs and block diagrams. A more recent, revised view of the geomorphological aspects was given by R.C. McDonald (1976). While the interior of the Eocene limestone mass (relatively pure, coarse-bedded Nummulite limestones), which has been stripped of its volcanic cover, is a wild, almost totally inaccessible, dissected plateau pockmarked by "cockpits" (karst solution holes) and covered with dense forest, the marginal plain at the foot of the 100-350 m high limestone walls and towers (= "Mogotes") as well as some small "poljes" are densely settled and cropped with typical "sawahs". In places, exposed karren surface and bizarre, mushroom-shaped "karren rocks" give evidence of corrosive processes, disproving earlier interpretations as a former cliff on a marine abrosion platform. However, McDonald has interpreted the plains along the foot of the karst towers rather by lateral erosion through meandering rivers than by corrosion alone. The area is widely covered with a micaceous, yellowbrown loam-soil on top of the impermeable substrate brought by rivers from the volcanic mountains (behind) into the karst region. This impermeable substrate on a relatively flat, but on closer examination quite broken terrain in front of the karst walls (from which karst springs emerge) offered favourable conditions for "sawah" wet-rice culture (Fig 12). The Bugis' villages, shaded by groves of trees, are located mainly (but not exclusively) on flat alluvial cones near smaller rivers at the foot of the wall. At first sight the settlement and cultivation of the area scarcely differ from the other coastal plains of S Sulawesi. A detailed study, however, reveals the special features resulting from the location on the edge of the karst. The numerous caves, which are hidden behind curtains of "external stalactites" (H. Lehmann) at the undercut foot of the rocks walls, and the karst springs occurring in the same location and providing a perennial supply of water even during the dry months. Excavations in the cave sediments permit the settlement to be placed in the 5th millenium BC8). Nowadays, the karst border plain is mostly covered with wet-rice fields ("sawahs") and - close to the settlements - orchards and vegetable gardens. Additional shifting cultivation ("ladang") occurs rather seldom at the edge of the karst on small sloping areas. On most of the permanent wet-rice fields - and this is the case almost throughout the entire coastal plain of Sulawesi - the traditional rotation of only one rice harvest per year (during the rainy season)9) is still prevailing (Fig 13). Following this harvest, most of the fields lie fallow; only those, where soil moisture is particularly favourable, bear a

39

i

Favourable agricultural area with karst springs (irrigation, 2 x rice, or 1 x rice - 1 x tobacco etc.~annum) Sawahs with technical irrigation (2 x rice/annum)

[~ "~

Sawahs on impounded rainfall or simple ditch irrigation (1 xriceduringtherainyseason) Weir for irrigation canals

Fig 12 Karst-borderplain and "Tower Karst" at IV]aros(SW Sulawesi) (H. Uhlig; cartogr. L. Dreher) second crop (soybeans, groundnuts or tobacco). Just as simple is the predominant method of irrigation to grow "rice on impounded rainfall"; each field is enclosed by an earthen dyke, and the rice is cultivated in the rainwater retained within these dykes. Occasionally, an additional simple ditch irrigation system is set up, fed from karst springs, and the fields are linked by some cuts through the dykes. Since the plain is not completely flat, the surface is convex at those places where groups of mogotes close off part of the plain like a valley: the terrain at the foot of the karst wall is somewhat lower (with the exception of alluvial cones) and usually moist. Proceeding from the foot of the rocks, the plain rises slightly; it has been incised by small channels discharging into the ditches of the supplementary irrigation system. The micro-relief at the same time gives rise to slight, step-like terracing of the rice fields. At the lower edge of the plain, these ditches discharge into sinkholes at the foot of the karst towers, incised (by solution) some 1 - 2 m below the surface of the plain. On the opposite edge of the karst rocks, in a narrow, lower zone along the limestone walls, there is a strip of intensively cultivated land, which is irrigated throughout the year by karst water from springs and can therefore be used for two rice crops per annum. In certain places, stagnant water is of sufficient depth to grow Nipah palms.

40

GeoJoumal 4.1/1980

Fig 13 Maros (Sulawesi) Karst-border plain at the foot of the "tower-karst'. Residual karrenrocks (grazing cattle in the middle may serve as a scale) between rice-fields on impounded rainfall (fallow during dry season). Mountains in the background: volcanic rocks E of the karst-area. (phot.: H. Uhlig, Sept. 1975) Where the possibility of providing irrigation at the foot of this wall is reduced (on the flat alluvial cones), a rotation of wet-rice during the rainy season and soybeans or tobacco during the dry period is practiced. The differences of only a few tens of centimetres in height, humidity and soil often result in a catena-like sequence: 1. Rock wall (with foot-caves and karst springs); 2. elevated alluvial cone (interrupted at the springs) with dry-field cultivation or horticulture; 3. moist low-lying zone (Nipah palms or wet-rice with two crops); 4. slightly elevated irrigation ditches (gradually built-up of the walls of the ditches due to the material removed by dredging); 5. in front of this again a slightly lower, more easily irrigated zone yielding two annual wet-rice crops; 6. a gradual rise towards the plain; some irrigated fields for wet rice in rotation with soybeans, peanuts, to bacco; 7. a higher plain: yielding only one rice crop (on impounded rainfall or with simple ditch irrigation during the rainy season), fallow during the dry season. The favourable irrigation conditions in the small, bay-like karst "poljes" penetrating the limestone mass are remarkable; for example the flat floor S of Lealleang, which is sealed by impermeable deposits, is irrigated throughout the year by perennial karst springs, and the area bears two rice crops per annum (Fig 14). At the S edge of the karst region of Maros, where the Bentimurung river emerges from a subterranean flow and deep gorges (coming allochthonously from the eruptive rocks E of the karst region), the karst water can be used for a large-scale "technical irrigation" project. When it emerges

Fig 14 Maros (Sulawesi) "Polje" within the "tower-karst". Perennial karst-spring led by short canal into the wet-rice "sawahs'; 2 rice-crops per year. (phot.: H. Uhlig, Sept. 1975)

into the plain, the river is impounded by a weir constructed by Dutch engineers, and the water is channelled via concrete canals to an irrigated area more than 70 km 2 in extent, which is capable of bearing two rice crops each year. Of course, this "technical irrigation" is not confined to karst regions, but the karst hydrography guarantees a regular supply of water for that largest irrigation area on Sulawesi, which is intensively cultivated and thus set apart from the rest of the coastal plain.

Further Examples of SE Asian Karst Regions There are more regions characterized by the struggle for water to make a living in karst environment. Most important in areal extent, population pressure and need for improvement, is the island of Madura. Apart from some minor coastal belts, nearly all of its 4382 km 2 consist of plateaus and hills (up to 450 m) of tertiary and pleistocene sedi-

GeoJournal 4.1/1980

ments, most of them permeable and thus lacking of surface water, considerable parts again consisting of 50-300 m thick limestone beds with typical features of the karst. Attempts to explore the possibilities of water development have been made by Flathe and Pfeiffer (1963 - including a hydro-geological map 1 : 250 000). Land use is dominated by dry-field cultivation (some dry rice on permanent fields, but maize and cassava being the staple food), restricted again to the wet season with nearly complete fallow during the dry months. Cattle raising arose as an alternative source of rural income, impressively interwoven with folk-tradition by Madura's famous oxen and buffalo races. Extensive problem areas of karstic limestone plateaus are found on several parts of the Lesser Sunda Islands. Eastern Timor, e.g., has both: uplands with a deep, hardbaking marl-soil, which is merely cultivated during the wet season (l. Metzner, 1977), and karst plateaus with a bare thorn-steppe, hardly to be utilized for cattle grazing. In other places, karst springs allow the irrigation of riceterraces, sometimes interrupted by dolines and sink-holes, as shown on photograph (Fig 15). Many smaller karst regions occur on the SE Asian mainland, stretching from Burma, through Laos and Thailand to Vietnam and likewise across the Malay peninsula. Due to the geological structure, most of them consist of long but narrow outcrops of limestone. Impressive tower karst features, but also saw-like chains and some half-cupola ("Kegel") karst as well, are the result, but in most cases the areal extent of those narrow limestone belts is too small for entire agricultural regions bearing the special features of the karst. There are, however, numerous examples of permanent dry-field cultivation of the corrosion plains (Fig 16) and polje-like basins near the karst rocks, benefitting from the good calcareous soils (Fig 17). For small ecotopes, advantage is taken of karst springs for irrigation of wet-rice fields at the foot of the rocks. Most impressive, but of little agricultural use, is the towering karst topography at the W coast of S Thailand (especially in Phangnga Province), where ingressions of the sea have converted the karst rocks into many islands of a phantastic shape. The "Hundred islands" of the Lingayen Gulf, north Luzon) came into existence by the same process, but consist of lower rocks of the "Kegel" karst type. Instead of agriculture, fishing and mangrove utilization - based on "water villages" built on high stilts in the tidal water - and, last not least, the development of tourism make up for the economic facilities there.

Other Economic and Cultural Aspects of the Tropical Karst of SE Asia

There are more peculiarities of the tropical karst areas, which can be touched on but briefly. Karst hollows for example provide favourable conditons for secondary

41

Fig 15 Eastern-Timor Doline collapsed over sub-terranean karst-caves amidst of sawahs, irrigated from karst-springs (near Baucau). (phot.: H. Uhlig, July 1971)

deposits of tin, tungsten, brown hematite, ilmenite, gold, phosphates etc. As a result, we not only find a concentration of mining activities in the vicinity of karst regions, but also the area surrounding the mining settlements was frequently developed for an additional land use, while normally, it would not have been put to much agricultural utilization. Mined-out open-cast pits have, in many cases, been developed by former (predominantly Chinese) miners or "squatters" into sites for market gardening (e.g. near Ipoh/WMalaysia, near Bau/Sarawak etc.). Of primary importance for regional development are the concrete (cement) industries based on the limestones most easily accessible in karst rocks. Maros (Sulawesi), dealt with in this paper, is an outstanding example. The availability of cement without high transportation costs could help to extend also the construction of cisterns for the benefit of the population living within the limestone regions. The significance of karst caves for prehistoric settlement has already been touched on - they have yielded much valuable information as is evident from the large number of cave temples and monasteries (Hinayana as well

42

Fig 16 Central Thailand (near Saraburi) Corrosion plain at the foot of limestone-hills with numerous "karren" (white), formed from the outcropping strata and exposed by recent clearing for dry-field cultivation (maize etc.). (phot.: H. Uhlig, Sept. 1977)

as Mahayana Buddhism - Chinese immigrants - but also Hindu temples and shrines). The link between the worship of their ancestors and of their dead, which is practiced by the Toraja in the highlands of Sulawesi, and their burials in karst caves in high limestone rock-faces, later enlarged by artificial caves dug into non-karstic rocks, too - is particularly impressive. In addition, the unusual physical manifestation of the karst topography - caves, springs and sinkholes, phantastically shaped stalactites etc. - have influenced people's minds and resulted in the accumulation of "holy places" in karst regions. This is also reflected by the romantic views of the tropical karst - especially of the "tower karst" - as depicted in art, e.g. on Chinese scroll-paintings. The romantic scenery of certain karst regions is also attracting a steadily increasing number of indigenous and foreign tourists. This is particularly the case in those karst regions, into which the sea ingresses and which have been broken up into clusters of picturesque islands. Significantly, limestone outcrops in higher elevations (and thus in a cooler climate) are occuring with geo-morphological characteristics of the temperate zone (e.g. in the Shah Highland, in Toraja land etc.) The accumulation of fertile soils in polje basins or large dolines are quickly utilized for permanent arable farming or for a somewhat improved shifting cultivation (as for instance by the Lissu hilltribe farmers on the slopes of mount Chiang Dao, N Thailand). On the other hand, karst regions consisting merely of harsh rocky terrain covered with dense tropical forest, may become "negative" areas which cannot be settled, and in some cases they are feared as hideouts of bandits and insurgents, or as barriers to transportation and traffic etc.

GeoJoumal 4.1/1980

Fig 17 Central Thailand, west of Uthaithani Recent clearing with settlement and maize-fields on the high-quality

soils of a "polje"-Iike basin, expending f.rom a corrosion-plain into a small areaof "tower-karst". (phot.: H. Uhlig, Aug.1976) Possibilities of Rural Development in Tropical Karst Regions Improved water supply for household use, cattle and whereever possible for irrigation is obviously the most deserving development need. Its improvement would be worthwhile not only to increase the carrying capacity of the nutrientrich limestone soils, but also to improve immensely the livelihood and the economic chances for these regions. Most pressing is the need in Gunung Sewu and Nusa Penida, where Java's and Bali's overpopulation have created a strong pressure on the utilization up to the last corner of that grim and rocky country, and where the access to water is most difficult. Hydrogeological reconnaissance (Flathe and Pfeiffer, 1962) has already yielded the following proposals, which would allow considerable improvements at economically feasible costs, e.g. dredging out the telaga to a deeper level to improve the storage capaciW (of course after careful investigation of the depth of the terra rossa layers, to avoid losses by trickling into the limestone). Leak-proofing of the clefts, karren, ponors and dolines of the catchment of a telaga by application of terra rossa, concrete or clay and subdivisions of the telaga by walls into separate units for drinking water, washing and bathing, and for use of the cattle would improve the hygienic conditions and the waterstoring capacity. R.W. Roundy raised the geo-medical problem of the disease hazards in the prevailing, mixed use of these telagal0). A great improvement for the collecting and storing of water and the reduction of losses by evaporation is brought by the construction of cisterns, plastering areas of up to 100 by 100 m with concrete, with flow-off into excavated, plastered and covered tanks, which could lead to the storage of 12,000-18,000 m 3 of chemically and bacteriologically "clean" water. The example of Bukit peninsula, Bali, demonstrates the feasibility of that device. Individual houses could furthermore easily catch water from the roofs through simple bamboo or tin eaves, piping

43

GeoJouma/ 4.1/1980

the water into stores (old petrol bins; big clay jars etc.) as exemplified on Nusa Penida (Fig 6). In certain locations, digging of wells or improvement of springs would be possible. Along the coast, the strongly flowing sweetwater springs at the foot of the cliffs could be tapped and pumped by hydraulic rams to storage and distribution tanks on elevated sites. The flow of these springs would yield 100-300 I/s of water without excessive costs. The installation of more expensive water pumps could allow the haulage of several thousands of I/s. These are examples of some fairly inexpensive installations for improvement. With more costly deep wells and pumping schemes, much more - even irrigation - could be achieved. It is disappointing to see that (apart from some improvements of telaga dams) little of the proposals - submitted by the above-mentioned hydro-geological surveys already more than 15 years ago - has been put into realization, or to find expensive windmill pumps, formerly installed for deep wells, falling into disuse. Bukit Petacu Peninsula in Southern Bali seems to be one of the few sites where improvements have been used more actively for the benefit of the population of these poorly endowed areas. In N Bone, pumping-wells could facilitate an improved tapping of water, running a few

meters underground on impermeable layers (some being already reached by "Jama"-like wells - i.e. natural vertical karst slots). The tower karst of Maros should allow the tapping of additional karst water to extend the already existing areas of technical irrigation. More tree-crops could be grown by help of agricultural extension work, The improvement of a road-network (marketing, services, better access to schooling and other facilities) would be another urgent development requirement. 13espite the adverse nature of the karst, rural development would be more rewarding in these areas as compared to adjoining dry hill-districts on a geological basis of neither limestone nor volcanic ashes, e.g. the entire Gunung Kidul (S Java), apart from its karst areas. In contrast, the nutrientrich limestone soils and the concealed, but technically accessible underground water of the karst offer considerable reserves for improvement. Altogether, the striking topography of the considerable number of tropical karst areas is a characteristic feature throughout SE Asia (and also in SW China). Apart from its interest for geomorphology and hydrogeology, it offers impressive examples of the interaction of various geofactors in the Man-Earth-Ecosystem, and special, but deserving targets for rural development.

Footnotes 1)

2)

An earlier German version was presented to the "Festschrift" for J. Rogli~, Zagreb. The present, altered and enlarged English paper was originally read to the meeting of the IGU Commission on Rural Development in connection with the Inter-Congress Meeting of the Pacific Science Organization, Bali, 1977. This regeneration of nutrients at the surface (as the rising soil moisture evaporates) seems to be a favourable factor in parts of the wet/dry monsoonal tropics; it increasesthe possibility of permanent dry-field cultivation, while under permanent wet tropical conditions "shifting cultivation" prevails.

5)

6)

7) 8) 9)

3)

"Dry rice" refers to rice cultivated on a rotation system of permanent dry fields without any irrigation (not even any dikes to impound precipitation). It is distinguished from 'upland rice' grown on periodically used slash-and-burn areas (Uhlig and Hill, 1969).

4)

I am grateful to Drs. Parmadi (Dep. of Geogr., Gadjah Mada Univ. of Yogjakarta) for assisting in the field and obtaining statistical data from the Census Bureau Yogjakarta (D IY).

It is not unusual to find tobacco cultivated on "ladang" areas, where the soil conditions are ideal for this plant. Land rotation is, in principle, also used in the large tobacco plantations of N Sumatra. These petrographic differences manifest themselves in the less pronounced and lesssharp-edgedsolution "cups" and "cavities" ("Lochkarren"), "Lapies" ("Rillenkarren") etc. of the limestone outcrops. Statistics from the Dept. Agraria, Ujung Padang. Resultsof the excavations by I.C. Glover (1976).

The rainy season - 5-6 relatively "wet" months - on the W coast of Sulawesi occurs from November to March; the peak precipitation is recorded in December and January (610-690 ram, respectively); about 4 dry months occur during summer, the driest being August (less than 10 mm), the total amount of precipitation is 2,300--2,500 mm and is thus similar to that in Bone (E side~see above). 10) During thedi~cussion of the author's paper atthe IGU Commission on Rural Development meeting at Bali, 1977. Similar proposals have been made already by Flathe and Pfeiffer.

44

References Bfgli, A.W.H.: Der Chemismus der USsungsprozesse und der Einfluf~ der Gesteinsbeschaffenheit auf die Entwicklung des Karstes. In: Report of the Commission on Karst Phenomena, (Lehmann, H., ed.), XVIIIth Internat. Geogr. Congress, Rio de ]aneiro, New York 1956. Dames, T.W.G.: The Soils of East Central Java. Contributions of the General Agricultural Research Station, Bogor, No. 141, 1955. Dane~, I.V.: Das Karstgebiet des Goenoeng Sewoe in Java. Sitzungsberichte der K6nigl. B~Shm. Ges. d. Wissenschaft in Prag, 1915. Direktorat Geologi: Geologic Map of Indonesia (1 : 1 Mio.), Ujung Pandang Sheet (R. Sukamto), Bandung, 1975. Escher, B.G.: De Goenoeng Sewoe en het probleem van de Karst in de Tropen. Handelingen van her XXIII. Nederl. Natuur-en Geneeskundig Congres 1931. Haarlem 1931. Flathe, H. and Pfeiffer, D.: Grundziige der hydrogeologischen Verh~iltnisse im Tafelhuk (Bali) Zeitschr. d. Deutschen Geol. Ges. (1963) Flathe, H. and Pfeiffer, D.: Outlines on the Hydrology of the Isle of Madura (Indonesia) In: Int. Ass. of Scient. Hydrology, Publ. No. 64, Berkeley 1963. Flathe, H. and Pfeiffer, D.: Grundziige der Morphologie, Geologie und Hydrologie im Karstgebiet Gunung Sewu/Java (Indonesien) Geologisches Jahrbuch, 83 (1965) Glover, I.C.: Ulu Leang Cave, Maros: A Preliminary Sequence of Post-Pleistocene Cultural Development in South Sulawesi. In: Archipel 11 (Paris) (1976) Helbig, K.: Der Kendeng. Eine Kalklandschaft auf SiJdost Java Geogr. Wochenschrift 881-887 (1935) Helbig, K.: Nusa Penida. Eine tropische Karstinsel. Mitt. Geogr. Ges. Hamburg 391 --410 (1941) Junghuhn, F.: Topographische und naturwissenschaftliche Reise dutch Java. Magdeburg 1845. Kayser, K.: Morphologische Studien in Westmontenegro II. Zeitschr. d. Ges. f. Erdkunde(1934) Kayser, K.: Karstrandebene und Poljeboden. Erdkunde (1955) Kornrumpf, M.: Mensch und Landschaft auf Celebes. Beiheft 8, Geogr. Wochenschrift, Breslau (1935) Leemann, A.: Bali - Insel der G6tter. I nnsbruck/Frankfurt/M. 1978. Lehmann, H.: Morphologische Studien auf Java. Geographische Abhandlungen 111/9,Stuttgart (1936) Lehrnann, H.: Der Einflul~ des Klimas auf die morphologische Entwicklung des Karstes. In: Report of the Commission on Karst Phenomena, Lehmann, H., ed., IVIIIth Internat. Geogr. Congress, Rio de Janeiro, New York 1956. Lehmann, H.: Der tropische Kegelkarst in Westindien. Deutscher Geographentag Essen. Tagungsberichte, Wiesbaden 1955. Lehmann, H.: Der tropische Kegelkarst auf den grol~en Antillen. Das Karstph:inomen in den verschiedenen Klimazonen, Erdkunde (1954) Lehmann, H.: Karstentwicklung in den Tropen. Die Umschau in Wissenschaft u. Technik (1953) Lehmann, O.: Die geographischen Ergebnisse der Reise (HandelMazetti) durch Guidschou (Kweitschou). Denkschrift d. Akademie d. Wiss. in Wien. Math.-Nat. KI. Bd. 100, 1927. Lehmann, O.: Die Hydrologie des Karstes. Leipzig-Wien 1932. Louis, H.: Die Entstehung der Pollen und ihre Stellung in der Karstabtragung auf Grund yon Beobachtungen im Taurus. Erdkunde X (1956)

GeoJoumal 4.1/1980

Louis, H.: Das Problem der Karst-Niveaus. In: Report of the Commission on Karst Phenomena. Lehmann, H., ed., XVlllth Internat. Geogr. Congress, Rio de Janeiro, New York 1956. McDonald, R.C.: Limestone Morphology in South Sulawesi, Indonesia. Zeitschr. f. Geomorphologie, Suppl. 26 (1976). Pannekoek, A.J.: Enige Karsterreinen in Indonesie. Tijdschr. Nederlandsch. Aardrijkskund. Genootsch. (1948) Paton, J.K.: The origin of the Limestone Hills of Malaya. lourn. Trop. Geogr. (1964) Pelzer, K.J.: Physical and Human Patterns. In: Indonesia. McVey, T., ed., HRAF Press, New Haven 1963. Rathjens, C.: Zur Frage der Karstrandebene im Dinarischen Karst Erdkunde (1959) RSII, W.: Wenig bekannte Formen der Bodennutzung auf Java Geogr. Rundschau (1974) Rogli~, J.: Karstprozess und fluviatile Erosion. In: Report of the Commission on Karst Phenomena. Lehmann, H., ed., XVIIIth Internat. Geogr. Congress, Rio de Janeiro, New York 1956. Rogli6, J.: Korrosive Ebenen im Dinarischen Karst. Erdkunde (1958) Rogli6, J." Das Verh~iltnis der Flusserosion zum Karstproz~ss. Zeitschrift f. Geomorphologie (1960) Sarasin, P. u. F.: Entwurf einer geographisch-geologischen Beschreibung der Insel Celebes. Wiesbaden 1901. Sunartadirdja, M.A.: Beitr~igezur Geomorphologie yon Siidwest-Sulawesi. Diss. Frankfurt/Main 1959. Sunartadirdja, M.A. and Lehmann, H.: Der tropische Karst yon Maros und Nord-Bone in SW-Celebes (Sulawesi). Zeitschr. f. Geomorphologie, Suppl. 2, Internat. Beitr~ige z. KarstmorphoIogie (1960) Uhlig, H. and Hill, R.D.: Draft Presentation of a Framework for the Geographical Terminology of Rice-Cultivation. In: Modernization of the Pacific Region, Inter-Congress Meeting, Pacific Science Ass., Kuala Lumpur, 1969 (Tokyo, 1969) Uhlig, H.: Siidostasien - AustraI-Pazifischer Raum. Fischer Uinderkunde 3, Frankfurt/Main 1975. Uhlig, H.: Die Agrarlandschaft im Tropenkarst. Beispiele ihrer geo6kologischen Differenzierung aus Java und Sulawesi. Geografski Glasnik (Zagreb) (1976) Verstappen, H.Th.: Some observations on Karst development in the Malay archipelago. Journ. of Trop. Geogr. (1960) Verstappen, H.Th.: Karst-Morphology of the Star Mountains, Central New Guinea; Zeitschr. f. Geomorphologie (1964) Voss, F.: Typische Oberfl~ichenformen tropischen Kegelkarstes auf den Philippinen. Geogr. Zeitschrift 58, 214--227 (1970) Wilford, G.E. and Wall, J.R.D.: Karst Topography in Sarawak. Journal of Tropical Geography (1965) Wissmann, H. v.: Der Karst in den humiden und sommerhei&en Gebieten Ostasiens. Das Karstph~inomen in den verschiedenen Klimazonen, Erdkunde (1954)