Elżbieta Gałka
GIS-based assessment of contemporary land use changes after agricultural abandonment of the loess terraces of the Kunów surroundings (Sandomierz Upland)
MSc thesis under the supervision of: dr hab. Jacek Kozak
MSc thesis submitted in the framework of, and according to the requirements of the UNIGIS Master of Science programme
(Geographical Information Science & Systems)
Jagiellonian University, Kraków, Paris Lodron University of Salzburg
2010
I declare that all sources used in the thesis were properly acknowledged. The thesis is fully my work and it was not and will not be submitted as a thesis elsewhere.
Date ………... Signature ………
TABLE OF CONTENTS
1. INTRODUCTION ...4
1.1. Aims...13
2. STUDY AREA ...14
2.1. Location and extent of the study area ...14
2.2. Geology...15
2.3. Geomorphology ...16
2.4. Climate...17
2.5. River network and underground waters...18
2.6. Soil cover ...19
2.7. Plants...20
2.8. History of land use in the Kunów region ...21
3. DATA AND METHODS ...27
4. GEOMORPHOLOGICAL CHARACTERISTICS OF THE AGRICULTURAL TERRACES IN STAWISKA AND CIOŁEK VALLEYS...31
4.1. The morphology and morphometry of terraces in the Stawiska and the Ciołek valleys ...31
4.2. Role of slope and aspect in forming of agricultural terraces ...36
4.3. Contemporary land use of the Stawiska and the Ciołek valleys...38
4.4. Anthropogenic and other natural factors shaping agricultural terraces within the Kunów region...39
5. DISCUSSION AND CONCLUSIONS ...46
5.1. Evaluation of methods ...46
5.2. Proposed ways of proper maintenance and recultivation of agricultural terraces ...47
6. REFERENCES ...52
7. LIST OF TABLES...58
8. LIST OF FIGURES ...59
9. LIST OF PHOTOGRAPHS...60
1. INTRODUCTION
Abandonment of agricultural land is widespread and increasing in many countries and can potentially lead to a considerable increase in erosion in semi-arid environments. Especially abandoned terrace fields are vulnerable because of gully erosion through the terrace walls (Lesschen et al. 2008; Lesschen et al. 2009). Terraces may be regarded as a human interference with the geomorphic system which drives the evolution of the terrestrial surface (Brancucci, Paliaga 2006), and a way to prevent erosion on steep slopes. Their abandonment results in a new interference with the geomorphic system: the lack of maintenance of a man-altered landscape implies the geomorphic system to gain the control back by means of erosion processes that cause land degradation. Loss of productive land, increase of natural hazard with diffuse problems of instability, the raise of the solid transport in the rivers, loss of biodiversity and disappearance of a rich cultural heritage are all consequences of the decay of terraced structures (Brancucci, Paliaga 2006; Bellin et al. 2009).
On the other hand, after agricultural abandonment, secondary vegetation succession in European moderate and semi-arid middle mountain and upland areas increases vegetation cover and improves soil properties by decreasing runoff and erosion (Lasanta et al. 2001; Poyatos et al. 2003; Wolski 2007; Latocha 2009).
Ancient and traditional agricultural terraces encompass a broad range of forms and functions, occurring in diverse environments on five continents and Oceania (Table 1.1). Likely centres of origin of agricultural terraces are southwestern and southeastern Asia, and the Americas (Sandor 1998 after Spencer, Hale 1961; Donkin 1979).
The earliest solid ages for terracing in most regions are similar at 2000-3000 yr B.P.
While some direct dates for terraced fields have been obtained, most are inferred from archaeological association. A few researchers suggest older dates of 4000-5000 yr B.P.
Spencer and Hale (1961) speculate that terracing began 5-9 millennia ago in the Near East. Familiar forms of ancient terracing and their geographic association include wet field terraces of southeastern Asia, bench terraces in the mountainous terrain of the Mediterranean, Himalayas, and Andes, runoff terraces in arid regions, and lynchet and rideaux fields in northwestern Europe (Table 1.2)
Table 1.1. Geography and approximate early ages for agriculture and terracing
Location Early Ages (yr B.P.)
Continent/Region Subregion Agriculture Terracing
Comments on Teraccing Ages
Eastern Asia China Japan/Korea
8500-11,500 3000-5000
3000
?
Uncertainty about older age
Southern to SE Asia and Oceania
India/Indochina Philippines Papua New Guinea Polynesia
5000-7000 3400-5000 9000 1000-3600
2300-3100 2000
? 1100
3100 yr B.P. Pakistan
Ancient but uncertain age
Southwestern Asia Near East 10,000 3000-5000
Possible 5000 yr B. P. age for gabarbands in
Baluchistan. 5000-9000 yr B.P. speculated for origin of terrace agriculture
Europe
Mediterranean
Eastern Europe Western Europe
8000
5000-7000 5000-7000
2500-4000
?
2000-3500
4000 yr B. P. Italy, 3700 yr B.P. Crete
Early ages for lynchets
Africa
North Africa
SubSaharan Africa 6500
3000-5000
3000
500
Runoff terraces; 2450 yr B. P. Ethiopia
Uncertainty about older age
Meso America South America North America
5000-10000 4000-5000 3000-5000
2500 2500 1000
Uncertainty about older age
Source: Sandor JA (1998) Steps toward Soil Care: Ancient Agricultural Terraces and Soils. In: Transactions of 16th International Congress of Soil Science, Montpellier, France
Table 1.2. Examples of common processes, soil management practices, and soil property changes documented in different kinds of ancient and traditional terrace agriculture
Geomorphic/
Pedogenic processes
Soil practices Morphology Chemistry Biology
Mountain slope decrease/
leveling, some colluvial sedimentation
relatively large walls,
construction filling, fertilization, some irrigated
thickened A horizons, buried horizons, plaggen, anthropic, agric horizons; horizon reshaping, texture and rock fragment changes, structure and pore changes
cases of organic C, N, P increase;
CEC change, pH variable change
soil fauna, enzyme activity changes
Wet- Field
paddy soil proc., anthraquic conditions, slope leveling
water impoundment, puddling, green manure, fertilization, soil additions/
emplacement e.g.,
(hydraulic filling)
new soil materials, constructed texture with clayey structure, soil thickening to several meters, plow pan, agric horizon
inverted gley, ferrolysis, altered clay minerals, some organic matter increases
aquatic, anaerobic organisms
Runoff
fluvial/colluvi al episodic sedimentation, slope decrease
relatively small walls/dams, sometimes deliberate watershed erosion
some A horizon thickening, buried horizons, increase in soil moisture and potential water retention
examples of both increase and decrease in organic C, N, P, pH
organic debris and microbial input via sedimenta- tion
Lynchet/
Rideaux
mainly colluvial sedimentation after land clearing, especially intrafield erosion in humid climate;
aeolian additions, agric processes (slaking, mobilization, translocation of fine sand, silt and clay), sediment mixing
relatively small field boundary walls, tillage
some A horizon thickening, buried horizons,
homogenization from
plowing/mixing but also heterogeneous fabrics, agric horizons, (e.g., dusty clay coatings, crust fragments), extrinsic additions
(e.g. charcoals, ceramics)
examples of lower to higher organic matter and P
common increase in biological activity if organic additions
Source: Sandor JA (1998) Steps toward Soil Care: Ancient Agricultural Terraces and Soils. In: Transactions of 16th International Congress of Soil Science, Montpellier, France
Functions of terracing for these major types include creation of a stable topographic base for crops, soil retention and erosion control, soil accumulation by sedimentation or hand filling, water control ranging from water spreading to runoff, management, irrigation, and ponding, and other microclimate effects. Two basic elements in nearly all terracing are the retaining walls (risers) and interwoven fields (treads). Walls vary from very low to several meters high, from single walls to complex series. Wall construction materials range from in situ bedrock to stones, earth, and living vegetation or other organic materials. Some terraces are built as permanent structures whereas in some systems such as runoff agriculture, their design, placement, and use are more flexible (Sandor 1998).
Landforms used for terracing are diverse at global to local scales, with underlying patterns relating to hydrology, soils, and microclimate. Common terraced landforms include hillslopes and mountainsides, valley margin landforms such a colluvial footslopes, alluvial fans, stream terraces, and drainage ways on upland slopes and in larger valleys. Diverse field placement is characteristic of many indigenous agricultural systems as part of a risk reduction strategy to offset climatic and other environmental uncertainty. Agricultural terraces often conform closely to natural landforms and landscape features. In some areas they mimic and take advantage of natural stepped topography and geologic formations. Many terraced agroecosystems, with their mosaic of microenvironments among alternating contoured walls and small field segments seem to approximate natural ecosystems in terms of diversity. Aesthetic and religious significance has been ascribed to terraces such as those in the Andes.
Because terracing is done to manage geomorphic processes and land and water resources, landscape properties such as slope geometry, drainage patterns, and sediment transport processes are necessarily changed. The stepped topography resulting from terrace wall construction and sediment filling is generally characterized by reduced field slope angle and length. Direct geomorphic changes spark indirect changes in other landscape and ecosystem components through feedback, complex response, and cascading processes. The spatial extent of surficial change is confined in some terraced systems, while in others entire landscapes are altered, as in many mountain and wet- field terraces or in lynchet areas displaying subtle but pervasive anthropogenic colluviation. Many ancient agricultural terraces have been long abandoned and may be obscured or overprinted by later land use, while others remain intact (Sandor 1998).
Geomorphic processes and agricultural management practices associated with terracing induce metapedogenic change in soil properties and development. The degree of soil change varies greatly, depending on particular processes and practices, duration of use, and environmental sensitivity and response (Fig. 1.1).
Some terraced soils differ slightly from their natural state while others are wholly anthropogenic. The most visible form of terraced soil change is surface horizon thickening and the burial of original horizons, which follows sediment filling upslope of retaining walls. At the low end of the range are slight increases (few centimeters) found in many hillslope runoff terraces and lynchets involving low terrace walls and natural sedimentation. Substantial thickening of one to several meters is more characteristic of extensive bench and wet-field terraces filled by hand during terrace construction. Multiple fills and complex stratigraphy are found where agricultural terraces were rebuilt or incrementally filled, as is common in runoff agriculture. Other common soil morphological changes involve texture and fabric. Soil chemical changes, such as in organic matter and phosphorus, have been reported in different kinds of terrace agriculture, but there are few biological studies except in terraced rice paddy soils. Under long-term transformation, many terraced soils develop properties of anthropogenic horizons such as plaggen, anthropic, and agric, which are recognized in other agricultural and archaeological contexts. Cultural debris and artifacts as well as elevated phosphorus levels (Sandor, Eash 1991) can be found in a number of terraced soils. Wet-field terraces produce anthraquic soils.
Fig. 1.1. Natural factors shaping agricultural terraces Source: Apuani T, Masetti M, Pedretti D, Conforto A (2008)
Some of the best examples known of long-term soil conservation involve terrace agriculture, which is significant given that successful care of land resources in the 10,000 year history of agricultural land use is rare relative to numerous cases of soil degradation. Yet if not properly maintained or if located in environments sensitive to disturbance, terracing can also lead to pronounced long-term land degradation.
Terracing can involve a relatively high degree of landscape alteration. Among the most vulnerable environments are slopes that become highly erodible following clearing of vegetative cover for cultivation. Examples of degraded terraced landscapes under these circumstances can be found in several geographic areas with a range of climate and geomorphology such as the Mediterranean, the loess region of China, the North American Southwest, and northwestern Europe. In the latter example, the lynchet form of terracing likely originated from accelerated erosion, but in the process more stable terraced land was achieved. In runoff agriculture especially, erosion plays an essential role in soil moisture and fertility, and actually may be encouraged.
Examples of long-term care of terraced lands are also diverse in geography, environment, and agricultural system, such as the Ifugao rice terraces in the Philippines and Andean terraces (Sandor, Eash 1991; Treacy, Denevan 1994). Criteria for long-term soil conservation in the Andes are enhancement of soil tilth and nutrient status relative to corresponding uncultivated soils.
Although more quantitative soil studies are needed, a number of terraced systems seem to have stood the test of time and are still productive under traditional management practices. Overall, it is likely that conservation was often preceded by soil degradation. Practices such as terracing may have evolved in response to land degradation when people were able to correct their mistakes in time (Sandor 1998).
Field investigations supported by variety of geographic information technologies, e.g., remote sensing, geographic information systems (GIS), satellite navigation are a source of a wide range of possibilities of assessing present state of the long cultivated agricultural areas. Such science elaborations have become a common form of controlling land use changes in recent decades in Europe (Lasanta et al. 2001;
Kozak 2003; Poyatos et al. 2003; Brancucci, Paliaga 2006; Lesschen et al. 2008;
Petanidou et al. 2008; Bellin et al. 2009; Lesschen et al. 2009). GI technologies become important e.g., in archaeological research of ancient agricultural systems, where they offer powerful logistical and analytical capabilities of satellite remote sensing, global
frequently incorporated into projects that investigate and manage substantial data sets of spatially distributed archaeological data, these technologies also offer tremendous potential in regions where far less archaeological research has been conducted. Satellite remote sensing, GPS and GIS technologies form a powerful analytical resource that can make an important contribution to multidisciplinary archaeological, geological and palaeoecological research. Ability to efficiently and accurately document the locations of archaeological sites and land-cover features would have been reduced dramatically without the use of these technologies to generate image maps, perform algorithmic classification, establish site locations, and collect, organize and analyse field data. With established techniques in the management of spatially distributed data and systematic high resolution site survey, archaeologists can collect samples highly appropriate for significant metric analyses (Harrower et al. 2002).
These methods give archeologists a lot of possibilities to reconstruct natural conditions of agriculture development of old civilizations. As an example, thanks to digital terrain analysis and geoarcheological field survey, ancient agricultural terraces in the Southern Shephelah (Israel) were investigated. Physical characteristics, such as elevation, aspect, inclination and surface cover were assessed for slopes and terraces.
Terrace retaining walls were mapped using GPS; the lengths of the walls and the distances between them were confirmed through manual measurement using meter tape.
This combined data provided the location of the retaining walls and allowed the compilation of a GIS layer of 13 terraces. Terrace borders delimited by the footslopes were marked manually on the airphoto. Soil depth pockets were also measured and DEM for calculating runoff was used. Large Nari (calcrete) outcrops on the footslopes generate high runoff values that improve water potential. Hydrological simulations and calculations show that 230 mm of direct rainfall generates a water potential equivalent to 300 mm of direct rainfall. Thanks to GIS application researches came to the conclusion that the presence of Nari enabled runoff agricultural farming in Byzantine and Early Arab (ca. 5th to 8th century C.E.) agricultural systems in the Shephelah region, even in drought years (Ackermann et al. 2008).
In Poland, in the Sandomierz and Lublin Upland loess regions the most common form of terraces are bench and ridge ploughed-on terraces. They are formed as a result of ploughing in direction transverse to a slope under conditions of “historical” field pattern across the slope or they are the effects of anti-erosion farm management (band- type filed system). The banded field pattern formed due to ploughing with the furrow
turned down the slope was introduced in large farms in 50–60’s of the 20th century.
In most cases, they were closed down due to difficulties associated with mechanization of field works. Although the ploughed-on terraces formed in a forced way by property boundaries remained as a relief form, in general, they are not used as arable lands (Patro et al. 2008). These forms are often described and referred to in Polish bibliography as anthropogenic linear forms, which seldom occur in natural environment (Zgłobicki 1998d). They were also described by Bac (1950), Ziemnicki (1955, 1959), Ziemnicki et al. (1975), Mazur et al. (1985), Pałys (1985), Harasimiuk et al. (1999), Baryła, Pierzgalski (2005). In this region, agricultural terraces within the Stawiska and the Ciołek loess valleys near the Kunów seem to be interesting anthropogenic relief mesoforms to investigate. Their actual state reflects trends in contemporary land use changes in Poland. Since early 1990s, due to agriculture restructuring, we can observe similar abandonment of cultivated loess fields, especially within areas difficult to plough or with low productivity. Fallows and idle lands became a common feature of loess rural landscape.
Another exemplary regions of occurrence of terraces in Poland are mountainous regions of the Sudetes and the Carpathians. The increasing population of mountain villages in the Sudetes at the end of the 19th century intensified its impact on the environment and the first management activities to limit soil erosion were undertaken (Latocha 2009). New forests were planted on steeper and higher hillslopes (spruce plantations), new ploughing techniques were introduced in mountain areas and agricultural terraces were built on cultivated hillslopes. The terraces became a characteristic feature of the mountain areas in the entire Sudetes. Terraces on hillslopes and forest plantations were the first signs of a long-lasting socio-economic trend that eventually replaced the natural environmental system.
From the end of the 19th century a reverse trend can be observed in the entire Sudetes region, with a constant population decline and land abandonment.
The agricultural terraces can still be recognized in the current Sudetes landscape, even though the hillslopes are no longer under agricultural use. In places, terraces can be found even within the present-day forests, which is the best evidence for land-use change within recent decades. Terraces in the Eastern Sudetes (Luty Potok, Konradowski Potok and upper Nysa Kłodzka basins) are located on hillslopes with gradients up to 30° and up to the height of around 800 m a.s.l.
investigated area are up to 0.4 km long, from 0.2 to 5.5 m high, with their front gradient from 20° to 65° (Latocha 2009).
According to science investigations in the first years after forming and cultivation of 12m-wide terraces on slope with 17.8% average inclination, inclination decreased by about 1.1% (average/year), later this process was less visible (0.35%).
Simultaneously, height and width of terraces increased. Borders of parcels occupy additional place (Nowicki 1977).
The variation of colluvium thickness is especially visible on hillslopes with agricultural terraces. Sedimentological analyses in the study area mentioned above showed that 1–1.5 m of sandy–silty sediments accumulated at the terrace edges, while in the upper parts of hillslopes the sediment thickness does not exceed 0.2 m. The effect of selective surface wash on hillslopes is also very well displayed within the terraced hillslopes. Each individual hillslope unit has a coarse grained cover in its upper part, where erosion dominates, while the lower part of the unit shows an increase in sandy–
silty fractions, deposited at the terrace edges. This microtopography causes degradation of crops, humus horizon, chemical properties of the soil and water conditions in the upper parts of the platform. In the lower parts of the platform better conditions occur (Nowicki 1977).
The efficiency of terracing is proved by the encountered deposition patterns.
The estimated denudation rate from hillslopes under cultivation has been calculated based on volumes of material stored within the agricultural terraces during the last 100 years. It varies between 0.15 and 2.67 mm year−1 (Latocha 2004).
Terraces ploughing has also a great capacity for storing water and snow and capacity for retention of soil moisture (Nowicki 1977; Ackerman et al. 2008; Apuani et al. 2008; Lesschen et al. 2009).
Both in the Carpathian Bieszczady Mountains and in the Carpathian foothills, rural terraces come from the middle or the first half of the 19th century (Drużkowski 1998; Wolski 2007). In the Bieszczady Mountains they have been abandoned for 60 years.
1.1. Aims
The main objective of this thesis is the assessment of contemporary land use changes after agricultural abandonment of loess terraces of the Kunów surroundings with geographic information systems (GIS). Thanks to GIS application in this MSc thesis, an output map of contemporary land use changes within investigated valleys was created. This map is an outcome of field investigations, GPS measurements, “heads-up”
digitizing on existing layers, editing and modifying in ArcView 9.2 GIS software of terraces and other important rural landscape features. This study has also other objectives: to examine the role played by natural and anthropogenic factors in contemporary land use change of long-cultivated agricultural terraces in the Kunów region, to assess the current state of rural terraces in the Kunów region, and to asses the role of terraces in shaping current rural landscape of the loess relief.
2. STUDY AREA
2.1. Location and extent of the study area
The area under investigation is situated on the northern margin of the Holy Cross Mts, in the northern part of the Opatów – Sandomierz loess cover, and in the marginal zone of the Kamienna valley (Jersak 1977) (Fig. 2.1). The Kunów region lies on the border line of two Kielce Upland mesoregions distinguished by Kondracki (2001):
Sandomierz Upland and Iłża Foreland. The study area compasses two loess valleys of the Kunów region: Ciołek and Stawiska, which are well-known to Polish geographers (Fig. 2.2).
Fig. 2.1. Location of the study area on the map of Poland Source: http://commons.wikimedia.org/wiki/Atlas_of_Poland
2.2. Geology
In the regional geological pattern of the central Europe, the Holy Cross Mts region is a part of Mid – Polish Anticlinorium – the Mesozoic rift inversed during Laramian tectonic movements. The region consists of two principal parts: Paleozoic Core and Permian – Mesozoic Marginal Zone. The area under investigation lies within northern Łysogóry - Radom Unit in the marginal zone of the East – European platform (Urban, Gągol 2008). The bedrock of the Quaternary sediments is built of the Liassic sandstones and siltstones, excavated in the Kunów region since 12th century. As regards the thermoluminescent (TL) dating of the loess profile at Bodzechów (Lindner et al. 1999), the oldest Pleistocene sediment is a bed of sand with gravel, TL dated at about 298 ka. This glaciofluvial outwash deposit was formed in front of the retreating ice sheet of the Odra Glaciation. The sand is covered with loess, in which there are symptoms of intensive soil – forming processes. This loess was TL dated at about 149 ka in the bottom and about 112 ka in the top. It corresponds to the so-called upper older loess, connected with the Warta Glaciation, and the younger soil- forming process during the Eemian Interglacial. The overlying loess was defined as the so – called younger loess of the Vistulian Glaciation. Its lower part was TL dated at about 65.6 ka and 27.6 ka, and it is separated from the upper part by initial interstadial paleosol dated at about 18.9 ka.
Within the Kamienna valley escarpment zone, the average thickness of the loess cover is 12 m (Jersak 1965). At the end of the last glaciation, this surface was dissected by a net of erosion-denudation valleys that were related to the relief of bedrock below the loess. In the region of Kunów, the well preserved, thick Late – Pleistocene and Holocene deposits are rich in fossil malacofauna and in fossil soils, which facilitate the reconstruction of the paleogeographic changes that took place in the last several thousands of years. These deposits fill fossil gullies and build one of the terrace horizons in side valleys (Jersak 1977).
The Kamienna valley flood plain is built of Holocene sediments. On the bottom of the valley there is 1m thick layer of alluvial soils and peat which locally contains oak trunks. This layer is covered with 2-3 m fine grained sands, covered with 1m layer of loams and clays. In the roof of those Holocene sediments there are alluvial soils 1-3 m thick.
The total thickness of the Holocene sediments in the Kamienna valley is 5 – 6 m (Romanek 1994).
The Iłża Foreland is covered with formations of the Central Polish glaciations mentioned above. The glacier has left traces here in the form of gravel mounds, eskers and sands. From under the diluvial sediments, Cretaceous and Jurassic rocks crop out (Samsonowicz 1934).
2.3. Geomorphology
The significant feature of the relief of the studied area is the orientation of the valley net. Statistical and cartometric analyses of valley directions show a rectangular type of valley pattern. Valley orientation is strictly controlled by a set of orthogonal system transversal NE-SW (azimuth 35-65°) and longitudinal NW-SE (azimuth 125- 155°) joints (Kosmowska – Suffczyńska 1998).
The recent topography of the Kunów surroundings is also shaped by its loess cover. The Kunów region has a wavy appearance strongly cut by dry valleys and gullies and is located at an altitude of 180–280 m a.s.l (Bukowska Mountain 277 m a.s.l.) (Fig. 2.2).
The southern part of the region is intensively branched by a net of young erosion ravines. This is the result of the low erosion base of the Kamienna river valley (180 m a.s.l.) and its side, the Ciołek and the Stawiska, valleys (190 m a.s.l.). In the investigated valleys three terrace horizons and the present-day bottom are preserved. High terrace with variable relative altitude, rises more than 30 m over the present-day bottom.
The deposits building two lower terrace horizons (relative altitude 14 -15 m and 5-6 m respectively) are inserted into the high terrace. At the mouth of the drained valleys into the Kamienna valley, favourable conditions for deposition of alluvial fan sediments occur, so these forms are common in the investigated area. Steep slopes and a 40 - 60 m relative height triggered forming of the anthropogenic terraces. In some places we can distinguish above 20 levels of these loess mesoforms along the slope. Another typical example of anthropogenic loess relief are road gullies. The total length of road gullies within the Sandomierz Upland is 485 km, area with gullies covers 93% of the upland (51% has a road density 0.5-1 km/km2) (Nowocień 1995). Some of them, like Prosięcy
Dół in the Ciołek valley, are abandoned and transformed by the current plant succession.
The Iłża Foreland has landscape typical for moraine areas with inland parabolic dunes and 1-2 m thick aeolian sands (Samsonowicz 1934). The absolute height of this terrain is about 235 m a.s.l.
Fig. 2.2. Relief of the Kunów region 2.4. Climate
According to the climate division proposed by Wiszniewski and Chechłowski (1975) the study area lies within the Holy Cross Mountains margin region. The annual rainfall is 550–600 mm, but in the summer season 350-400 mm occurs. The mean annual temperature is 7.3/7.4 °C, the coldest month is January -3.5°C, the warmest June + 17.3°C. Surface evaporation is 505-510 mm, steaming from the surface of water is 550 mm.
According to Bielec-Bąkowska (2000), the investigated region lies within the Nadwiślański region (A5); we can observe here an increasing number of days with heavy rainfalls (>30), which has a great influence on loess relief transformation.
The maximum 1-day precipitation sum in the Kunów region is > 60 mm. Great intensity (>1 mm/min) and amount (several dozen mm) of precipitation cause impetuous flow and strong erosion. Loessy areas of the Kunów region belong to those favouring
occurrence of heavy rainfalls. Geological conditions together with surface features increase intensive, secondary and anthropogenically conditioned erosion processes.
The historical records refer to the disastrous consequences of torrential rainfalls in the Kunów region. Scarps dividing areas with different thermic and moisture conditions create and force vertical air currents, and thus help atmospheric circulation factors (Rodzik et al. 1998). In such conditions the torrential rainfall waters flow quickly down the gully bottoms of considerable inclinations, concentrating on the bottom of confluences of the Kamienna river valley. As a result, it leads to flooding or silting of crops, the roads of the Kunów region were destroyed or silted many times and the properties completely flooded. Another very important climatic factor which is responsible for shaping the loess cover are melt waters. In the case of the Denków meteorological station, snow cover appears on 23 November and vanishes on 25 February There are about 44 days with snow cover and its average thickness is 7- 8 cm (Biernat 1992). The average wind speed is 2-5 m/s and western winds prevail (42%) in the Kunów region (Wiszniewski, Chechłowski 1975). From the geomorphological point of view, the most effective wind activity is observed in winter (Maruszczak 1986).
During the vegetation period, lasting 220 days, (Kaczorowska 1986) erosional activity of wind is held up, the role of waters is also limited.
2.5. River network and underground waters
Character of older subsoil formations, mainly of sandstone and mid-Jurrasic silt slates, in this area does not favour the retention of large quantities of subterranean water. Good conditions for accumulation of rich, economically useful waters exist in quaternary formations and mainly in the Kamienna river valley. In this area there predominates one water-bearing level connected with the main valley depression.
Perched waters can also be found locally. The subterranean water level is generally inclined towards the Kamienna river valley, which performs a draining role in relation to the subterranean waters. Depth to the first water-bearing level decreases along with passage to the zone connected with the Kamienna river valley, where waters are reached at the depth of about one meter. This is a cause of considerable incidence here of permanent and periodical marshes. This situation favours the occurrence of mists and affects the state of thermic-humidity relations (Burchard, Maksymiuk 1985).
The Ciołek and the Stawiska valleys go to the Kamienna valley which is tributary of the Vistula river. In the Kamienna River valley, the iron ore exploitation had been carried out for a very long time. The intensification of the mining took place in the 18th and 19th century. Stanisław Staszic played an important role in this region.
He intended that the Kamienna River be a source of energy and way of transport.
Therefore, the river canalization and intensive training was undertaken, in consequence the river course was straightened and shortened, which resulted in the significant change in the river dynamics. Meander elimination and introduction of a uniform cross-section resulted in deterioration of habitat. Present-day Kamienna River has deeply incised bed, which causes the drainage of surrounding grounds. After the analysis of the old maps and the river cross-sections it was found that it is impossible to restore the old river bed, because of the important erosion and cut off of the sediment transport by dams on Świślina and Kamienna Rivers. Moreover, the canalized river along with some industrial vestiges is a part of technical patrimony (Lenar-Matyas et al. 2006).
According to the Kunów gauge, the average discharge of the Kamienna river is 5.53 m3/s, its confluences conduct small amounts of water (25-125 dm3/s) (Burchard, Maksymiuk 1985).
2.6. Soil cover
The contemporary soil cover is of a mosaic character. The soils in the loess area are to a large extent subject to erosion. A considerable percentage of the Sandomierz Upland soils constitute brown soils (B) (Fig. 2.3) developed from loess and loess-like deposits with medium or high degree of erosion, and in the areas of the highest inclinations – weakly developed and initial soils. At the bottom of the Kamienna valley and its largest confluences, as a result of human activity, alluvial soils got transformed into alluvial -deluvial soils (F) 1-3 m thick. The Iłża Foreland is covered by brown, brown leached and podzolic soils (AB) developed from slightly loamy sands, loamy sands and gravels (Bednarek, Prusinkiewicz 1999).
Fig. 2.3. Soil cover of the Kunów region on the background of the north-eastern margin of the Holy Cross Mts. Source:Own elaboration ofsoil - agricultural map vector layers
2.7. Plants
According to the geo-botanical division of Poland (Szafer, Zarzycki 1977) the area of studies belongs to two districts: Sandomierz-Opatów and Radom-Kozienice.
The forests of the investigated area have lost their specific character due to reconstruction of the stands, a part, however, has preserved its natural and even primeval features (Głazek 1976). From among the distinguished associations, Pino – Quercetum, Potentillo albae-Quercetum and Peucedano-Pinetum typicum occupy the largest areas. Tilio – Carpinetum stachyetosum, Tilio - Carpinetum abietetosum, Tilio – Carpinetum typicum, Tilio Carpinetum calamagrostietosum, Tilio – Carpinetum moldavici as well as Carici elongatae-Alnetum, Vaccinio uliginosi-Pinetum and Cladonio-Pinetum are but seldom encountered. Tilio – Carpinetum typicum and Potentillo albae-Quercetum are of completely natural character
Large areas in the investigated Iłża Foreland forests are occupied by Pinus silvestris monocultures introduced into the Potentillo albae-Quercetum and Pino- Quercetum habitats.
Long lasting development of agriculture caused deforestation of most of the fertile loess cover of the Sandomierz Upland. At present, we can observe forests and pastures only in areas difficult to plough. At the bottom of the valleys we can observe different plant communities of wetland and meadow vegetation.
The Sandomierz Upland and the Iłża Foreland are characterized by a relatively large number of habitats with relict steppe and xerothermic plant communities. These two subregions are a most favourable area for the settlement of sward communities and xerothermic brushwood owing to the numerous ravines, gorges and depressed roads, deep river canyons with steep banks and southern slopes, and finally owing to the warm loess and calcareous substratum and the specific microclimate of these sites (Głazek 1968). The course of succession of the xerothermic vegetation on the Sandomierz Upland and Iłża Foreland is dependent on various factors: the substratum, the humus and CaCo3 content in the soil, exposure, slope, microclimate, relative altitude and the economic activity of man. The final stage of these different initial forms liable to succession is the brushwood of Prunus spinosa, of the association Peucedano- Coryletum or else the community including Juniperus communis, formed owing to cattle grazing.
2.8. History of land use in the Kunów region
The basin of the Kamienna river has imposed direction of settlement development for thousands of years. The traces of human activity from 10 thousands years ago remained here. The area connected with the settlements from the late stage of the Stone Age received the status of the "Rydno" archaeological reserve. Towards the close of the paleolith, groups of hunters dwelling here dealt with flint processing as well as obtaining hematite - ochre used as a dye then. In the Starachowice administrative district we can also trace back the beginnings of farming on our lands on the examples of relics of the people settlement belonging to the "ceramic engraved band culture"
discovered in Bukówka in the Pawłów commune (Iron Roots 2007). The Magdalenian culture period began around 15,000 years ago in southwestern France. The Mały Gawroniec hill in Ćmielów is one of several archeological sites with Magdalenian artifacts in Poland (Krajcarz 2007).
The Sandomierz Loess Upland is one of the key-regions for the Neolithic in Poland and the distinct historical area for the later periods. Contrary to the earlier periods, the Neolithic has here a very good representation. There are above 2000 Neolithic sites actually known from the whole area of the Sandomierz Upland, including open and fortified settlements, camps, workshops, graves, cemeteries, hoards.
The whole sequence of Neolithic cultures is represented there, starting by the Linear Pottery and other Danubian cultures (Stroke Pottery and Lengyel), followed by the Funnel Beaker and Globular Amphora cultures as well as Corded Ware, Złota and Bell Beaker cultures of the Late Neolithic. The first fortified settlements in this region belong to the White Painted Pottery Culture; they are known from Złota-Grodzisko I and Sandomierz-Wzgórze Zawichojskie. Both are situated in places defensive in nature:
the isolated loess promontories. Some traces of copper metallurgy have been discovered there as well as some evidences of long-distance exchange.
The Middle Neolithic (Funnel Beaker Culture) is represented by different kinds of finds forming the heterogeneous settlement network composed of open settlements, hill-sites, camps, flint workshops, hoards, isolated graves as well as cemeteries.
The settlement patterns of that period are not similar to the previous ones. The biggest sites were disposed in regular way at the whole area of the Upland; the total number of sites is considerably higher. Several sites revealed particular connections with flint mines, e.g. Ćmielów with the mine in Krzemionki and Zawichost – with the mine of Świeciechów (on the right of the Vistula).
The fortified site in Stryczowice belongs to the biggest sites of the Funnel Beaker Culture (about 35 hectars of area). The ditch unearthed there isolated a surface of about 5 hectars. Another sites, so-called hill-sites (Ćmielów-Gawroniec, Grzegorzowice-Zagaje, Kamień Łukawski, Ptkanów, Zawichost), are situated in places defensive in nature (Kowalewska-Marszałek 2004).
Early settlers started burning out the forest and cultivate loess fertile soils.
Forests were destroyed to a large extent and first traces of gully erosion from this period were also noticed. Erosion was, however, restricted during the low settlement or population movement periods, when forest vegetation encroached on the farmland.
Numerous traces of settlement from the Bronze Age and the early Iron Age have been found on the banks of the Kamienna river and its southern tributaries. One of the most interesting stages in the history of this area was the existence of the largest ancient district of iron metallurgy in Central-Eastern Europe, on the territory of 800 sq.m. from
Bodzentyn to Opatów. The metallurgical centre on north-eastern peripheries of the Łysogóry mountain range had an influence on the area to the north of the Kamienna river, where production enclave is present in the vicinity of the rivers Iłżanka and Krępianka. The beginnings of the metallurgy in the Świętokrzyskie region relate to the final stage of the old era. In the first centuries after Christ, one of the parts of the trade route connecting Roman provinces at the Dunajec river with central Poland was running along the Kamienna river. At this time, called the period of Roman influence, especially from 1st to the middle of the 3rd century, in the area of the Świętokrzyskie (Holy Cross) Mountains thousands of pit furnaces originated, where iron was obtained from the brown and white iron ores easily available there. It is highly probable that within a few centuries about 8 thousand tons of iron were produced cumulatively in the Świętokrzyskie centre. The amount was calculated on the basis of the researches conducted by Prof. Kazimierz Bielenin who estimated the number of slag-pit furnaces operating on such an extensive area as about 400 thousand (Iron Roots web page).
Within Kunów and its surroundings, traces of the slag-pit furnaces and settlements from early to late period of Roman influence were also found and were investigated (Bielenin 1972).
This first industrial (next to rural) man activity phase is marked in the Świślina river in meadow terrace by presence of sands, trunks and charcoals. Deforestation did not cause serious morphological changes in Kunów and its surroundings because the extent of this first “iron activity” was scattered and wasn’t significant. Lack of loess material in the sediments of the Świślina river is an evidence of small slope material movement to the axis of the valley. Homogeneous forest protected loess cover of the Świślina basin from erosional processes (Klatka 1958). Serious deforestation of natural plant cover caused the next phase of the linear slag-pit furnaces. In river sediments, we can find many artifacts such as: charcoals, slags and iron clumps. The first gullies and ravines started to form. It was a period in which soil denudation was activated and persisted to nowadays. In a very short period of time 5 m thick layer of terrace sediments was formed. Dark hue of the deposits is a witness of destruction of the most fertile humus soil horizons.
The next wave of settlers entered the Kunów region in the Middle Ages.
The area of the Holy Cross Mountains was almost unpopulated until the 11th century when the first hunters established permanent settlements at the outskirts of the
started hunting in the nearby vast forests and had settled most of the area now known as Małopolska and present-day Świętokrzyskie Voivodeship. Kunów is one of the oldest towns located along the Kamienna river valley. In 1848 in Nietulisko Duże, on the neighbouring hill, traces of early Slavic cemetery was found. In the early 12th century Kunów became a property of the Bishops of Kraków, who built a manor. In the mid-thirteenth century Kunów suffered two consecutive Tatar and Konrad Mazowiecki invasions in 1241 and 1247, respectively. Under the rule of the King Kazimierz Wielki Kunów had about 240 inhabitants and covered 63 km2. In 1365 Kunów received its charter. In the 15th century cardinal Zbigniew Oleśnicki extended Kunów.
A St Vladislav wooden church existed in his times. A capacious pond was built, which was a source of water power for sandstones quarries and woollen cloths factory. In the second half of the 15th century rise of the manorial system caused first serious changes in natural environment in the investigated area (Strzemski 1961).
In 1502, Kunów lost its charter after the Tatar invasion. In 1535, Kunów regained its charter and in the middle of the 16th century the manor of the Bishops of Kraków was reconstructed. The city entered a period of fast growth thanks to new privileges and tax credits. In 1616, Kunów had 130 houses and two, St Szymon and St Juda, wooden churches. In 1638, under St Władysław stone church was erected.
Intensification of settlement was combined with extension of arable land at the expense of forest. Until the 12th century, crops (mainly wheat and rye) were sent along the Kamienna river from here through Sandomierz and Gdańsk all over the Western Europe. Wood and grain export contributed to intensive deforestation and in the 16th-17th centuries an anthropogenic landscape predominated. Climatic changes consisting in periodical increase in precipitation overlapped with human activity. Relief of the loess cover, especially old and new gullies and ravines, were strongly dissected and transformed. Next to sheet erosion, piping started to develop instantly (Strzemski 1961). At the same time the road net between the settlements of the Opatowska Upland was developed and density of new roads leading to fields was also increasing (Wąsowicz 1967). Second half of the 17th century, 18th century and first half of the 19th century – this is the long time of relative weakness of erosional processes. During The Deluge the town was pillaged and burnt by the Swedes. The number of houses decreased to 63 and Kunów was inhabited by 530 persons. In 1827, Kunów had 119 houses and 730 habitants, in 1860 145 and 1121, respectively. In 1863, Kunów took part in the January Uprising and in 1869 lost its charter until 1990. In the 19th century,
Kunów lost its significance because new industrial centre was growing - Ostrowiec Świętokrzyski. Today, Kunów with the population of 10260 is a developing city, of growing regional importance.
The introduction of the root crops cultivation, modern crop rotation as well as new agriculture techniques took place at the beginning of the 19th century and further increased the anthropogenic pressure on the land (Maruszczak 1988). In 1834-1845 the first iron rolling-mill and dam on the Świślina river in Nietulisko Fabryczne was built, which triggered forming of 5 m thick flood plain between Biskupie Doły and Nietulisko Fabryczne (Klatka 1958). It is assumed that the next period of ravine erosion took place in the 19th century. An increase in population was followed by almost total deforestation and considerable diminution of farm sizes, and hence an increase in number of approach cart-road took place. Deforestation started in the steep sides of the valleys (and even some of the ravines) as a result of overpopulation and “hunger for land”. It intensified soil erosion process that led to destruction of the soil profile and denudation of the loess. As a result, not only the bottoms of the erosion-denudation valleys that concentrated surface runoff but also their sides and even some fragment of the planation level got dissected (Gardziel et al. 1998).
The last phase of deforestation took place at the end of the 19th century and at the beginning of the 20th century when villages were extended and even new villages were founded. In this period of time, in Biskupie Doły, a cardboard factory was built.
Its first owners were parents of a famous Polish writer – Witold Gombrowicz. After the land reform in 1944/1945, meadows and pastures were ploughed. Because of the limited amount of arable lands, even the gully sides were temporarily ploughed (Strzemski 1961). At present, a considerable part of the Stawiska and the Ciołek valleys is covered with forests, but it is mostly the result of young afforestation and secondary plant succession.
Current agricultural holdings up to 1ha dominate in the Kunów rural area (647 against 1661 farms) (Table 2.1). Agricultural holdings with farms from 2 to less than 5 ha (454) come second. An old pattern with small parcels from the middle of the 19th century survived. In the Kunów region, winter wheat, oats, spring and winter barely, rye, potatoes and vegetables cultivation prevail (Regional Data Bank, Agricultural Census 2002).
The soil and gully erosion led to accumulation of colluvial deposits with
of agriculturally used slopes, calculated on the basis of the 137Cs method, equals 2.0-7.4 mm/year, while the average rate of material redeposition on the bottoms of dry valleys is about 3.0-6.0 mm/year (Zgłobicki 2002).
Table 2.1. Agricultural census by holdings headquarter (2002)
M. u. 2002
AGRICULTURAL CENSUS BY HOLDINGS HEADQUARTER Agricultural holdings by type
agricultural holdings farm 1 661
private farms farm 1 661
private farms with more than 1 ha of agricultural
land farm 1 014
Agricultural holdings by type and area groups of agricultural land agricultural holdings
total farm 1 661
up to 1 ha farm 647
over 1 and less than 2 ha farm 438
from 2 to less than 5 ha farm 454
from 5 to less than 7 ha farm 0
from 7 to less than 10 ha farm 30
from 10 to less than 15 ha farm 18
from 15 to less than 20 ha farm 0
from 20 to less than 50 ha farm 0
Source: Regional Data Bank, Agricultural Census 2002
3. DATA AND METHODS
GIS-based analyses were conducted mainly on spatial data available at the Head Office of Geodesy and Cartography, Regional Świętokrzyskie Voivodeship level Inspectorate in Kielce.
Table 3.1. Sources of data used in this thesis
Raster topographic maps were there scanned and georeferenced, and then were used in this thesis as a backdrop and provided geographic context for other data (Table 3.1). Raster topographic maps in the 1:10 000 scale have the 0.85 x 0.85 m cell size and are projected to the National Geodetic Coordinate System in Poland - PUWG 1992. One section in the TIFF format comprises about 21 km2. Thanks to “heads-up” digitizing and vectorization of these mosaicked maps a land use map of investigated valleys was created in the following steps:
- first, with the GIS-software ArcGIS 9.2 (ESRI, Redlands, US), watershed polygon feature was digitized manually on-screen to delineate an extent of the study area,
Spatial data
Raster Vector Attribute data
- scanned and georeferenced topographic paper maps
(1:10 000):
Kunów (M-34-43-B-a-3), Prawęcin (M-34-43-A-b-4)
Doły Biskupie (M-34-43-A-b-2) Kunów – Piaski Kunowskie
(M-34-43-B-a-1) - orthophotomaps (Source:
geoportal.gov.pl)
- TINs M34043Ba3.tin M34043Ab4.tin M34043Ab2.tin M34043Ba1.tin - soil - agricultural map
vector layers (1:100 000) - cadastre layers (Source:
geoportal.gov.pl)
- Agricultural Censuses (1996, 2002) (Regional Data Bank,
Internet) - meteorological data (Institute of Meteorology and Water Management)
- flood losses (Kunów Town Hall)
- within this delineated border, built-up areas, orchards, meadows and pastures, afforested land, abandoned land, partially cultivated land and agricultural land polygon features (main land use types) were digitized, edited and modified,
- digitized terraces, rivers, access roads, gully roads, and major roads line features were added and connected to polygon features,
- finally, title, legend, north arrow and scale text were added to a map layout.
TIN maps with hillshade illumination effect in 2D application constitute the background of the land use map. TINs came from the same source as raster maps.
Polygons of the particular land use types were delineated by way of digitizing raster maps, but their present state was also confirmed by field investigations, GPS measurements and orthophotomaps. Black & white orthophotomaps used in the study were made on the basis of aerial photographs made for the Świętokrzyskie Voivodeship in 2003-2004 in the 1:13 000 scale (with accuracy of 1:10 000 maps), in TIFF format, and are projected to the National Geodetic Coordinate System in Poland - PUWG 1992.
Ground resolution of pixel is about 0.25m. Section division of the orthophotomaps is 1:5000. Thanks to ArcGIS 9.2 software, GPS measurements were added to the map and additionally compared with land use seen on orthophotomaps. During field investigations, besides GPS measurements, photographic documentation of study area was carried out. Relations between contemporary natural and anthropogenic factors shaping agricultural terraces were also investigated.
As of the end of March 2010, new color orthophotomaps presenting the status of my study area in 2009 are available on geoportal.gov.pl. The land use interpreted using these data does not differ significantly from the state in 2003 – 2004.
Because loess upland regions are most susceptible to land degradation caused by sheet and linear erosion I decided to asses erosion risk for the terraces of the Kunów surroundings. The analysis was performed on the basis of the method described by Józefaciuk (1996), which introduces five grades of erosion intensity, distinguished by an overlay operation of spatial layers representing: soil type (texture), slope, average annual rainfall and land use type. Terraces under conventional and conservational tillage with plough direction and under orchards and permanent grass-lands were included there (Table 3.2).
Table 3.2. The grades of the intensity of surface water erosion described by Józefaciuk (1996)
The grades of the intensity of surface water erosion:
0. no erosion: does not occur in a given area; 1. weak erosion: causes only small surface soil losses; 2.
moderate erosion: causes visible wash-off of humus horizon and worsening of soil properties. The full regeneration of soil is not always possible through conventional tillage; 3. average erosion: may lead to total reduction of humus horizon and development of soils with typologically un-formed profiles. Terrain dismemberment is starting. Considerable debris flow into surface waters; 4. strong erosion: can cause total destruction of soil profile, including the parent rock. This results in large fragmentation of terrain’s relief and deformation of hydrology; 5. very strong erosion: effects similar to grade 4, but more intensive, driving into permanent degradation of ecosystems.
Small-area fields Orchards
Conventional tillage with plow direction:
Conservational tillage with plow direction:
Soil groups according
to their susceptibi-
lity to water erosion
Slope inclina-
tion Slope along
Perpen- dicular to slope
Terraces Slope along
Perpen- dicular to slope
Terraces On terraces
and sod
In sod belts perpen- dicular to
slope
Perma- nent grass-
lands
Very high susceptibi-
lity Loess and loess-like,
silts
0-3˚
3-6˚
6-10˚
10-15˚
>15˚
1 2 3 4 5
0 0 1 2 3
0 0 1 2 3
0 1 2 3 4
0 0 0 1 2
0 0 0 1 2
0 0 0 1 2
0 0 1 2 3
0 0 0 1 2
Source:Wawer R, Nowocień E (2007) Digital map of water erosion risk in Poland. A qualitative, vector – based approach. Polish J. of Environ. Stud. Vol. 16, No. 5: 763-772
Terraces under conventional tillage, located on loess slopes with inclination >
15˚ are most susceptible to water erosion (3). Conservational tillage on slopes with the same inclinations gives better results (2). As for orchards and permanent grass-lands, moderate erosion (2) occurs.
To asses erosion risk within investigated terraces reclassification of slope inclination values after TIN-raster conversion was necessary. It was possible thanks to 3D Analyst Tools. Cell size of an output DTM is 21x21m. Due to Spatial Analyst Tools > Surface > Slope application slope maps were created. After conversion of all maps, thanks to Data Management Tolls > Raster > Mosaic to New Raster application an output slope raster map has been prepared, which was reclassified in the following ranges: 0-3˚, 3-6˚, 6-10˚, 10-15˚ and >15˚. After adding the terraces layer, relations between inclinations of slopes and terraces occurrence (density, length) as well as
between their land use and erosion grade were described. The aspect map was obtained in the same way (without reclassification) and, after adding the terraces layer, relations between aspect and terraces occurrence as well as between aspect and land use and slope processes were described.
TIN maps were also used to derive such basic parameters of terraces as: length, width, height, front gradients, platform elevations, inclinations and aspects.
4. GEOMORPHOLOGICAL CHARACTERISTICS OF THE
AGRICULTURAL TERRACES IN STAWISKA AND CIOŁEK VALLEYS
4.1. The morphology and morphometry of terraces in the Stawiska and the Ciołek valleys
Within the Stawiska valley both slopes are terraced at an altitudes of 200-240 m a.s.l. due to transverse cultivation forced by property boundaries. Agricultural ploughed-on terraces appear mainly on the left, south and south-east facing sides of the valley. In the central part of the valley there are maximum 9 terraces along the slope, including the lowest one (along the valley bottom edge) without bottom scarp. Bench of this terrace was formed due to ploughing along the field’s upper boundary. In the upper parts of the slope the extent of terraces is limited by road gulley which dissects on 7.5 m local remnants of the planation level. Areas located close to Kunów and to the gorge section of the local water course have short, fragmented terraces (Fig. 4.1).
The average height of those terraces is 2.0 m, min 0.20 m and max 9 m. Width of benches ranges from 4 to 22 m, length from 14 to 490 m. The front gradient of the terraces ranges from 14° to 70° (Fig. 4.2). At present, almost all platforms are abandoned and secondary plant succession in different stadiums dominates (Photo 4.1).
Fig. 4.1. Distribution of agricultural terraces within central parts of the Stawiska and the Ciołek valleys
On the other, north facing side of the valley, terraces are short (<150 m), fragmented and are scattered on the fields neighbouring with afforested part of the Stawiska valley. Their course is interrupted by approach road gullies or ravines (Fig. 4.2). What is interesting, about 15 terraces are hidden in the today’s forest, which is an evidence of rural activity in the past. It was a period when deforestation started in the steep sides of the valleys as a result of overpopulation and “hunger for land”
in the second half of the 19th and after 1944/1945 land reform. Presence of the young erosional incisions next to afforested terraces implies, that fields located on the steep slopes (11° to 22°) at an altitude of 200-260 m a.s.l. (relative altitude 60 m) were cultivated until degradation and dissection of the loess soil cover started. This extensive rural activity presence of young incisions destitute of plant cover must have triggered sheet and linear erosion. Cultivation was arduous for local inhabitants, so they were forced to stop rural activity on their fields. Short terraces also occur in the vicinity of the Bukowska Góra (Bukowska Mountain).
Distribution of agricultural terraces within the Ciołek valley is more complex.
Agricultural terraces occur on both sides of the investigated valley. They cover a much bigger surface than in the case of the previous valley. They form continuous, long linear forms from Kunów to the Przymiarki ravine. In the central part of the Ciołek valley, on the north facing side, we can distinguish above 20 levels of terraces. From the Przymiarki to Wilczy Dół ravines terraces are short and fragmented, usually occur perpendicular to slope or surround small ravines: Wronia Góra, Dół Stoczkowy and Wilczy Dół (Fig. 4.1).
The slopes similar to those of the Stawiska valley are cut with small valleys, which causes that such parameters as longitudinal and transverse inclinations of benches as well as scarps heights and inclinations change greatly within particular terraces of the investigated valleys (Fig. 4.2).
