- Department of Geoenvironmental Research
Institute of Geography
Polish Academy of Sciences
Jana 22
31-018 Krakow
Poland
Drought, a recurring natural phenomenon in South Asia's monsoon climate, presents challenges in delineating its spatio-temporal patterns within complex topographies. This study investigated the impact of the orographic barrier in the... more
Drought, a recurring natural phenomenon in South Asia's monsoon climate, presents challenges in delineating its spatio-temporal patterns within complex topographies. This study investigated the impact of the orographic barrier in the rice-dominated agricultural region of northeastern India and Bangladesh on drought characteristics during 1951-2020, employing the relative Standardised Precipitation Index (rSPI) and relative Standardised Precipitation-Evapotranspiration Index (rSPEI) across 3-, 6-, and 12month scales. The results indicate that even in the rainiest region of the world, droughts extend beyond the limits of the dry season inherent in the monsoon regime. These mostly regional droughts exhibit weak correlations with the core of the Indian subcontinent and other parts of Bangladesh. The region's orographic barrier has a greater influence on drought intensity than on frequency. The rSPI index, which depends solely on rainfall, may overestimate drought intensity and frequency in regions with high seasonal/annual rainfall and substantial intermonthly variability. In contrast, the rSPEI index, which depends on both rainfall and potential evapotranspiration (PET), better reflects the spatial variation of drought in complex terrain, identifying the leeward hinterland of the orographic barrier as the most drought-prone area. The two indices give similar results for drought characteristics away from the barrier. Furthermore, the orographic barrier exerts a negligible influence on the trends in rSPI and rSPEI. Principal component analysis (PCA) highlights the influences of the rainfall coefficient of variation and elevation on rSPI, while the PET coefficient of variation strongly influences rSPEI. Strategies to minimise the adverse effects of drought in complex topography and year-round cropping should be local and season-specific. These include using shorter-growing, drought-resistant rice varieties and adjusting planting schedules in rain shadow areas during the summer monsoon. These efforts should be complemented by integrating indigenous irrigation methods with modern practices such as roof water harvesting and tube wells in winter.
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This study illustrates the temporal dynamics of tourism development in a peripheral region of Northeast India (Cherrapunjee area) with an extreme rainfall. The analysis indicates that tourism development has accelerated in the last two... more
This study illustrates the temporal dynamics of tourism development in a peripheral region of Northeast India (Cherrapunjee area) with an extreme rainfall. The analysis indicates that tourism development has accelerated in the last two decades as a result of the administrative opening of Meghalaya State and the dynamic development of tourism throughout India. Peripheral locations with curious environmental features may by potentially attractive tourism localities, with a common focal point for development of marketing opportunities and narratives about the location. A local leader in a strong position pointing the way additionally plays an important role in creating a tourism space.
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The Sikkim-Darjeeling Himalaya region receives the highest amount of rainfall along the whole southern Himalayan margin and is known for the occurrence of extreme hydrometeorological and geomorphological events. The massive amounts of... more
The Sikkim-Darjeeling Himalaya region receives the highest amount of rainfall along the whole southern Himalayan margin and is known for the occurrence of extreme hydrometeorological and geomorphological events. The massive amounts of water and sediment transported each year through the mountain part of the Teesta River drainage system (~8150 km 2)-the largest river in the region-have been severely impacted by dam construction in recent decades. The aim of the current study was to determine, for the first time in this part of the Himalaya region, the dynamics of suspended sediment transfer at a number of points distributed through the mountainous part of the Teesta River catchment prior to dam construction and preliminarily assess the impact of dam operations on the suspended sediment. Sediment sources were identified using a database of landslide inventories from 1965-2019, combined with visual interpretation of satellite imagery from the U.S. Corona programme and Google Earth. Hydrological and sediment data up to the second half of the 1990s were used to reconstruct the discharge and suspended sediment dynamics before direct human intervention in the river channels. The beginning and end of the construction of the reservoirs was determined by analyzing satellite images. The impact of dam operations on the suspended sediment was compiled from the available literature. The results of the current study indicate that the primary sources of sediment are landslides caused by the interaction of rainfall and road undercutting of slopes as well as channel erosion. During extreme rainfall events, the influence of deforested areas in the mobilization and delivery of sediment to the river network increases. The current analysis reveals that reconstruction of the suspended sediment dynamics should take into account the course of extreme events responsible for supplying material to the river network, as well as the longterm remobilization of already deposited sediment in the river channel. It was found that the mean suspended sediment load (SSL) following extreme rainfall, flooding, and landslides in the Teesta River catchment can be up to four times higher than its average values for the same catchment unaffected by such an event, and the effects can be observed for more than a decade afterwards. Under these conditions, the mean suspended sediment yield can reach 12,000 and up to 20,000 t/km 2 y in individual years, which is among the highest in the Himalaya region and, indeed, the world. The construction of 13 dams in the last 30 years has disrupted the hydrological regime and sediment transport in the Teesta River catchment along 70% of its main course and largest tributaries, and this has resulted in the selective retention
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This paper is an introduction to a collection of nine studies that are intended to fill the gap in the literature associated with landform development and landscape changes related to natural forces and human activities in the Central... more
This paper is an introduction to a collection of nine studies that are intended to fill the gap in the literature associated with landform development and landscape changes related to natural forces and human activities in the Central European Mountains and their close forelands. The papers are grouped into four general categories that describe the influence of climate on glacial landforms and snow avalanches, the evolution of slopes in high mountains, the development of mid-mountain relief, and changes in fluvial systems in mountains and their forelands. This paper summarises the contributions of these studies to this special issue and attempts to outline possible avenues of future research on landforms and landscapes in mountainous areas.
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Purpose Agricultural land use associated with intensification in plant growing affects the physicochemical parameters of soils and thus soil quality. The aim of this study was to identify the quality of soils in the Peshok catchment in... more
Purpose Agricultural land use associated with intensification in plant growing affects the physicochemical parameters of soils and thus soil quality. The aim of this study was to identify the quality of soils in the Peshok catchment in the Eastern Himalayas under different types of land use (tea, horticulture, rice), under high monsoon rainfall conditions.
Methods Physical and chemical analysis were used, e.g. bulk density, pH, TOC, major and trace element content (such as Ca, Fe, K, Mg, Mn, Na, P, Ag, As, Ba, Cd, Co, Cr, Cu, Ga, Li, Mo, Ni, Pb, Sr and Zn) based on AntonPaar Multiwave 3000 microwave system and nitrogen and sulphur content using CNS Elementar Vario MAX cube analyser. In addition, ecotoxicological analyses were performed using the Microtox test. Soil quality was assessed on the basis of chemical indicators related to the mobility of trace elements (risk assessment code, individual contamination factor and global contamination factor); geochemical indicators (geoaccumulation index, enrichment factor, contamination factor, contamination degree, modified contamination degree, pollution load index and improved Nemerow pollution index); and ecological indicators (potential ecological risk coefficient and potential ecological risk index). A statistical package of Statistica v13 was used for statistical analysis.
Results Soils in the analysed catchment are characterised by low contents of macro- and microelements. It was shown that natural factors, such as high precipitation and steep slopes, favour strong leaching of elements from the soil, and farming systems based on natural and chemical fertilisation, terracing and irrigation are not able to balance them fully. The contents of TOC and N as well as pH were determined mainly by the land use. Results of statistical analyses and geochemical indicators revealed the predominantly natural origins of elements. The higher Ga content indicated a relationship with the local geology and the higher Cu content with the use of fertilisers. Indicators showed a low ecological risk related to the presence of trace elements, and soil ecotoxicity to A. fischeri was generally determined by the acidic pH of the tested soils. Low mobility was observed for most elements, and regardless of the land use, the residual fraction predominated.
Conclusion The study showed that use of many indicators can more fully describe soil quality in relation to land use, especially in the case of a low content of trace elements. Moreover, this approach helps to better understand the changes taking place in soil quality under different land uses in mountains with high rainfall.
Methods Physical and chemical analysis were used, e.g. bulk density, pH, TOC, major and trace element content (such as Ca, Fe, K, Mg, Mn, Na, P, Ag, As, Ba, Cd, Co, Cr, Cu, Ga, Li, Mo, Ni, Pb, Sr and Zn) based on AntonPaar Multiwave 3000 microwave system and nitrogen and sulphur content using CNS Elementar Vario MAX cube analyser. In addition, ecotoxicological analyses were performed using the Microtox test. Soil quality was assessed on the basis of chemical indicators related to the mobility of trace elements (risk assessment code, individual contamination factor and global contamination factor); geochemical indicators (geoaccumulation index, enrichment factor, contamination factor, contamination degree, modified contamination degree, pollution load index and improved Nemerow pollution index); and ecological indicators (potential ecological risk coefficient and potential ecological risk index). A statistical package of Statistica v13 was used for statistical analysis.
Results Soils in the analysed catchment are characterised by low contents of macro- and microelements. It was shown that natural factors, such as high precipitation and steep slopes, favour strong leaching of elements from the soil, and farming systems based on natural and chemical fertilisation, terracing and irrigation are not able to balance them fully. The contents of TOC and N as well as pH were determined mainly by the land use. Results of statistical analyses and geochemical indicators revealed the predominantly natural origins of elements. The higher Ga content indicated a relationship with the local geology and the higher Cu content with the use of fertilisers. Indicators showed a low ecological risk related to the presence of trace elements, and soil ecotoxicity to A. fischeri was generally determined by the acidic pH of the tested soils. Low mobility was observed for most elements, and regardless of the land use, the residual fraction predominated.
Conclusion The study showed that use of many indicators can more fully describe soil quality in relation to land use, especially in the case of a low content of trace elements. Moreover, this approach helps to better understand the changes taking place in soil quality under different land uses in mountains with high rainfall.
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Factors governing the spatiotemporal soil development on a deglaciated area of Pindari Glacier in the Indian Central Himalaya were investigated over a timespan of 170 years. Glacier retreat exposed sediments to weathering, decarbonation,... more
Factors governing the spatiotemporal soil development on a deglaciated area of Pindari Glacier in the Indian Central Himalaya were investigated over a timespan of 170 years. Glacier retreat exposed sediments to weathering, decarbonation, illuviation, acidification and melanisation. The spatiotemporal scales of soil transformation in this proglacial environment are significantly greater than in other chronosequences in the alpine environment. The accumulation of SOC and N in the oldest moraine is reflected in high accumulation rates of 52.6 g C m-2 year-1 and 4.8 g N m-2 year-1 in the 20-cm deep soil layer. Reference data from the topsoil of the rhododendron woodlands indicate that the oldest moraine topsoil is close to reaching some sort of a steady state. At least 100 years was required to stabilise the soil cover in most of the proglacial area. The results highlight the importance of rapid glacier retreat as well as inhibited weathering due to plant succession in soil formation, under impact of local climate characterized by high precipitation, temperatures and moisture delivery.
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The study compares the quality of the habitats of mountain streams in sections without visible human integration and those permanently transformed by human activity between mountain areas in different climate zones. Three mountain streams... more
The study compares the quality of the habitats of mountain streams in sections without visible human integration and those permanently transformed by human activity between mountain areas in different climate zones. Three mountain streams with small catchments (10-20 km 2) characterized by different natural conditions were selected for the research. The selected streams are Bystrzanka (Beskid Niski, Polish Carpathians), Peshok (Darjeeling Himalaya in India), and Fanshen (Hengduan Shan in China). Field studies were carried out using the British River Habitat Survey (RHS) method. Habitat quality was analyzed based on the following indicators: Habitat Quality Assessment (HQA) and Habitat Modification Score (HMS). The obtained results indicated that sections of mountain streams located in upper catchment areas show greater habitat naturalness in relation to stream sections in lower areas. This results from the greater variety and number of natural hydromorphological elements in streams and the close vicinity of channels. In both upper and lower stream sections, regardless of the degree of naturalness and anthropopressure, the same RHS attributes have the greatest impact on the HQA and HMS values. Similar regularities in the degree of naturalness and anthropogenic modifications of the habitat between the upper and lower reaches of streams can be also expected in other mountain areas, apart from areas not affected by human activities.
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The aims of this study were to review human-environment interactions during the Meghalayan and to search for the stratigraphic boundary of a new epoch, informally termed the Anthropocene, as well as to determine whether the stratigraphic... more
The aims of this study were to review human-environment interactions during the Meghalayan and to search for the stratigraphic boundary of a new epoch, informally termed the Anthropocene, as well as to determine whether the stratigraphic signals of human activity on the Meghalaya Plateau in Northeast India can be correlated globally. This plateau is the base of the Meghalayan Age that was determined from a speleothem in a cave located on it. Review indicates that study region developed on the periphery of ancient Indian civi-lisation, with stratigraphic signals of human activity being apparent in only the last few thousand years; that is, substantially later than the neighbouring ancient Indian civilisation. The stratigraphic signals are heterogeneous and diachronous, not only as a result of various human activities, but also in the effect of the diverse sensitivities of the environment to anthropogenic disturbances. A discrete and visible cultural layer that relates to the development of settlements and the production of new materials is still being formed and reworked. The only synchronous stratigraphic signal with a global range seems to be associated with the artificial radio-nuclide fallout from nuclear weapons testing, which covers a topsoil layer of up to tens of centimetres thick.
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Long-term land use/land cover (LULC) assessments, based on remote-sensing data, play a leading role in gathering information on land degradation that has an impact on food security, soil quality and species habitats with all the... more
Long-term land use/land cover (LULC) assessments, based on remote-sensing data, play a leading role in gathering information on land degradation that has an impact on food security, soil quality and species habitats with all the accompanying social implications. The aim of this study was to determine the LULC changes of severely degraded land using high-resolution remote-sensing data from the last ~50 years in order to determine whether human activities have led to improvements or further land degradation. An area of 70 km 2 near Cherrapunji in Northeast India, which receives 11,000 mm of rainfall annually and was deforested in historical times, was selected for this analysis. Despite severe land degradation, the population density of this area has been continuously increasing, standing at ~300 inhabitants km − 2 in 2011. A visual interpretation technique, combined with field surveys, was used for LULC mapping, based on satellite images from the US Corona programme for 1965, pansharpened Indian Remote Sensing (IRS) images IRS-1D for 1998 and Google Earth for 2017. This analysis indicated the dominance of grassland (73.2%), with a small contribution of forest (17.6%), settlements (5.8%), mining (2.3%), cropland (0.7%) and water bodies (0.4%) in 2017. The LULC structure was the result of a largely degraded land contribution inherited from the past and the emergence of new driving forces behind land-use change. The LULC trends in 1965-2017 included a decrease of forest (4%) and grassland (5%), stability of cropland, and an increase of land-use classes which, in non-degraded land under a monsoonal climate, are usually of small extension, such as settlements (85%), mining (132%) and water bodies (525%). These changes reflect both, attempts to utilise existing environmental resources and to adapt to living in a degraded environment caused by growing human population. From the land degradation perspective, the trends in LULC change show two opposing directions-further land degradation mainly associated with the expansion of settlements and mining (accounting for ~79% of the total LULC changes), and land improvement and neutral change, including the recovery of natural vegetation and the construction of water bodies. The relationships between the LULC changes and direct measurements of biomass and carbon stocks of forest and grassland ecosystems indicated that their balance was negative for the Cherrapunji spur in 1965-2017. A strategy aimed at restoring the sustainability of the Cherrapunji spur environment should focus on the replacement of grassland by forest through the abandonment of uncontrolled grass burning, animal grazing and coal mining with the simultaneous provision of alternative gainful employment for the local population such as tourism and aquaculture.
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Zarys treści. W artykule zwrócono uwagę na rosnące zainteresowanie problemem degradacji powierzchni ziemi w związku z obecną i przewidywaną w przyszłości dużą presją na zasoby środowiska przyrodniczego. Dokonano przeglądu definicji... more
Zarys treści. W artykule zwrócono uwagę na rosnące zainteresowanie problemem degradacji powierzchni ziemi w związku z obecną i przewidywaną w przyszłości dużą presją na zasoby środowiska przyrodniczego. Dokonano przeglądu definicji degradacji i jej postrzegania z punktu widzenia różnych dyscyplin naukowych. Zaprezentowa-no przykładowe metody identyfikacji i oceny degradacji w różnych skalach czasowo-przestrzennych, wskazując ich zalety i ograniczenia. Ponadto przedstawiono perspektywy badań degradacji powierzchni ziemi, wykazu-jąc konieczność rozwoju prac nad identyfikacją czynników degradacji i ich wzajemnego oddziaływania w strefie umiarkowanej na poziomie regionu i kraju. W tym kontekście szczególnie interesująca wydaje się możliwość połączenia oceny degradacji ziemi z oceną świadczenia usług ekosystemowych. Słowa kluczowe: środowisko przyrodnicze, degradacja, pustynnienie, wylesianie, zaludnienie.
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Three pairs of small, fourth-to sixth-order catchments (approximately 5-80 km 2), draining the margin of the Darjeeling Himalayas into the piedmont, were selected for a comparison of the land-use impact on the morphology and sedimentology... more
Three pairs of small, fourth-to sixth-order catchments (approximately 5-80 km 2), draining the margin of the Darjeeling Himalayas into the piedmont, were selected for a comparison of the land-use impact on the morphology and sedimentology of their stream channels. Each pair experienced similar annual rainfall and comprised similar metamorphic bedrock, steep topography, and brown soils; the members of each pair contrast with respect to their land-use structure as they comprise large forest cover (forest > 90%) and a significant contribution of agricultural land with tea plantations (forest < 63%), respectively. A set of rainfall, cross-sectional, and sediment data were collected for the characterization of the stream channels. The obtained results revealed that, under extreme rainfall and high denudation rates as well as frequent flash floods, the geomorphic response to land-use changes involving agricultural expansion at the expense of forest cover was less pronounced in the mountain channels than in the piedmont. Significant differences between the studied pairs of mountain streams draining forested and agricultural catchments were observed only at bankfull width and baseflow depth in fourth-order streams and baseflow depth in fifth-order streams. Local environmental factors such as bedrock channel boundaries, steep topography, high material supply to river networks, and selective sediment mobilization during extreme rainfall and floods override the effects of land use and exert dominant control over stream channels in mountain catchments. However, the effects of agricultural activity in mountains are propagated downstream. In the agricultural catchment in the piedmont, a local rapid decrease in river slope and an increase in water infiltration into alluvia facilitates the deposition of eroded material. In addition, the stream in the agricultural catchment exhibited a rise in the riverbed with the expansion of a braided channel over a dozen kilometers below the Himalayan front in the piedmont, while the streams in the forested catchment revealed a distinct tendency towards incision. The present-day channel morphologies and sediment patterns observed in forested catchments are most likely similar to those that existed in the studied rivers prior to the development of tea plantations and settlements in the mid-19th century.
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The subtropics within the monsoonal range are distinguished by intensive human activity, which affects stream water chemistry. This paper aims to determine spatio-temporal variations and flowpaths of stream water chemical elements in a... more
The subtropics within the monsoonal range are distinguished by intensive human activity, which affects stream water chemistry. This paper aims to determine spatio-temporal variations and flowpaths of stream water chemical elements in a long-term anthropogenically-modified landscape, as well as to verify whether the water chemistry of a subtropical elevated shield has distinct features compared to other headwater areas in the tropics. It was hypothesized that small catchments with homogenous environmental conditions could assist in investigating the changes in ions and trace metals in various populations and land uses. Numerous physico-chemical parameters were measured, including temperature, pH, electrical conductivity (EC), dissolved organic carbon (DOC), major ions, and trace metals. Chemical element concentrations were found to be low, with a total dissolved load (TDS) below 52 mg L −1. Statistical tests indicated an increase with significant differences in the chemical element concentration between sites and seasons along with increases of anthropogenic impact. Human influence was clearly visible in the case of cations (Ca 2+ , K + , Mg 2+ , Na +) and anions (Cl − , HCO 3 − , NO 3 − , SO 4 2−), compared to trace metals. The order of most abundant metals Fe > Zn > Al > Sr was the same in springs and streams, regardless of population density, land use, and season. Principal component analysis (PCA) demonstrated that major ion concentrations in stream water followed the pattern forest < cultivated land < grassland < built-up area. Surface water chemistry of the subtropical elevated shield has mixed features of tropical and temperate zones. Low concentrations of chemical elements; small seasonal differences in headwater streams; and increased concentrations of NO 3 − , SO 4 2− , DOC, and Zn in the wet monsoon season are similar to those observed in the tropics. The role of long-term cultivation without chemical fertilizers in ions supply to streams is less than in other headwater areas of the tropical zone. Strong control of water chemistry in densely populated built-up areas is analogous to both tropical and temperate regions. Population density or a built-up area may be used as a proxy for the reconstruction or prediction of the anthropogenic impact on stream water chemistry in similar subtropical elevated shields.
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Reconstructing the long-term impacts of tea plantations on land use and cover (LULC) change over time is important for making policy decisions on management and conservation. This can be very effectively done by integrating historical and... more
Reconstructing the long-term impacts of tea plantations on land use and cover (LULC) change over time is important for making policy decisions on management and conservation. This can be very effectively done by integrating historical and remote sensing data; however, such approach has rarely been used to date. The present study analysed the role of the large tea plantation system in the forest cover change in 2105.9 km 2 of the Himalayan piedmont in India's West Bengal state, from the first settled agriculture in the mid-19th century to present day. The impact of domestic and international markets together with local factors such as floods on tea plantation development were also investigated to identify potential scenarios of LULC change in the next few decades. Analysis of historical and remote sensing data as well as census reports revealed that between 1874 and 2010, forest area decreased by 69.5% and land under tea cultivation increased to 30.7%. Population density grew as much as 5122.2% to 470 people km −2 between 1872 and 2011. Piedmont development was not uniform and denoted two periods: new land use structure formation (1874-1930) and its further stabilization (1930-2010). The first period showed rapid deforestation at an annual rate of 16-30 km 2 , with an increase of tea production areas up to 16 km 2 per year. The second period saw slower deforestation rates (2-4 km 2 annually) and steady growth of tea production areas (2 km 2 annually). Population growth changed from workforce immigration to settled families. Limited space for settlement expansion favoured population concentration and initiated urbanization processes. Despite the initiation of deforestation and migration through the location of tea gardens, the close relationship between deforestation and population density has not been found in piedmont. At the early stages of plantation development, the greatest deforestation occurred at the lowest population density in the piedmont history. Later, a significant decline in the deforestation rate was accompanied by a demographic explosion. At the same time, reserved forest played the very important role in preserving the remnants of forest cover. Features of the natural environment and land use policy led to tea cultivation approaching maximum expansion in the studied area.
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A hilly catchment (4 km 2) was selected to quantify the changes in physico-chemical soil properties when traditional shifting cultivation is converted to sedentary swidden cultivation (elements of slash and burn cultivation with short... more
A hilly catchment (4 km 2) was selected to quantify the changes in physico-chemical soil properties when traditional shifting cultivation is converted to sedentary swidden cultivation (elements of slash and burn cultivation with short fallow period), locally called bun (cropping in rows of raised beds formed from soil), in the central part of the Megha-laya Plateau. Assuming that the monsoonal climate, deep-weathered granites, and time are relatively uniform over the small catchment, the differences in soil were compared on two contrasting landforms (flat ridges and steep slopes) and three land use types (natural deciduous forest, sedentary swidden cultivation of potatoes, and fallow land with pine forest) within each landform. In contrast to previous studies in region, soil fertility indices calculated in the present study indicated that the bun system can also improve soil quality. Soil response significantly varied at spatial scales, however, and in terms of the possibility of continuing sustainable cultivation in the future. At a local scale on flat terrain upon granites, soil under swidden cultivation had the higher fertility indices, than fallow land and natural forest, whereas steep slope cultivated soil had the lowest fertility indices, following fallow land and natural forest. Therefore, bun system can be efficient in tropical regions with gentle terrain and limited forest resources. At a regional scale, low potato yield combined with a growing food demand forces farmers to expand potato cultivation on steep slopes, the dominant landform in the Meghalaya, increasing the risk of soil degradation. Introducing agroforestry with pine trees into bun cultivation can mitigate the rates of soil degradation on steep slopes.
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Replacement of forests by cultivation in hilly regions can dramatically increase overland flow and soil erosion, frequently resulting in land degradation. This study aimed to determine the impact of long-term human activity and natural... more
Replacement of forests by cultivation in hilly regions can dramatically increase overland flow and soil erosion, frequently resulting in land degradation. This study aimed to determine the impact of long-term human activity and natural geomorphic processes in land degradation of 2 catchments located in the Meghalaya Plateau in northeast India. Both catchments are built by deeply weathered granites with hilly topography but have contrasting land uses. Forested catchment (1.5 ha) is covered by natural deciduous forest, whereas deforested catchment (3.5 ha) is affected by slash and burn cultivation and boulder extraction. Detailed geomorphological mapping and sediment pattern analysis revealed a complex anthropogenic role in land degradation.
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The present study focuses on the Balason river running through the Himalayan piedmont zone (near Siliguri, India). The objective of the study is an assessment of the environmental effects of river bed material extraction by humans and the... more
The present study focuses on the Balason river running through the Himalayan piedmont zone (near Siliguri, India). The objective of the study is an assessment of the environmental effects of river bed material extraction by humans and the dependence of indigenous people on the river and its ecosystem services. The analysis is based on results of field work consisting of geodetic measurements of the river channel and interviews among the local community from the Nimtijot village. Historical hydrological data were also used for the study. The results of the investigation show that the Balason river is heavily affected by excessive exploitation of river bed material during dry season and the replenishment of extracted material in a monsoon season is not always sufficient. It leads to channel deepening. The local community working in the river heavily depends for its livelihood on continuing this activity. A decreasing amount of bed material to be extracted may lead to degradation of the strong relationship between the local community and their natural environment (river).
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We researched local residents’ perceptions of a dam and reservoir construction project in the Teesta River catchment basin (Darjeeling Himalayas) within 1.5 years of its completion, using a questionnaire survey. Most survey participants... more
We researched local residents’ perceptions of a dam and reservoir construction project in the Teesta River catchment basin (Darjeeling Himalayas) within 1.5 years of its completion, using a questionnaire survey. Most survey participants expressed negative perceptions of the project, citing a declining quality of life (loss of jobs and loss of access to river sites that had been important for religious practices and livelihoods) and a sense of insecurity (risk of landslides). These results may help predict attitudes toward similar reservoir projects that are planned for the Teesta basin.
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The article presents the role of the newly built reservoir in the formation of the hydrochemistry of water of the Teesta River (a tributary of the Brahmaputra) in its Himalayan course. Field research were performed in the post-monsoon... more
The article presents the role of the newly built reservoir in the formation of the hydrochemistry of water of the Teesta River (a tributary of the Brahmaputra) in its Himalayan course. Field research were performed in the post-monsoon season of the period 2013-2015. Sampling and measuring points were located in five points over 43 km of the Teesta River in the Darjeeling Himalaya. Analysis of water along of river longitudinal profile above and below the reservoir suggest that the reservoir caused decrease most of the basic ions concentrations (Cl – , K + , Na + , Mg 2+ , NO3 – and PO4 3–). An inverse trend was observed only with respect to Ca 2+ , SO4 2– and NH4 +. The dam does not influent on the F – concentration. The reservoir causes minor enrichment most of the heavy metals such Cu, Ni, Zn, Cr, Cd and Sr. The lower enrichment of Teesta water below the dam indicates the water self-purification processes for metals by the Teesta Reservoir. The changes of physicochemical properties and concentrations of ions caused by the reservoir are usually normalised by environmental factors before the Teesta River outlet from the Himalayas (within 15 km of the river).
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Multiscale interaction between monsoonal circulation and the local topography causes the southern front of the Darjeeling–Bhutan Himalaya to receive one of the highest annual rainfalls (3000–6000 mm) and most frequent heavy rains (up to... more
Multiscale interaction between monsoonal circulation and the local topography causes the southern front of the Darjeeling–Bhutan Himalaya to receive one of the highest annual rainfalls (3000–6000 mm) and most frequent heavy rains (up to 800 mm day-1) along the whole southern Himalayan margin. An examination of the patterns of annual rainfall, rainfall concentration, overland flow generation and slope instability indices in the Darjeeling–Bhutan Himalaya for 1986–2015 indicates that the mountain front disturbs rainfall gradient between the Bay of Bengal and the Tibetan Plateau. The results show that the precipitation concentration indices are lowest at the Himalayan front where the annual rainfall and the number of rainy days are highest. The Himalayan front has the highest predisposition to produce overland flow compared to adjacent foreland and the mountain interior. The average probability of the rainfall initialising the shallow landslides increases from 0.6% for a 1-day rainfall threshold of 144 mm to 6.1% for a 4-day rainfall threshold of 193 mm in the study area. The highest probability (up to 10%) of 2-day and longer low-intensity storms at the mountain front indicate that its area is threatened with particularly larger and deeper landslides. The multivariate regression analysis reveals statistically significant linear relationships of rainfall hazard indices with elevation and the distance to the mountain front in the mountain foreland and Himalaya, respectively. Regionally, the Darjeeling Himalaya reveals lower values of rainfall hazard indices, in comparison to the
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Known in Poland as the " Mieg Map " , the first topographic map of Galicia, at a scale of 1:28,800 represented one result of The First Military Survey of the Habsburg Empire in the late 18th century. This paper discusses the history of... more
Known in Poland as the " Mieg Map " , the first topographic map of Galicia, at a scale of 1:28,800 represented one result of The First Military Survey of the Habsburg Empire in the late 18th century. This paper discusses the history of that survey in brief, and describes the map's content and first edition in Poland. Attention is also paid to the Galicia map's status as a unique historical source suitable for GIS analysis and evaluation of developmental trends in the landscape.
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The Meghalaya Plateau is an area where human activity has caused deforestation which, in the extreme monsoonal rainfall conditions, has led to soil degradation and expansion of grasslands at higher altitudes. The shortening of the... more
The Meghalaya Plateau is an area where human activity has caused deforestation which, in the extreme monsoonal rainfall conditions, has led to soil degradation and expansion of grasslands at higher altitudes. The shortening of the shifting cultivation cycle resulting from the demographic growth, is generally considered to be the major cause of deforestation and the degradation of soil in this area. Analysis of the land use and land cover indicates a lack of response of the forest and grassland area to the population increase in the twentieth century. The radiocarbon dating of iron slags and supplemented data from historical reports has led to the formulation of a new hypothesis, connecting the deforestation with the 2000 year-old practice of charcoal production for smelting iron. High rainfall and impoverished soil together with the annual practice of vegetation burning are the causes of the present day stability of the land use and land cover system inherited from the past.
Research Interests:
The daily rainfall data for the twentieth century, from three stations across the region, constitute the basis for statistical analysis. However, the low signal-to-noise ratio makes it difficult to find any significant departure from the... more
The daily rainfall data for the twentieth century, from three stations across the region, constitute the basis for statistical analysis. However, the low signal-to-noise ratio makes it difficult to find any significant departure from the simplest null hypothesis of the stability of the rain record at individual stations in northeast India. Only the coarsest possible view, i.e. comparing the two halves of the century, provided strongly significant results in the numbers of days with extreme rain. Using a more general approach, the number of Fourier transform extreme amplitudes also differed significantly. Increasingly heavy events during the summer monsoon season, and partly in the pre- and post-monsoon seasons, are offset by a weakening in the winter monsoon season, so that the annual mean rainfall does not show a significant trend over the Meghalaya Hills. Apart from a greater number of years with noticeable extreme rainfall events in the second half of the twentieth century, we can also observe a more pronounced quasi-periodicity of 10–20 and 30–60 days during the same period. The detection of the latter periodicity indicates that the Madden–Julian oscillation plays an important role in the formation of extreme rainfall events over the Meghalaya Hills during extreme monsoon years.
Research Interests:
Natural and human causes of change in land use and soil properties were studied in the Sikkim Himalayas piedmont over the last 150 years, with a special emphasis on the period 1930-2010. Analysis of historical reports, combined with the... more
Natural and human causes of change in land use and soil properties were studied in the Sikkim Himalayas piedmont over the last 150 years, with a special emphasis on the period 1930-2010. Analysis of historical reports, combined with the visual interpretation of topographic maps and satellite images, indicates that the land reforms related to the location of tea gardens caused rapid deforestation of the
higher elevated terraces in the late 19th century. Continuous population growth between 1930 and 2010 caused a shift in the major land use changes from the terraces to the floodplains. As a consequence, a gradual extension of tea plantation and forestry development helped in stabilizing the land use of the terraces, while the parallel deforestation of mountain catchments and floodplains for rice cultivation
intensified fluvial activity. The enlargement of river-channel area by about 42% between 1930 and 2010 excluded a large part of the floodplains from cultivation and increased risk of soil degradation. The replacement of natural forest by monocultural tea and rice cultivation influenced the physical and chemical properties of the soil. Statistically significant changes were observed only in some chemical properties of the topsoil. Tea cultivation reduced the total carbon content by 26% and total nitrogen content by 33% in the surface soil horizon. The influence of rice tillage on the soil properties is masked by the fluvial activity. The combined effect of flooding and rice cultivation is reflected in the lower content of total carbon and nitrogen in the surface of the soil, namely, 76% and 77% respectively. Taking into account the long-term nature of the plantation, the soil still has the capability to support tea production. The productivity of rice depends partly on fertilization levels and partly on the natural deposition of fresh sediment eroded from mountains.
higher elevated terraces in the late 19th century. Continuous population growth between 1930 and 2010 caused a shift in the major land use changes from the terraces to the floodplains. As a consequence, a gradual extension of tea plantation and forestry development helped in stabilizing the land use of the terraces, while the parallel deforestation of mountain catchments and floodplains for rice cultivation
intensified fluvial activity. The enlargement of river-channel area by about 42% between 1930 and 2010 excluded a large part of the floodplains from cultivation and increased risk of soil degradation. The replacement of natural forest by monocultural tea and rice cultivation influenced the physical and chemical properties of the soil. Statistically significant changes were observed only in some chemical properties of the topsoil. Tea cultivation reduced the total carbon content by 26% and total nitrogen content by 33% in the surface soil horizon. The influence of rice tillage on the soil properties is masked by the fluvial activity. The combined effect of flooding and rice cultivation is reflected in the lower content of total carbon and nitrogen in the surface of the soil, namely, 76% and 77% respectively. Taking into account the long-term nature of the plantation, the soil still has the capability to support tea production. The productivity of rice depends partly on fertilization levels and partly on the natural deposition of fresh sediment eroded from mountains.
The Meghalaya Plateau is a distinct horst located on the northeastern flank of Peninsular India. It is one of the rainiest, most tectonically active areas in the world and hosts the richest types of karst phenomena in India. The... more
The Meghalaya Plateau is a distinct horst located on the northeastern flank of Peninsular India. It is one of the rainiest, most tectonically active areas in the world and hosts the richest types of karst phenomena in India. The combination of its regional uplift, associated river incision, headward erosion and chemical weathering in varied lithology, has facilitated the development of diverse landforms. This has resulted in deep valleys with magnificent waterfalls contrasting with mature undulating hills and karst topography over short distances. Meghalaya is a region of great scenic beauty and is an interesting tourist destination, in addition to its importance as an area for investigating the interaction between climate, tectonics and erosion.