Physiographic Units Research Articles

The bedrock geology under the Inland Ice: the next major challenge for Greenland mapping

Geological maps are of vital importance for documenting and advancing geological knowledge and they are a prerequisite for any meaningful evaluation of economic resources. In Greenland, mapping is taking place on the mainland – that for two centuries has been the traditional exploration target – and offshore, where only in the last decades has hydrocarbon exploration moved to the continental shelves. Greenland with its 2 166 000 km2 is the largest island in the world. However, the land is overwhelmed by ice. A central ice sheet – the Inland Ice – blankets some 81% of the country reducing rock outcrop to a coastal fringe 0 to 300 km wide (Fig. 1). The continental shelves comprise a little more than twice the area of this fringe, c. 830 000 km2. This preamble serves to emphasise that Greenland’s three physiographic units – exposed fringe, offshore and Inland Ice – are of very different size and that mapping has focused on the smallest acreage. Piecing together the composition of the largest, and hitherto unexplored, unit constitutes the next chapter of Greenland mapping.

LANDSAT IMAGERY TECHNIQUE FOR LAND EVALUATION IN AGRICULTURAL PURPOSES AT SOME AREAS OF EL-MENYA GOVERNORATE , EGYPT

03' east. By applying the technique ofLandsat Imagery (ETM7, Enhanced Thematic Mapper 7) and thephysiographic approach, the area under study at El-MenyaGovernorate could be identified as a best model for representingmany landscape features in Egypt. The studied area includes both thecontinental alluvium deposits of River Nile and desert sediments thatwere derived from the local parent rocks. These deposits aredeveloped on many physiographic units such as the Nile alluvialplain, River bank, Islands, Alluvial terraces, Aeolian plain and Wadis.In addition, the rock structures are delineated as a rock outcrops. Thedifferences between the studied physiographic units are representedby twelve soil profiles. The studied soil profiles were fully describedand soil samples were collected for laboratory analysis.Soil taxa were categorized into three orders according to

Identifying common near-surface and subsurface stratigraphic units using EM34 signal data and fuzzy k-means analysis in the Darling River valley

In irrigated areas of central and northern New South Wales secondary soil salinisation is of increasing concern. This is particularly the case for the Bourke Irrigation District (mid-Darling River valley) where incipient traces of point-source salinisation are evident. Much of this is attributed to significant changes in the water balance and in particular increased deep drainage and mobilisation of primary salts. In the first instance, near-surface prior-stream channels and subsurface paleochannels evident within Cenozoic alluvial deposits act as significant hydrological features. Owing to the porosity and connectivity of the Cenozoic sediments, deep draining water interacts with ancient and highly saline Cretaceous marine mudstones. Unfortunately, natural resource data on the spatial distribution of near-surface and subsurface stratigraphy are not readily available to understand these processes or determine best management. In this paper, we demonstrate how fuzzy k-means (FKM) analysis of EM34 signal data collected across the Bourke Irrigation District can be used to identify and map common near-surface and subsurface stratigraphic units. EM34 survey was carried out in the horizontal mode of operation with measurements made at coil spacing of 10, 20 and 40 m (i.e. EM34-10, -20 and -40, respectively). In all, 1236 sites were visited on a ∼0.5–1 km grid. The EM34 signal data were classified numerically using the FKM clustering algorithm. The iteration of fuzzy exponents (f) and various indices, including the fuzziness performance index (FPI) and normalised classification entropy (NCE) enabled the determination of f = 1.6 and k = 4 classes to be selected for further investigation. Using fuzzy canonical analysis we find that the EM34-10 and EM34-20 signal data best discriminate the classes. The resulting k = 4 classes (i.e. Class A, B, C and D) are then mapped using a method that ensures summation of class membership (m) values to unity and using local ordinary kriging. Class A represents saline and clay-rich sediments associated with outcrops of the Cretaceous marine mudstone. Class D represents interbedding of sand within the clay units indicative of the Cenozoic alluvial deposits that overly the Cretaceous mudstone. Similarly, Class B represents Cenozoic sediments with the presence of paleochannel(s). Class C characterises the eolian dune and alluvial floodplain physiographic units. The use of a confusion index (CI) highlights areas of uncertainty in the FKM classification mapping and indicates where the collection of additional information is appropriate. Validation of the FKM approach is confirmed by calculating near-surface (0–6 m) and subsurface (6–12 m) class average soil physical and chemical property (i.e. clay content, cation exchange capacity and salinity) variance (i.e. S2 Z ) and total within-class variance (i.e. S 2 T ) of a FKM map. Overall, the average subsurface ECe data produces the greatest reduction in variance. This suggests the FKM classification of EM34 signal data is influenced by saline groundwater-tables in the Cenozoic sediments which lie above the Cretaceous marine mudstone. The FKM class memberships and CI along a short but detailed transect across the Bourke Irrigation District are interpreted with respect to the spatial distribution of near-surface and subsurface soil property data. We conclude the FKM analysis of EM34 provides a better understanding of the spatial distribution and horizontal layering of the various stratigraphic units which characterise the Bourke Irrigation District. The results help explain the broad hydrological processes driving point source secondary soil salinisation and provides a framework for the deployment of measuring and monitoring sites.

Assessing land degradation hazard intensity and management plans using subjective models and the Analytical Hierarchy Process in Gorgan, Iran

Land use planning is a comprehensive master plan for any sustainable development action plan and can integrate all land resources and natural hazards management alternatives (strategies, plans and scenarios). This can be done via a multi-attribute decision method such as Analytical Hierarchy Process (AHP) under data and decision uncertainty. In this paper, fi rst, the potential land degradation hazard was mapped at 1:250,000 scale as four hazard classes. This was done in the context of 14 micro (unit) and six macro (type) physiographic units, regarding the synergetic effects of fi ve key processes (salinization, ponding, water erosion, wind erosion, and vegetation deterioration). A fi ve-class numerical subjective model was used. Secondly, with respect to the nature of land degradation mechanism and intensity in the Gorgan coastal plain (a complex mosaic for land use planning and natural hazard management) four hazard mitigation plans were proposed These were aligned with the goals of national combating of desertifi cation. These include: (1) Drainage and surface fl ow water collection, (2) shrub plantation and green belt creation, (3) soil physicochemical improvement, and (4) protection and preservation. Finally, the relative weights and priorities of management plan alternatives were determined in each hazard class zone. This was accomplished with respect to the hazard intensity and plan implementation cost and effectiveness using AHP model (CR=0.04 for plans, and CR=0.03 for hazard classes). The results indicate land degradation hazard classes I, II, III and IV which are extended with a spatially ordered pattern from forest covered mountain in the south to steppic coastal plain in the north along a sharp geo-ecological gradient of the study area. The differences of hazard class weights and surface areas, and the priority weights of the plans are signifi cant at 0.01 and 0.05 level, respectively. These differences lead to different possible alternatives for hazard management plans and decision making.

Effect of physiographic conditions on the spatial variation of seasonal topsoil moisture in Mediterranean soils

This paper studies the spatial variation of topsoil moisture within different soil types in a medium-size catchment at the Spanish Pre-Pyrenees (Estaña catchment, 2.5 km2) using seasonal data at high spatial resolution. Topsoil moisture was measured with a Delta-T Theta Probe ML2x device to 80 mm soil depth and at seasonal scale during 2005 and 2006. Measured values were related to the soil water content at field capacity to calculate the relative topsoil moisture (θR, %). The highest values of θR were obtained in autumn (53.2%) and the lowest in summer (32.1%), showing a positive correlation with seasonal precipitation and an inverse relationship with seasonal solar radiation (SR). Steep northern slopes presented the highest values of θR in spring, summer, and winter, and topsoil moisture progressively decreased from steep northern slopes to gentle slopes and from gentle slopes to steep southern slopes, defining a topographical trend. Any topographical trend was observed in autumn when values of θR were very high within the whole catchment. No significant correlation was found between values of θR and those of topographic wetness index (TWI) except in summer. Relative topsoil moisture varied greatly for the different soil types, and the highest values were also measured in steep northern slopes in spring, summer, and winter. Correlation between θR and SR was good for the different soil types in winter when SR varied the most for the different physiographic units and the range of values of θR was the highest. No significant correlation was found in autumn for any soil type due to the very low values of solar radiation. Results of this work draw attention to the importance of considering the slope steepness and aspect conditions for a more precise characterisation of moisture-sensitive areas in Mediterranean environments and soils at seasonal scale.

Caracterização de alguns atributos do solo e sua correlação com a paisagem em uma porção do noroeste do Estado do Paraná

The objective of this study was to integrate, into a geospatial database, information regarding the distribution of soils in the landscape, as well as their attributes inside a Natural Heritage Private Reserve (RPNP) located in the city of Lobato. All physical and morphologic characteristics were incorporated into a Geographical Information System (GIS). Based on the analyzed data and the study of their spatial distribution, these physiographic units were eventually mapped.

Geoinformatics as a tool for the assessment of the impact of ground water quality for irrigation on soil health

Secondary salinisation is the most harmful and extended phenomenon of the unfavourable effects of irrigation on the soil and environment. An attempt was made to study the impact of poor quality ground water on soils in terms of secondary salinisation and availability of soil nutrients in Faridkot district of Punjab of northern India. Based on physiographic analysis of IRS 1C LISS-III data and semi-detailed soil survey, the soil map was finalized on a 1:50,000 scale and digitized using Arc Info GIS. Georeferenced surface soil samples (0–0.15 m) from 231 sites were collected and analyzed for available phosphorus (P) and potassium (K). Interpolation by kriging produced digital spatial maps of available P and K. Ground water quality map was generated in GIS domain on the basis of EC (electrical conductivity) and RSC (residual sodium carbonate) of ground water samples collected from 374 georeferenced tube wells. Integration of soil and ground water quality maps enabled generating a map showing degree (high, moderate and low) and type (salinity, sodicity and both) of vulnerability to secondary salinization. Fine-textured soils have been found to be highly sensitive to secondary salinisation, whereas medium-textured soils as moderately sensitive to secondary salinisation. The resultant map was integrated with available P and K maps to show the combined influence of soil texture and ground water quality on available soil nutrients. The results show that available P and K in the soils of different physiographic units were found in the order of Ap1 22.5 kg / ha) and medium available K (135–335 kg ha−1) in most of the test sites when irrigated with saline, sodic or poor quality water.

History of landslide susceptibility and a chorology of landslide-prone areas in the Western Ghats of Kerala, India

Kerala is the third most densely populated state in India. It is a narrow strip of land, of which 47% is occupied by the most prominent orographic feature of peninsular India, The Western Ghats mountain chain. The highlands of Kerala experience several types of landslides, of which debris flows are the most common. They are called “Urul Pottal” in the local vernacular. The west-facing Western Ghats scarps that runs the entire extent of the mountain system is the most prone physiographic unit for landslides. The highlands of the region experience an annual average rainfall as high as 500 cm through the South-West, North-East and Pre-Monsoon showers. A survey of ancient documents and early news papers indicates a reduced rate of slope instability in the past. The processes leading to landslides were accelerated by anthropogenic disturbances such as deforestation since the early 18th century, terracing and obstruction of ephemeral streams and cultivation of crops lacking capability to add root cohesion in steep slopes. The events have become more destructive given the increasing vulnerability of population and property. Majority of mass movements have occurred in hill slopes >20° along the Western Ghats scarps, the only exception being the coastal cliffs. Studies conducted in the state indicates that prolonged and intense rainfall or more particularly a combination of the two and the resultant pore pressure variations are the most important trigger of landslides. The initiation zone of most of the landslides was typical hollows generally having degraded natural vegetation. A survey of post-landslide investigation and news paper reports enabled the identification of 29 major landslide events in the state. All except one of the 14 districts in the state are prone to landslides. Wayanad and Kozhikode districts are prone to deep seated landslides, while Idukki and Kottayam are prone to shallow landslides.

Landscape planning and management strategies for the Zir Valley, near Ankara, Turkey

This paper proposes a landscape planning and management method for river basins within the context of the European Landscape Convention (ELC) and European Water Framework Directive (WFD). This method has been applied to the Zir Valley in Ankara, Turkey. Landscape planning is identified by the ELC (European Treaty Series No. 176, 2000) as an important, forward-looking action to enhance, restore or create landscapes. The ELC also states that landscape management should promote sustainable development to ensure the non-degradation of landscapes and to help harmonize inevitable changes. The WFD (Directive 2000/60/EC of the European Parliament and of the Council, 2000) is a set of guidelines for managing large bodies of water. Its principle directive is to identify water bodies and the adjacent land areas that influence, and are influenced by, those water bodies. These are called River Basin Districts, and act as essential physiographic landscape units. While several regulations related to environmental planning, and used on a national as well as European basis, tend to utilize the same tools in practice, there are dissimilarities in how they are specifically applied and little effort is being made to promote a cooperative approach. In this paper, a National Approach for River Basin Management is proposed. This approach, which includes a landscape planning and management method based on landscape form and function, was developed to address the common purposes of the ELC and WFD.

Satellite evidence of a topographic sink‐source system in a small semi‐arid watershed

Water is a limiting factor for biological processes in drylands and consequently it is expected that vegetation cover along slopes will be affected by runoff flow regime and shape of topography. Nevertheless, spaceborne remote sensing data have hardly been used to study the effect of hydrological processes on vegetation pattern at the slope scale. This Letter reports on the spatio‐temporal variation in spaceborne‐derived Normalized Difference Vegetation Index (NDVI) data, in physiographic units of unique pedo‐hydrological characteristics, in a semi‐arid watershed. It was found that NDVI values in the footslope and shoulder physiographic units are significantly (p<0.0001) higher than those of the interfluve and the backslope. This difference, observed during the entire phenological cycle, was enhanced towards the peak season but was of less significance during the early season and towards senescence. These results support the hypothesis that water redistribution can significantly increase plant production in sink areas, also in the slope‐scale.

Study on the seasonal changes of land cover and their impact on surface albedo in the northwestern part of Bangladesh using remote sensing

In the present work, the dynamic behaviour of surface albedo of a coupled soil–vegetation–atmosphere (SVA) system has been studied in relation to landform characteristics, seasonally varying surface cover, and hydro‐meteorological condition using multi‐temporal Landsat TM data. Two adjacent, sharply contrasted and physiographically different land areas, (1) the semi‐arid Barind Tract area and (2) the flood plain areas of the rivers Ganges and Mahananda situated in the northwestern part of Bangladesh, have been selected for this study. Spatio‐temporal analysis of Landsat TM‐derived spectral signatures manifests quite contrasted response characteristics for different physiographic land units in the two study sites and shows a seasonal trend that is consistent with field observations. Coupling of satellite‐derived land cover information with landform and hydro‐climatic data reveals that the observed variability in surface cover and its condition, as well as seasonal transformation of surface categories (e.g. soil, vegetation, and water) over time and space, are a function of landform characteristics and the prevailing hydro‐climatic condition of the area. Particularly, depth of flooding in relation to land elevation during the wet season in the flood plain areas and soil moisture deficit during the dry season in the Barind Tract area seemed to be the two major determinative variables governing land use of the area. Climatic variables, particularly precipitation, appear to be the main driving force that brings out the dynamic changes in the geo‐environmental condition in both study sites. The changes in vegetation cover in response to the rainfall amount show a much higher sensitivity of the Barind tract areas in comparison to the flood plain areas. Land cover information as derived from multidate Landsat TM data demonstrates a relatively high change (about 68 per cent) in the aerial extent of vegetation cover in the Barind Tract and a small change (only about 8 per cent) in the flood plain areas between summer and the rainy season. The flood plain areas are found to be moderately vegetated throughout different seasons, which is in contrast to the semi‐arid Barind Tract area that remains either mostly bare (about 90 per cent) or highly vegetated (vegetation cover greater than 75 per cent), depending on the season, though both sites receive an almost similar amount of seasonal and annual precipitation. Variation in soil moisture and vegetation condition, as well as transformation of bare land into a vegetated or seasonally flooded area in response to seasonally varying precipitation, introduce sequential variability in the surface absorption level, thereby provoking seasonal rhythmic variation in the surface albedo over the area. It is found that the transformation of bare land into a crop area in the Barind Tract reduces the surface albedo values by about 60–75 per cent. Relatively higher spectral responses in summer over most of the semi‐arid area depict a deficit in moisture content in the soil layer, as compared to that in the relatively moist flood plain area, except the sandy area, whereas transformation of land into water due to seasonal flooding, especially in the flood plain areas in the wet season, associates a decrease in albedo from 13 per cent in summer to about 6 per cent in winter. Increased albedo, particularly over the river area in summer, indicates the presence of suspended sediments originating from erosion due to surface runoff and nearby riverbank shifting. As a whole, surface albedo seems to be a land type‐dependent seasonal indicator of the area.

サンゴ礁裾礁における空間構造把握のための自然地理的ユニットの設定―与論島東部サンゴ礁を例に―

The spatial structures of a 101-103 m scale on coral reefs were understood by reading aerial photographs and investigating the topography of the fringing reef at the eastern part of Yoron Island, Ryukyu Islands. This study set a new physiographic unit (PGU) at the coral reefs as well as studied zonation. PGU has the following characteristics. (1) In an aerial photo, a linear pattern comprising micro-landform arrangements is recognized on the reef flat; (2) Seawater flowing beyond the reef crest from the open sea and entering the moat before returning to the open sea through a breakout in the reef crest or a channel flowing parallel to the shoreline constitute a very common pattern in the research area; (3) The series of currents observed in the area constitute a water system resembling a drainage water system on land and 4 systems were arranged at the eastern part of Yoron Island ; (4) The movement of seawater is controlled by landforms such as reef crests, channels and lands (a cape), which might qualify as borders of PGUs ; (5) Movements controlled by such landforms are dominant, and tend to be longer in terms of time. In this study, a physiographic unit is defined as follows. (1) A unit that is distinguishable from other adjacent areas by its geomorphological borders ; (2) And, a unit that is distinguishable from other adjacent areas when referring to the movement systems of seawater and materials.The notion of spatial structures of coral reefs of a 101-103 meter scale was substantiated by this research using the overlapping zonation approach known here as PGU on reef flats. The spatial structure makes a frame of the coral reef ecosystem. Therefore, setting a PGU is thought to be effective for application to coral reef conservation.

Climatic influence on slope dynamics and shoreline variations: examples from Marche region (Central Italy)

The present work aims to establish relationships between shoreline historical variations (close to the river mouths) and slope dynamics on mountain and hilly areas: these are considered as fundamental physiographic units of the Adriatic central Italy. The study deals about the deltaic system of the Chienti river, which is representative of the deltaic systems of the main Marchean rivers. Goal is to recognize possible geomorphological indicators of climatic variations during late Holocene. Debris flows on the Sibillini Mts were analysed and interpreted. Their activation can be associated with: late Pleistocene-early Holocene deglaciation, with regard to the oldest phenomena; agricultural, forestry and grazing activities during the Late Middle Ages, even though evidence of climatic conditioning is also present. Moreover, some important landslide phenomena on the high hilly areas were examined: historical data demonstrated an intense post-Middle Age activity (XVth-XVIIIth centuries) related to the strong rainfall increase as a consequence of climatic worsening.

Soil resource appraisal towards land use planning using satellite remote sensing and gis a case study in patloinala micro-watershed, district puruliya, west bengal

Visual interpretation of IRS ID LISS-III fused with PAN data (1:12,500 scale) ofPatloinala micro-watershed of Puruliya district, West Bengal was carried out for delineating the physiographic units based on the variations in image characteristics. The major physiographic units identified were upland(Tanr), medium land(Baid), and low land(Bahal andKanali). The satellite remote sensing data coupled with ground truth were translated in terms of soils using composite interpretation map as base. The abstraction level attained was phases of soil series based on Soil Taxonomy. On the basis of physiographic variation and soil or soil site characteristics such as texture, depth, slope, erosion etc. the problem areas were identified and land use plan has been suggested for the overall development of the micro-watershed.

Global coastal segmentation and its river catchment contributors: A new look at land‐ocean linkage

Here we present the COSCATs global database of 151 catchments in exorheic areas. The catchments connect to oceans through coastal segments according to three sets of criteria: natural limits (continents, oceans, regional seas, major capes, and bays), continental shelf topography (sills, basins, island chains), and geophysical dynamics (climate, ocean currents and tectonics). The COSCATs segmentation scheme is designed to improve Earth System analysis and to harmonize reporting of global riverine transfers from land to oceans. Each COSCAT is characterized by its coastal segment limits and length (median 2 400 km), by its catchment characteristics, including area (median 0.45 M km2), width, latitudinal range, runoff average value and direction, including its related physiographic units (n = 500). We apply the COSCAT segmentation to all 151 basins to estimate water discharge and total nitrogen impacts to oceans and find that the average runoff (mm/yr) and N yields (YN in kg km−2 yr−1) range over more than 3 orders of magnitude at this coarse resolution, and that their average population density ranges over 2 orders of magnitude. Hyperactive regions, defined as segments with 5 to 10 times the world average yield (river transfers per unit area of land), are differentially placed for water runoff and total contemporary nitrogen. COSCATs have been designed to facilitate the budget reporting and the analysis of global scale heterogeneity for riverine fluxes and can be applied to other material, such as suspended solids, carbon species or other nutrients, particularly for areas draining into regional seas.

Pedogenesis and clay mineralogical investigation of soils formed on gypsiferous and calcareous materials, on a transect, southwestern Iran

This study examined pedogenesis, as well as the clay mineralogy of soil and rock samples obtained from a transect of gypsiferous and calcareous materials. The main objectives of this research were to study the relationship between clay minerals and physiographic units as well as the relative importance of key pedogenic processes in controlling clay mineralogy. Palygorskite, chlorite, illite, smectite, quartz and interstratified minerals were observed in both soil and rock samples, using XRD, TEM and EDX analyses. Illite, chlorite, and interstratified minerals are inherited largely from parent rocks. Most of the smectite is inherited from highly smectite marl formations, although some may be the product of palygorskite weathering and transformation of illite particularly at the surface horizons. Neoformation of palygorskite, as a result of calcite and gypsum precipitation, seems to be a major pathway for the occurrence of this mineral, especially on plateau physiographic units, although inheritance has less importance. Gypsiferous soils showed more pedogenic palygorskite as compared to calcareous soils. Three morphological forms of palygorskite, related to degree of weathering, were identified in the studied pedons. New great groups and subgroups of Ustepts (Aridic Gypsiustepts and Aridic–calcic Gypsiustepts) are suggested to be included in Soil Taxonomy based on the properties of some of the studied pedons. Dissolution and transport of anhydrite from outcrops, is considered the main source of pedogenic gypsum in these soils. Micromorphological studies, including thin section observations and SEM analyses indicated variable habits of gypsum crystals suggested a dynamic soil environment.

Hydrology of subarctic Canadian Shield: heterogeneous headwater basins

A field study near Yellowknife, Northwest Territories, was conducted to understand and conceptualize better the runoff generation processes of Canadian Shield headwater basins. Results indicate that these basins can be viewed as a number of hydrological elements, defined as physiographic units, with behaviours, defined by the pattern of their functions over time, which are similar within their boundaries and dissimilar with areas adjacent. A key finding of this study is that available storage at any location is dictated by hydrological processes within the individual elements as well as inputs from adjacent elements. Runoff from an element is generated only when its saturation threshold is exceeded. The importance of inputs from adjacent elements in addressing storage demands causes their geometry and topology on the landscape to control where, when and how runoff is generated. The physical manifestation of these processes is a cascading runoff pattern through the headwater basins as their downstream locations saturate and generate runoff. The element threshold concept is proposed as the hydrological framework encompassing these processes and patterns that prevail in the shield environment.

Functional morphology of a sarcocaulescent desert scrub in the bay of La Paz, Baja California Sur, Mexico

A functional morphology study of a sarcocaulescent scrub in the Baja California peninsula was performed with the goal of identifying plant functional types. We sampled 11 quadrats in three distinct physiographic units within the sarcocaulescent scrub ecoregion: the open scrub, the clustered scrub, and the closed scrub. We found 41 perennial species, which we characterized using 122 morphology-functional characteristics, corresponding to vegetative parts (stem and leaf), reproductive parts (flower and fruit), and functional phases (phenology, pollination, and dispersion). We used principal components analysis PCA to analyse the relationship between morphological attributes and species, between species and sites, and between morphological attributes and sites. Stem morphology was highly associated with groups of plant species and also with specific communities, forming recognizable stem-morphology syndromes. We also found that flower and fruit attributes are highly correlated with stem morphology. Our analysis allowed the clear identification of four morphological groups in our study area: (a) crassicaulescent plants, or succulent cacti, (b) sarcocaulescent species, (c) woody trees, and (d) woody shrubs. Cacti and sarcocaulescent plants dominate in the open scrub, woody shrubs dominate in the mounds of the clustered scrub, and woody trees, together with all the previous life-forms, form the more mesic closed scrub. Our results indicate that Forrest Shreve's classification of desert communities based on the external morphology of the plants is statistically robust and reflects a significant underlying pattern.

Developing a suitability index for land uses and agricultural land covers: A case study in Turkey

This study was aimed at determining the land-use and land-cover (LULC) potentials of a southeastern Mediterranean area (Antakya, Turkey) of 36 816 ha for a total of 23 different LULC types: nine horticultural crops, nine field crops and five non-agricultural lands. Land evaluation was carried out by using a combination of SENOL Land Evaluation System and ILSEN computer program adapted to Turkey from FAO land evaluation principles. Our assessment resulted in the identification of nine physiographical units, 27 different soil series, and 110 land mapping units. Nearly 49% of the study area was determined as suitable for agricultural land cover types, and 35% for non-agricultural land use types. A map showing potential suitability of LULC was derived for the study area. The quantification of LULC suitability assists decision makers in ensuring that lands are used according to their capacities to satisfy human needs for present and future generations, thus sustaining ecological and economic productivity of natural resources.

Soil erosion modeling using MMF model -A remote sensing and GIS perspective

Hardly any part of the world has remained unchanged since the arrival of the speciesHomo sapiens including the mountain ecosystems. Himalayan physiographic unit of India in due course has become populated and is tolerating all kinds of human interventions. Soil erosion in this region has been identified as a major problem due to both natural and anthropogenic factors. Remote sensing and Geographical Information system (GIS) techniques hold great promises in the assessment and conservation of natural resources including the surface soil. The major objective of the present study was to apply a process based model to quantify soil erosion and to prioritize the sub-watershed on this basis. The sub-watershed located at Jakhan rao area of Western Dun in lower Himalayan belt was taken as the test site for the study at 1: 50,000 scale. Deforestation, unscientific agricultural practices, terrace farming, cattle grazing and land degradation in the sub-watershed are some of the anthropogenic factors causing soil erosion in the area. Here, MMF model was used for estimation of soil erosion by incorporating layers derived from both remote sensing and ancillary data. IRS 1C LISS III satellite data was used for the preparation of land use map that was used to derive RD map, BD map and K map. Digital Elevation Model (DEM) provided slope map, an intermediate layer used in equation 6 to generate G map, and soil map provided MS map, BD map and K map. The above intermediate layers generated were then integrated in GIS domain to estimate the amount of soil erosion in the sub-watershed area. Results show high values 4572.333 kg/m2 for G map, which depicted transport capacity of overland flow. Comparatively lower values 13.15, and 7.98 kg/m2were observed for F map, which depicted soil detachment by raindrop impact. The subtracted image of the aforesaid layers produced the real picture, where in the highest value 3.770 kg/m2 was found in the midland region of the site. The crossed erosion map was then classified into different erosion classes for sub-watershed area. This study illustrates the applications of remote sensing and GIS techniques for soil erosion modeling.