Terraced Land Research Articles

Regional difference and prevention strategy of farmland erosion induced by extreme rainstorms in the Loess area and Rocky mountain area of Northern China

AbstractElucidating the mechanism of soil erosion caused by extreme rainstorms could improve agroecosystems' resilience to the extreme climate. However, less attention has been paid to the regional difference of soil erosion during extreme rainstorms through multiple field investigations. Using six field surveys of extreme rainstorms, soil erosion and its driving mechanism were investigated on farmland in the Loess area and the Rocky mountain area. Conclusions are as follows: (1) Farmland was severely eroded in comparison with abandoned land and forest–grass land. The erosion modulus of farmland in the Loess area (51 606.51 t/km2) was greater than that in the Rocky mountain area (2582.75 t/km2). (2) In both the Loess area and the Rocky mountain area, the main erosion types on sloped cropland and terraced land were rills/gullies and embankment failure, respectively. Terracing is an appropriate measure that can effectively control farmland erosion in rainstorm events. (3) Concentrated flow is a major driver of soil erosion, with nearly all rills/gullies occurring in the flow paths. Drainage measures can prevent the formation of concentrated flow, weakening rills/gullies erosion in farmland. (4) Building bio‐embankment, planting high‐coverage crops, and implementing local protection measures could reduce the farmland erosion influenced by extremely heavy rainfall. Combining drainage and agronomic measures is the common strategy to combat extreme rainstorm events for reducing farmland erosion in the two regions. These results can be applied to improve the ability of agricultural systems to cope with extreme rainstorms.

MENUMBUH KECINTAAN PEKERJAAN PERTANIAN BAGI GENERASI Z (GEN-Z) PADA LAHAN TERASIRING DENGAN SMART MACHINE PORTABEL MULTIFUNCTION

Education has shifted the work mindset of Generation Z (Gen-Z) in mountainous areas. A fairly good education, for example a high school/vocational school graduate, has shifted the desire to become a worker in the non-agricultural industrial sector, leaving behind the agricultural work that his parents started. From the preliminary survey, the main reason is actually the hard work of being a rice farmer on mountain slopes or terraced land. Many agricultural machines (agricultural tools) that have been created, starting from plows, rice harvesters and rice threshers, are still dominated for agricultural land in flat areas. This can be seen from the size of the existing machines which are very large and very difficult to use on terraced land. The application of smart machine technology is to make the rice harvesting process easier. The aim of this service is to foster a love of agricultural work for Gen-Z and to create food self-sufficiency. This service methodology starts from designing, manufacturing rice cutting and threshing machines, simulating and practicing. Then they will be taken to the service location to socialize on the use of the machine and the benefits that will be obtained by farmers. At the time of this service implementation, the service location in Tlahab Lor Village, Karangreja District, Purbalingga Regency, did not yet have rice ready to be harvested, therefore the service implementation only showed how the machine worked. It is said to be a smart machine because this machine has 3 (three) functions, namely cutting rice stalks, threshing rice and its main function is cutting grass. This machine is also portable because it only weighs less than 15 kg so it can be carried by itself to the harvest location in a terraced rice field model

What is the extension of bench terrace construction for forest plantations? The case of North Central Portugal

AbstractOver the last decades, the establishment of new fast‐growing forest plantations has been prospering. Although the European continent has the lowest share worldwide of forest plantations out of its total forest area, the Portuguese reality contrasts this. Since the last century, eucalypt plantations have increased widely in Portugal, and nowadays, it represents 36% of the total country's forests. Consequently, the soils of these plantations are commonly targeted with intensive soil mobilization by heavy machinery before planting, which in the case of sloped areas, frequently results in bench terracing. This study aims to quantify the widespread bench terracing implementation over the last 20 years in the Caramulo Mountains in north central Portugal. To do so, an analysis of satellite imagery was performed with Google Earth Pro, which allowed determining the coverage of forest areas where new terraces have been implemented, and their respective temporal dynamics. These results were then compared with additional spatiotemporal databases on land cover, topography, and bedrock, in order to understand the drivers of terrace implementation. Till date, 15% of the forest area in the mountains of Caramulo is under terraces, and over the last 20 years, the construction rate of new terraced land decreased in time, from 4% between 2000 and 2004 to 2% between 2015 and 2019. Among the two bedrock types existent in the area, terracing was found nearly exclusive over schist bedrock type (97%), while few areas were implemented over granites (3%). Their distribution was found limited above 30° of slope angle while 39% were found implemented below 15° of slope angle, conflicting with literature recommendations. Terracing was also found to be a driver of land cover change in 12% of the newly constructed terraces, whereas 8% were constructed over previous pine plantations and 4% on shrublands. This study allowed identifying several knowledge gaps associated with terracing implementation. Therefore, the authors of this work suggest a multidisciplinary approach when planning new terraces for a better assessment of the benefits and impacts of such land management practices.

Geological Hazards of Housing Development of a Pliocene Terrace Land Plot in the City of Rostov-on-Don

Introduction. In Rostov-on-Don the industrial and civil construction is carried out under a number of geological hazards: soils subsiding deformations, landslides, underfloodings, suffusions. Building up the new urban districts has always led to the groundwater surge. The Pliocene terrace building conditions in the eastern part of the city are characterised by the high risk of underflooding due to the shallow groundwater, low hydraulic gradients and water permeability of soils. The data on the present state of the groundwater level is not published in the media. Based on the materials on the territory geological structure and hydrogeological conditions, as well as on the numerical hydrogeological modeling, the present paper aims to investigate the groundwater balance determining factors and to develop the geofiltration monitoring recommendations for constraining the underflooding.Materials and methods. The geological structure and hydrogeological conditions of the territory were analysed using the published reading and graphical materials, as well as the engineering and geological survey results. The aquifers’ geometrical parameters analysis and the spatial data visualisation were made by means of the QGIS geographic information system. For creating and analysing the numerical geofiltration models, the Visual Modflow software product of Aquaveo company was used.Research results. The natural and technogenic geofiltration state of the territory under investigation had been forming for many years. The study of the designed numerical hydrogeological model indicates on the high risk of local underflooding as well as defines the conditions of its spreading throughout the entire territory. The role of the ravine-gully system that drains the aquifer and constrains the underflooding has been assessed. To control the territory groundwater balance and to specify the aquifers’ parameters, the layout of the observational hydrogeological wells network has been developed. Discussion and conclusion. The existing groundwater balance is vulnerable. Building up the territory is highly likely to cause additional infiltration of technogenic water and to lead to underflooding. The territory development project should envisage the geofiltration process monitoring and groundwater draining solutions.

Reclamation of ancient agricultural terraces in the Negev Highlands; soil, archeological, hydrological, and topographical perspectives

AbstractAncient terraced lands are considered badlands without profitable utilization except for urbanization. Nevertheless, this attitude prevents further agricultural utilization in addition to the loss of archaeological data. The study hypothesizes that the main influencing part in these systems is the retaining walls (RW). An analysis of their current influence on soil fertility, stability, and hydrology will indicate their adequate reclamation strategy. The objectives are to gather the influences and correlate them to the RW constructional state. In the Yeroham Hills, three parallel located terraced systems (one on the Wadi Shualim channel and the other, which is located on its banks) were studied. Their ancient agricultural utilization was dated, after in‐site excavations, to the Roman until early Islamic eras. Ten representative RWs were chosen, five from each terraced system. Their influences on the soil fertility, hydrology, and physical properties of the adjacent soil and 2 m ahead (the terrace) were studied. The finding indicates that the RW serves as a physical ecosystem engineer with positive influences on soil organic matter (0.5% higher content compared to the terrace) and land stability properties (maturated soil biocrust and higher aggregate stability). Comparison of the finding from both terraced irrigation systems, which differ in their conservation state, enables to determine the agricultural utilization and land stabilization after an adequate reclamation strategy, which is based on the RWs constructional parameters analyzed in‐site, and adaption to the current floodwater paths. The study's principles and analysis scheme enable the study and conservation of similar areas worldwide for increased utilization and profitability.

Spatial Patterns of Infiltration on a Bench Terraced Hillslope in Kigezi Highlands, South-Western Uganda

The spatial patterns of infiltration on bench terraced hillslopes are not fully understood. Moreover, these patterns are pivotal for assessing hydrological processes affecting water distribution, surface flow and soil erosion, and groundwater recharge. Our objective was to determine the spatial patterns of steady-state infiltration rates on a bench terraced hillslope; and assess the influence of soil properties on the infiltration process. We employed Geo-Information Science (GIS) to stratify the terraced bench hillslope into three slope position sequences, namely, Upslope, Middle slope, and Downslope. Besides, in each slope position segment, a bench terrace was randomly selected; and later stratified into three plot segments, namely, Upper (A), Middle (B), and Bottom (C), for purposes of conducting infiltration experiments. At each plot segment, three infiltration experiments were replicated to ascertain the intra-bench and inter-bench terrace steady-state infiltration rates. The experimental field design consisted of three slope position sequences, three plot segments, and three replicates, hence, leading to a total of twenty-seven (27) experiments. The infiltration measurements were conducted using a standard double-ring infiltrometer. We sampled soil for two different depths, namely; 0-15 cm and 15-30 cm, at each infiltration experiment to establish its relationship to the infiltration process. Using a Spatial Autocorrelation tool embedded in ArcGIS 10.2, we analysed the spatial patterns of infiltration along the hillslope. Furthermore, a Two-Way analysis of variance (ANOVA) was used to determine differences between the means of the infiltration rates across the hillslope sequences. Descriptive Statistics were used to investigate the Degree of Variability in infiltration rates. Results showed that beyond 15 m, infiltration rates vary significantly (P<0.018) from 5 cm hr-1 to 40 cm hr-1 between the bench terraced hillslope sequences, with a mean rate of 21 cm hr-1. Intra-bench steady-state infiltration rates varied higher in the Bottom (C) compared to Upper (A) and Middle (B) segments, especially in the Upslope sequence, where rates varied from 6 cm hr-1 to 20 cm hr-1 with a coefficient of variation (CV) of 45%. The clay content in the soil had a significant influence (P<0.003) on infiltration in the study sites of the hillslope with a correlation coefficient (R, r2 = -0.5). We concluded that the spatial patterns of infiltration on a bench-terraced hillslope are influenced by slope position. Infiltration is higher at the Downslope and Middleslope bench terraces as compared to the Upslope bench terrace. Soil texture and the structural condition of the bench terraces themselves play a cardinal role in the variations in infiltration. Within the bench terraced land parcels, infiltration is higher on the downslope and lower in the upslope positions. Since percent clay content increased with slope, it was noted as a fundamental soil characteristic affecting infiltration within the bench terraces. Our recommendation was that in bench terraces where steady-state infiltration was high such as in downslope and middle slope positions, the terrace bunds should be strengthened with grass and stone embarkments to consolidate them coherently. This strategy may reduce terrace bund breakages and consequently counter surface flow on the bench terraced hillslope. Besides, in areas where low steady-state infiltration rates were recognised, such as the upslope position, agronomic practices should be enhanced.

Rainfall-related impacts on a terraced landscape: Sóller valley (Mallorca, Spain) December 2016-January 2017

High Precipitation Events (HPEs) are common in the Mediterranean basin, causing effects such as floods or landslides. Those effects cause impacts, ranging from economic damages to the loss of life. Amongst the damages, the impact on man-made landscapes is also common, affecting both rural and urbanized spaces. The terraced land, built across the Mediterranean, for farming purposes, suffers from HPEs when the terraces cannot cope with the large amount of falling rain. In that sense, it is important to study how rainfall affects the terraces in terms of rock fall and mass movements. Such impacts can damage the economic purpose of the farmlands but also affect other activities developed on rural spaces, like trekking or biking. In this research, the impact of precipitation over a heavily terraced valley in Mallorca is studied, both in terms of impacts and regarding human-related leisure activities as well. The methodology follows five steps, combining aerial photos and satellite images analysis with fieldwork and the study of the obtained data using computer tools. The results show how the terraces cannot cope with large amounts of rain, which increase the risk of collapse and affecting activities developed in these areas. The need of measures to protect those cultural landscapes is highlighted as well as the need of an improved statistical analysis, because results show a moderate correlation between rainfall and stones movement across terraces.

Double no-till and rice straw retention in terraced sloping lands improves water content, soil health and productivity of lentil in Himalayan foothills

Designing suitable conservation tillage and rice straw management practices are vital to conserve limited soil water in sloping terraced lands for growing a second crop like lentil (Lens esculentum L.) after rice (Oryza sativa L.). A field study was conducted to evaluate the effects of tillage, rice straw management and supplemental irrigation on soil physico-chemical properties and productivity of lentil grown in rice fallow land. The maximum soil water content in lentil was observed in plots under rice residue retention as mulch (@ 5 Mg ha−1) which was followed by 20 cm standing rice stubble and residue removal. Rice residue retention and 20 cm standing stubble also increased infiltration rate, cumulative infiltration and sorptivity. Adoption of double no-till (NT) for rice and subsequent lentil crop increased soil organic carbon (SOC) concentration by 2.8%, 3.4% and 7.4% at 0–5, 5–10 and 10–15 cm soil depth, respectively than those under conventional tillage (CT). Soil available nitrogen and phosphorus contents were higher under residue retention either as mulch or standing rice stubble as compared to residue removal. Double NT and added residues (mulch and 20 cm standing stubble) increased soil microbial biomass carbon and dehydrogenase activity than CT without rice residues. Application of one supplemental irrigation did not significantly influence the soil properties. The NT in both rice and lentil enhanced lentil yield by 10–18% than lentil grown after rice under CT. Rice residue retention as mulch @ 5 Mg ha−1 and 20 cm standing rice stubble gave 35–42% and 23–27% higher lentil yield against residue removal over the years, respectively. Therefore, NT in both rice and subsequent lentil along with rice residue retention @ 5 Mg ha−1 as mulch or 20 cm standing stubble would pay substantial dividends for improving the soil health, enhancing lentil productivity and ensuring double cropping in rice fallow areas of Himalayan foothills and in similar agro-ecologies elsewhere.

Variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh

The study was conducted under three land uses, viz., terrace, jhum and forest to assess the variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh. The soil pH was strong to moderate acidic in reaction (pH 4.6 to 6.1). Organic carbon ranged from 10.7 to 46.0 g kg-1 which was found to be highest in forest ecosystem among the land uses. Cation exchange capacity (CEC) ranged between 7.9 and 22.8 cmol (p+) kg -1 and had significant positive correlation with organic carbon (r=0.68**). Bulk density varied from 1.10 to 1.56 Mg m-3, and showed significant negative correlation with organic carbon(r= -0.61*). Bulk density of forest was recorded to be the lowest. Water holding capacity (WHC) varied from 37.0 to 64.2 %, and was found higher under forest land use. WHC had significant positive correlation with organic carbon (r=0.55*) and significant negative one with sand (r=-0.62*). Hydraulic conductivity varied from 0.21 to 1.86 cm hr-1, and was found lowest under terrace land uses. Water stable aggregates (WSA > 0.25) ranged from 83.0 to 96.8 %. Mean weight diameter of the soil varied from 0.52 to 0.88 mm. The textural classes of various soils under different land use systems were loam, sandy loam and silt loam. The dispersion ratio varied from 30.2 to 47.9, which was very high in all the land uses. It had significant positive correlation with sand (r=0.76**) and significant negative correlation with organic carbon (r= -0.74**) and clay (r=-0.56**). Erosion index ranged from 48.1 to 89.9, and the highest was observed under terrace land use and lowest under forest land use. Erosion index had significant positive correlation with sand (r=0.72**) and dispersion ratio (r=0.74**) and significant negative one with organic carbon (r=-0.69**) and clay (r=-0.68**). The dispersion ratio and erosion index of all the land uses were very high indicating that the soils are highly erodible.

Variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh

The study was conducted under three land uses, viz., terrace, jhum and forest to assess the variability of soil properties in Sikhe village under Lower Subansiri district, Arunachal Pradesh. The soil pH was strong to moderate acidic in reaction (pH 4.6 to 6.1). Organic carbon ranged from 10.7 to 46.0 g kg-1 which was found to be highest in forest ecosystem among the land uses. Cation exchange capacity (CEC) ranged between 7.9 and 22.8 cmol (p+) kg -1 and had significant positive correlation with organic carbon (r=0.68**). Bulk density varied from 1.10 to 1.56 Mg m-3, and showed significant negative correlation with organic carbon(r= -0.61*). Bulk density of forest was recorded to be the lowest. Water holding capacity (WHC) varied from 37.0 to 64.2 %, and was found higher under forest land use. WHC had significant positive correlation with organic carbon (r=0.55*) and significant negative one with sand (r=-0.62*). Hydraulic conductivity varied from 0.21 to 1.86 cm hr-1, and was found lowest under terrace land uses. Water stable aggregates (WSA > 0.25) ranged from 83.0 to 96.8 %. Mean weight diameter of the soil varied from 0.52 to 0.88 mm. The textural classes of various soils under different land use systems were loam, sandy loam and silt loam. The dispersion ratio varied from 30.2 to 47.9, which was very high in all the land uses. It had significant positive correlation with sand (r=0.76**) and significant negative correlation with organic carbon (r= -0.74**) and clay (r=-0.56**). Erosion index ranged from 48.1 to 89.9, and the highest was observed under terrace land use and lowest under forest land use. Erosion index had significant positive correlation with sand (r=0.72**) and dispersion ratio (r=0.74**) and significant negative one with organic carbon (r=-0.69**) and clay (r=-0.68**). The dispersion ratio and erosion index of all the land uses were very high indicating that the soils are highly erodible.

Characterization and Taxonomy Classification of Soils of Hill Slope Land and Stream Terrace Land Located at North-Eastern Ghat Agro-Climatic Zone of Odisha, India

The present investigation was carried out to study the characterization, fertility status and taxonomic classification of some soils of North-Eastern Ghat Agro-Climatic zone of Odisha. Hill slope (pedon 1) and stream terrace land (pedon 2) two representative pedons of the Nayagarh district located in different topographic positions were studied for their physico-chemical characteristics and taxonomic classification. Results show that in pedon 1, percentage of sand, silt and clay range between 78.4 to 86.4, 3.2 to 3.4 and 10.4 to 17.4 respectively and in pedon 2, sand, silt and clay percentages range between 72 to 84, 3.2 to 7.2 and 10.8 to 18.8 respectively in different horizons. In pedons 1 and 2, pH increases along with depth from 4.80 to 5.82 and 5.80 to 7.60 respectively. Organic carbon content in pedons 1 and 2, ranges from 3.4 to 5.1 and 1.6 to 6.3 g kg-1 respectively. Cation exchange capacity decreases in pedon 1 from 13.25 to 8.66 c mol (p+) kg-1 and in pedon 2, range 7.66 to 16.65 c mol (p+) kg-1. The exchangeable sodium percentage in pedon 1 and 2, ranges from 4.53 to 9.23, and 2.56 to 6.53 per cent in different horizons respectively. The base saturation percentage in pedon 1, range from 58.11 to 98.15 per cent and in pedon 2, from 59.54 to 97.91 percent. The Hill slope (pedon 1) and stream terrace land (pedon 2) have little or no evidence of development of pedogenic horizons except ochric epipedon, therefore these soil are classified under the order Entisols. These soils have A-C profile with no distinct horizonation. Pedon 1, are classified under sub order Orthents, great group Ustorthents and sub group Typic Ustorthents. In case of pedon 2 the soils are put under the sub order Aquents, great group Fluvaquents and sub group Aeric Fluvaquents.

Responses of flood peaks to land use and landscape patterns under extreme rainstorms in small catchments - A case study of the rainstorm of Typhoon Lekima in Shandong, China

Investigations of the formation mechanisms of flood peaks in small catchments facilitate flood prediction and disaster prevention under extreme rainstorms. However, there have been few studies on the responses of flood peaks to land use landscape patterns using field surveys during extreme rainstorm events. Based on field data from 17 small catchments near the rainstorm center of Typhoon Lekima, 7 landscape indices were chosen. The flood peak and its sensitivity to the land use landscape were investigated by combining remote sensing interpretation and related analysis. The conclusions are as follows: (1) The peak discharge of the small catchment was 2.36–56.50 m3/s, the peak modulus was 8.00–48.89 m3/(s·km2), and the flood index K ranged from 3.61 to 4.55. (2) Under similar rainfall conditions, the flood peak modulus, K and the proportion of sloping cropland had significantly positive correlations (p < 0.05). The flood peak modulus was significantly negatively correlated with the proportion of forest-grassland and terrace (p < 0.05), and K and the proportion of forest-grassland and terraced land exhibited a negative correlation. (3) The flood peak modulus and K were positively correlated with the landscape fragmentation. (4) The sensitivities of small catchments to floods were evaluated to be moderate compared to K values from other studies. The ability of small catchments to cope with extreme rainstorms can be improved by increasing the areas of forest-grassland, and terraces and reducing landscape fragmentation. Our results could be applied to provide a basis for land use planning and support for the response against disasters caused by extreme floods.

Effects of transforming forest land into terraced land on the characteristics of soil carbon, nitrogen, phosphorus and their stoichiometry in North Guangdong, China.

To examine the effects of land use change on soil stoichiometry, we selected four kinds of land use soils in northern Guangdong: forest land (FL), sloping orchard (SO), dry land terraces (DLT) and paddy terraces (PT) to explore the changes of the contents, stocks and stoichiometry of organic carbon, nitrogen and phosphorus in the 20 a process of transforming from forest land into terraced land. Results showed that land use significantly changed the contents and stoichiometric characteristics of soil carbon, nitrogen and phosphorus. With the increase of soil depth, organic carbon (OC) and total nitrogen (TN) contents of DLT and PT decreased significantly, while FL and SO showed a "V"-shaped change trend. There was no difference in total phosphorus (TP) content among the four land use types. The OC content of PT was the highest, with an average value of 12.36 g·kg-1, followed by FL (10.32 g·kg-1) and DLT (8.80 g·kg-1), while SO was the lowest (5.96 g·kg-1). TN content was decreased in order of PT (1.01 g·kg-1)>DLT (0.78 g·kg-1)>FL (0.66 g·kg-1)>SO (0.33 g·kg-1). TP content of DLT (0.71 g·kg-1) was the highest, and SO (0.22 g·kg-1) was the lowest. C:N was between 8.87 and 22.94, and SO was the highest. C:P was between 8.73 and 81.74, N:P was between 0.77 and 5.13, with both of which being the highest in FL. Land use, soil depth and their interaction significantly affected the contents, stocks, and stoichiometric ratio of soil carbon, nitrogen and phosphorus, with soil bulk density, pH, and clay content as important influencing factors. The research results could provide a scientific basis for land use of subtropical low mountain forest land and rational fertilization of terraced ecosystems.

Integration of Abandoned Lands in Sustainable Agriculture: The Case of Terraced Landscape Re-Cultivation in Mediterranean Island Conditions

Agriculture terraces constitute a significant element of the Mediterranean landscape, enabling crop production on steep slopes while protecting land from desertification. Despite their ecological and historical value, terrace cultivation is threatened by climate change leading to abandonment and further marginalization of arable land imposing serious environmental and community hazards. Re-cultivation of terraced landscapes could be an alternative strategy to mitigate the climate change impacts in areas of high vulnerability encouraging a sustainable agroecosystem to ensure food security, rural development and restrain land desertification. The article presents the case study of abandoned terrace re-cultivation in the Aegean Island of Andros, using a climate smart agriculture system, which involves the establishment of an extensive meteorological network to monitor the local climate and hydrometeorological forecasting. Along with terrace site mapping and soil profiling the perfomance of cereal and legume crops was assessed in a low-input agriculture system. The implementation of a land stewardship (LS) plan was indispensable to overcome mainly land fragmentation issues and to transfer know-how. It was found that climate data are key drivers for crop cultivation and production in the island rainfed farming system. The study revealed that terrace soil quality could be improved through cultivation to support food safety and stall land degradation. In line with global studies this research suggest that cultivation of marginal terraced land is timely through a climate smart agriculture system as a holistic approach to improve land quality and serve as means to combat climate change impacts. The study also discusses land management and policy approaches to address the issue of agricultural land abandonment and the benefits gained through cultivation to the local community, economy and environment protection and sustainability.

Geomorphological Study of Jaflong Area near Dauki Fault Using Remote Sensing and Geographic Information System

Geomorphology is closely related to geology, soil science, hydrology and environmental science and is being increasingly applied in planning, mining and hydrological sectors, and within environmental consultancy and tourism. The study area lies in the north-eastern part of the country and tectonically this area belongs to Surma Basin situated into Bengal Fore deep zone of Bengal Basin also known as Sylhet Trough. Under this study an attempt was made to establish the relationship between geomorphic unit and existing landuse based on remote sensing data. In the study area nine landuse categories were identified through remote sensing and GIS techniques. Two different physiographic units which are North-Eastern Terrace Land and Surma-Kushiyara Flood Plain are belongs to the study are. Moreover two surface geological units include Young Gravelly Sand and Marsh Clay and Peat are also there. From analysis no relationship has been found between landuse classes with its physiography and surface geology.&#x0D; Environ. Sci. &amp; Natural Resources, 12(1&amp;2): 151-155, 2019

Soil loss hinders the restoration potential of tree plantations on highly eroded ravine slopes

Soil erosion and loss threatens vast tracts of agricultural and non-agricultural land, worldwide. High soil erosion severely affects establishment of vegetation via effects on plant growth and productivity on already degraded lands. However, information on soil loss impact on tree plantation and their relationships is scarce in the ravine lands. Therefore, we assessed soil loss effects on tree growth and soil characteristics, and role of conservation measures in degraded ravine land. The study consisted of comparing three systems, i.e., terracing, trenching, and sole slope to observe the effects on soil erosion and the resultant losses. In first system, a terraced land was designed from ravine top to bottom by dividing the slope into the four plots. In second system, ninety-seven trenches sized 2.0 m × 0.5 m × 0.5 m were designed on slope, while in third system, a continuous slope was maintained. Twenty-seven trees were planted at 8 m × 8 m spacing in each system. In all the systems, annual runoff, soil loss, tree growth, biomass and carbon stock, and soil properties were observed for the 7 years. Annual soil loss was recorded highest (5.1 t ha−1 year−1) in slope followed by trench (4.4 t ha−1 year−1) and terrace (3.8 t ha−1 year−1) systems, during the 7 years. In the slope system, increased soil loss resulted in the decreased tree height and collar diameter growth by 3–12% and 12–21%, respectively. Total biomass, carbon stock, and CO2 sequestration declined by 44–86% with the increased soil loss on the slope during the same period. Tree canopy area was also recorded lower in the slope, compared to terrace and trench measures. The soil loss relationship with tree characteristics revealed that growth, biomass, carbon stock, and canopy area consistently declined with the increased soil loss. In soil, proportional loss of organic carbon (11–21%), nitrogen (10–13%), phosphorus (25–32%), and potassium (4–13%) was also observed with increased soil erosion on the slope, compared to conservation measures. In contrast, soil loss reduction in the terrace and trench based measures improved the tree growth, biomass, carbon stock, and soil properties during the same period. The soil loss negatively affected the tree growth, productivity and their restoration potential, while soil conservation measures showed strong potential to ameliorate the highly eroded ravine slopes. Therefore, tree plantations should be augmented with the appropriate soil and water conservation measures for achieving greater ecological and economic benefits in degraded ravine lands.

Classification of Landforms for Digital Soil Mapping in Urban Areas Using LiDAR Data Derived Terrain Attributes: A Case Study from Berlin, Germany

In this study, a knowledge-based fuzzy classification method was used to classify possible soil-landforms in urban areas based on analysis of morphometric parameters (terrain attributes) derived from digital elevation models (DEMs). A case study in the city area of Berlin was used to compare two different resolution DEMs in terms of their potential to find a specific relationship between landforms, soil types and the suitability of these DEMs for soil mapping. Almost all the topographic parameters were obtained from high-resolution light detection and ranging (LiDAR)-DEM (1 m) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)-DEM (30 m), which were used as thresholds for the classification of landforms in the selected study area with a total area of about 39.40 km2. The accuracy of both classifications was evaluated by comparing ground point samples as ground truth data with the classification results. The LiDAR-DEM based classification has shown promising results for classification of landforms into geomorphological (sub)categories in urban areas. This is indicated by an acceptable overall accuracy of 93%. While the classification based on ASTER-DEM showed an accuracy of 70%. The coarser ASTER-DEM based classification requires additional and more detailed information directly related to soil-forming factors to extract geomorphological parameters. The importance of using LiDAR-DEM classification was particularly evident when classifying landforms that have narrow spatial extent such as embankments and channel banks or when determining the general accuracy of landform boundaries such as crests and flat lands. However, this LiDAR-DEM classification has shown that there are categories of landforms that received a large proportion of the misclassifications such as terraced land and steep embankments in other parts of the study area due to the increased distance from the major rivers and the complex nature of these landforms. In contrast, the results of the ASTER-DEM based classification have shown that the ASTER-DEM cannot deal with small-scale spatial variation of soil and landforms due to the increasing human impacts on landscapes in urban areas. The application of the approach used to extract terrain parameters from the LiDAR-DEM and their use in classification of landforms has shown that it can support soil surveys that require a lot of time and resources for traditional soil mapping.

Identifikasi dan Informasi Teknologi Penanggulangan Logam Berat pada Lokasi Pengembangan Padi Organik di Kabupaten Batang

Increasing market demand for organic rice consumption correlates with increasing organic rice development area. Identifications aim to determine residual content of metals before development conducted and alternatives implemented technology. Survey conducted on a stretch of terraced land in Central Java organic rice development area in Getas Village, Bawang District, Batang Regency. Soil samples were taken in terraced based on irrigation water flow or height place, namely: upper, upper-middle, middle, middle bottom, and lower. Soil samples were taken zigzag in 0-20 and 20-40 cm depth, where each position was taken 8 single points and composite. Soil samples were tested to determine the content of heavy metals Pb, Cd, and Cu. Based on test results, metals are found on each depth. In 0-20 cm depth the soil contains Pb, Cd and Cu respectively of 24.62; 1.70; 25.07 mg/kg, and in 20-40 cm depth containing 25.0 ; 1.72 and 25.96 mg/kg. Critical limits of Pb, Cd, and Cu metals in soils are 100-400; 3,3 and 50-140 mg/kg, respectively. Implemented technology in minimizing metals by adding organic material and biochar to soil and phytoremediation using water plants at the entrance of water.

Reproduction of sediment deposition and prediction of 137Cs concentration in the major urban rivers of Tokyo

Radioactive caesium- 137 (137Cs) can be used as a tracer to infer sediment dynamics due not only to its long radioactive half-life but also its affinity for fine sediment. A novel advanced interpolation assessment was conducted to examine radionuclide activity in terraced land covered with volcanic ash soil in Tokyo, Japan, which had a time-dependent input function and incorporated the effects of mixed-sediment particle dynamic behaviour on radioactive decay. In addition, transport parameters derived from Chernobyl measurements were applied as predictors of the long-term contamination of the cardinal urban rivers by the fallout from the Tokyo Electric Power Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011. The behaviour of suspended sediment substances, incorporating the effects of deposition and pickup, was assessed using a mixed-sediment particle dynamics model. The concentrations of 137Cs adsorbed on fine sediment particles of each size fraction were determined. Removal of 137Cs from the cardinal urban river channel had significant effects on both long-term decline, including extreme flash flood events, and the dynamic and time-dependent behaviours of interspersed 137Cs and sediment activity. A novel advanced interpolation assessment method was used to examine radionuclide activity in terraced land covered with volcanic ash soil in Tokyo, Japan. The assessment procedure has a time-dependent input function and incorporates the effects of mixed-sediment particle dynamics on this time dependence. The results indicated that sediment and 137Cs concentrations could decline more rapidly than observed in the Fukushima and Chernobyl regions. This rate of decrease depended on terraces covered with volcanic ash soil, which incorporated the effects of fine sediment behaviour for particle adsorption. In addition, comparatively large impacts were observed during extreme flash flooding events, which were associated with the land cover of the major urban river catchments in Tokyo. This work provides a new perspective for understanding 137Cs behaviour associated with reproduction of sediment deposition and prediction of 137Cs concentration in the major urban rivers of Tokyo, incorporating the effects of baseline 137Cs behaviour with the impact of sediment particle adsorption in a volcanic ash soil-covered terrace.

Agricultural land use and management weaken the soil erosion induced by extreme rainstorms

Elucidation of the soil erosion processes induced by extreme rainstorms provides better understanding and responding of agricultural system to global climate change. However, less attention has been given to the field investigation of soil erosion in the actual event of heavy rainfall. The purpose of this study was to assess the response capacity of agricultural land use and management to the heavy rainfall on northern rocky mountain area of China. (1) Compared with abandoned land and forest-grass land, the agricultural land experienced strong erosion. The erosion modulus (Em) of terrace land dominated by embankment failure (9490 t km−2) was less than that of sloped cropland dominated by rill/gully erosion (11,252 t km−2). (2) Concentrated flow was the main factor causing soil erosion, and almost all erosion occurred in the flow path. (3) Appropriate agricultural land use and management, such as terraced land, drainage channels, bio-embankments and plant pit cofferdam, could weaken soil erosion during extreme rainstorms. However, plastic film mulching aggravated soil erosion by rapidly forming concentrated flow. (4) To reduce the soil erosion on agricultural land under heavy rain event, we suggest managers should protect the bare soil with vegetation, conduct drainage measures, build high standard terraces in appropriate locations, and strengthen farmer training on agronomic measures. Our results could be applied to the response strategies of agricultural systems to global climate change.