scholarly journals Spatial Variation Characteristics of Soil Erodibility in the Yingwugou Watershed of the Middle Dan River, China

2020 ◽  
Vol 17 (10) ◽  
pp. 3568
Author(s):  
Xiaojun Liu ◽  
Yi Zhang ◽  
Peng Li
Keyword(s):  
Water Conservation ◽  
Soil Depth ◽  
Spherical Model ◽  
Kriging Interpolation ◽  
Soil Erodibility ◽  
K Value ◽  
Technological Support ◽  
Average Value ◽  
Variation Characteristics ◽  
Soil Erosion And Conservation

Knowledge of soil erodibility (k-value) is vital for measuring soil erosion and conservation planning. Through field sampling, laboratory analysis, and geostatistical analysis, the effects of land use type and soil depth on soil erodibility were studied in a typical watershed of China. The spatial distribution of k-value was determined by Kriging interpolation. Results showed that: (1) soil organic carbon (SOC) content in the study aera is 0.09–150.00 g/kg, and the soil is dominated by silt. The soil erodibility k-values obeyed normal distribution, with an average value of 0.032 t·hm2·h/(MJ·mm·hm2) and a medium degree variation. (2) k-values increased with soil depth. The k-values of surface soil (0–10 cm) for the six different vegetation types ranked in the following order: oak forest > peanut field > grassland > pine forest > tea field > corn field. (3) The theoretical semivariogram model of k-values was a spherical model; k-values in the study area gradually decreased from south to north and east to west, with an obvious banding distribution. Human activities have the greatest effect on k-value such that specific corresponding managements are needed. This could provide scientific and technological support for soil and water conservation measures and comprehensive utilization of the resources.

Site Suitability Analysis for Water Conservation Using AHP and GIS Techniques: A Case Study of Upper Sina River Catchment, Ahmednagar (India)

2020 ◽  
Vol 3 (2) ◽  
pp. 49-59 ◽  
Author(s):  
Yogesh Badhe ◽  
Ravindra Medhe ◽  
Tushar Shelar
Keyword(s):  
Water Conservation ◽  
Soil Depth ◽  
Land Use Land Cover ◽  
Suitability Analysis ◽  
Site Suitability ◽  
Gis Techniques ◽  
Multi Criteria Evaluation ◽  
Conservation Activity ◽  
Suitable Site

The site suitability for construction of water conservation structures is an important step towards groundwater conservation in arid and semi-arid regions. Water is the most crucial for maintaining an environment and ecosystem which is helpful to sustaining all forms of the life. The increasing water scarcity day to day has been one of the common problems over a period of time. On top of it, when the area is a part of rain shadow zone like Ahmednagar district, water conservation activities are become more important. The present study aims to identify the suitable zones for water conservation activity. Multi- criteria evaluation is carried out using Geographic Information System (GIS) techniques to help the choice makers in defining suitable site for construction of water conservation structures. Different layers which were considered for multi-criteria evaluation: slope, land use land cover, soil texture, lithology, soil depth, soil erosion, wells, lineaments and drainage network. Analytical Hierarchy Processes (AHP) is used for weighted sum to find suitable sites for implementation of water conservation activity using selected criterions. The site suitability map was classified into four classes: highly suitable, moderately suitable, less suitable and not suitable with area of 19.19%, 26%, 49.03% and 5.78, respectively. This map will help for selection of suitable sites for construction of Mati Nala Bund (MNB), Check Dam, Cement Nala Bund (CNB) and Continuous Contour Trenches (CCT) for conservation of groundwater resource in the region.

scholarly journals Spatial variability of soil chemical properties after coffee tree removal

2009 ◽  
Vol 33 (5) ◽  
pp. 1507-1514 ◽  
Author(s):  
Sidney Rosa Vieira ◽  
Osvaldo Guedes Filho ◽  
Márcio Koiti Chiba ◽  
Heitor Cantarella
Keyword(s):  
Spatial Variability ◽  
Spatial Dependence ◽  
Crop Yields ◽  
Management Strategies ◽  
Chemical Properties ◽  
Spherical Model ◽  
Soil Chemical Properties ◽  
Kriging Interpolation ◽  
Geostatistical Methods ◽  
Plant Removal

Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were applied to assess the central tendency and dispersion moments. Geostatistical methods were applied to evaluate and to model the spatial variability of variables by calculating semivariograms and kriging interpolation. Spatial dependence patterns defined by spherical model adjusted semivariograms were made for all cited soil properties. Moderate to strong degrees of spatial dependence were found between 31 and 60 m. It was still possible to map soil spatial variability properties in the layers 0-20 cm and 20-40 cm after plant removal with bulldozers.

scholarly journals SPATIAL DISTRIBUTION OF BRACKISHWATER POND SOIL CHARACTERISTICS IN PEKALONGAN CITY CENTRAL JAVA PROVINCE

2011 ◽  
Vol 6 (1) ◽  
pp. 91
Author(s):  
Andi Indrajaya Asaad ◽  
Akhmad Mustafa
Keyword(s):  
Spatial Distribution ◽  
Soil Depth ◽  
Research Result ◽  
Soil Characteristics ◽  
Kriging Interpolation ◽  
Total N ◽  
Central Java ◽  
Kriging Interpolation Method ◽  
Brackishwater Pond ◽  
Central Java Province

Spatial distribution of brackishwater pond soil has a vital role in the system of bioenvironment including brackishwater pond environment. This research was aimed to determine the spatial distribution of brackishwater pond soil characteristics in Pekalongan City, Central Java Province. A total of 59 sampling points each with two different soil depth samplings were determined by simple random method. A total of 21 soil characteristics were measured in the field and analyzed further in the laboratory. Geostatistic with Kriging Interpolation method in the ArcGIS 9.3 software were used to depict the distribution of the data across the landscape. Furthermore, the spatial distribution was presented by using ALOS AVNIR-2 image. Research result indicates that in general, pond soil in Pekalongan City can be classified as soil with high variability or relatively heterogenic with the value of variation coefficient more than 36%. Soil characteristics which have similar pattern of spatial distribution are acid sulfate soil and soil nutrient content. High value of pH, organic matter, and total-N of soil, and on the other hand, low value of PO4 were generally found in the pond area of Krapyak Lor Village, while in Pekalongan City, it was found high clayish soil content but relatively homogenous. It is recommended that pond management must be based on soil characteristics which are different from one area to another. The soil characteristics itself can be drawn and assessed through spatial distribution.

scholarly journals Characteristics of Soil Erodibility K Value and Its Influencing Factors in the Changyan Watershed, Southwest Hubei, China

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Xiaofang Huang ◽  
Lirong Lin ◽  
Shuwen Ding ◽  
Zhengchao Tian ◽  
Xinyuan Zhu ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Spatial Variability ◽  
Influencing Factors ◽  
Soil Type ◽  
Soil Survey ◽  
Purple Soil ◽  
Soil Erodibility ◽  
K Value ◽  
K Factor

Soil erodibility K factor is an important parameter for evaluating soil erosion vulnerability and is required for soil erosion prediction models. It is also necessary for soil and water conservation management. In this study, we investigated the spatial variability characteristics of soil erodibility K factor in a watershed (Changyan watershed with an area of 8.59 km2) of Enshi, southwest of Hubei, China, and evaluated its influencing factors. The soil K values were determined by the EPIC model using the soil survey data across the watershed. Spatial K value prediction was conducted by regression-kriging using geographic data. We also assessed the effects of soil type, land use, and topography on the K value variations. The results showed that soil erodibility K values varied between 0.039–0.052 t·hm2·h/(hm2·MJ·mm) in the watershed with a block-like structure of spatial distribution. The soil erodibility, soil texture, and organic matter content all showed positive spatial autocorrelation. The spatial variability of the K value was related to soil type, land use, and topography. The calcareous soil had the greatest K value on average, followed by the paddy soil, the yellow-brown soil (an alfisol), the purple soil (an inceptisol), and the fluvo-aquic soil (an entisol). The soil K factor showed a negative correlation with the sand content but was positively related to soil silt and clay contents. Forest soils had a greater ability to resist to erosion compared to the cultivated soils. The soil K values increased with increasing slope and showed a decreasing trend with increasing altitude.

scholarly journals Electrical resistivity and spatial variation in agriculture terraces: statistical correlation between ert and flow direction algorithms

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
J. Fernandes ◽  
C. Bateira ◽  
A. Costa ◽  
B. Fonseca ◽  
R. Moura
Keyword(s):  
Electrical Resistivity ◽  
Standard Deviation ◽  
Spatial Variation ◽  
Soil Depth ◽  
Flow Direction ◽  
Statistical Correlation ◽  
Average Value ◽  
Digital Elevation ◽  
Elevation Model ◽  
Soil Electrical Resistivity

AbstractThe construction of earthen embankment terraces in the Douro Region raises a set of problems related to hydrological processes. The main objective of this study is the evaluation of the spatial variation of electrical resistivity in agriculture terraces at Douro valley (Portugal). To achieve this objective, two variables are analysed, the soil electrical resistivity and the flow direction algorithm. In a field survey we recorded 13 electrical resistivity profiles. The contributing area was calculated with the algorithms D∞ (Deterministic Infinity Flow) and MFD (Multiple Flow Direction) and the results are the base of the internal runoff modelling, both supported by the digital elevation model with a spatial resolution of 1m2. A correlation between the spatial variation of the soil electrical resistivity represented by the standard deviation of the electrical resistivity for each profile and the average value of the contributing area coincident with each profile was established. The electrical resistivity standard deviation seems to be moderately well correlated according to the D∞ algorithm at about 1m of depth, and it has a good correlation at 1,5m to 2m of depth with the MFD algorithm. Taken together, the results show a significant positive statistical correlation between the electrical resistivity standard deviation and the contributing areas (MFD and D∞) depending on the soil depth.

Vertical Eddy Diffusion Studies in the Thermocline of a Small Stratified Lake

1973 ◽  
Vol 30 (10) ◽  
pp. 1491-1500 ◽  
Author(s):  
R. Hesslein ◽  
P. Quay
Keyword(s):  
Point Source ◽  
Eddy Diffusion ◽  
K Value ◽  
Stratified Lake ◽  
Average Value ◽  
Northwestern Ontario ◽  
Temperature Method ◽  
Diffusion Studies ◽  
Vertical Eddy ◽  
Vertical Eddy Diffusion

Values for K, the coefficient of vertical eddy diffusion in the thermocline of lake 227, a small, highly stratified, and artificially eutrophied lake in northwestern Ontario, Canada, are presented. Three methods: the classical temperature method of McEwen, a dye method, and a new method using a RAGAPOS (Radon Gas Point Source), were used. Results ranged from 2 × 10−4 cm2/sec by the Rn method to 34 ×10−4 cm2/sec by temperature method; the dye method resulted in an average value of 12 × 10−4 cm2/sec. The recycling of ΣCO2 resulting from particulate degradation below the epilimnion was calculated. The results ranged from 8 to 53% of the net loss of carbon from the empilinion depending on the K value used. Results from the radon method are considered to be more accurate than results from the temperature method.

scholarly journals Review on Dynamics of Soil Erosion and Conservation Efforts in Ethiopia

2020 ◽  
pp. 27-32
Author(s):  
Yibeltal Yihunie
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Temporal Dynamics ◽  
Participatory Approach ◽  
Soil And Water Conservation ◽  
International Standards ◽  
Research Activities ◽  
Conservation Measures ◽  
Soil Erosion And Conservation ◽  
Soil And Water

This paper was aimed to review the spatial and temporal dynamics of soil erosion and conservation efforts being practiced in Ethiopia. In the country, there is highly fluctuating dynamics of soil erosion and its loss rate is large as per the stated international standards. Even if the efforts to conserve soil and water in the country are affected by different factors like agro ecology and the choice of conservation measures, it was practiced since 1970s. Apart from the government’s effort as well as the contribution of different non-governmental organizations in increasing the awareness and understanding towards the impacts of soil erosion, the land tenure system, the existence of poor technology, lack of finance, limited technical support and limited participation of the local community are some of the challenges in Ethiopia restricting the effectiveness of conservation efforts. In addition, the research activities done regarding soil and water conservation in the country are not following integrated and participatory approach. Thus, this makes the efforts regarding research and finding out the best approach for sustainable soil and water conservation practices inefficient. Therefore, promoting integrated and participatory approach as well as linking with income generating business like carbon trading through climate change mitigation is the best options for the expansion and sustainability of soil and water conservation measures in Ethiopia.

scholarly journals Producing Global Solar Radiation maps in Iraq Using Geographic Information Systems

2018 ◽  
Vol 226 (1) ◽  
pp. 41-48
Author(s):  
Hussain Zaydan Ali ◽  
Ghusoon Idan Arb ◽  
Ziena Jameel yusif
Keyword(s):  
Solar Radiation ◽  
Spherical Model ◽  
Energy System ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Surface Radiation ◽  
Kriging Interpolation ◽  
Radiation Data ◽  
Circular Model ◽  
Climatic Information

The design and operation of any solar energy system requires a good knowledge of the solar radiation data in a location. This data finds application in agriculture, climatology, meteorology, etc. Since the solar radiation reaching the earth’s surface varies with climatic conditions of a place, a study of solar radiation under local climatic condition is essential. Global solar radiation is of economic importance as renewable energy alternatives. In this research 14 Iraqi climatic stations radiation data were used for the years 2013 to 2015.  Data have been designed and calculated by using Excel.  ArcGIS 10.2 is used for spatial interpolation and mapping activities. Surface radiation map have been generated by using ordinary kriging interpolation technique. Different models are tested, namely Spherical, Gaussian and Circular model. Creation of digital grid maps makes it possible to obtain climatic information at any point, whether there is a weather station or not. Results show that the spherical model outperforms Gaussian and circular models.                                      

scholarly journals Spatial Dependence of the Site Index of Pinus taeda L. Production Forests, in the Southern Central Region of the State of Paraná, Brazil

2019 ◽  
Vol 11 (13) ◽  
pp. 319
Author(s):  
Maite dos Santos Ribeiro ◽  
Julio Eduardo Arce ◽  
Afonso Figueiredo Filho ◽  
Marcos Felipe Nicoletti
Keyword(s):  
Pinus Taeda ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Spherical Model ◽  
Site Index ◽  
Coefficient Of Determination ◽  
Site Classification ◽  
Optimal Method ◽  
Average Value ◽  
Production Forests

A spatial analysis of the site index used for the classification of Pinus taeda production forests was performed using dominant height data from 402 continuous inventory plots. The data were examined with simple descriptive statistics and fit with four semivariogram models by the GS + program. The best model was then used to predict the site index in unsampled areas by ordinary kriging in ArcView. All models showed that site index values exhibited spatial dependence, with the degree of spatial dependence ranging from strong to moderate. The spherical model was used for kriging. In this model, the degree of spatial dependence was 29% and the range was 5,330 m, with a residual sum of squares (RSS) of 3.00 and coefficient of determination (r²) of 0.776. Measured and predicted values were compared by cross-validation, which produced a linear regression of observed versus predicted value with a slope coefficient of 1.068, slope standard error of 0.070, and intercept coefficient of -1.45. The site classification map generated by kriging divided the studied forests into five classes. Before kriging, all of the forest stands had one global average value for the site index, but after kriging this was changed to there being two or three values of the site index for many stands. Ordinary kriging proved to be an optimal method for interpolating the site index of unsampled areas to permit their classification, as is the case for young plantations for which inventory samples have not yet been taken.

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