scholarly journals Spatial and temporal analysis of natural resources degradation in the Likodra River watershed

2016 ◽  
pp. 169-188 ◽  
Author(s):  
Sinisa Polovina ◽  
Boris Radic ◽  
Ratko Ristic ◽  
Vukasin Milcanovic

Soil is an important natural resource whose proper use requires a good knowledge of all endogenous and exogenous factors that cause different types of degradation. Erosion is one of the forms of soil degradation. Erosion processes are characterized by a distinctive complexity and the factors affecting them are dynamics and change in space and time. A complex system degradation requires a multidisciplinary approach to the use of modern methods and techniques. Today, a large number of models are available for the assessment of soil loss through erosion as well as the levels of risk from erosion, today. Most of these are based on the logics of GIS thanks to its ability to sublimate heterogeneous information. In this paper, the analysis of spatial and temporal degradation of natural resources is carried out in the Likodra River watershed. The Likodra River is located in the northwestern part of the Republic of Serbia, and is positioned in the municipality of Krupanj. The main stream in the immediate vicinity of the town of Krupanj formed from four small streams that have expressed torrential character (the Bogostica with the Krzava and the Cadjavica with the Brstica). In May 2014, the urban area and rural parts of the municipality Krupanj were affected by catastrophic flash floods that resulted in the loss of human lives and enormous material damage. Soil degradation in the study area was analyzed using the Erosion Potential Method (EPM). The method is characterized by a high degree of reliability for determining the intensity of erosion, calculation of sediment yield and transport. The advantage of this method compared to other methods its lower complexity in terms of quantity of input parameters, simplicity and the possibility of application in GIS. In addition, the method has the advantage of choice, because it was developed in this area. The method is based on the analytical processing of data on factors affecting erosion. As the erosion spatial phenomenon appears on the map according to the classification on the basis of the calculated analytical erosion coefficient (Z), which depends on the characteristics of the soil, vegetation cover, relief and visible degree of erosion. By applying the Erosion Potential Method (EPM) an erosion map has been developed, showing the spatial distribution of erosion processes in the catchment area of the Likodra River watershed. The erosion map provides an insight into the state of erosion processes of different intensity and character. For the study basin, all its visible manifestations are manifested in the medium coefficient of erosion Zsr = 0.204. The current state of erosion was analyzed in comparison with the situation in the original 1983 erosion map of FR Serbia.

2017 ◽  
Vol 18 (1) ◽  
pp. 9-26
Author(s):  
Lenin Heredia G. ◽  
Germán E. Bravo C.

Hotspots analysis is essential in the criminology field and quite important in decisions making for police agencies because it permits the enhancement of allocation of police resources for timely and adequate actions. There exist different techniques for analysis and generation of hotspots, limited by its difficulty to consider other urban and demographic factors that could be the cause of the emergence of these hotspots or their influence over other factors. On the other hand, it is also difficult and unusual to analyze hotspots in a temporal context. This paper seeks, through spatial-temporal operations based in hotspots, to go beyond of classical crime analysis with hotspots, by looking for the spatial influence of other spatial factors over and analyzing also their relationship in a temporal context. The paper initially presents and analyze the performance of various techniques for hotspot generation and determines that STAC technique from CrimeStat is the more suitable for the proposed objective. Then, it defines a hotspot algebra allowing the combined study of crime and spatial factors affecting it and/or been affected by crime events. Temporal analysis includes the hotspots generation for days of the week and/or months in a year. In this way it is possible to study causality relationships and/or correlations among the studied phenomena and the spatial-temporal environment where crime occurs. Therefore, it is possible to define and apply informed actions, primarily concerning the allocation of police resources. Finally, it shows some application examples, thematic as well as temporal analysis, of hotspot algebra using crime data from Bogota for the years 2011 to 2013; finally, some future works in the subject are proposed.


2017 ◽  
pp. 89-98
Author(s):  
Eli Pavlova-Traykova ◽  
Ivan Marinov ◽  
Petar Dimov

This investigation has been carried out at Badinska River watershed - one of the most famous torrents in Bulgaria. The purpose of the survey is tos analyse the main erosion factors and erosion potential of territories, with a view to assess soil erosion risk and opportunity of high water formation from watershed. A methodical approach for determination and mapping of the territories in terms of the class of erosion risk with the use of GIS is applied. Assessments are made according to the ?Methodology for preparing the national long term programme for protection against erosion and flooding in forestlands?. The total assessment for Badinska river watershed is ?low to moderate? potential risk and ?very low to low? actual erosion risk. About of 5% of the forest stock territory is with ?moderate? and ?moderate to high? actual risk, and the biggest part of this territory (about 63%) is in the main stream watershed above the Yaloviko tributary.


Author(s):  
Myroslav Voloshchuk

Based on generalization of literary sources, normative legal, stock materials and experimental data, the complex situation of soil degradation is highlighted. Different types and intensity of the manifestation of soil degradation, their distribution and characteristics are described. The threatening situation of manifestation of degradation processes in some regions of Ukraine is shown, among which soil erosion occupies the leading place. More than 4.5 million hectares are occupied by medium and strongly ground soils, including 68 thousand hectares completely lost their humus horizon. Particularly large areas of eroded soils are distributed on arable land in the Vinnytsia, Luhansk, Donetsk, Odesa, Chernivtsi and Ternopil regions, where the average annual ground wash is 24.5–27.8 t/ha with a tolerance of 2.5–3.7 t/ha. As a result of erosion processes from the total area of agricultural land, about 500 million tons of fertile soil layer is washed out on average annually, which contains about 24 million tons of humus, 0.96 million tons of nitrogen, 0.68 million tons of phosphorus and 9.4 million tons of potassium equivalent to 320–333 million tons of organic fertilizers, and ecological and economic losses due to erosion exceed 9 billion UAH. Flat soil was associated with linear erosion. The main indicators characterizing the degree of damage to land by linear erosion are the density of ravines, the distance and area between them, the slope, the properties of soils and rocks, the morphometric parameters of the ravines and their catchment areas. According to various estimates, the area of land affected by linear erosion in the country increases by 5–10 thousand ha annually. The effect of the ravines on the complete destruction of the land, deformation of the soil cover is highlighted. Information on various types of soil pollution by poison chemicals, industrial waste is given. According to the prediction of scientists in such a situation, 120–150 years on the planet can destroy the fertile soil layer. Key words: erosion, dehumidification, pollution, waterlogging, acidity, degraded land.


This chapter contains the factors affecting the soil resistivity and grounding resistance such as the soil moisture content, soil mineral content and soil temperature. It discusses the methods of measuring of soil resistivity and grounding resistance using Wenner method. Method to obtain the required samples for obtaining accurate site resistivity is presented. Soil resistivity measurement procedure is given in this chapter. The chapter contains three electrode method or fall-of-Potential method, dead earth method, and ground resistance testing existing systems using ‘Selective' Clamp-on-Measuring of high voltage transmission towers feet resistance. Methods of calculating the apparent soil resistivity of Multi-Layers, apparent soil resistivity of two layers and apparent soil resistivity of three layers are presented in this chapter.


2019 ◽  
Vol 11 (12) ◽  
pp. 3369 ◽  
Author(s):  
Shuyue Feng ◽  
Hui Wen ◽  
Shimin Ni ◽  
Junguang Wang ◽  
Chongfa Cai

In the subtropical hilly areas of China, a collapsing gully, a particular type of permanent gully, poses a great threat to the productivity and sustainability of the local ecological and agricultural systems. However, few studies have been performed regarding the effects of collapsing gully erosion on soil degradation. The aim of this study was to evaluate the effects of collapsing gully erosion on soil-quality-related physical and chemical properties. The collapsing gullies that were severely affected by erosion processes were considered at three stages (initial, active and stable stages) and corresponding soil samples were collected to analyze the spatial variation of the soil physical and chemical quality at each stage. The changes in the properties were assumed to be considerable in the regions affected by the erosion process compared with those unaffected by this process. Soil physical properties were more susceptible than soil nutrients to collapsing gully erosion in different spatial locations. The soil quality index (SQI) system consists of total nitrogen (TN), total phosphorus (TP), pH, capillary porosity (CP), sand content (SA), soil cohesion (SC) and root density (RD). Collapsing gully erosion was found to affect the soil physical and chemical properties by progressively reducing the SQI. The mean SQI value was the lowest in the active stage of the collapsing gully, with a higher soil degradation. For the different spatial positions in the collapsing gullies, the scour channel showed the lowest SQI value. The limiting indicators varied in the different stages or spatial sites in the collapsing gullies.


2020 ◽  
Vol 10 (16) ◽  
pp. 5416 ◽  
Author(s):  
Hao Wang ◽  
Zhiying Lv ◽  
Jianwei Zhang ◽  
Jianwei Yue ◽  
Hongyu Qin ◽  
...  

The Yuanzishan landslide is an unstable slope in Langzhong County, located in northeast Sichuan province, China. The Guangyuan-Nanchong expressway passes through the front edge of the unstable slope, and subgrade excavation has resulted in slope deformation, which threatens the safety of the highway construction. Emergency landslide control requires reduction of the slope disturbance. This study aims to investigate the use of buried-boring piles as a potential method for emergency landslide control. A simplified calculation method was used for the design of the buried-boring piles, according to the limit equilibrium of the soil and the elastic foundation coefficient method. The measured internal force changes of the pile were compared, in order to determine the distribution coefficients of the driving force. A relationship between the driving force of the shared pile ratio and the buried depth ratios was then established. Furthermore, a variety of factors affecting the internal forces of the buried-boring pile and the lateral reaction of the soil were also studied. The results revealed that (1) there was a quadratic relationship between the driving force of the pile-shared ratio and the sliding depth ratios; (2) the maximum bending moment of the pile increased with an increase in the sliding depth ratio of the pile, following a power law relationship; (3) increasing the buried depth of the pile head reduced the influence of the pile diameter on the maximum internal forces; (4) increasing the pile diameter decreased the maximum lateral reaction of the soil. The buried-boring piles can be used in similarly unstable regions for emergency control of deforming slopes.


Author(s):  
Wojciech Gotkiewicz

The aim of this article is to analyze and evaluate the factors affecting the low level of interest of farmers in the agri-environment program. Modern agriculture in significant contributor to environmental degradation. To prevent this, the EU has created many instruments, including a mandatory agri-environment program. Based on the research conducted in 2016 in the Mława County on two groups of farmers (45 beneficiaries of the program and 45 people who did not join it), the program is an effective tool, but not without defects. The most important of them is too much emphasis on formal issues, which causes many farmers, especially the older and less educated, to be afraid of joining the program. There is also a lack of research that will answer the question of whether and how the program affects the preservation of natural resources. Eliminating these barriers would certainly increase the number of beneficiaries of the program, thus contributing to an even better protection of the environment.


2020 ◽  
Author(s):  
Silvia Kohnová ◽  
Zuzana Németová

<p>At present, the occurrence of extreme precipitation events is becoming more and more frequent and therefore it is important to quantify their impact on the landscape and soil degradation processes. Until now a wide range of soil erosion models have been developed and many significant studies performed to evaluate soil erosion processes at local and regional level, but there are still many modeling principles that suffer from a range of problems. The general problem in soil erosion modelling lies in the validation and verification of the methodologies used. The validation of erosion models is a very complicated and complex process due to lack of suitable sites, financial demands and due to the high temporal and spatial variability. The paper points to validate the physically and event-based Erosion-3D model predominantly developed to calculate the amounts of soil loss, surface runoff, and depositions resulting from natural and design rainfall events. In the study two different erosion assessment methods were chosen in order to compare diverse evaluation approaches. Both water erosion assessment methods used have certain advantages and disadvantages, but nowadays the use of physically-based models, which are a younger generation of models, are regarded to be a more innovative and effective technique for the evaluation of complex runoff-erosion processes, deposition and transport processes. The significant contribution of physically-based models is seen in their more precise representation of the erosion and deposition processes, a more proper calculation of the erosion, deposition and sediment yields and the application of more complicated characteristics, including fluctuating soil conditions and surface properties in comparison with empirical models. The validation of the models was performed based on the continuous rainfall events for the period selected (2015, 2016 and 2017). The extreme rainfall events occurring during the period were chosen and their serious impact on the agricultural land was modeled. The modelled sediment data were compared with the measured sediment deposition data obtained by a bathymetry survey of the Svacenicky Creek polder. The polder is situated in the middle of the Myjava hill lands in the western part of Slovakia and the bathymetry measurement were conducted using a hydrographical survey using the EcoMapper Autonomous Underwater Vehicle (AUV) device. The results of the study include a comparison between the modelled and measured data and an assessment of the impact of the intensive rainfall events on the investigated territory.</p><p>Key words: intensive rainfall events, agricultural land, soil degradation processes, hydrological extremes, physically-based model</p>


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