1,528 research outputs found
A Model for Evaluating Soil Vulnerability to Erosion Using Remote Sensing Data and A Fuzzy Logic System
Soil vulnerability is the capacity of one or more of the ecological functions of the soil system to be harmed. It is a complex concept which requires the identification of multiple environmental factors and land management at different temporal and space scales. The employment of geospatial information with good update capabilities could be a satisfactory tool to assess potential soil vulnerability changes in large areas. This chapter presents the application of two land degradation case studies which is simple, synoptic, and suitable for continuous monitoring model based on the fuzzy logic. The model combines topography and vegetation status information to assess soil vulnerability to land degradation. Topographic parameters were obtained from digital elevation models (DEM), and vegetation status information was derived from the computation of the normalized difference vegetation index (NDVI) satellite images. This spectral index provides relevance and is updated for each scene, evidences about the biomass and soil productivity, and vegetation density cover or vegetation stress (e.g., forest fires, droughts). Modeled output maps are suitable for temporal change analysis, which allows the identification of the effect of land management practices, soil and vegetation regeneration, or climate effects
Water Management in Irrigation Systems by Using Satellite Information
Changes in agriculture are associated to the availability of resources and the economic and social demands. One of the more important transformations is to change rainfed into irrigated crops to increase the yield. In most of the cases, water resource and irrigation reservoirs are needed to maintain the yield. However, evaporation from ponds can be an important economic loss and an unsustainable strategy for water management, especially in arid and semiarid regions. Efficient methods for water storage should be established. In this study, a selected area located close to the city of Cartagena (Murcia) and the south of Alicante (Spain) has been studied, where there was an important transformation from rainfed to irrigated crops. Because of the high temperatures and insolation, the increment of the number of reservoirs detected by using remote sensing data and GIS tools may be inefficient for water management. The characterization of these reservoirs, to quantify the potential loss of water due to evaporation, has been done. The use of these tools for analysis could be interesting to find more efficient storage solutions (i.e., better spatial distribution of reservoirs, an increment of depth, and reduction of surface exposure) for improving the water storage and management
Using Landsat Images to Determine Water Storing Capacity in Mediterranean Environments
Reservoirs play an important role in water management and are key elements for water supply. Monitoring is needed in order to guarantee the quantity and quality of stored water. However, this task is sometimes not easy. The objective of this study was to develop a procedure for predicting volume of stored water with remote sensing in water bodies under Mediterranean climate conditions. To achieve this objective,multispectral Landsat 7 and 8 images (NASA) were analyzed for the following five reservoirs: La Serena,La Pedrera, Beniarrés, Cubillas and Negratín (Spain). Reservoirs water surface was computed with the spectral angle mapper (SAM) algorithm.After that, cross-validation regression models were computed in order to assess the capability of water surface estimations to predict stored water in each of the reservoirs. The statistical models were trained with Landsat 7 images and were validated by using Landsat 8 images. Our results suggest a good capability of water volume prediction from free satellite imagery derived from surface water estimations. Combining free remote sensing images and open source GIS algorithms can be a very useful tool for water management and an integrated and efficient way to control water storage,especially in low accessible sites
All-Arthroscopic Triangular Fibrocartilage Complex Ligamentoplasty: Technique and Results
Objective The aim of the study is to describe the modified all-arthroscopic technique
for triangular fibrocartilage complex (TFCC) ligamentoplasty in chronic injuries of the
TFCC with distal radioulnar joint (DRUJ) instability, and to present the results obtained.
Methods A prospective study was conducted including 11 consecutive patients with
chronic TFCC injury with DRUJ instability who underwent an all-arthroscopic TFCC
ligamentoplasty. During follow-up, the range of joint motion, grip strength, pain
according to the visual analog scale (VAS), functional outcomes according to the Mayo
Wrist Score (MWS), and the QuickDASH Score were measured, and any complications
and necessary reinterventions were recorded
Results We analyzed 11 patients with distal radioulnar ligament injury treated using
the all-arthroscopic ligamentoplasty technique. Mean follow-up was 31.5 4.4 (range
12–58) months. The technique presented achieved DRUJ stability in 100% of cases at
12 months. Grip strength and pain, showed a statistically significant improvement
between the preoperative score and the two postoperative assessments. Functional
assessment using the QuickDASH score and the MWS also improved significantly.
Conclusion The all-arthroscopic technique for the reconstruction of irreparable
peripheral TFCC tears is a reliable technique, intended not only to minimize the
surgical trauma to reduce postoperative pain and to facilitate rehabilitation, but also to
improve both the quality of the reconstruction and the functional outcome.Medicin
Physical Properties of Soils Affected by the Use of Agricultural Waste
This chapter provided an overview of the physical properties of soils and their importance on the mobility of water and nutrients and the development of a vegetation cover. It also gives some examples of why the use of agricultural residues can affect positively soil physical properties. The incorporation of agricultural wastes can be a sustainable practice to improve soil characteristics, favoring a model of zero waste in agricultural production and allowing better management of soils. We review and analyze the effect of the use as amendments of different agricultural residues, on physical properties of the soil (e.g., bulk density, porosity, and saturated hydraulic conductivity), especially related to the movement of water in the soil
Land recycling, food security and Technosols
The world population will grow up to 9.8 billion by 2050. The intensification in urban growth will occur on all continents and in all sizes of cities, especially in developing countries, experiencing a greater rising in urban agglomerations of 300,000 to 500,000 people, those of 500,000 to 1 million and those of 1 to 5 million, by 2035. In this way, the demand of soil to host human activities (land take) will increase, mainly affecting soils with greater agricultural potential close to cities, at the same time as the need for food will increase. Land rehabilitation can contribute to human food security, to enhance ecosystem services and, if made by waste Technosols, those are viable as substrate for urban agroforestry systems.Although the references for brownfield reclamation for urban agriculture,adding constructed Technosols and de-sealed soils can recover its ecosystem functions even food supply services and would be the solution in urban areas
Arthroscopic Scapholunate Capsuloligamentous Repair: Suture With Dorsal Capsular Reinforcement for Scapholunate Ligament Lesion
Scapholunate ligament (SLL) injury is the most frequent injury of the intrinsic carpal ligaments. The dorsal part
of the SLL is the most important part for the stability of the scapholunate joint, and tears of this part and at least one of its
secondary capsular attachments cause scapholunate dissociation. The arthroscopic technique most frequently used for
acute injuries is reduction and fixation with Kirschner wires, and techniques that involve a primary repair of the injured
ligament are performed by open surgery with efficient results. However, they lead to significant stiffness of the wrist due to
injury to the soft tissue caused by damage to the secondary dorsal stabilizers; the dorsal blood supply; and in many cases,
the proprioceptive innervation of the posterior interosseous nerve. We present an all-arthroscopic technique for the direct
repair of acute injuries of the dorsal part of the SLL using bone anchors, complemented by a dorsal arthroscopic plication
that reconstructs the dorsal capsulo-scapholunate septum of the scapholunate complex.Medicin
A Review of Landsat TM/ETM based Vegetation Indices as Applied to Wetland Ecosystems
A review of vegetation indices as applied to Landsat-TM and ETM+ multispectral data is presented. The review focuses on indices that have been developed to produce biophysical information about vegetation biomass/greenness, moisture and pigments.In addition, a set of biomass/greenness and moisture content indices are tested in a Mediterranean semiarid wetland environment to determine their appropriateness and potential for carrying redundant information.The results indicate that most vegetation indices used for biomass/greenness mapping produce similar information and are statistically well correlated.
On a Dynamical Approach to Some Prime Number Sequences
In this paper we show how the cross-disciplinary transfer of techniques from
Dynamical Systems Theory to Number Theory can be a fruitful avenue for
research. We illustrate this idea by exploring from a nonlinear and symbolic
dynamics viewpoint certain patterns emerging in some residue sequences
generated from the prime number sequence. We show that the sequence formed by
the residues of the primes modulo are maximally chaotic and, while lacking
forbidden patterns, display a non-trivial spectrum of Renyi entropies which
suggest that every block of size , while admissible, occurs with different
probability. This non-uniform distribution of blocks for contrasts
Dirichlet's theorem that guarantees equiprobability for . We then explore
in a similar fashion the sequence of prime gap residues. This sequence is again
chaotic (positivity of Kolmogorov-Sinai entropy), however chaos is weaker as we
find forbidden patterns for every block of size . We relate the onset of
these forbidden patterns with the divisibility properties of integers, and
estimate the densities of gap block residues via Hardy-Littlewood -tuple
conjecture. We use this estimation to argue that the amount of admissible
blocks is non-uniformly distributed, what supports the fact that the spectrum
of Renyi entropies is again non-trivial in this case. We complete our analysis
by applying the Chaos Game to these symbolic sequences, and comparing the IFS
attractors found for the experimental sequences with appropriate null models.Comment: 18 pages, 20 figure
The Use of Composted Municipal Solid Waste under the Concept of Circular Economy and as a Source of Plant Nutrients and Pollutants
The European Union (EU) is one of the major producers of municipal solid wastes and has a common policy based on circular economy to reuse the wastes. However, there are differences between countries and the methods for disposal and treatments. Municipal solid waste (MSW) can be composted and recycled as a source of plant nutrients and improves soil properties. This chapter analyzed the production in the EU and the effects on plant nutrients and environmental pollutants when MSW is added to the soil. The origin of the waste and the compost-like output (CLO) derived is important to determine the expectative of nutrient availability and other possible risks. MSW is so heterogeneous, but after a good pretreatment, an organic-rich matter mix can be composted giving a stabilized organic matter. The addition of the CLO to the soils can improve the nutrient status and favor the bioavailability of nutrients (macronutrients and micronutrients). In general, an increment of N and P was found in the soils. Moreover, important micronutrient availability (Fe, Mn, Cu, and Zn) has been described. However, the presence of pollutants and their mobility should be considered as an environmental risk
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