Investigation of NDVI in relation to the growth phases of beech leaves in forest

The main objective of the science of phenology is to identify the time of the occurrence of conspicuous periodic phenomena in plants under the impact of climatic factors. The study of phonologic phenomena through visual observations and terrestrial studies and temperature registration using a thermo hydrometer in different altitudinal levels and using the satellite data of IRS1C/1D LISSIII in twelve 1-ha plots in pure beech stands in the altitudinal range of 500 to 1,200 m above the sea level from April to December was carried out in such a way that for each month, one image of sensor was allocated. The produced vegetation indices were matched with terrestrial observations of the phenology periods in each month in the beech plots. The results show that the increase of the altitude above the sea level functions like latitude and its most remarkable impact is the decreasing of the temperature and the shortening of growing season. The terrestrial observations carried out in the plots show that a sudden increase in the temperature leads to the faster growth and emergence of the leaves. The produced correlation coefficient between the temperature and the emergence of the leaves was (p?=?0.01) r?=?0.87. Moreover, the end of fall in the studied region has a direct and significant relation with temperature. The amount of correlation coefficient between the temperature and end of fall in the studied region is equal to (p?=?0.01) r?=?0.91. Normalized difference vegetation index (NDVI) is more related to the growth and nurturing of the leaves. The amount of NDVI during the growth of the leaves, completion of the leaves, and fall of the leaves is equal to 0.35, 0.6, and 0.25, respectively.     

An analysis of vegetation indices in relation to tree species diversity using by satellite data in the northern forests of Iran

Vegetation indices have been introduced for analyzing and assessing the status of quantitative and qualitative characteristics of vegetation using satellite images. However, choosing the best indices to be used in forest biodiversity and vegetation is one of the important problems faced by the users. The purpose of this research is to evaluate six vegetation indices in the analysis of tree species diversity in the northern forests of Iran. The present research uses LISS III sensor data from IRS-P6 satellite. Geometric rectification of images was performed using ground control points, and Chavez model was used for atmospheric correction of the data. The six spectral vegetation indices included NDVI, IPVI, Ashburn Vegetation Index (AVI), TVI, TTVI, and RVI. Shannon–Wiener species diversity index was used to analyze diversity, and the value of the index was calculated in each sample plot. Then, the spectral values of each sample plot were extracted from different bands. The best subset regression was used to analyze the relationship between species diversity and the related bands. The results obtained from the regression showed that polynomial equations under scrutiny as independent variables can assess tree and shrub species diversity better than other bands and compounds used (R ²?=?0.47). The obtained results also indicated a higher capacity in the case of the AVI index for estimating tree species diversity in the under study area.     

Dissolution of calcitic marble and dolomitic rock in high iron concentrated acid mine drainage: application to anoxic limestone drains

Oxidation of sulphide mining waste can generate acid mine drainage (AMD) that has the potential to seriously affect the ecosystems. Acid mine drainage is characterised by a high acidity, high concentrations of sulphates and metals. To reduce the environmental impacts due to AMD, neutralisation using limestone drains is an option proposed in the literature and used around the world. The present study focuses on the influence of the carbonate rock mineralogy and their particle size on the neutralising capacity. The tests were performed in two different anoxic conditions: in batch reactors, and in columns having a hydraulic retention time of 15?h. The results showed that the neutralisation capacity of calcite was more important than for dolomitic rock, and smaller particle size gave higher alkalinity production (fine calcite dissolved faster in contact with AMD). A characterization of metal precipitate in sludge and in limestone coating was performed and demonstrated that gypsum, lepidocrocite and goethite were the predominant secondary minerals to be formed. Finally, this study underlines that anoxic limestone drain cannot be used alone to treat high iron concentrated AMD.     

The application of geochemical pattern recognition to regional prospecting: A case study of the Sanandaj–Sirjan metallogenic zone,Iran

In regional exploration programs, the distribution of elements in known mineral deposits can be used as a guide for the classification of deposits, search for new prospects and modeling ore deposit patterns. The Sanandaj–Sirjan Zone (SSZ) is a major metallogenic zone in Iran, containing lead and zinc, iron, gold, copper deposits. In the central part of the SSZ, lead and zinc mineralization is widespread and hitherto exploration has been based on geological criteria. In this study, we used clustering techniques applied to element distribution for classification lead and zinc deposits in the central part of the SSZ. The hierarchical clustering technique was used to characterize the elemental pattern. Elements associated with lead and zinc deposits were separated into four clusters, encompassing both ore elements and their host rock-forming elements. It is shown that lead and zinc deposits in the central SSZ belong to two genetic groups: a MVT type hosted by limestone and dolomites and a SEDEX type hosted by shale, volcanic rocks and sandstone. The results of elemental clustering were used for pattern recognition by the K-means method and the respective deposits were classified into four distinct categories. K-means clustering also reveals that the elemental associations and spatial distribution of the lead and zinc deposits exhibit zoning in the central part of the SSZ. The ratios of ore-forming elements (Sb, Cd, and Zn) vs. (Pb and Ag) show zoning along an E–W trend, while host rock-forming elements (Mn, Ca, and Mg) vs. (Ba and Sr) show a zoning along a SE–NW trend. Large and medium deposits occur mainly in the center of the studied area, which justify further exploration around occurrences and abandoned mines in this area. The application of a pattern recognition method based on geochemical data from known mineralization in the central SSZ, and the classification derived from it, uncover elemental zoning, identify key elemental associations for further geochemical exploration and the potential to discover possible target areas for large to medium size ore deposits. This methodology can be applied in a similar way to search for new ore deposits in a wide range of known metallogenic zones.     

Analytical Reduced Models for the Non-stationary Diabatic Atmospheric Boundary Layer

Geophysical boundary-layer flows feature complex dynamics that often evolve with time; however, most current knowledge centres on the steady-state problem. In these atmospheric and oceanic boundary layers, the pressure gradient, buoyancy, Coriolis, and frictional forces interact to determine the statistical moments of the flow. The resulting equations for the non-stationary mean variables, even when succinctly closed, remain challenging to handle mathematically. Here, we derive a simpler physical model that reduces these governing unsteady Reynolds-averaged Navier–Stokes partial differential equations into a single first-order ordinary differential equation with non-constant coefficients. The reduced model is straightforward to solve under arbitrary forcing, even when the statistical moments are non-stationary and the viscosity varies in time and space. The model is successfully validated against large-eddy simulation for, (1) time-variable pressure gradients, and (2) linearly time-variable buoyancy. The new model is shown to have a superior performance compared to the classic Blackadar solutions (and later improvements on these solutions), and it covers a much wider range of conditions.     

Land use/land cover change impact on groundwater quantity and quality: a case study of Ajman Emirate,the United Arab Emirates,using remote sensing and GIS

Ajman is a rapidly urbanizing emirate with land development succeeding at a fast pace. This study aims to monitor land use/land cover changes and assesses the impact of these changes on groundwater quality and quantity of the shallow aquifer using multitemporal remote sensing data and geographic information system (GIS). To monitor the land use/land cover changes, the Spectral Angle Mapper (SAM) and the Normalized Difference Vegetation Index (NDVI) algorithms were utilized. The obtained maps were correlated against a set of total dissolved solid (TDS); Mg, Cl, and NO₃ groundwater quality index; and depth to the groundwater table maps constructed from groundwater data. The spatial analysis revealed a sharp depletion in groundwater quality and quantity related to the increase in the land use/land cover classes. The mean total TDS is from 21,971 to 26,450 mg/L and depth to groundwater level from ?12.33 to ?17.2 m over a period of 15 years. Maps of normalized difference and groundwater quality sustainability showed that the eastern side of the study area has a high value of groundwater quality sustainability and normalized difference, while the western side of the study area has a minimal value of groundwater quality sustainability and normalized difference. This study is of great assistance for decision makers and land developers to relate to municipal land allotment in rapidly developing regions such as Ajman.     

Evaluating the structural model from ambient vibration recordings and shallow seismic refraction techniques. A case study of Zagazig City,Egypt

This study uses the seismic refraction and noise measurements to investigate the velocity structure of the subsurface and emphasize the advantage of ambient vibration over the conventional seismic refraction technique. Field measurements were carried out at nine sites in and around Zagazig city. Shallow seismic refraction data were interpreted using the delay time method to obtain the two-dimension ground model at each site. Ambient vibration arrays are used to infer the one-dimensional compressional and shear wave velocity profiles through two main steps. The first step is to derive the dispersion curve from the recorded signals using the frequency-wavenumber method. The second is to invert the dispersion curve to obtain the site velocity profiles. The results of the compressional wave velocities obtained from seismic refraction technique showed that the subsurface consists of a number of layers ranging from two to four layers and give a good agreement with the results of the seismic wave velocities obtained from the ambient vibration arrays. The ambient vibration arrays gave a deeper depth of penetration than the other method, providing more information on the subsurface structure without any disturbance to the environment. This work provides reliable estimates of the seismic velocity structures of both shallow and deep sedimentary layers within the area of interest.