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Continuous canopy status monitoring is an essential factor to support and precisely apply orchard management actions such as pruning, pesticide and foliar treatment applications, or fertirrigation, among others. For that, this work proposes the use of multispectral vegetation indices to estimate geometric and structural orchard parameters from remote sensing images (high temporal and spatial resolution) as an alternative to more time-consuming processing techniques, such as LiDAR surveys or UAV photogrammetry. A super-intensive almond (Prunus dulcis) orchard was scanned using a mobile terrestrial laser (LiDAR) in two different vegetative stages (after spring pruning and before harvesting). From the LiDAR point cloud, canopy orchard parameters, including maximum height and width, cross-sectional area and porosity, were summarized every 0.5 m along the rows and interpolated using block kriging to the pixel centroids of PlanetScope (3 × 3 m) and Sentinel-2 (10 × 10 m) image grids. To study the association between the LiDAR-derived parameters and 4 different vegetation indices. A canonical correlation analysis was carried out, showing the normalized difference vegetation index (NDVI) and the green normalized difference vegetation index (GNDVI) to have the best correlations. A cluster analysis was also performed. Results can be considered optimistic both for PlanetScope and Sentinel-2 images to delimit within-field management zones, being supported by significant differences in LiDAR-derived canopy parameters. [ABSTRACT FROM AUTHOR]

Knowledge of lithologic discontinuities (LDs) provides important information about sedimentology processes and soil development. The main objective of this research was to evaluate different criteria from the Soil Taxonomy (ST) system to detect LDs in soils of arid and semi-arid regions. For that, five sites in Iran were selected, and several parameters were measured to identify LDs in studied pedons, these were: profile morphology, depth functions of clay-free particle size distribution, clay-free sand to silt ratio, uniformity value index, particle size parameters (mean, sorting, skewness and kurtosis) and particle size mode, morphology of quartz grains and chronological data. Results confirmed that, in some occasions, field evidences (differences in texture, color and parent material that are not the result of pedogenic processes) failed to reveal LDs, laboratory data could show this diagnostic soil characteristic. Also, the results showed that quartz grains morphology revealed a lithologic discontinuity (LD) between the Btk and Cry1 horizons within the pedon at site 1. Skewness and kurtosis parameters and particle size mode of differnt horizons were useful parameters to distinguish and confirm the presence of LD in the soil. Moreover, results showed that the clay-free depth functions of particle size distribution were useful to ascertain the presence of LDs so long, as far as sufficient amounts of the silt and sand fractions were available. Since field evidences were not always clear, the revision of some qualitative rules of the ST system and defining quantitative criteria for an abrupt change in particle size distribution seems necessary to improve its ability for LDs detection. [ABSTRACT FROM AUTHOR]

Copyright of Cuaternario y Geomorfología is the property of Cuaternario y Geomorfologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Susceptibility to landslides in mountain areas results from the interaction of various factors related to relief formation and soil development. The assessment of landslide susceptibility has generally taken into account individual events, or it has been aimed at establishing relationships between landslide-inventory maps and maps of environmental factors, without considering that such relationships can change in space and time. In this work, temporal and space changes in landslides were analysed in six different combinations of date and geomorphological conditions, including two different geological units, in a mountainous area in the northcentre of Venezuela, in northern South America. Landslide inventories from different years were compared with a number of environmental factors by means of logistic regression analysis. The resulting equations predicted landslide susceptibility from a range of geomorphometric parameters and a vegetation index, with diverse accuracy, in the study area. The variation of the obtained models and their prediction accuracy between geological units and dates suggests that the complexity of the landslide processes and their explanatory factors changed over space and time in the studied area. This calls into question the use of a single model to evaluate landslide susceptibility over large regions. [ABSTRACT FROM AUTHOR]

Land evaluation is a critical step in land-use planning. Although many methods have been developed since the formulation of the FAO framework for land evaluation, several of the more traditional approaches still remain in widespread use but have not been adequately evaluated. Contrary to more recent land evaluation systems, which need considerable data, these systems only require basic soil and landscape information to provide a general view of land suitability for major types of land use. As the FAO initially presented its qualitative framework for land-use planning, based on two previous methods developed in Iran and Brazil, in this study we assessed the reliability and accuracy of a traditional land evaluation method used in Iran, called land classification for irrigation ( LCI), comparing its results with several qualitative and quantitative methods and actual yield values. The results showed that, although simpler than more recently developed methods, LCI provided reliable land suitability classes and also showed good relationships both with other methods analysed and with actual yields. Comparisons between qualitative and quantitative methods produced similar results for common crops (a barley-alfalfa-wheat-fallow rotation). However, these methods performed differently for opportunist crops (such as alfalfa) that are more dependent on income and market conditions than on land characteristics. In this work, we also suggest that using the FAO method to indicate LCI subclasses could help users or managers to recognize limitations for land-use planning. [ABSTRACT FROM AUTHOR]

The present research shows the results of possible effects of climate change on runoff and soil loss in a rainfed basin located in the Alt Penedès and Anoia region (NE Spain). Viticulture is an important economic activity in this region, and vines for the production of high-quality wines and 'cavas' are the main land use. Climate data for the period 2000-2012 and detailed soil and land use maps were used as input data for soil and water assessment tool to model the effects of climate change. The analysis compared simulated results for years with different climatic conditions during that period with predicted temperature and precipitation data for 2020, 2050 and 2080 based on data obtained from the Hadley Centre Coupled Model, version 3, A2 scenario and the trends observed in the area. The research confirmed the difficulty of predicting future soil loss in this region, which has very high inter-annual climate variability. Despite only small changes in precipitation, the model simulated a decrease in soil loss associated with a decrease in runoff, mainly driven by an increase in evapotranspiration. However, the trend in soil losses may vary when changes in precipitation balance the increase in evapotranspiration and when rainfall intensity increases. An increase in maximum rainfall intensity in spring and autumn (main rainy seasons) produced significant increases in soil loss: as high as 12 % for the 2020 scenario and 57 % for the 2050 scenario. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the possibilities of using sub-basin data for calibration of the Soil and Water Assessment Tool (SWAT) model in a small (46 ha) ungauged basin (i.e. where the water flow is not systematically measured) and its response. This small basin was located in the viticultural Anoia-Penedès region (North-east Spain), which suffers severe soil erosion. The data sources were: daily weather data from an observatory located close to the basin; a detailed soil map of Catalonia; a 5-m resolution digital elevation model (DEM); a crop/land use map derived from orthophotos taken in 2010 and an additional detailed soil survey (40 points) within the basin, which included properties such as texture, soil organic carbon, electrical conductivity, bulk density and water retention capacity at −33 and −1500 kPa. A sensitivity analysis was performed to identify and rank the sensitive parameters that affect the hydrological response and sediment yield to changes of model input parameters. A 1-year calibration and 1-year validation were carried out on the basis of soil moisture measured at 0·20-m intervals from depths of 0·10 to 0·90 m in two selected sub-basins, and data related to estimations of runoff and sediment concentrations in runoff collected in the same sub-basins. The present paper shows a methodological approach for calibrating SWAT in small ungauged basins using soil water content measurements and runoff samples collected within the basin. The SWAT satisfactorily predicted the average soil water content, runoff and soil loss for moderate intensity events recorded during the study periods. However, it was not satisfactory for high-intensity events which would require exploring the possibilities of using sub-daily information as an input model parameter. [ABSTRACT FROM PUBLISHER]

This paper presents the analysis of mean daily temperature and precipitation from 1950 to 2010 in an area with Mediterranean climate of NE Spain including some coastal areas near Barcelona and the Penedès and Camp de Tarragona Depressions located between the Coastal Mountain Range and the Mediterranean Sea. Their variability, with especial attention to the frequency of extreme events, was analysed by using 18 indexes: seven for temperature and 11 for precipitation were analysed for four meteorological observatories. A multivariate analysis was performed in order to analyse the temperature and precipitation trends. During the analysed period, an increase in mean annual maximum temperature was observed in all observatories ranging between 1.5 and 2.2°C associated with an increase in the number of days with high extreme temperatures. Minimum temperature only increased significantly in the coast observatories (about 1.4°C). By seasons, temperature trends were greater at Vilafranca del Penedès and Barcelona observatories and lower at Reus airport. Maximum spring temperature increased between 1.5 and 2.5°C, summer temperature increased between 1.6 and 2.5°C and autumn temperature increased by up to 2.2°C. Precipitation presented a high variability from year to year, without significant trends. The most significant results were related to the dry conditions observed in spring 2000s, the wet conditions recorded in summer 2000s and 1980s and the longer dry periods in autumn 2000s. The increase of temperatures determined the increase of evapotranspiration, and due to the higher irregular distribution, water deficits for crop development were recorded. An advance of phenological dates and a reduction of grape yield are associated to climate trends. [ABSTRACT FROM AUTHOR]

Knowledge of spatial variability of soil fertility and plant nutrition is critical for planning and implementing site-specific vineyard management. To better understand the key drivers behind vineyard variability, yield mapping from 2002 to 2005 and 2007 (the monitor broke down in 2006) was used to identify zones of different productive potential in a Pinot Noir field located in Raimat (Lleida, Spain). Simultaneously, the vineyard field was sampled in 2002, 2003 and 2007, applying three different schemes (depending on the number of target vines in different grape yield zones). The sampling carried out in 2002, which involved different soil, topographic and crop properties (mineral contents in petiole), made it possible to evaluate the influence of these parameters on the grape yield variability. The zones of lowest yield coincided with locations in which the nutritional status of the crop exhibited the lowest values, particularly with respect to petiole contents of calcium and manganese. Sampling systems adopted in 2003 and 2007 (grape quality and soil attributes) confirmed the inverse spatial correlation between grape yield and some grape quality parameters and, more importantly, showed that the percentage of soil carbonates had a great influence on grape quality probably due to the reduced availability of manganese in calcareous soils. Site-specific vineyard management could therefore be considered using two different strategies: variable-rate application of foliar fertilizers to increase the yield in areas with low production and also foliar or soil fertilizers to improve the quality specifications in some areas. [ABSTRACT FROM AUTHOR]

Copyright of Cuadernos de Investigación Geográfica is the property of Universidad de la Rioja, Servicio de Publicaciones and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses a study which examined the spatial variability of runoff and erosion rates in vineyards of Northeastern Spain. The study examined plots with high disturbance (HD) and low disturbance (LD) of the soil profile and evaluated whether soil surface properties were conditioning runoff and erosion rates. It discusses soil and rainfall characteristics as well as runoff differences in the HD and LD plots and differences in sediment concentration.

Since the 1970s and 1980s, the vineyard areas in the Mediterranean region of north east Spain have undergone profound transformation to allow greater mechanization. This has involved land levelling, deep ploughing and the elimination of traditional soil conservation measures. Recently the EU Common Agricultural Policy encourages this through the vineyard restructuring and conversion plans (Commission Regulation EC No 1227/2000 of 31 May 2000) by subsidizing up to 50% of the cost of soil preparation such as soil movement and land levelling. A clear example of the problems that this causes is in the Penedès vineyard region (Catalonia, north east Spain), and the present research analyses the changes in soil properties caused by erosion, deep ploughing and land levelling. The study was carried out in an area of 30 000 ha for which a Soil Information System at a scale of 1:50 000 was developed based on 394 field observations (89 soil profiles and 251 auger hole samples down to 120 cm). The results show that 74% of the described soil profiles are disturbed with evidence of soil mixing and/or profile truncation due to erosion, deep ploughing and/or land levelling. The evidence from the topsoils is mainly the presence of fragments of calcic or petrocalcic horizons, marls and sandstones. Other important properties for crops such as organic matter (OM) content and soil depth show statistically significant differences between disturbed soils and undisturbed soils (22.3–33.3% OM content depletion and 35.1% soil depth reduction). These results confirm that the soils of the region are significantly altered by mechanical operations which also influence soil erosion and contribute to global warming effect through depletion of soil OM. [ABSTRACT FROM AUTHOR]

The article presents a study on the agricultural trajectories and farming systems in the Priorat region in Spain. In the Priorat region, as well as in the other mountain regions of Mediterranean European countries, the intensification of crops is said to be based on either land leveling or terracing, and the abandonment of usual land use management practices. One of the objectives of the study is to relate the coexisting farming systems in Priorat to the landscape impacts they involve. The researchers combined multivariate statistical techniques to understand the heterogeneity of farming systems on a local scale.

Automated mapping of land cover using black and white aerial photographs, as an alternative method to traditional photo-interpretation, requires using methods other than spectral analysis classification. To this end, textural measurements have been shown to be useful indicators of land cover. In this work, a neural network model is proposed and tested to map historical land use/land cover (LUC) from very detailed panchromatic aerial photographs (5 m resolution) using textural measurements. The method is used to identify different land use and management types (e.g. traditional versus mechanized vineyard systems). These have been tested with known ground reference data. The results show the potential of the methodology to obtain automatic, historic, and very detailed cartography information from a complex landscape such as the mountainous and Mediterranean region to which it is applied here, and the advantages that this method has over traditional methods. [ABSTRACT FROM AUTHOR]

The high variability of the Mediterranean climate from year to year and within each year makes it difficult to assess changes that could be associated with a climate change. In this paper some indices, such as changes in the precipitation concentration during the year, maximum 1-day and 5-day precipitation, number of wet days (total and those with precipitation higher than the 75th and 95th percentile), magnitude and frequency of extreme events (considered as the rainfall higher than that corresponding to the 99th percentile), fraction of annual total precipitation due to events exceeding the 95th and 99th percentile, strength of the events, and length and frequency of dry period (days between consecutive rains) are evaluated for the Penedès-Anoia region (NE Spain). A 80-year daily dataset (1923-2002) and two 40-year series were used to assess possible trends. The indices indicate an increase in precipitation in winter and summer and a positive trend of concentration in autumn, with a higher number of extreme events separated by longer dry periods. The total number of wet days per year increased, although it was irregularly distributed over the year, with an increase in the extremes and in the fraction of total rainfall that these events represent in autumn and winter, and with an increase of the strength of the events in autumn. These changes in rainfall distribution have negative effects on water availability for crops and contribute to accelerate erosion processes in the area. [ABSTRACT FROM AUTHOR]

Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR-33kPa) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach’s PTF presented the best performance in relation to the others and could be used to estimate WR-33kPa in soils of Caramacate River basin. The calculated PTFs had a R2 of 0.65. This was slightly higher than the R2 of the Urach’s PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR-33kPa. [ABSTRACT FROM AUTHOR]