Person: Giménez Díaz, Rafael
Loading...
Email Address
person.page.identifierURI
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Giménez Díaz
First Name
Rafael
person.page.departamento
Ingeniería
person.page.instituteName
IS-FOOD. Research Institute on Innovation & Sustainable Development in Food Chain
ORCID
0000-0003-3210-0578
person.page.upna
6698
Name
17 results
Search Results
Now showing 1 - 10 of 17
Publication Open Access Factors controlling sediment export in a small agricultural watershed in Navarre (Spain)(Elsevier, 2012) Giménez Díaz, Rafael; Casalí Sarasíbar, Javier; Grande Esteban, Ildefonso; Díez Beregaña, Javier; Campo-Bescós, Miguel; Álvarez Mozos, Jesús; Goñi Garatea, Mikel; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta Proiektuak; Gestión de Empresas; Enpresen Kudeaketa; Gobierno de Navarra / Nafarroako GobernuaIt is recognised that the hydrological and erosion processes in watersheds are very much conditioned by the (inter)action of a number of variables. This paper covers a 15-year period of studying those factors that have a major influence on the sediment yield and transport during individual hydrological events in a small Mediterranean agricultural watershed. Multivariate statistical techniques such as cluster analysis and principal component analysis were applied for the interpretation of datasets. In addition, the relationships between suspended sediment concentration and discharge (hysteretic loops) were also analysed. The hydrological response of the studied watershed is mainly controlled by the antecedent condition of the flow. Most of the runoff and sediment are generated during the wet season when vegetation cover is scant and saturation overland flow occurs promptly as a response to almost any rainfall events. In contrast, during the dry seasons even if high-intensity rainfalls normally occur, very scant runoffs are, however recorded, at the exit of the watershed. Most of the eroded sediment seems to come from riparian areas. The discharge registered at the watershed outlet up to 1 h prior to the flood is a very good surrogate for antecedent soil moisture.Publication Open Access Runoff, nutrients, sediment and salt yields in an irrigated watershed in southern Navarre (Spain)(Elsevier, 2018) Merchán Elena, Daniel; Casalí Sarasíbar, Javier; Valle de Lersundi, Jokin del; Campo-Bescós, Miguel; Giménez Díaz, Rafael; Preciado, Beatriz; Lafarga, Alberto; Landa Ingeniaritza eta Proiektuak; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Proyectos e Ingeniería RuralThe environmental impact of irrigated agriculture on water quality was assessed in Landazuria watershed (Navarre, northeast Spain), a 479.5 ha watershed with 53% of irrigated agricultural land. In the framework of a long-term monitoring program, precipitation and discharge were measured at 10-min intervals and compound daily water samples were collected during the agricultural years (September to August) 2007–2016, and analysed for nitrate (NO3−), phosphate (PO43−), sediment and total dissolved solids (TDS) concentrations. Typical agricultural management (including crop surfaces, irrigation and fertilization rates) was obtained from inquiries to farmers. Concentration and yield of the studied variables presented a high degree of variation, both intra- and inter-annual. Median concentration for the entire study period were 185, <0.05, 31 and 2284 mg L−1 for NO3−, PO43−, sediment and TDS, respectively. NO3−-N and PO43−-P yields averaged 74 and 0.04 kg ha−1 year−1, respectively. NO3 −-N yield was higher than in other agricultural land uses in Navarre and in the order of magnitude of other irrigated areas in the Middle Ebro Valley. PO43−-P yield was in the same order of magnitude than in rainfed watersheds in Navarre but lower than in intensively grazed watersheds. Sediment yield was extremely variable, averaging 360 kg ha−1 year−1, with 44% of the total measured load recorded in a few days. It was in the lower range of those measured in Navarre for rainfed agriculture and similar to those estimated in other irrigated areas of the Middle Ebro River. TDS concentration presented a significant decreasing trend since available salts were being washed out, while TDS yield averaged 1.8 Mg ha−1 year−1. Long-term monitoring of irrigated areas is required to understand pollution processes in these agroecosystems and to adequately characterize the environmental impact of current agricultural practices on water quality, in order to implement, and adequately assess, measures to reduce agricultural pollution.Publication Open Access Hydrological effects of the sediments deposited off a hillslope affected by rill erosion: project outlines and preliminary results(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Giménez Díaz, Rafael; Casalí Sarasíbar, Javier; Campo-Bescós, Miguel; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta ProiektuakThe main objectives of this project are (i) to evaluate the sedimentation rate generated by rill erosion in a hillslope and the granulometric characteristics of the sediment deposited off this hillslope, and (ii) to determine the incidence of this sediment on the hydrological properties of the sedimentation area. In addition, an extra aim is to gain insight into the spatial and temporal evolution of a rill network under field condition.Publication Open Access Assessment of soil factors controlling ephemeral gully erosion on agricultural fields(Wiley, 2017) Ollobarren del Barrio, Paul; Campo-Bescós, Miguel; Giménez Díaz, Rafael; Casalí Sarasíbar, Javier; Landa Ingeniaritza eta Proiektuak; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Proyectos e Ingeniería Rural; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThe soil factor is crucial in controlling and properly modeling the initiation and development of ephemeral gullies (EGs). Usually, EG initiation has been related to various soil properties (i.e. sealing, critical shear stress, moisture, texture, etc.); meanwhile, the total growth of each EG (erosion rate) has been linked with proper soil erodibility. But, despite the studies to determine the influence of soil erodibility on (ephemeral) gully erosion, a universal approach is still lacking. This is due to the complex relationship and interactions between soil properties and the erosive process. A feasible soil characterization of EG erosion prediction on a large scale should be based on simple, quick and inexpensive tests to perform. The objective of this study was to identify and assess the soil properties – easily and quickly to determine – which best reflect soil erodibility on EG erosion. Forty‐nine different physical–chemical soil properties that may participate in establishing soil erodibility were determined on agricultural soils affected by the formation of EGs in Spain and Italy. Experiments were conducted in the laboratory and in the field (in the vicinity of the erosion paths). Because of its importance in controlling EG erosion, five variables related to antecedent moisture prior to the event that generated the gullies and two properties related to landscape topography were obtained for each situation. The most relevant variables were detected using multivariate analysis. The results defined 13 key variables: water content before the initiation of EGs, organic matter content, cation exchange capacity, relative sealing index, two granulometric and organic matter indices, seal permeability, aggregates stability (three index), crust penetration resistance, shear strength and an erodibility index obtained from the Jet Test erosion apparatus. The latter is proposed as a useful technique to evaluate and predict soil loss caused by EG erosion.Publication Open Access Effect of topography on retreat rate of different gully headcuts in Bardenas Reales area (Navarre, Spain)(Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, 2007) Campo-Bescós, Miguel; Álvarez Mozos, Jesús; Casalí Sarasíbar, Javier; Giménez Díaz, Rafael; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta ProiektuakIn Northeast Spain, gullying is a widespread phenomenon. This type of erosion is especially intense in Bardenas Reales (Navarre) where at least two major typical kinds of gully headcut are present. A first group developed in soil material (named, conventional gully headcut), and second group of gully headcut with a sandstone layer as a top horizon (named, sandstone gully headcut). In addition, within the former group, we can distinguish a subgroup of gully headcuts developed in soils particularly prone to piping and tunnelling due to the dispersive condition of the materials (named piping associated gully headcut). In this situation, a question arises: to what extent simple topographic parameters account for the retreat rate of the different kind of gully headcuts observed in the region of Bardenas Reales? The aim of this study was to investigate and gain insight in this issue.Publication Open Access Assessing soil properties controlling interrill erosion: an empirical approach under Mediterranean conditions(Wiley, 2017) Ollobarren del Barrio, Paul; Giménez Díaz, Rafael; Campo-Bescós, Miguel; Landa Ingeniaritza eta Proiektuak; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Proyectos e Ingeniería Rural; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaSoil erodibility is a complex phenomenon that comprises a number of different soil properties. However, most current (empirical) erodibility indices are based on only a few soil properties. A feasible soil characterization of interrill erosion (IE) prediction at large scale should be based on simple, quick and inexpensive tests to perform. The objective of this work was to identify and assess those soil properties that best reflect soil vulnerability to IE. Twenty‐three agricultural soil samples located in Spain and Italy were studied. Forty‐nine different physical and chemical soil properties that presumably underpin IE were defined. Experiments were carried out in the field (in microplots using simulated rainfall) and in the lab. The most relevant variables were detected using multivariate analysis. Six key variables were finally identified: RUSLE K factor, a granulometric/organic matter content index, exchangeable sodium percentage, shear strength, penetration resistance and permeability of soil seal. The latter is proposed as a useful technique to evaluate soil susceptibility to crusting even when the crust is not present at the time of the field survey. The selected variables represented a wide range of soil properties, and they could also be successfully applied to different soils with different characteristics than those evaluated in our experiments.Publication Open Access Toward optimal irrigation management at the plot level: evaluation of commercial water potential sensors(MDPI, 2023) Campo-Bescós, Miguel; Virto Quecedo, Íñigo; Giménez Díaz, Rafael; Aldaz Lusarreta, Alaitz; Ciencias; Zientziak; Ingeniería; Ingeniaritza; Institute on Innovation and Sustainable Development in Food Chain - ISFOODProper irrigation practice consists of applying the optimum amount of water to the soil at the right time. The porous characteristics of the soil determine the capacity of the soil to absorb, infiltrate, and store water. In irrigation, it is not sufficient to only determine the water content of the soil; it is also necessary to determine the availability of water for plants: water potential. In this paper, a comprehensive laboratory evaluation—accuracy and variability—of the world’s leading commercial water potential sensors is carried out. No such comprehensive and exhaustive comparative evaluation of these devices has been carried out to date. Ten pairs of representative commercial sensors from four different families were selected according to their principle of operation (tensiometers, capacitive sensors, heat dissipation sensors, and resistance blocks). The accuracy of the readings (0 kPa–200 kPa) was determined in two soils of contrasting textures. The variability in the recordings—repeatability and reproducibility—was carried out in a homogeneous and inert material (sand) in the same suction range. The response in terms of accuracy and value dispersion of the different sensor families was different according to the suction range considered. In the suction range of agronomic interest (0–100 kPa), the heat dissipation sensor and the capacitive sensors were the most accurate. In both families, registrations could be extended up to 150–200 kPa. The scatter in the readings across the different sensors was due to approximately 80% of the repeatability or intrinsic variability in the sensor unit and 20% of the reproducibility. Some sensors would significantly improve their performance with ad hoc calibrations.Publication Open Access Gully geometry: what are we measuring?(European Geosciences Union, 2015) Casalí Sarasíbar, Javier; Giménez Díaz, Rafael; Campo-Bescós, Miguel; Proyectos e Ingeniería Rural; Landa Ingeniaritza eta ProiektuakMuch of the research on (ephemeral) gully erosion comprises the determination of the geometry of these eroded channels, especially their width and depth. This is not a simple task due to uncertainty generated by the wide range of variability in gully cross section shapes found in the field. However, in the literature, this uncertainty is not recognized so that no criteria for their measurement are indicated. The aim of this work is to make researchers aware of the ambiguity that arises when characterizing the geometry of an ephemeral gully and similar eroded channels. In addition, a measurement protocol is proposed with the ultimate goal of pooling criteria in future works. It is suggested that the geometry of a gully could be characterized through its mean equivalent width and mean equivalent depth, which, together with its length, define an “equivalent prismatic gully” (EPG). The latter would facilitate the comparison between different gullies.Publication Open Access Relationship of weather types on the seasonal and spatial variability of rainfall, runoff, and sediment yield in the western Mediterranean basin(MDPI, 2020) Peña Angulo, D.; Nadal-Romero, Estela; Campo-Bescós, Miguel; Casalí Sarasíbar, Javier; Giménez Díaz, Rafael; Ingeniaritza; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; IngenieríaRainfall is the key factor to understand soil erosion processes, mechanisms, and rates. Most research was conducted to determine rainfall characteristics and their relationship with soil erosion (erosivity) but there is little information about how atmospheric patterns control soil losses, and this is important to enable sustainable environmental planning and risk prevention. We investigated the temporal and spatial variability of the relationships of rainfall, runoff, and sediment yield with atmospheric patterns (weather types, WTs) in the western Mediterranean basin. For this purpose, we analyzed a large database of rainfall events collected between 1985 and 2015 in 46 experimental plots and catchments with the aim to: (i) evaluate seasonal differences in the contribution of rainfall, runoff, and sediment yield produced by the WTs; and (ii) to analyze the seasonal efficiency of the different WTs (relation frequency and magnitude) related to rainfall, runoff, and sediment yield. The results indicate two different temporal patterns: the first weather type exhibits (during the cold period: autumn and winter) westerly flows that produce the highest rainfall, runoff, and sediment yield values throughout the territory; the second weather type exhibits easterly flows that predominate during the warm period (spring and summer) and it is located on the Mediterranean coast of the Iberian Peninsula. However, the cyclonic situations present high frequency throughout the whole year with a large influence extended around the western Mediterranean basin. Contrary, the anticyclonic situations, despite of its high frequency, do not contribute significantly to the total rainfall, runoff, and sediment (showing the lowest efficiency) because of atmospheric stability that currently characterize this atmospheric pattern. Our approach helps to better understand the relationship of WTs on the seasonal and spatial variability of rainfall, runoff and sediment yield with a regional scale based on the large dataset and number of soil erosion experimental stations.Publication Open Access Dissolved solids and suspended sediment dynamics from five small agricultural watersheds in Navarre, Spain: a 10-year study(Elsevier, 2019) Merchán Elena, Daniel; Luquin Oroz, Eduardo Adrián; Hernández García, Iker; Campo-Bescós, Miguel; Giménez Díaz, Rafael; Casalí Sarasíbar, Javier; Valle de Lersundi, Jokin del; Ingeniaritza; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaDissolved solids (DS) and suspended sediment (SS) loads are considered relevant environmental problems. They are related to a wide range of on-site and off-site impacts, such as soil erosion or salinization of water bodies. In this study, the dynamics of DS and SS concentrations and loads were assessed in five small watersheds covering representative agricultural land uses in Navarre (Spain). To this end, discharge, DS and SS concentration data were collected during ten hydrological years at each watershed outlet, and loads were computed from discharge and concentration values. DS concentration followed a seasonal pattern imposed by the availability of water, with higher concentrations recorded in low-flow periods and lower concentration in the high-flow period. SS concentration was extremely variable, with a range of 2–4 orders of magnitude in concentration for any specific discharge. Temporal variations (both intra- and inter-annual) in DS loads were explained by differences in runoff, whereas those of SS were not, being the SS loads associated mainly with specific high flow events. These temporal patterns were observed for both agricultural (this study) and non-agricultural (literature) watersheds. From the data in the Navarrese watersheds and those available in the literature, we inferred that agricultural land use, in general, tends to increase the concentration of both DS and SS. Regarding DS and SS yields, the effects of agricultural land use on DS yields are controlled by the changes in runoff rather than the (small) changes in DS concentration. In this sense, land uses changes expected to increase runoff (i.e., a shift from forested to arable or from rainfed to irrigated agriculture) would increase DS yields. On the other hand, agricultural land use tends to increase SS yields, although the effect is highly variable depending on site-specific factors, both natural (e.g., watershed shape) and anthropogenic (e.g., degree of soil conservation practices). In the Navarrese watersheds, DS yields ranged from 1.1 to 2.2 Mg ha−1 year−1 whereas SS yields ranged from 0.3 to 4.3 Mg ha−1 year−1. DS yields seem to dominate under non-agricultural conditions and in most agricultural land uses at the small watershed scale. On the other hand, SS yields dominate in watersheds with increased soil erosion as a consequence of arable land use over erosion-prone watersheds.