Publications by authors named "Ivan Lizaga"

The depletion of fertile topsoil presents a critical challenge in tropical mountain agroecosystems. Impacts are intensified during heavy storm events that strip unprotected topsoils and pose risks to downstream water ecosystems. To better understand such dynamics, we investigated an agricultural mountainous catchment located on the Democratic Republic of the Congo shore of Lake Kivu.

View Article and Find Full Text PDF

To ensure sustainable agricultural management, there is a need not only to quantify soil erosion rates but also to obtain information on the status of soil water content and soil loss under different soil types and land uses. A clear understanding of the temporal dynamics and the soil moisture spatial variability (SMSV) will help to control soil degradation by hydrological processes. This study represents the first attempt connecting cosmic-ray neutron sensors (CRNS) with soil erosion research, a novel approach to explore the complex relationships between soil water content (SWC) and soil redistribution processes using two of the most powerful nuclear techniques, CRNS and fallout Cs.

View Article and Find Full Text PDF

Unsustainable human activities have disrupted the natural cycle of trace elements, causing the accumulation of chemical pollutants and making it challenging to determine their sources due to interwoven natural and human-induced processes. A novel approach was introduced for identifying the sources and for quantifying the contribution of trace elements discharge from rivers to soils. We integrated fingerprinting techniques, soil and sediment geochemical data, geographically weighted regression model (GWR) and soil quality indices.

View Article and Find Full Text PDF

Purpose: Identifying best practices for sediment fingerprinting or tracing is important to allow the quantification of sediment contributions from catchment sources. Although sediment fingerprinting has been applied with reasonable success, the deployment of this method remains associated with many issues and limitations.

Methods: Seminars and debates were organised during a 4-day Thematic School in October 2021 to come up with concrete suggestions to improve the design and implementation of tracing methods.

View Article and Find Full Text PDF

Sediment fingerprinting has emerged as a valuable tool for elucidating soil erosion processes and assessing the sources of sediment and particle-bound chemicals. Due to its upward trend in popularity and the parallel advances in analytical methods, different types of tracers such as Compound-Specific Stable Isotopes (CSSIs) have been incorporated to identify the potential sources. However, the physical processes of CSSIs, usually characterised by the ratio of two stable isotopes, also depends on the isotopic content requiring specific fingerprinting models.

View Article and Find Full Text PDF

Fingerprinting technique is a widely used tool to assess the sources of sediments and particle bound chemicals within a watershed, and the results obtained from unmixing models are becoming valuable data to support soil and water resources monitoring and conservation. Nowadays, numerous studies have used fingerprinting techniques to examine specific catchment management problems. Despite its shortcomings and the lack of standardization, the technique continues on an upward trend globally.

View Article and Find Full Text PDF

A Compound Specific Stable Isotope (CSSI) sediment tracing approach is applied for the first time in a Mediterranean mountain agroforestry catchment subjected to intense land use changes in the past decades. Many Mediterranean mountain environments underwent conversion of rangelands into croplands during the previous centuries to increase agricultural production. Converted land has increased the risk of erosion and in some cases has led to loss of the entire fertile topsoil.

View Article and Find Full Text PDF

Soil erosion and fine particle exports are two of the major concerns of soil nutrient loss and water quality decrease nowadays. In Mediterranean mountainous environments, agricultural practices during different cropland stages likely increase sediment supplies and the export of fertilisers and pesticides out into the drainage system. In this study, we attempt to evaluate the soil response to different agricultural practices implemented during the agricultural cycle by monitoring the bare soil cropland area through the use of remote sensing and applying the sediment fingerprinting technique together with the newly consensus-based tracer selection method.

View Article and Find Full Text PDF

Soil erosion and fine particle transport are two of the major challenges in food security and water quality for the growing global population. Information of the areas prone to erosion is needed to prevent the release of pollutants and the loss of nutrients. Sediment fingerprinting is becoming a widely used tool to tackle this problem, allowing to identify the sources of sediments in a catchment.

View Article and Find Full Text PDF

Soil erosion induced by runoff is a main hydrological pathway for lateral transport of carbon in terrestrial landscapes. More information about how water erosion influences the carbon gains and losses at different erosional and depositional landform positions is critical, especially in fragile agroecosystems with a variety of land uses and ephemeral hydrological and sedimentological pulses, typical of Mediterranean environments. The purpose of this study is to characterize the lateral mobilization of soil organic and inorganic carbon (SOC and SIC) along topographically driven transects over a period of four decades in a sub-humid karstic area in northern Spain.

View Article and Find Full Text PDF

In the Mediterranean region, floods are expected to increase as a result of climate change and knowledge of soil erosion hot spots during exceptional rainfalls is required to support mitigation measures. This study quantifies the main sediment sources during an exceptional rainfall event in 2012 (235 mm) at the outlet of two catchments located in NE Spain. To this purpose, suspended sediments were collected during the flood event, complemented with entrapped sediments in mat taken one year after the event.

View Article and Find Full Text PDF

The present dominant trend of retreating and shrinking glaciers is leading to the formation of new soil in proglacial zones. The Cordillera Blanca located in the Peruvian Andes includes the Lake Parón catchment known for the Artesonraju Glacier and its rapid retreat, forming the largest proglacial lake in the region. This work aims to gain knowledge of soil and vegetation development on the most representative proglacial landforms existing in the Parón catchment.

View Article and Find Full Text PDF

Increasing complexity in human-environment interactions at multiple watershed scales presents major challenges to sediment source apportionment data acquisition and analysis. Herein, we present a step-change in the application of Bayesian mixing models: Deconvolutional-MixSIAR (D-MIXSIAR) to underpin sustainable management of soil and sediment. This new mixing model approach allows users to directly account for the 'structural hierarchy' of a river basin in terms of sub-watershed distribution.

View Article and Find Full Text PDF

Many ice-free environments in Maritime Antarctica are undergoing rapid and substantial environmental changes in response to recent climate trends. This is the case of Elephant Point (Livingston Island, South Shetland Islands, SSI), where the glacier retreat recorded during the last six decades exposed 17% of this small peninsula, namely a moraine extending from the western to the eastern coastlines and a relatively flat proglacial surface. In the southern margin of the peninsula, a sequence of Holocene raised beaches and several bedrock plateaus are also distributed.

View Article and Find Full Text PDF