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Vegetation protects soil against erosion by intercepting rain, increasing flow resistance, promoting soil infiltration and improving soil strength. However, the representation of vegetation dynamics in Landform Evolution Models (LEMs) is very simplified, which could result in over/under estimations of erosion rates. Here we use a new model framework to study the differences in erosion rates when considering different processes associated with vegetation protection. We analysed the changes in erosion rates by considering: (1) the effect of root biomass on soil erodibility, (2) the effect of leaf cover on soil diffusivity, (3) the effect of litter on flow resistance, and (4) the effect of soil carbon on soil infiltration. We implemented the model in an open-forest savannah catchment situated in Howard Springs (Northern Territory, Australia) and ran simulations using daily time step for 100 years. The modelling framework comprises a coupled Landform Evolution Model (LEM) with dynamic biochemical vegetation and biomass pools dynamics. Our results show that bare soil conditions generate a 100% increase in erosion compared to those using the full dynamic vegetation (that include protection from all carbon pools). We find that the effects from vegetation protection and rainfall are asynchronous, with substantial vegetation growth typically lagging behind substantial rainfall events. This means that rainfall events at the beginning of the rainy season contribute heavily to erosion. For the specific case of Howard Springs, leaves and roots are the most important factors that control erosion except when they are not fully recovered after the dry season. At this time the effect of the litter, and to a lesser extent the soil carbon, turn out to be determinant. Overall, this study highlights the importance of including dynamic vegetation and the effects of the biomass pools on controlling erosion in order to estimate erosion rates.
Juan Quijano Baron; Patricia Saco; Jose Rodriguez. Asynchronous effects of vegetation protection on landform evolution. 2021, 1 .
AMA StyleJuan Quijano Baron, Patricia Saco, Jose Rodriguez. Asynchronous effects of vegetation protection on landform evolution. . 2021; ():1.
Chicago/Turabian StyleJuan Quijano Baron; Patricia Saco; Jose Rodriguez. 2021. "Asynchronous effects of vegetation protection on landform evolution." , no. : 1.
Changes in hydro-geomorphic connectivity have been previously linked to catastrophic shifts in landscape structures and function leading to irreversible degradation. Here we present evidence and new observations to better understand the link between connectivity of water and sediments and possible phase transitions for the case of semiarid ecosystems at the catchment and hillslope scales. We first focus on rangelands, where coevolving vegetation and landform structures lead to a distinct connectivity pattern responsible for the healthy functioning of the system. Positive feedbacks, triggered by disturbances in vegetation, water or sediment structures can alter the hydro-geomorphic connectivity leading to degradation. Our results for rangelands in Australia, from both simulations and observations, suggest that an increase in connectivity beyond a threshold may lead to irreversible degradation, meaning that the system return to a functional state is unlikely without extensive management interventions. We also analyse the case of semi-arid floodplain wetlands of the Murray-Darling Basin, where we observe that dis-connectivity during droughts promote terrestrial vegetation encroachment and degradation. Simulations and observations also indicate the presence of thresholds beyond which the recovery of the system is unlikely without interventions.
Patricia Saco; Mariano Moreno-De Las Heras; Jose Rodriguez; Steven Sandi; Samira Azadi; Juan Quijano. Applications of a hydro-geomorphic (dis)connectivity framework to study vegetation transitions in semiarid ecosystems. 2021, 1 .
AMA StylePatricia Saco, Mariano Moreno-De Las Heras, Jose Rodriguez, Steven Sandi, Samira Azadi, Juan Quijano. Applications of a hydro-geomorphic (dis)connectivity framework to study vegetation transitions in semiarid ecosystems. . 2021; ():1.
Chicago/Turabian StylePatricia Saco; Mariano Moreno-De Las Heras; Jose Rodriguez; Steven Sandi; Samira Azadi; Juan Quijano. 2021. "Applications of a hydro-geomorphic (dis)connectivity framework to study vegetation transitions in semiarid ecosystems." , no. : 1.
Vegetation not only controls but is also controlled by erosion processes. This tight feedback effect leads to the coevolution of vegetation and erosion patterns that modulate landform shape, and regulate many other landscape processes. These tight interactions are particularly important in semiarid landscapes. We have studied these interactions using a landform evolution model that accounts for the effect (and feedbacks) of spatially and temporally varying hydrologic and vegetation patterns.
We apply the modelling framework to improve our understanding of the coevolution of landforms and vegetation patterns in different semiarid landscapes in Australia. The vegetation of the selected sites is Acacia Aneura (Mulga) which covers vast areas of Australia. These sites display a sparse vegetation cover and strong patterns of water redistribution, with sources located in the bare areas and sinks in the vegetation patches which characterize the observed hydrologic connectivity. This effect triggers high spatial variability of erosion/deposition rates that affects the evolving topography and induces feedbacks to the dynamic vegetation patterns. We run simulations for 1000 years using local rainfall and erosion and vegetation parameters previously calibrated for similar sites in the Northern territory. Our numerical modelling results are validated by comparing simulated and observed patterns of vegetation and landforms obtained from satellite, airborne remote sensing and field data. We further investigate the effect of alterations in hydrologic connectivity induced by climate change and/or anthropogenic activities, which affect water and sediment redistribution and can be linked to loss of resources leading to degradation.
Our simulations are able to reproduce observed banded vegetation and landform patterns for the Northern territory in Australia. We show that an increase in hydrologic connectivity can trigger changes in vegetation patterns inducing feedbacks with landforms leading to degraded states. These transitions display non-linear behaviour and in some cases can lead to thresholds with an abrupt reduction in productivity. Critical implications for effective long-term restoration efforts are discussed.
Patricia Saco; Juan Quijano; Mariano Moreno-De Las Heras; Garry Willgoose; Jose Rodriguez. The effect of vegetation dynamics on erosion processes, sediment dynamics, and landscape evolution in semiarid areas with sparse plant cover. 2020, 1 .
AMA StylePatricia Saco, Juan Quijano, Mariano Moreno-De Las Heras, Garry Willgoose, Jose Rodriguez. The effect of vegetation dynamics on erosion processes, sediment dynamics, and landscape evolution in semiarid areas with sparse plant cover. . 2020; ():1.
Chicago/Turabian StylePatricia Saco; Juan Quijano; Mariano Moreno-De Las Heras; Garry Willgoose; Jose Rodriguez. 2020. "The effect of vegetation dynamics on erosion processes, sediment dynamics, and landscape evolution in semiarid areas with sparse plant cover." , no. : 1.
Irrigated agriculture has been identified as using approximately 72% of water globally. Many regions of the world are subject to water sharing plans that cross government boarders which contain a mixture of management policies, leading to the requirement to monitor irrigation water use. The study reported here aims to develop and test an approach using Landsat observations to monitor irrigation water use over paddock scales without the need for in-situ observations, ground data or knowledge of planting dates. Using conservative assumptions about agricultural land management practice (i.e. negligible runoff, drainage and soil moisture change), the irrigation is calculated over 25 m x 25 m Landsat images. The approach uses a combination of three vegetation indices derived from Landsat images to calculate crop coefficients (Kc) based on multiple published relationships. These are combined through the FAO56 methodology using gridded rainfall and two gridded reference evapotranspiration (ETo) products to estimate actual evapotranspiration, providing six ETo - Kc combinations which are then compared to actual/recorded irrigation volumes from test sites. The method was tested over an almond farm, two vineyards and a cotton field; in addition to Goulburn-Murray Water’s (GMW) individual farm scale sites with unknown crops, all located within Australia. The developed approach provided estimated irrigation volumes that closely matched measured data for almond and cotton farms, while vineyards returned less accurate results due to localised management techniques that do not agree with land management assumptions made. The results from GMW showed some indication of the irrigation water use, although more details of the site being assessed needs to be available (i.e. crop type and extent). This study demonstrates the ability of certain remote sensing Kc relationships for sensing irrigation water use and shows the potential applications of the developed approach in monitoring irrigation over paddock scale environments.
David Bretreger; In-Young Yeo; Juan Quijano; John Awad; Greg Hancock; Garry Willgoose. Monitoring irrigation water use over paddock scales using climate data and landsat observations. Agricultural Water Management 2019, 221, 175 -191.
AMA StyleDavid Bretreger, In-Young Yeo, Juan Quijano, John Awad, Greg Hancock, Garry Willgoose. Monitoring irrigation water use over paddock scales using climate data and landsat observations. Agricultural Water Management. 2019; 221 ():175-191.
Chicago/Turabian StyleDavid Bretreger; In-Young Yeo; Juan Quijano; John Awad; Greg Hancock; Garry Willgoose. 2019. "Monitoring irrigation water use over paddock scales using climate data and landsat observations." Agricultural Water Management 221, no. : 175-191.
The implementation of sustainable urban drainage systems (SUDS) is increasing due to their advantages, which transcend runoff control. As a result, it is important to find the appropriate SUDS locations to maximize the benefits for the watershed. This study develops a multiscale methodology for consolidated urban areas that allows the analysis of environmental, social, and economic aspects of SUDS implementation according to multiple objectives (i.e., runoff management, water quality improvements, and amenity generation). This methodology includes three scales: (a) citywide, (b) local, and (c) microscale. The citywide scale involves the definition of objectives through workshops with the participation of the main stakeholders, and the development of spatial analyses to identify (1) priority urban drainage sub-catchments: areas that need intervention, and (2) strategic urban drainage sub-catchments: zones with the opportunity to integrate SUDS due the presence of natural elements or future urban redevelopment plans. At a local scale, prospective areas are analyzed to establish the potential of SUDS implementation. Microscale comprises the use of the results from the previous scales to identify the best SUDS placement. In the latter scale, the SUDS types and treatment trains are selected. The methodology was applied to the city of Bogotá (Colombia) with a population of nearly seven million inhabitants living in an area of approximately 400 km2. Results include: (a) The identification of priority urban drainage sub-catchments, where the implementation of SUDS could bring greater benefits; (b) the determination of strategic urban drainage sub-catchments considering Bogotá’s future urban redevelopment plans, and green and blue-green corridors; and (c) the evaluation of SUDS suitability for public and private areas. We found that the most suitable SUDS types for public areas in Bogotá are tree boxes, cisterns, bioretention zones, green swales, extended dry detention basins, and infiltration trenches, while for private residential areas they are rain barrels, tree boxes, green roofs, and green swales.
Sara Lucía Jiménez Ariza; José Alejandro Martínez; Andrés Felipe Muñoz; Juan Pablo Quijano; Juan Pablo Rodríguez; Luis Alejandro Camacho; Mario Díaz-Granados. A Multicriteria Planning Framework to Locate and Select Sustainable Urban Drainage Systems (SUDS) in Consolidated Urban Areas. Sustainability 2019, 11, 2312 .
AMA StyleSara Lucía Jiménez Ariza, José Alejandro Martínez, Andrés Felipe Muñoz, Juan Pablo Quijano, Juan Pablo Rodríguez, Luis Alejandro Camacho, Mario Díaz-Granados. A Multicriteria Planning Framework to Locate and Select Sustainable Urban Drainage Systems (SUDS) in Consolidated Urban Areas. Sustainability. 2019; 11 (8):2312.
Chicago/Turabian StyleSara Lucía Jiménez Ariza; José Alejandro Martínez; Andrés Felipe Muñoz; Juan Pablo Quijano; Juan Pablo Rodríguez; Luis Alejandro Camacho; Mario Díaz-Granados. 2019. "A Multicriteria Planning Framework to Locate and Select Sustainable Urban Drainage Systems (SUDS) in Consolidated Urban Areas." Sustainability 11, no. 8: 2312.
Sandra Alzate; Daniel Guyumus; Juan Quijano; Mario Díaz-Granados. Two-dimensional hydraulic flood modelling in domains with multiple tributaries areas for risk analysis. River Flow 2016 2016, 1 .
AMA StyleSandra Alzate, Daniel Guyumus, Juan Quijano, Mario Díaz-Granados. Two-dimensional hydraulic flood modelling in domains with multiple tributaries areas for risk analysis. River Flow 2016. 2016; ():1.
Chicago/Turabian StyleSandra Alzate; Daniel Guyumus; Juan Quijano; Mario Díaz-Granados. 2016. "Two-dimensional hydraulic flood modelling in domains with multiple tributaries areas for risk analysis." River Flow 2016 , no. : 1.
Levels and determinants of indoor carbon monoxide (CO) pollution were characterised in a pilot sample of households in Bogota, Colombia, in which natural gas appliances (NGA) were frequently used. Real-time CO concentration measurements were conducted using Langan T15 electrochemical cells in kitchen and living rooms, at 73 homes. Results show that the use of NGA has a direct impact on indoor air quality with CO concentrations ranging between 5 and 150 parts-per-million. In 14 out of the 73 homes, CO concentrations were above the World Health Organization standards during at least 10% of the day. This is a matter of concern for local public health authority since the number of reported cases of CO involuntary intoxications in the city has significantly increased since 2008. Evidence presented hereby has important implications in regard to NGA installation standards and housing polices (especially in the case of low income dwelling). It urges to involve healthy-house concepts in building codes, to prevent inadequate indoor air quality and to improve people living conditions.
Juan Felipe Franco; Diana Carolina Obando; Juan Quijano; Eduardo Behrentz. Indoor air pollution associated with the use of natural gas appliances in households in Bogota, Colombia: levels and determinants. International Journal of Environmental Technology and Management 2016, 19, 120 .
AMA StyleJuan Felipe Franco, Diana Carolina Obando, Juan Quijano, Eduardo Behrentz. Indoor air pollution associated with the use of natural gas appliances in households in Bogota, Colombia: levels and determinants. International Journal of Environmental Technology and Management. 2016; 19 (2):120.
Chicago/Turabian StyleJuan Felipe Franco; Diana Carolina Obando; Juan Quijano; Eduardo Behrentz. 2016. "Indoor air pollution associated with the use of natural gas appliances in households in Bogota, Colombia: levels and determinants." International Journal of Environmental Technology and Management 19, no. 2: 120.
Urban drainage system models can be useful to assess and manage system performance and to plan its development. However, due to data and computational costs, sophisticated, high-resolution contemporary models of the sewer system may not be applicable. This constraint is particularly marked in developing country mega-cities where catchments can be large, data tend to be scarce, and there are many unknowns, for example regarding sources, losses and wrong connections. This paper presents work undertaken over the last 7 years to develop a suitable monitoring and modelling framework to support operation and development of the wastewater system of Bogotá (Colombia). Components of the framework covered here are: (a) the flow and water quality database, (b) a wastewater pollution load generator, and (c) a semi-distributed sewer network model, which aims at a complexity that matches the information available from the previous two components. Results from a catchment within Bogotá, area 150 km(2) and with 2.5 million inhabitants, show that the model outputs capture the scale and dynamics of the observed concentrations and loads at various points on the sewer system. However uncertainty is high because much of variability of observed dry weather flow profiles is apparently random. Against this variability, the effects of in-sewer processes were not identifiable except where backwaters caused particularly high retention times. Hence the work has resulted in an operational model with a scientifically justified, yet useful, level of complexity for Bogotá. More generally, the work demonstrates the value of monitoring and modelling programmes, including having modellers actively involved in monitoring specification and operations; and the insights into suitable level of model complexity that may be gained by uncertainty and sensitivity analysis.
Juan Pablo Rodríguez; Neil McIntyre; Mario Díaz-Granados; Juan Quijano; Čedo Maksimović. Monitoring and modelling to support wastewater system management in developing mega-cities. Science of The Total Environment 2013, 445-446, 79 -93.
AMA StyleJuan Pablo Rodríguez, Neil McIntyre, Mario Díaz-Granados, Juan Quijano, Čedo Maksimović. Monitoring and modelling to support wastewater system management in developing mega-cities. Science of The Total Environment. 2013; 445-446 ():79-93.
Chicago/Turabian StyleJuan Pablo Rodríguez; Neil McIntyre; Mario Díaz-Granados; Juan Quijano; Čedo Maksimović. 2013. "Monitoring and modelling to support wastewater system management in developing mega-cities." Science of The Total Environment 445-446, no. : 79-93.