scholarly journals Large-scale impacts of hydropower development on the Mompós Depression wetlands, Colombia

2017 ◽  
Author(s):  
Héctor Angarita ◽  
Albertus J. Wickel ◽  
Jack Sieber ◽  
John Chavarro ◽  
Javier A. Maldonado-Ocampo ◽  
...  

Abstract. A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America. Annual large-scale inundation of floodplains and associated wetlands regulates water-, nutrient-, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we present a comparative analysis of the potential effects of hydropower expansion to meet projected electricity requirements by 2050, in terms of 1) basin-level implications of cumulative changes in streamflow regime, sediment trapping, and loss of river connectivity, and 2) the impact of upstream regulation on the hydrologic dynamics of the Mompós Depression wetlands at a monthly to decadal scale. To this end, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the Mompós Depression floodplains water balance at a medium scale (~1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. Our results indicate that potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry periods and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.

2018 ◽  
Vol 22 (5) ◽  
pp. 2839-2865 ◽  
Author(s):  
Héctor Angarita ◽  
Albertus J. Wickel ◽  
Jack Sieber ◽  
John Chavarro ◽  
Javier A. Maldonado-Ocampo ◽  
...  

Abstract. A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompós Depression wetlands, one of the largest wetland systems in South America at 3400 km2. Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity. The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development. The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements. As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale (∼ 1000 to 10 000 km2) and evaluation of the potential impacts of upstream water management practices. In the case of the Mompós Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry years and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompós Depression.


Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 964
Author(s):  
Ioannis K. Tsanis ◽  
Konstantinos D. Seiradakis ◽  
Sofia Sarchani ◽  
Ioanna S. Panagea ◽  
Dimitrios D. Alexakis ◽  
...  

The risk of erosion is particularly high in Mediterranean areas, especially in areas that are subject to a not so effective agricultural management–or with some omissions–, land abandonment or wildfires. Soils on Crete are under imminent threat of desertification, characterized by loss of vegetation, water erosion, and subsequently, loss of soil. Several large-scale studies have estimated average soil erosion on the island between 6 and 8 Mg/ha/year, but more localized investigations assess soil losses one order of magnitude higher. An experiment initiated in 2017, under the framework of the SoilCare H2020 EU project, aimed to evaluate the effect of different management practices on the soil erosion. The experiment was set up in control versus treatment experimental design including different sets of treatments, targeting the most important cultivations on Crete (olive orchards, vineyards, fruit orchards). The minimum-to-no tillage practice was adopted as an erosion mitigation practice for the olive orchard study site, while for the vineyard site, the cover crop practice was used. For the fruit orchard field, the crop-type change procedure (orange to avocado) was used. The experiment demonstrated that soil-improving cropping techniques have an important impact on soil erosion, and as a result, on soil water conservation that is of primary importance, especially for the Mediterranean dry regions. The demonstration of the findings is of practical use to most stakeholders, especially those that live and work with the local land.


2021 ◽  
Author(s):  
Jaana Bäck ◽  
Werner Kutsch ◽  
Michael Mirtl

<p>Ecosystem Research Infrastructures around the world have been designed, constructed, and are now operational as a distributed effort. The common goal is to address research questions that require long-term ecosystem observations and other service components at national to continental scales, which cannot be tackled in the framework of single and time limited projects.  By design, these Research Infrastructures capture data and provide a wider range of services including access to data and well instrumented research sites. The coevolution of supporting infrastructures and ecological sciences has developed into new science disciplines such as macrosystems ecology, whereby large-scale and multi-decadal-scale ecological processes are being explored. </p><p>Governments, decision-makers, researchers and the public have all recognized that the global economy, quality of life, and the environment are intrinsically intertwined and that ecosystem services ultimately depend on resilient ecological processes. These have been altered and threatened by various components of Global Change, e.g. land degradation, global warming and species loss. These threats are the unintended result of increasing anthropogenic activities and have the potential to change the fundamental trajectory of mankind.  This creates a unique challenge never before faced by society or science—how best to provide a sustainable economic future while understanding and globally managing a changing environment and human health upon which it relies.</p><p>The increasing number of Research Infrastructures around the globe now provides a unique and historical opportunity to respond to this challenge. Six major ecosystem Research Infrastructures (SAEON/South Africa, TERN/Australia, CERN/China, NEON/USA, ICOS/Europe, eLTER/Europe) have started federating to tackle the programmatic work needed for concerted operation and the provisioning of interoperable data and services. This Global Ecosystem Research Infrastructure (GERI) will be presented with a focus on the involved programmatic challenges and the GERI science rationale.</p>


2021 ◽  
Author(s):  
Qin Yang ◽  
Hua Cheng ◽  
Hongmei Pu ◽  
Xuechun Zhao ◽  
Rui Dong ◽  
...  

Abstract Context Fine-scale spatial vegetation patterns are ubiquitous and can have profound impacts on large scale ecological processes including surface runoff, soil erosion, and livestock forage efficiency. However, we have limited knowledge of the fine-scale spatial vegetation patterns in humid grasslands.Objectives The objectives were to characterize the spatial vegetation patterns at centimeter scale in humid grasslands, quantify the vegetation patterns variation under different image pixel sizes and plant covers, and explore the potential ecological implications of the spatial vegetation patterns.Methods Seventy plots with plant covers ranging from 30.8–99.3% were selected from seven humid grasslands in southwest China and their spatial vegetation patterns quantified at image pixel sizes of 0.04, 0.25, 1, and 4 cm.Results With increasing pixel size, plant patch density and total edge density decreased, plant patch size increased, and the plant patch shape became more regular. At a plant cover level below 50%, increasing plant cover will result in increasing patch density and patch size, leading to greater spatial heterogeneity. At plant cover levels above 50%, increasing plant cover will cause the rapid expansion of patch size, along with a lower patch density, forming a more homogeneous landscape dominated by plant patches. The small stems, branches, and leaves of grasses fragmented non-plant patches into smaller patches with increasing plant cover; this fragmentation resembles road-induced landscape fragmentation processes.Conclusions Medium plant cover has the highest heterogeneity of spatial vegetation pattern at the fine scale, which may have significant implications on ecological processes and related management practices.


2021 ◽  
Author(s):  
Alessandro Cestaro ◽  
emanuela coller ◽  
Davide Albanese ◽  
erika stefani ◽  
Massimo Pindo ◽  
...  

Agricultural soils harbor rich and diverse microbial communities that have a deep influence on soil properties and productivity. Large scale studies have shown the impact of environmental parameters like climate or chemical composition on the distribution of bacterial and fungal species. Comparatively, little data exists documenting how soil microbial communities change between different years. Quantifying the temporal stability of soil microbial communities will allow us to better understand the relevance of the differences between environments and their impact on ecological processes on the global and local scale. We characterized the bacterial and fungal components of the soil microbiota in ten vineyards in two consecutive years. Despite differences of species richness and diversity between the two years, we found a general stability of the taxonomic structure of the soil microbiota. Temporal differences were smaller than differences due to geographical location, vineyard land management or differences between sampling sites within the same vineyard. Using machine learning, we demonstrated that each site was characterized by a distinctive microbiota, and we identified a reduced set of indicator species that could classify samples according to their geographic origin across different years with high accuracy.


Koedoe ◽  
2005 ◽  
Vol 48 (1) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp

Long-term conservation ecosystems require a broader understanding of the ecological processes involved. Because ecosystems react differently to different management practices, it is important that a description and classification of the vegetation of an area are completed. A vegetation survey of the valley areas of the Kammanassie Nature Reserve was undertaken as part of a larger research project to assess the environmental impacts of large-scale groundwater abstraction from Table Mountain Group aquifers on ecosystems in the reserve. From a TWFNSPAN classification, refined by Braun-Blanquet procedures, 21 plant communities, which can be grouped into 13 major groups, were identified. A classification and description of these communities, as well as a vegetation map of the different areas are presented. Associated gradients in habitat w ere identified by using an ordination algorithm (DECORANA). The diagnostic species as well as the prominent and less conspicuous species of the tree, shrub, forb and grass strata are outlined. The study also resulted in a total number of 481 species being identified and the discovery of a new Erica species. These vegetation surveys and descriptions provide baseline information for management purposes and that allows monitoring as well as similar surveys to be conducted in future.


2018 ◽  
Vol 10 (11) ◽  
pp. 3968 ◽  
Author(s):  
Filippo Brandolini ◽  
Mauro Cremaschi

Fluvial environments have always played a crucial role in human history. The necessity of fertile land and fresh water for agriculture has led populations to settle in floodplains more frequently than in other environments. Floodplains are complex human–water systems in which the mutual interaction between anthropogenic activities and environment affected the landscape development. In this paper, we analyzed the evolution of the Central Po Plain (Italy) during the Medieval period through a multi-proxy record of geomorphological, archaeological and historical data. The collapse of the Western Roman Empire (5th century AD) coincided with a progressive waterlogging of large floodplain areas. The results obtained by this research shed new light on the consequences that Post-Roman land and water management activities had on landscape evolution. In particular, the exploitation of fluvial sediments through flood management practices had the effect of reclaiming the swamps, but also altered the natural geomorphological development of the area. Even so, the Medieval human activities were more in equilibrium with the natural system than with the later Renaissance large-scale land reclamation works that profoundly modified the landscape turning the wetland environment into the arable land visible today. The analysis of fluvial palaeoenvironments and their relation with past human activities can provide valuable indications for planning more sustainable urbanized alluvial landscapes in future.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244619
Author(s):  
Amaia Albizua ◽  
Elena M. Bennett ◽  
Guillaume Larocque ◽  
Robert W. Krause ◽  
Unai Pascual

The social-ecological effects of agricultural intensification are complex. We explore farmers’ perceptions about the impacts of their land management and the impact of social information flows on their management through a case study in a farming community in Navarra, Spain, that is undergoing agricultural intensification due to adoption of large scale irrigation. We found that modern technology adopters are aware that their management practices often have negative social-ecological implications; by contrast, more traditional farmers tend to recognize their positive impacts on non-material benefits such as those linked with traditions and traditional knowledge, and climate regulation. We found that farmers’ awareness about nature contributions to people co-production and their land management decisions determine, in part, the structure of the social networks among the farming community. Since modern farmers are at the core of the social network, they are better able to control the information flow within the community. This has important implications, such as the fact that the traditional farmers, who are more aware of their impacts on the environment, rely on information controlled by more intensive modern farmers, potentially jeopardizing sustainable practices in this region. We suggest that this might be counteracted by helping traditional farmers obtain information tailored to their practices from outside the social network.


2018 ◽  
Vol 115 (16) ◽  
pp. 4045-4050 ◽  
Author(s):  
Yongcun Zhao ◽  
Meiyan Wang ◽  
Shuijin Hu ◽  
Xudong Zhang ◽  
Zhu Ouyang ◽  
...  

China’s croplands have experienced drastic changes in management practices, such as fertilization, tillage, and residue treatments, since the 1980s. There is an ongoing debate about the impact of these changes on soil organic carbon (SOC) and its implications. Here we report results from an extensive study that provided direct evidence of cropland SOC sequestration in China. Based on the soil sampling locations recorded by the Second National Soil Survey of China in 1980, we collected 4,060 soil samples in 2011 from 58 counties that represent the typical cropping systems across China. Our results showed that across the country, the average SOC stock in the topsoil (0–20 cm) increased from 28.6 Mg C ha−1 in 1980 to 32.9 Mg C ha−1 in 2011, representing a net increase of 140 kg C ha−1 year−1. However, the SOC change differed among the major agricultural regions: SOC increased in all major agronomic regions except in Northeast China. The SOC sequestration was largely attributed to increased organic inputs driven by economics and policy: while higher root biomass resulting from enhanced crop productivity by chemical fertilizers predominated before 2000, higher residue inputs following the large-scale implementation of crop straw/stover return policy took over thereafter. The SOC change was negatively related to N inputs in East China, suggesting that the excessive N inputs, plus the shallowness of plow layers, may constrain the future C sequestration in Chinese croplands. Our results indicate that cropland SOC sequestration can be achieved through effectively manipulating economic and policy incentives to farmers.


2021 ◽  
Vol 21 (6) ◽  
pp. 1807-1823
Author(s):  
Donghoon Lee ◽  
Hassan Ahmadul ◽  
Jonathan Patz ◽  
Paul Block

Abstract. Floods are the most common and damaging natural disaster in Bangladesh, and the effects of floods on public health have increased significantly in recent decades, particularly among lower socioeconomic populations. Assessments of social vulnerability on flood-induced health outcomes typically focus on local to regional scales; a notable gap remains in comprehensive, large-scale assessments that may foster disaster management practices. In this study, socioeconomic, health, and coping capacity vulnerability and composite social-health vulnerability are assessed using both equal-weight and principal-component approaches using 26 indicators across Bangladesh. Results indicate that vulnerable zones exist in the northwest riverine areas, northeast floodplains, and southwest region, potentially affecting 42 million people (26 % of the total population). Subsequently, the vulnerability measures are linked to flood forecast and satellite inundation information to evaluate their potential for predicting actual flood impact indices (distress, damage, disruption, and health) based on the immense August 2017 flood event. Overall, the forecast-based equally weighted vulnerability measures perform best. Specifically, socioeconomic and coping capacity vulnerability measures strongly align with the distress, disruption, and health impact records observed. Additionally, the forecast-based composite social-health vulnerability index also correlates well with the impact indices, illustrating its utility in identifying predominantly vulnerable regions. These findings suggest the benefits and practicality of this approach to assess both thematic and comprehensive spatial vulnerabilities, with the potential to support targeted and coordinated public disaster management and health practices.


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