Modeling and evaluation of the effect of afforestation on the runoff generation within the Glinščica catchment (Slovenia)

Author(s):  
Gregor Johnen ◽  
Klaudija Sapač ◽  
Simon Rusjan ◽  
Vesna Zupanc ◽  
Andrej Vidmar ◽  
...  

<p><strong>Modeling and evaluation of the effect of afforestation on the runoff generation within the Glinščica catchment (Slovenia)</strong></p><p><strong>Gregor Johnen<sup>1</sup>, Klaudija Sapač<sup>2</sup>, Simon Rusjan<sup>2</sup>, Vesna Zupanc<sup>3</sup>, Andrej Vidmar<sup>2</sup>, Nejc Bezak<sup>2</sup></strong></p><p><sup>1 </sup>Radboud University Nijmegen, Faculty of Science</p><p><sup>2</sup> University of Ljubljana, Faculty of Civil and Geodetic Engineering</p><p><sup>3</sup> University of Ljubljana, Biotechnical Faculty</p><p><strong> </strong></p><p><strong>Abstract</strong>:</p><p>Increases in the frequency of flood events are one of the major risk factors induced by climate change that lead to a higher vulnerability of affected communities. Natural water retention measures such as afforestation on hillslopes and floodplains are increasingly discussed as cost-effective alternatives to hard engineering structures for providing flood regulation, particularly when the evaluation also considers beneficial ecosystem services other than flood regulation. The present study provides combined modelling approach and a cost-benefit analysis (CBA) of the impacts of afforestation on peak river flows and on selected ecosystem services within the Glinščica river catchment in Slovenia. In order to investigate the effects, the hydrological model HEC-HMS, the hydraulic model HEC-RAS and the flood damage model KRPAN, that was developed specifically for Slovenia, are used. It was found that increasing the amount of tree cover results in a flood peak reduction ranging from 9-13 %. Flood extensions were significantly lower for most scenarios leading to reduced economic losses. However, a 100-years CBA only showed positive net present values (NPV) for one of the considered scenarios and the benefits were dominated by the flood regulation benefits, which were higher than for example biodiversity or recreational benefits. Based on our findings we conclude that afforestation as a sole natural water retention measure (NWRM) provides a positive NPV only in some cases (i.e. scenarios) and if additional ecosystem co-benefits are considered.</p>

2021 ◽  
Author(s):  
Pia Laue ◽  
Paul Quinn ◽  
Mary Bourke ◽  
Darragh Murphy ◽  
Mark Wilkinson ◽  
...  

<p>In recent decades, land-use and climate change have dramatically altered catchment runoff rates. For example, agriculture intensification has led to increased flood risks by decreasing  soil permeability and reducing channel-floodplain connectivity. Natural Water Retention Measures (NWRM) is an approach that has been adopted European-wide for the attenuation of peak floods and the provision of wider ecosystem services. A reduction in peak flow is achieved by increasing water storage potential in the landscape and by modifying natural flow pathways. In agricultural areas (~70% of Irish land use),  runoff attenuation features such as offline ponds, earthen bunds, sediment traps and leaky dams are frequently deployed natural retention measures.</p><p>Despite the growing evidence across Europe of their efficacy for flood peak reduction, water quality enhancement and biodiversity on the local scale, NWRM features have not been adopted in Ireland as a flood mitigation approach. In order to build a case that will help address this, this presentation will detail a NWRM demonstrate site in Ballygow, Co. Wexford.  The construction and instrumentation of a network of features developed at the field-scale (~1km<sup>2</sup>) is shown. This site is an intensive pasture, small-hold farm. We aim to quantify the effectiveness of these NWRM features to demonstrate their potential to attenuate flood peaks on agricultural areas using temporary storage, whilst minimising the impact on farming.</p><p>The constructed measures consist of a flood swale that connects the channel to the floodplain during high flows, an earthen bund, an offline pond with a sediment trap, that can retain the water from the channel and contributing field slopes, for <12 hours. On-site video footage and eyewitnesses confirm that the flood water flows along the field without draining back into the stream. At approximately 800m across the field, the water is retained temporarily, permitting water storage and the opportunity for suspended sediment to settle out of the water column. Flood water is returned to the channel via a perched 20 cm diameter pipe in the bund. Four automated water level recorders (In-Situ Rugged Troll 100) continuously monitor water levels in the stream and the offline pond at 5 min intervals. In addition, local rainfall (EML Event Logger) is monitored. These data are used to identify the hydrograph characteristics of several storm events and are used to determine the effectiveness of the NWRM structures for flood attenuation. The quantification of the effectiveness of NWRM features will use the observed time series combined with hydraulic and hydrological modelling. </p><p>The quantitative evidence provided by our findings will contribute to establishing vital evidence for the implementation of local and national NWRM schemes in Ireland.</p>


2021 ◽  
Author(s):  
Giacomo Bernello ◽  
Elena Mondino ◽  
Lucia Bortolini

<p>Heavy rainfall is one of the hydrogeological hazards increasingly connected with climatic changes. Natural Water Retention Measures (NWRMs) implementation represents a chance to build resilient communities and to reduce potential damage. This water management approach has several designs and can be adopted at different scales. However, NWRMs are not widespread, and in some cases they are even ignored by both citizens and public administrations. Understanding how people perceive NWRMs is the first step to promote the implementation of these structures. This study aims at exploring people’s knowledge of NWRMs and their attitudes towards them. We conducted a survey in the Veneto Region (Northeastern Italy) in 2020. Preliminary data exploration shows that the overall knowledge of NWRMs varies depending on the type of retention measure. Respondents’ attitudes towards NWRMs are positive in public areas (e.g. green spaces, parking lots), but are more heterogeneous when it comes to private properties (e.g. houses, private gardens). Further investigations are therefore needed concerning the last point. This study provides a deeper understanding of the dynamics behind water management systems’ implementation to reduce heavy rainfall and flood damage and can inform policymakers dealing with flood risk management.</p>


2012 ◽  
Vol 16 (3) ◽  
pp. 573-591 ◽  
Author(s):  
Kirsten Barrett ◽  
Judson Valentim ◽  
B. L. Turner

2012 ◽  
Vol 43 (3) ◽  
Author(s):  
Daniele De Wrachien ◽  
David Proverbs

The terms flood or flooding are often used in different ways. According to the International Commission on Irrigation and Drainage (ICID), <em>flooding is defined as the overflowing or failing of the normal confines of a river, stream, lake, canal, sea or accumulation of water as a result of heavy precipitation where drains are lacking or their discharge capacity is exceeded</em>. The occurrence of floods is the most frequent amongst all natural disasters. Although flooding is a serious hazard in humid regions, it can also be devastating in semiarid areas, where high rates of runoff following storms produce widespread flood damage down valley. These hazards involve tragic loss of life, damage to buildings and natural environments, and massive short-term disruption to the lives of the affected population. One-third of the annual natural disasters and economic losses, and more than half of the respective victims are flood-related.


2018 ◽  
Vol 04 (04) ◽  
pp. 1850022 ◽  
Author(s):  
Benjamin A. Jones ◽  
John Fleck

Managing outdoor water use while maintaining urban tree cover is a key challenge for water managers in arid climates. Urban trees generate flows of ecosystem services in arid areas, but also require significant amounts of irrigation. In this paper, a bioeconomic-health model of trees and water use is developed to investigate management of an urban forest canopy when irrigation is costly, water has economic value, and trees provide ecosystem services. The optimal tree irrigation decision is illustrated for Albuquerque, New Mexico, an arid Southwest US city. Using a range of monetary values for water, we find that the tree irrigation decision is sensitive to the value selected. Urban deforestation is optimal when the value of water is sufficiently high, or alternatively starts low, but grows to cross a specific threshold. If, however, the value of water is sufficiently low or if the value of tree cover rises over time, then deforestation is not optimal. The threshold value of water where the switch is made between zero and partial deforestation is well within previously identified ranges on actual water values. This model can be applied generally to study the tradeoffs between urban trees and water use in arid environments.


Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1247 ◽  
Author(s):  
Sikhululekile Ncube ◽  
Annie Visser ◽  
Lindsay Beevers

River systems provide diverse ecosystem services (ES), such as flood regulation (regulating), fresh water (provisioning), nutrient cycling (supporting), and recreation (cultural), among others. The construction of infrastructure (e.g., for hydropower, irrigation) enhances the delivery of tangible ES for example food or energy (generally provisioning) to meet human needs. However, the resulting change to river flows threatens both the ecological health of a river and its ability to provide intangible but vital ES, for example those which support the delivery of other services. Understanding these supporting ES processes in river systems is essential to fully recognise the impact of water resources development on ES delivery. Whilst approaches for assessing instream supporting ES are under development, to date few provide quantitative methods for assessing delivery. Thus, this paper sets out a framework for the assessment of instream supporting ES using hydroecological modelling. It links supporting ES delivery to fluvial hydrological indicators through the use of ecologically relevant hydrological indices and macroinvertebrate flow preferences. The proposed framework is demonstrated on the Beas River basin (Western Himalayas, India), and is flexible enough to be transferred to a basin-wide model, thereby allowing ES relationships to be accounted for in basin-wide water resources planning.


Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1210
Author(s):  
Xiaoyan Li ◽  
Gulinaer Suoerdahan ◽  
Zhenyu Shi ◽  
Zihan Xing ◽  
Yongxing Ren ◽  
...  

Rapid urbanization drives land cover change, affecting urban ecosystems and inducing serious environmental issues. The study region of Changchun, China was divided into three urbanization categories according to different urbanization levels and the characteristics of urban sprawl and changes and relationships between typical ecosystem services (ESs) under rapid urbanization were analysed. The results showed that Changchun has undergone considerable urban expansion since 2000, which has significantly impacted all ESs in terms of spatial and temporal heterogeneity. Habitat suitability and crop yield have relatively stronger service capacity in the study area. Since the expansion of large-scale infrastructures, the mean ES values of developed urban areas are the lowest among the three zones, except for water retention and sandstorm prevention in 2015, when the balance between all services decreased. Over the past 16 years, habitat suitability in developing urban areas has decreased to a large extent due to urban sprawl. Because of the improvement in agricultural science and technology, crop yield in three regions increased, while the area of cropland reduced from 1720 km2 to 1560 km2 (9.3%). Synergies between habitat suitability and carbon storage and habitat suitability and soil retention were detected in three areas. A trade-off between habitat suitability and water retention was detected in three areas. The interactions between crop yield and carbon storage, habitat suitability, and soil retention were more complex in this study region. In addition to water retention, urbanization index has a negative correlation with ESs. According to the results, some suggestions to alleviate ES loss during the process of rapid urbanization were proposed, which may guide scientific urban planning for sustainable urban development.


Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 584 ◽  
Author(s):  
Zuzheng Li ◽  
Xiaoqin Cheng ◽  
Hairong Han

Ecosystem services (ES), defined as benefits provided by the ecosystem to society, are essential to human well-being. However, it remains unclear how they will be affected by land-use changes due to lack of knowledge and data gaps. Therefore, understanding the response mechanism of ecosystem services to land-use change is critical for developing systematic and sound land planning. In this study, we aimed to explore the impacts of land-use change on the three ecosystem services, carbon storage (CS), flood regulation (FR), and soil conservation (SC), in the ecological conservation area of Beijing, China. We first projected land-use changes from 2015 to 2030, under three scenarios, i.e., Business as Usual (BAU), Ecological Land Protection (ELP), and Rapid Economic Development (RED), by interactively integrating the Markov model (Quantitative simulation) with the GeoSOS-FLUS model (Spatial arrangement), and then quantified the three ecosystem services by using a spatially explicit InVEST model. The results showed that built-up land would have the most remarkable growth during 2015–2030 under the RED scenario (2.52% increase) at the expense of cultivated and water body, while forest land is predicted to increase by 152.38 km2 (1.36% increase) under the ELP scenario. The ELP scenario would have the highest amount of carbon storage, flood regulation, and soil conservation, due to the strict protection policy on ecological land. The RED scenario, in which a certain amount of cultivated land, water body, and forest land is converted to built-up land, promotes soil conservation but triggers greater loss of carbon storage and flood regulation capacity. The conversion between land-use types will affect trade-offs and synergies among ecosystem services, in which carbon storage would show significant positive correlation with soil conservation through the period of 2015 to 2030, under all scenarios. Together, our results provide a quantitative scientific report that policymakers and land managers can use to identify and prioritize the best practices to sustain ecosystem services, by balancing the trade-offs among services.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Andrew Hansen ◽  
Kevin Barnett ◽  
Patrick Jantz ◽  
Linda Phillips ◽  
Scott J. Goetz ◽  
...  

Abstract Remotely sensed maps of global forest extent are widely used for conservation assessment and planning. Yet, there is increasing recognition that these efforts must now include elements of forest quality for biodiversity and ecosystem services. Such data are not yet available globally. Here we introduce two data products, the Forest Structural Condition Index (SCI) and the Forest Structural Integrity Index (FSII), to meet this need for the humid tropics. The SCI integrates canopy height, tree cover, and time since disturbance to distinguish short, open-canopy, or recently deforested stands from tall, closed-canopy, older stands typical of primary forest. The SCI was validated against estimates of foliage height diversity derived from airborne lidar. The FSII overlays a global index of human pressure on SCI to identify structurally complex forests with low human pressure, likely the most valuable for maintaining biodiversity and ecosystem services. These products represent an important step in maturation from conservation focus on forest extent to forest stands that should be considered “best of the last” in international policy settings.


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