scholarly journals Mapping the suitability of groundwater-dependent vegetation in a semi-arid Mediterranean area

2019 ◽  
Vol 23 (9) ◽  
pp. 3525-3552 ◽  
Author(s):  
Inês Gomes Marques ◽  
João Nascimento ◽  
Rita M. Cardoso ◽  
Filipe Miguéns ◽  
Maria Teresa Condesso de Melo ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Model ◽  
Groundwater Resources ◽  
Relative Proportion ◽  
Woody Species ◽  
Groundwater Depth ◽  
Climate Change Scenarios ◽  
Simple Linear Model ◽  
Southern Portugal ◽  
Semi Arid

Abstract. Mapping the suitability of groundwater-dependent vegetation in semi-arid Mediterranean areas is fundamental for the sustainable management of groundwater resources and groundwater-dependent ecosystems (GDEs) under the risks of climate change scenarios. For the present study the distribution of deep-rooted woody species in southern Portugal was modeled using climatic, hydrological and topographic environmental variables. To do so, Quercus suber, Quercus ilex and Pinus pinea were used as proxy species to represent the groundwater-dependent vegetation (GDV). Model fitting was performed between the proxy species Kernel density and the selected environmental predictors using (1) a simple linear model and (2) a geographically weighted regression (GWR) to account for autocorrelation of the spatial data and residuals. When comparing the results of both models, the GWR modeling results showed improved goodness of fit as opposed to the simple linear model. Climatic indices were the main drivers of GDV density, followed by a much lower influence by groundwater depth, drainage density and slope. Groundwater depth did not appear to be as pertinent in the model as initially expected, accounting only for about 7 % of the total variation compared to 88 % for climate drivers. The relative proportion of model predictor coefficients was used as weighting factors for multicriteria analysis to create a suitability map for the GDV in southern Portugal showing where the vegetation most likely relies on groundwater to cope with aridity. A validation of the resulting map was performed using independent data of the normalized difference water index (NDWI), a satellite-derived vegetation index. June, July and August of 2005 NDWI anomalies, for the years 1999–2009, were calculated to assess the response of active woody species in the region after an extreme drought. The results from the NDWI anomalies provided an overall good agreement with the suitability to host GDV. The model was considered to be reliable for predicting the distribution of the studied vegetation. The methodology developed to map GDVs will allow for the prediction of the evolution of the distribution of GDV according to climate change and aid stakeholder decision-making concerning priority areas of water resource management.

scholarly journals Mapping the suitability of groundwater dependent vegetation in a semi-arid Mediterranean area

2018 ◽  
Author(s):  
Inês Gomes Marques ◽  
João Nascimento ◽  
Rita M. Cardoso ◽  
Filipe Miguéns ◽  
Maria Teresa Condesso de Melo ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Model ◽  
Spatial Data ◽  
Aridity Index ◽  
Resource Depletion ◽  
Agroforestry Systems ◽  
Climatic Conditions ◽  
Climate Change Scenarios ◽  
Simple Linear Model ◽  
Southern Portugal

Abstract. The forecasted groundwater resource depletion under future climatic conditions will greatly influence subsurface groundwater dependent ecosystems and their associated vegetation. In the Mediterranean region this will create harsh conditions for the maintenance of agroforestry systems dependent on groundwater, such as cork oak woodlands. The threat of increasing aridity conditions will affect their productivity and eventually induce a shift in their geographical distribution. Thus, characterizing and modelling the relationship between environmental conditions and subsurface groundwater dependent vegetation (subsurface GDV) will allow to identify the main drivers controlling its distribution and predict future impacts of climate change. In this study, we built a model that explains subsurface GDV distribution in southern Portugal from climatic, hydrological and topographic environmental variables. To achieve this, we relied on the density of Quercus suber, Quercus ilex and Pinus pinea as proxy species of subsurface GDV. Model fitting was performed between the proxy species Kernel density and the selected environmental predictors using (1) a simple linear model and (2) a Geographically Weighted Regression (GWR), to account for auto-correlation of the spatial data and residuals. When comparing the results of both models, the GWR modelling results showed improved goodness of fitting, as opposed to the simple linear model. Soil type was the main driver of subsurface GDV density closely followed by the aridity index. Groundwater depth did not appear to be as pertinent in the model as initially expected. Model predictor coefficients were used as weighting factors for multicriteria analysis, to create a suitability map to the subsurface GDV in southern Portugal. A validation of the resulting map was performed using independent data of integrated potential distribution of each proxy tree species in the region and overall, there was an accordance between areas of good suitability to subsurface GDV. The model was considered reliable to predict the distribution of the studied vegetation, however, lack of data quality and information was shown to be the main cause for suitability discrepancies between maps. Our new methodology on mapping of subsurface GDV's will allow to predict the evolution of the distribution of subsurface GDV according to climate change scenarios and aid stakeholder decision-making concerning priority areas of water resources management.

Selection of models to describe the temperature-dependent development of Neoleucinodes elegantalis (Lepidoptera: Crambidae) and its application to predict the species voltinism under future climate conditions

2021 ◽  
pp. 1-9
Author(s):  
Hevellyn Talissa dos Santos ◽  
Cesar Augusto Marchioro
Keyword(s):  
Climate Change ◽  
Linear Model ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Temperature Dependent ◽  
Dependent Development ◽  
Degree Day ◽  
Non Linear ◽  
The Impact

Abstract The small tomato borer, Neoleucinodes elegantalis (Guenée, 1854) is a multivoltine pest of tomato and other cultivated solanaceous plants. The knowledge on how N. elegantalis respond to temperature may help in the development of pest management strategies, and in the understanding of the effects of climate change on its voltinism. In this context, this study aimed to select models to describe the temperature-dependent development rate of N. elegantalis and apply the best models to evaluate the impacts of climate change on pest voltinism. Voltinism was estimated with the best fit non-linear model and the degree-day approach using future climate change scenarios representing intermediary and high greenhouse gas emission rates. Two out of the six models assessed showed a good fit to the observed data and accurately estimated the thermal thresholds of N. elegantalis. The degree-day and the non-linear model estimated more generations in the warmer regions and fewer generations in the colder areas, but differences of up to 41% between models were recorded mainly in the warmer regions. In general, both models predicted an increase in the voltinism of N. elegantalis in most of the study area, and this increase was more pronounced in the scenarios with high emission of greenhouse gases. The mathematical model (74.8%) and the location (9.8%) were the factors that mostly contributed to the observed variation in pest voltinism. Our findings highlight the impact of climate change on the voltinism of N. elegantalis and indicate that an increase in its population growth is expected in most regions of the study area.

Germination strategies under climate change scenarios along an aridity gradient

2020 ◽  
Vol 13 (4) ◽  
pp. 470-477
Author(s):  
Alexander Zogas ◽  
Evsey Kosman ◽  
Marcelo Sternberg
Keyword(s):  
Climate Change ◽  
Seed Banks ◽  
Arid Ecosystems ◽  
Annual Rainfall ◽  
Strong Impact ◽  
Climate Change Scenarios ◽  
Aridity Gradient ◽  
Soil Seed Banks ◽  
Seed Germinability ◽  
Semi Arid

Abstract Aims Climate change in the eastern Mediterranean region will have a strong impact on ecosystem functioning and plant community dynamics due to a reduction in annual rainfall and increased variability. We aim to understand the role of seed banks as potential buffers against climatic uncertainty determined by climate change. Methods We examined germination strategies of 18 common species present along an aridity gradient. Data were obtained from soil seed banks germinated during nine consecutive years from arid, semi-arid, Mediterranean and mesic Mediterranean ecosystems. At the semi-arid and Mediterranean sites, rainfall manipulations simulating 30% drought and 30% rainfall increase were applied. Germination strategies were tested under optimal irrigation conditions during three consecutive germination seasons to determine overall seed germinability in each soil sample. Changes in germination strategy were examined using a novel statistical approach that considers the climatic and biotic factors that may affect seed germinability. Important Findings The results showed that dominant species controlled their germination fractions by producing seeds with a different yearly germination fraction probability. The amount of rainfall under which the seeds were produced led to two major seed types with respect to germinability: high germinability, seeds leading to transient seed banks, and low germinability, seeds leading to persistent seed banks. We conclude that differential seed production among wet and dry years of both seed types creates a stable balance along the aridity gradient, enabling the soil seed bank to serve as a stabilizing mechanism buffering against rainfall unpredictability. Additionally, we present a general model of germination strategies of dominant annual species in Mediterranean and arid ecosystems that strengthens the notion of soil seed banks as buffers against climatic uncertainty induced by climate change in the region.

scholarly journals The Response of Groundwater Level to Climate Change and Human Activities in Baotou City, China

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1078
Author(s):  
Yingjie Cui ◽  
Zilong Liao ◽  
Yongfu Wei ◽  
Xiaomin Xu ◽  
Yifan Song ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activities ◽  
Groundwater Resources ◽  
Reduction Rate ◽  
Northern China ◽  
Groundwater Depth ◽  
Wavelet Coherence ◽  
Confined Water ◽  
Groundwater Exploitation ◽  
Decrease Rate

The response mechanism of groundwater to climate change and human activities in cities within arid and semi-arid regions, such as the Urban Planning Area of Baotou City (UPABC), northern China, is a complicated problem to understand. We analyzed the climate change relationships, including precipitation and temperature, and analyzed changes in human activities, such as groundwater consumption, and then statistically analyzed the main factors affecting groundwater depth. Furthermore, cross-wavelet and wavelet coherence methods were used to analyze the response relationship and hysteresis of groundwater depth to precipitation to better understand the groundwater depth response law. The results showed that the annual precipitation in the UPABC reduction rate was 3.3 mm/10 yr, and the annual average temperature increase rate was 0.43 °C/10 yr, from 1981 to 2017. The unconfined water decrease rate was 0.50 m/yr, and the confined water decrease rate was 0.7 m/yr. The unconfined and confined water depths were affected by precipitation and groundwater exploitation, respectively, with correlation coefficients of 0.58 and 0.57, respectively. The hysteresis of groundwater depth to precipitation was about 9–14 months. However, changes in groundwater depth, especially confined water depth, were greatly affected by groundwater exploitation. This reflected the imbalance in consumption and recharges in the UPABC, highlighting the long-term risk in areas relying on access to this resource. Therefore, arid inland zones of northern China, such as the UPABC, should pay more attention to the rational development of groundwater and strengthen the management and protection of groundwater resources.

scholarly journals Long-Term Impacts of Partial Afforestation on Water and Salt Dynamics of an Intermittent Catchment under Climate Change

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1067 ◽  
Author(s):  
Hossein Daneshmand ◽  
Sina Alaghmand ◽  
Matteo Camporese ◽  
Amin Talei ◽  
Pat J.-F. Yeh ◽  
...  
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
General Circulation Models ◽  
Soil Salinization ◽  
Tree Planting ◽  
Climate Change Scenarios ◽  
Global Environmental ◽  
Salt Depletion ◽  
Hadley Centre ◽  
Semi Arid

Soil salinization is a major environmental issue in arid and semi-arid regions, and has been accelerated in some areas by removal of native vegetation cover. Partial afforestation can be a practical mitigation strategy if efficiently integrated with farms and pastures. Using an integrated surface-subsurface hydrological model, this study evaluates the water and salt dynamics and soil salinization conditions of a rural intermittent catchment in the semi-arid climate of southeast Australia subjected to four different partial afforestation configurations under different climate change scenarios, as predicted by several general circulation models. The results show that the locations of afforested areas can induce a retarding effect in the outflow of groundwater salt, with tree planting at lower elevations showing the steadier salt depletion rates. Moreover, except for the configuration with trees planted near the outlet of the catchment, the streamflow is maintained under all other configurations. It appears that under both Representative Concentration Pathways considered (RCP 4.5 and RCP 8.5), the Hadley Centre Global Environmental Model represents the fastest salt export scheme, whereas the Canadian Earth System Model and the Model for Interdisciplinary Research on Climate represent the slowest salt export scheme. Overall, it is found that the location of partial afforestation generally plays a more significant role than the climate change scenarios.

scholarly journals Groundwater Nitrate Contamination Integrated Modeling for Climate and Water Resources Scenarios: The Case of Lake Karla Over-Exploited Aquifer

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1201 ◽  
Author(s):  
Pantelis Sidiropoulos ◽  
Georgios Tziatzios ◽  
Lampros Vasiliades ◽  
Nikitas Mylopoulos ◽  
Athanasios Loukas
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Management Practices ◽  
Hydrological Modeling ◽  
Hydrological Cycle ◽  
Groundwater Resources ◽  
Future Climate Change ◽  
Agricultural Activity ◽  
Climate Change Scenarios ◽  
Modeling Tools

Groundwater quantity and quality degradation by agricultural practices is recorded as one of the most critical issues worldwide. This is explained by the fact that groundwater is an important component of the hydrological cycle, since it is a source of natural enrichment for rivers, lakes, and wetlands and constitutes the main source of potable water. The need of aquifers simulation, taking into account water resources components at watershed level, is imperative for the choice of appropriate restoration management practices. An integrated water resources modeling approach, using hydrological modeling tools, is presented for assessing the nitrate fate and transport on an over-exploited aquifer with intensive and extensive agricultural activity under various operational strategies and future climate change scenarios. The results indicate that climate change affects nitrates concentration in groundwater, which is likely to be increased due to the depletion of the groundwater table and the decrease of groundwater enrichment in the future water balance. Application of operational agricultural management practices with the construction and use of water storage infrastructure tend to compensate the groundwater resources degradation due to climate change impacts.

Is the impact of climate change on desertification predictable?

2020 ◽  
Author(s):  
YaoJie Yue ◽  
Min Li
Keyword(s):  
Climate Change ◽  
Inner Mongolia ◽  
North China ◽  
Evaluation Model ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Arid Areas ◽  
Sandy Land ◽  
Desertification Risk ◽  
Semi Arid

<p>Desertification, as one of the gravest ecological and environmental problems in the world, is affected both by climate change and human activities. As the consequences of global warming, the temperature in global arid and semi-arid areas is expected to increase by 1-3℃ by the end of this century. This change will significantly influence the spatial and temporal pattern of temperature, precipitation and wind speed in global arid and semi-arid areas, and in turn, ultimately impact the processing of desertification. Although current studies point out that future climate change tends to increase the risk of desertification. However, the future global or regional desertification risk under different climate change scenarios hasn’t been quantitively assessed. In this paper, we focused on this question by building a new model to evaluate this risk of desertification under an extreme climate change scenario, i.e. RCP8.5 (Representative Concentration Pathways, RCPs). We selected the northern agro-pastoral ecotone in China as the study area, where is highly sensitive to desertification. Firstly, the risk indicators of desertification were chosen in both natural and anthropic aspects, such as temperature, precipitation, wind speed, evaporation, and population. Secondly, the decision tree C5.0 algorithm of the machine learning technique was used to construct the quantitative evaluation model of land desertification risk based on the database of the 1:100,000 desertification map in China. Thirdly, with the support of the simulated meteorological data by General Circulation Models of HadGEM2-ES, the risk of desertification in the agro-pastoral ecotone in the north China under the RCP 8.5 scenario and SSP3 scenario (Shared Socioeconomic Pathways, SSPs) were predicted. The results show that the overall accuracy of the C5.0-based quantitative evaluation model for desertification risk is up to 83.32%, indicating that the C5.0 can better distinguish the risk of desertification according to the status of desertification impacting factors. Under the influence of future climate change, the agro-pastoral ecotone in northern China was estimated to be dominated by mild desertification risk, covering an area of more than 70%. Severe and moderate desertification risk is mainly distributed in the vicinity of Hulunbuir sandy land in the northeast of Inner Mongolia and the Horqin sandy land in the junction between Inner Mongolia, Jilin and Liaoning provinces. Compared with the datum period, the risk of desertification will decrease under the RCP8.5-SSP3 scenario. However, the desertification risk in Hulunbuir sandy land and that in the northwest of Jilin province will increase. The results of this study provide a scientific basis for developing more effective desertification control strategies to adapt to climate change in the agro-pastoral ecotone in north China. More importantly, it shows that the desertification risk can be predicted under the different climate change scenarios, which will help us to make a better understanding of the potential trend of desertification in the future, especially when the earth is getting warmer.</p>

scholarly journals Modeling impacts of climate change and human activities on groundwater resources using MODFLOW

2017 ◽  
Vol 9 (1) ◽  
pp. 156-177 ◽  
Author(s):  
Hossein Malekinezhad ◽  
Fatemeh Barzegai Banadkooki
Keyword(s):  
Climate Change ◽  
Irrigation System ◽  
Groundwater Resources ◽  
Circulation Model ◽  
Hydraulic Head ◽  
Water Levels ◽  
Climate Change Scenarios ◽  
Cropping Patterns ◽  
Aquifer Storage ◽  
Impacts Of Climate Change

Abstract This paper analyzes the impacts of climate change and human pressures on Yazd-Ardakan aquifer using the Hadley Centre Coupled Model, version 3 (HADCM3) circulation Model and A2 emission scenario. Water levels in the study aquifer were simulated using three-dimensional finite-difference groundwater model (MODFLOW 2000) with GMS 8.3 as pre- and postprocessing software. Input for groundwater recharge time series under the climate change scenarios were derived using a regression equation based on the cumulative deviation from mean rainfall using MATLAB. Human pressures on the aquifer were modeled through climate change impacts on water requirements of cultivated areas. Three scenarios were simulated to represent the effects of climate change and human pressures on aquifer storage and hydraulic head. Climate change and human pressures (scenario 1) will reduce aquifer storage and result in decreasing hydraulic head by −0.56 m year−1. Reduction in pumping water under scenario 2 (irrigation system modification) and scenario 3 (irrigation system modification and cropping patterns) will result in groundwater level fluctuation of about −0.32 and 0.08 m year−1, respectively. Scenario 3 is capable of restoring and protecting the groundwater resources in Yazd-Ardakan aquifer. The results of this study are useful to obtain sustainable groundwater management in Yazd-Ardakan aquifer.

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