Water-Sediment Physicochemical Dynamics in a Large Reservoir in the Mediterranean Region under Multiple Stressors

Nowadays, the Mediterranean freshwater systems face the threat of water scarcity, along with multiple other stressors (e.g., organic and inorganic contamination, geomorphological alterations, invasive species), leading to the impairment of their ecosystem services. All these stressors have been speeding up, due to climate variability and land cover/ land use changes, turning them into a big challenge for the water management plans. The present study analyses the physicochemical and phytoplankton biomass (chlorophyll-a) dynamics of a large reservoir, in the Mediterranean region (Alqueva reservoir, Southern Portugal), under diverse meteorological conditions and land cover/land use real scenarios (2017 and 2018). The most important stressors were identified and the necessary tools and information for a more effective management plan were provided. Changes in these parameters were further related to the observed variations in the meteorological conditions and in the land cover/land use. The increase in nutrients and ions in the water column, and of potentially toxic metals in the sediment, were more obvious in periods of severe drought. Further, the enhancement of nutrients concentrations, potentially caused by the intensification of agricultural activities, may indicate an increased risk of water eutrophication. The results highlight that a holistic approach is essential for a better water resources management strategy.

Download Full-text

CHANGES IN PARAMETERIZATIONS OF REGIONAL CLIMATE MODEL REGCM4.4.5: THE ROLE OF LAND COVER ON REGIONAL CLIMATE OVER MEDITERRANEAN

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11811 ◽

2017 ◽

Vol 50 (2) ◽

pp. 1062

Author(s):

K. Velikou ◽

K. Tolika ◽

Ch. Anagnostopoulou

Keyword(s):

Land Use ◽

Land Cover ◽

Regional Climate Model ◽

Mediterranean Region ◽

Climate Model ◽

Heat Waves ◽

Regional Climate ◽

Land Use Changes ◽

Mediterranean Forests ◽

The Mediterranean

A parameter that affects significantly the local, regional and global climate system is land cover and the changes that may occur to it. During winter season, heavy precipitation assists vegetation growth of Mediterranean forests and woodlands, whereas during summer, absence of precipitation and severe heat waves result to arid and semiarid vegetation. For that reason, it was quite interesting to track the changes that may occur in the climate of the Mediterranean region due to land cover/land use changes on regional climate over the Mediterranean region. The main objective of the study is the assessment of the impacts of land cover/land use changes on regional climate over the Mediterranean region. The examined regional climate model used in the study is RegCM4.4.5. Its spatial resolution is 25x25km and different simulations were performed with changes in land cover/land use for the time period 1981-1990. The different simulated data were compared in order to examine the modifications that occur from land cover/land use changes in evapotranspiration and surface albedo to direct and diffuse radiation in the domain of study.

Download Full-text

Impacts of land use/cover change on soil properties in the Mediterranean region of northwestern Jordan

Land Degradation and Development ◽

10.1002/ldr.847 ◽

2008 ◽

Vol 19 (4) ◽

pp. 397-407 ◽

Cited By ~ 41

Author(s):

Sa'eb Khresat ◽

Jawad Al-Bakri ◽

Ragheb Al-Tahhan

Keyword(s):

Land Use ◽

Soil Properties ◽

Mediterranean Region ◽

The Mediterranean

Download Full-text

Dynamics of human-induced lakes and their impact on land surface temperature in Toshka Depression, Western Desert, Egypt

10.21203/rs.3.rs-229433/v1 ◽

2021 ◽

Author(s):

Rasha Abou Samra

Keyword(s):

Land Use ◽

Land Cover ◽

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Vegetation Index ◽

Research Area ◽

Western Desert ◽

Severe Drought ◽

Land Use Land Cover

Abstract Land surface temperature (LST) is a significant environmental variable that is appreciably influenced by land use /land cover changes. The main goal of this research was to quantify the impacts of land use/land cover change (LULC) from the drying of Toshka Lakes on LST by remote sensing and GIS techniques. Landsat series TM and OLI satellite images were used to estimate LST from 2001 to 2019. Automated Water Extraction Index (AWEI) was applied to extract water bodies from the research area. Optimized Soil-Adjusted Vegetation Index (OSAVI) was utilized to predict the reclaimed land in the Toshka region until 2019. The results indicated a decrease in the lakes by about 1517.79 km2 with an average increase in LST by about 25.02 °C between 2001 and 2019. It was observed that the dried areas of the lakes were converted to bare soil and are covered by salt crusts. The results indicated that the land use change was a significant driver for the increased LST. The mean annual LST increased considerably by 0.6 °C/y between 2001 and 2019. A strong negative correlation between LST and Toshka Lakes area (R-square = 0.98) estimated from regression analysis implied that Toshka Lakes drying considerably affected the microclimate of the study area. Severe drought conditions, soil degradation, and many environmental issues were predicted due to the rise of LST in the research area. There is an urgent need to develop favorable strategies for sustainable environmental management in the Toshka region.

Download Full-text

Modelling the effects of land-cover changes on surface climate in the Mediterranean region

Climate Research ◽

10.3354/cr00841 ◽

2010 ◽

Vol 41 ◽

pp. 91-104 ◽

Cited By ~ 28

Author(s):

A Anav ◽

PM Ruti ◽

V Artale ◽

R Valentini

Keyword(s):

Land Cover ◽

Mediterranean Region ◽

Land Cover Changes ◽

Surface Climate ◽

The Mediterranean

Download Full-text

Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-4997-2015 ◽

2015 ◽

Vol 8 (6) ◽

pp. 4997-5040 ◽

Cited By ~ 2

Author(s):

M. Fader ◽

W. von Bloh ◽

S. Shi ◽

A. Bondeau ◽

W. Cramer

Keyword(s):

Land Use ◽

Mediterranean Region ◽

Management Practices ◽

Climate Change Impacts ◽

Biodiversity Loss ◽

Ecosystem Model ◽

The Mediterranean ◽

Olive Trees ◽

Agricultural Yields ◽

Fodder Grasses

Abstract. Climate and land use change in the Mediterranean region is expected to affect natural and agricultural ecosystems by decreases in precipitation, increases in temperature as well as biodiversity loss and anthropogenic degradation of natural resources. Demographic growth in the Eastern and Southern shores will require increases in food production and put additional pressure on agro-ecosystems and water resources. Coping with these challenges requires informed decisions that, in turn, require assessments by means of a comprehensive agro-ecosystem and hydrological model. This study presents the inclusion of 10 Mediterranean agricultural plants, mainly perennial crops, in an agro-ecosystem model (LPJmL): nut trees, date palms, citrus trees, orchards, olive trees, grapes, cotton, potatoes, vegetables and fodder grasses. The model was successfully tested in three model outputs: agricultural yields, irrigation requirements and soil carbon density. With the development presented in this study, LPJmL is now able to simulate in good detail and mechanistically the functioning of Mediterranean agriculture with a comprehensive representation of ecophysiological processes for all vegetation types (natural and agricultural) and in a consistent framework that produces estimates of carbon, agricultural and hydrological variables for the entire Mediterranean basin. This development pave the way for further model extensions aiming at the representation of alternative agro-ecosystems (e.g. agroforestry), and opens the door for a large number of applications in the Mediterranean region, for example assessments on the consequences of land use transitions, the influence of management practices and climate change impacts.

Download Full-text

Erosion Modelling In A Mediterranean Subcatchment Under Climate Change Scenarios Using Pan-European Soil Erosion Risk Assessment (PESERA)

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-7-w3-359-2015 ◽

2015 ◽

Vol XL-7/W3 ◽

pp. 359-365 ◽

Cited By ~ 8

Author(s):

A. Cilek ◽

S. Berberoglu ◽

M. Kirkby ◽

B. Irvine ◽

C. Donmez ◽

...

Keyword(s):

Climate Change ◽

Risk Assessment ◽

Land Use ◽

Soil Erosion ◽

Mediterranean Region ◽

Geographical Information ◽

Climate Change Scenarios ◽

Erosion Risk ◽

Soil Erosion Risk ◽

The Mediterranean

The Mediterranean region is particularly prone to erosion. This is because it is subject to long dry periods followed by heavy bursts of erosive rainfall, falling on steep slopes with fragile soils, resulting in considerable amounts of erosion. In parts of the Mediterranean region, erosion has reached a stage of irreversibility and in some places erosion has practically ceased because there is no more soil left. With a very slow rate of soil formation, any soil loss of more than 1 t ha−1 yr−1 can be considered as irreversible within a time span of 50-100 years. The objectives of this study were i) to estimate the temporal and spatial distribution of soil erosion under climate change scenarios in study area ii) to assess the hydrological runoff processes. In this study, climate data, land use, topographic and physiographic properties were assembled for Egribuk Subcatchment at Seyhan River Basin in Turkey and used in a process-based Geographical Information System (GIS) to determine the hydrological sediment potential and quantify reservoir sedimentation. The estimated amount of sediment transported downstream is potentially large based on hydrological runoff processes using the Pan-European Soil Erosion Risk Assessment (PESERA) model. The detailed model inputs included 128 variables derived mainly from, soil, climate, land use/cover, topography data sets. The outcomes of this research were spatial and temporal distribution of erosion amount in t ha−1 yr−1 or month−1.

Download Full-text

Analysis of streamflow response to land use and land cover changes using satellite data and hydrological modelling: case study of Dinder and Rahad tributaries of the Blue Nile (Ethiopia–Sudan)

Hydrology and Earth System Sciences ◽

10.5194/hess-21-5217-2017 ◽

2017 ◽

Vol 21 (10) ◽

pp. 5217-5242 ◽

Cited By ~ 10

Author(s):

Khalid Hassaballah ◽

Yasir Mohamed ◽

Stefan Uhlenbrook ◽

Khalid Biro

Keyword(s):

Land Use ◽

Land Cover ◽

Satellite Data ◽

Hydrological Modelling ◽

Model Parameters ◽

Land Cover Changes ◽

Severe Drought ◽

Blue Nile ◽

Large Expansion ◽

Streamflow Response

Abstract. Understanding the land use and land cover changes (LULCCs) and their implication on surface hydrology of the Dinder and Rahad basins (D&R, approximately 77 504 km2) is vital for the management and utilization of water resources in the basins. Although there are many studies on LULCC in the Blue Nile Basin, specific studies on LULCC in the D&R are still missing. Hence, its impact on streamflow is unknown. The objective of this paper is to understand the LULCC in the Dinder and Rahad and its implications on streamflow response using satellite data and hydrological modelling. The hydrological model has been derived by different sets of land use and land cover maps from 1972, 1986, 1998 and 2011. Catchment topography, land cover and soil maps are derived from satellite images and serve to estimate model parameters. Results of LULCC detection between 1972 and 2011 indicate a significant decrease in woodland and an increase in cropland. Woodland decreased from 42 to 14 % and from 35 to 14 % for Dinder and Rahad, respectively. Cropland increased from 14 to 47 % and from 18 to 68 % in Dinder and Rahad, respectively. The model results indicate that streamflow is affected by LULCC in both the Dinder and the Rahad rivers. The effect of LULCC on streamflow is significant during 1986 and 2011. This could be attributed to the severe drought during the mid-1980s and the recent large expansion in cropland.

Download Full-text