Impacts of wildfire and post-fire land management on hydrological and sediment processes in a humid Mediterranean headwater catchment

The extensive afforestation of the Mediterranean rim of Europe in recent decades has increased the number of wildfire disturbances on hydrological and sediment processes, but the impacts on headwater catchments is still poorly understood, especially when compared with the previous agricultural landscape. This work monitored an agroforestry catchment in the north-western Iberian Peninsula, with plantation forests mixed with traditional agriculture using soil conservation practices, for one year before the fire and for three years afterwards, during which period the burnt area was plowed and reforested. During this period, continuous data was collected for meteorology, streamflow and sediment concentration at the outlet, erosion features were mapped and measured after major rainfall events, and channel sediment dynamics were monitored downstream from the agricultural and the burnt forest area. Data from 202 rainfall events with over 10 mm was analysed in detail.Results show that the fire led to a notable impact on sediment processes during the first two post-fire years, but not on streamflow processes; this despite the small size of the burnt area (10% of the catchment) and the occurrence of a severe drought in the first year after the fire. During this period, soil loss at the burnt forest slopes was much larger than that at most traditionally managed fields, and, ultimately, led to sediment exhaustion. At the catchment scale, storm characteristics were the dominant factor behind streamflow and sediment yield both before and after the fire. However, the data indicated a shift from detachment-limited sediment yield before the fire, to transport-limited sediment yield afterwards, with important increases in streamflow sediment concentration. This indicates that even small fires can temporarily change sediment processes in agroforestry catchments, with potential negative consequences for downstream water quality.

Download Full-text

Spatial and temporal patterns of suspended-sediment yield in the Saskatchewan River basin

Canadian Journal of Earth Sciences ◽

10.1139/e88-138 ◽

1988 ◽

Vol 25 (9) ◽

pp. 1450-1463 ◽

Cited By ~ 32

Author(s):

P. E. Ashmore ◽

T. J. Day

Keyword(s):

Suspended Sediment ◽

River Basin ◽

Sediment Yield ◽

Sediment Concentration ◽

Suspended Sediment Transport ◽

Spatial And Temporal Patterns ◽

Prairie Streams ◽

The North ◽

Discharge Regime ◽

Pattern Of Variation

Long-term suspended-sediment concentration and load records are available for 23 Water Survey of Canada sediment-monitoring stations in the Saskatchewan River basin, where the drainage areas range from 10 to over 300 000 km2. Mean annual sediment yield is greatest in the western Alberta Plains along the Oldman and Red Deer rivers (over 100 t km−2 year−1) and tends to increase downstream along the North and South Saskatchewan rivers until major reservoirs in Saskatchewan intervene. Average sediment concentration shows a pattern of variation similar to that of yield. Temporal aspects of suspended-sediment transport vary along the drainage network. The range and skewness of the yield–duration and concentration–duration curves are greater in the intermediate-size basins close to the Rocky Mountains and in two small basins with Prairie sources than they are in the large Prairie streams with mountain sources and the glacier-fed upper North Saskatchewan River. Similarly, infrequent flows transport a larger proportion of the annual load in the smaller Foothills and western Plains basins than in the large Prairie streams because of differences in drainage area and discharge regime.

Download Full-text

The Impact of Sanctions on North Korea’s Foreign Trade from the Perspective of the Comparative Advantage Theory

Economics and Management ◽

10.35854/1998-1627-2019-6-4-15 ◽

2019 ◽

pp. 4-15

Author(s):

I. A. Korgun ◽

G. D. Toloraya

Keyword(s):

Foreign Trade ◽

Competitive Advantage ◽

National Economy ◽

North Korea ◽

Rent Seeking ◽

Economic Transformation ◽

Global Trade ◽

Negative Consequences ◽

The North ◽

The Impact

The presented study analyzes the opportunities for North Korea to capitalize on its competitive advantages in foreign trade in the context of sanctions.Aim. The study aims to identify mechanisms that allow North Korea to engage in foreign trade in circumvention of UN sanctions and to analyze their impact on the national economy.Tasks. The authors analyze the structure of North Korea’s national economy, its initial competitive advantage, identify the specific features of North Korea’s foreign trade in the context of sanctions, and determine the consequences of illicit trade in circumvention of sanctions for the national economy.Methods. This study uses an interdisciplinary approach that combines the classical theory of competitive advantage with the concept of rent seeking, with the concept of rent seeking and analysis of trade flows.Results. The study shows that, despite the restrictions imposed by sanctions, North Korea strives to make the most of its advantages, such as resource availability and cheap labor, in global trade. The country builds its own export-import chains in circumvention of sanctions. These chains are rather mobile, flexible, and controlled by the elite. As a result, benefits from trade that could be evenly distributed among the population are concentrated in the hands of a narrow segment of society. ‘Rent seeking’ makes it possible to formulate the negative consequences of these processes for the North Korean economy and the international community.Conclusions. Solving the North Korean issue requires an economic transformation in the country through the replacement of restrictive sanctions with more constructive ones. The exclusion of North Korea from open global trade leads to the country’s marginalization and impairs the transparency of international commodity flows.

Download Full-text

Tree-Ring Analysis of Intermediate Hawthorn (Crataegus media Bechst.) in NW Poland

Forests ◽

10.3390/f12010029 ◽

2020 ◽

Vol 12 (1) ◽

pp. 29

Author(s):

Anna Cedro ◽

Bernard Cedro

Keyword(s):

Tree Ring ◽

Tree Rings ◽

Agricultural Landscape ◽

Positive Influence ◽

Dominant Factor ◽

Incremental Growth ◽

High Precipitation ◽

Ring Analysis ◽

Uncultivated Land ◽

Nw Poland

Intermediate hawthorn (Crataegus × media Bechst.) is broadly distributed in Europe but very rarely examined by dendrochronologists. In NW Poland, it is one of three naturally occurring hawthorn species, growing mainly at forest margins, along roads, in mid-field woodlots, and on uncultivated land. Biocenotically, it is a very valuable species. This study aimed to determine the age of trees, tree-ring dynamics, and growth–climate relationship for intermediate hawthorn. Signature years were also determined. Samples for analysis were collected from 22 trees growing in a typical agricultural landscape in a monospecific mid-field woodlot comprised of several hundred specimens of various ages and forms (shrubs and trees). Using classic methods of dendrochronological dating, a 40-year long chronology spanning 1981–2020 was constructed. The radial growth rate of intermediate hawthorn is comparable to other tree species forming stands in NW Poland and equals 2.41 mm/year. Considerable intersubject variability is noted, from 1.48 to 4.44 mm/year. The chronology was also used for dendroclimatological analyses, including correlation and response function and signature years. Of the meteorological parameters analyzed, annual incremental growth in hawthorn is the most strongly shaped by precipitation totals from May to August of the current vegetation year: high rainfall favors the formation of wide tree-rings. Statistically significant growth–climate relationships were also obtained for winter months (December of the preceding vegetation year, January and February), for which period negative correlation and regression values are noted for air temperature and insolation. Furthermore, high precipitation, low-temperature and low insolation late in the preceding vegetation year (especially in August) make a positive influence on the condition of trees in the upcoming growing season. Signature year analysis clearly pointed to precipitation as the dominant factor in shaping tree-rings in the studied hawthorn population. As there are no dendrochronological papers concerning indigenous hawthorn species, future studies should be expanded to include diverse geographic locations and habitat conditions and should include all three species of hawthorn occurring in Poland.

Download Full-text

Holocene polynya dynamics and their interaction with oceanic heat transport in northernmost Baffin Bay

Scientific Reports ◽

10.1038/s41598-021-88517-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rebecca Jackson ◽

Anna Bang Kvorning ◽

Audrey Limoges ◽

Eleanor Georgiadis ◽

Steffen M. Olsen ◽

...

Keyword(s):

Sediment Cores ◽

Active Role ◽

Atlantic Water ◽

The Arctic ◽

Negative Consequences ◽

Baffin Bay ◽

The North ◽

North Water ◽

History Of ◽

Ocean Conditions

AbstractBaffin Bay hosts the largest and most productive of the Arctic polynyas: the North Water (NOW). Despite its significance and active role in water mass formation, the history of the NOW beyond the observational era remains poorly known. We reconcile the previously unassessed relationship between long-term NOW dynamics and ocean conditions by applying a multiproxy approach to two marine sediment cores from the region that, together, span the Holocene. Declining influence of Atlantic Water in the NOW is coeval with regional records that indicate the inception of a strong and recurrent polynya from ~ 4400 yrs BP, in line with Neoglacial cooling. During warmer Holocene intervals such as the Roman Warm Period, a weaker NOW is evident, and its reduced capacity to influence bottom ocean conditions facilitated northward penetration of Atlantic Water. Future warming in the Arctic may have negative consequences for this vital biological oasis, with the potential knock-on effect of warm water penetration further north and intensified melt of the marine-terminating glaciers that flank the coast of northwest Greenland.

Download Full-text

Torrential Flood Water Management: Rainwater Harvesting through Relation Based Dam Suitability Analysis and Quantification of Erosion Potential

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi10010027 ◽

2021 ◽

Vol 10 (1) ◽

pp. 27

Author(s):

Bilal Ahmad Munir ◽

Sajid Rashid Ahmad ◽

Raja Rehan

Keyword(s):

Sediment Yield ◽

Soil Loss ◽

Rainwater Harvesting ◽

Suitability Analysis ◽

Valley Bottom ◽

The North ◽

Roughness Index ◽

Dam Site ◽

Very High

In this study, a relation-based dam suitability analysis (RDSA) technique is developed to identify the most suitable sites for dams. The methodology focused on a group of the most important parameters/indicators (stream order, terrain roughness index, slope, multiresolution valley bottom flatness index, closed depression, valley depth, and downslope gradient difference) and their relation to the dam wall and reservoir suitability. Quantitative assessment results in an elevation-area-capacity (EAC) curve substantiating the capacity determination of selected sites. The methodology also incorporates the estimation of soil erosion (SE) using the Revised Universal Soil Loss Equation (RUSLE) model and sediment yield at the selected dam sites. The RDSA technique identifies two suitable dam sites (A and B) with a maximum collective capacity of approximately 1202 million m3. The RDSA technique was validated with the existing dam, Gomal-Zam, in the north of Sanghar catchment, where RDSA classified the Gomal-Zam Dam in a very high suitability class. The SE estimates show an average of 75 t-ha−1y−1 of soil loss occurs in the study area. The result shows approximately 298,073 and 318,000 tons of annual average sediment yield (SY) will feed the dam A and B respectively. The SE-based sediment yield substantiates the approximate life of Dam-A and Dam-B to be 87 and 90 years, respectively. The approach is dynamic and can be applied for any other location globally for dam site selection and SE estimation.

Download Full-text

DIET QUALITY OF MOROCCAN ADOLESCENTS LIVING IN MOROCCO AND IN SPAIN

Journal of Biosocial Science ◽

10.1017/s0021932016000183 ◽

2016 ◽

Vol 49 (2) ◽

pp. 173-186 ◽

Cited By ~ 3

Author(s):

M. Del Pilar Montero ◽

Ana Isabel Mora-Urda ◽

Karim Anzid ◽

Mohamed Cherkaoui ◽

M. Dolores Marrodan

Keyword(s):

Diet Quality ◽

Eating Habits ◽

Meat Consumption ◽

Negative Consequences ◽

The North ◽

Socioeconomic Changes ◽

Cholesterol Intake ◽

Growth Development ◽

And Migration

SummaryIntra-population socioeconomic changes and migration are powerful factors in changing eating habits. Changes in eating habits could affect the nutritional status, growth, development and health of adolescents. The aim of this study was to compare the diet of adolescents of Moroccan origin living in Spain with that of adolescents living in Morocco. The sample comprised 428 Moroccan adolescents aged from 12 to 19 recruited in high schools: 327 living in Ouarzazate (Morocco) and 101 living in Madrid (Spain). The variables studied were energy intake (kcal/day), diet quality indicators (adherence to the Mediterranean Adequacy Index (MAI); cholesterol intake (mg/day); fibre intake (g/day) and energy profile)); and indicators of keeping traditional customs (halalmeat consumption, bread made at home). Teenagers from Morocco living in Madrid consumed more calories, proteins, saturated fats and simple sugars (p<0.001) than those living in Morocco. Their diet was of lower quality than that of their peers in Morocco. This difference was more marked in boys than in girls. Changes in eating habits associated with migration from the south to the north Mediterranean basin can benefit young migrants in an immediate way (through greater availability of energy and nutrients), but later in life it could have negative consequences for their health, increasing the risk of overweight, obesity and cardiovascular and metabolic problems.

Download Full-text

Stress-testing groundwater and baseflow drought sensitivity to recharge

10.5194/egusphere-egu21-10511 ◽

2021 ◽

Author(s):

Jost Hellwig ◽

Michael Stoelzle ◽

Kerstin Stahl

Keyword(s):

Fractured Rock ◽

Drought Severity ◽

Severe Drought ◽

Stress Tests ◽

Drought Sensitivity ◽

The North ◽

Groundwater Response ◽

Dry Spells ◽

Groundwater Drought ◽

Fractured Rock Aquifers

Groundwater is the main source of freshwater and maintains streamflow during drought. Potential future groundwater and baseflow drought hazards depend on the systems' sensitivity to altered recharge conditions. We performed groundwater model experiments using three different generic stress tests to estimate the groundwater- and baseflow drought sensitivity to changes in recharge. The stress tests stem from a stakeholder co-design process that specifically followed the idea of altering known drought events from the past, i.e. asking whether altered recharge could have made a particular event worse. Here we show that groundwater responses to the stress tests are highly heterogeneous across Germany with groundwater heads in the North more sensitive to long-term recharge and in the Central German Uplands to short-term recharge variations. Baseflow droughts are generally more sensitive to intra-annual dynamics and baseflow responses to the stress tests are smaller compared to the groundwater heads. The groundwater drought recovery time is mainly driven by the hydrogeological conditions with slow (fast) recovery in the porous (fractured rock) aquifers. In general, a seasonal shift of recharge (i.e., less summer recharge and more winter recharge) will therefore have low effects on groundwater and baseflow drought severity. A lengthening of dry spells might cause much stronger responses, especially in regions with slow groundwater response to precipitation. Water management may need to consider the spatially different sensitivities of the groundwater system and the potential for more severe groundwater droughts in the large porous aquifers following prolonged meteorological droughts, particularly in the context of climate change projections indicating stronger seasonality and more severe drought events.

Download Full-text

Improving MUSLE performance for sediment yield prediction at micro-watershed level using seasonal classified data

Water Practice & Technology ◽

10.2166/wpt.2018.061 ◽

2018 ◽

Vol 13 (3) ◽

pp. 505-512

Author(s):

Hamzeh Noor ◽

Mohammad Rostami Khalaj

Keyword(s):

Sediment Yield ◽

Traditional Approach ◽

Estimation Error ◽

Superior Performance ◽

North East ◽

Erosion Processes ◽

The North ◽

East Of Iran ◽

Different Seasons

Abstract Separating erosion data and assessing season-based models are of great importance considering the variation in soil erosion processes in different seasons, especially in semi-arid regions. However, evaluation of an erosion model using seasonal classification of data and at a micro-watershed level have rarely been considered. Therefore, the present study was conducted to evaluate the modified universal soil loss equation (MUSLE): 1) with the seasonal classification of data and 2) with the traditional approach (no classification of data), in the Sanganeh research micro-watershed. This watershed has an area of 1.2 ha and is located in the north east of Iran. The results showed that the original MUSLE overestimated the sediment yield in the study watershed. Also, after calibration of MUSLE, the seasonal classification of data (with a relative estimation error (RE) of 34%) showed its superior performance compared with the traditional calibration approach (with a RE of 62%). In this regard, the obtained REs of 33, 40, and 31% respectively for spring, autumn, and winter are within or close to the acceptable range.

Download Full-text

ANALYSIS OF SUCTION DISTRIBUTION RESPONSE TO RAINFALL EVENT AND TREE CANOPY

Jurnal Teknologi ◽

10.11113/jt.v78.9627 ◽

2016 ◽

Vol 78 (8-5) ◽

Author(s):

Mohd FakhrurazziIshak ◽

Nazri Ali ◽

Azman Kassim

Keyword(s):

Matric Suction ◽

Field Monitoring ◽

Rainfall Event ◽

Tree Canopy ◽

Dominant Factor ◽

Residual Soil ◽

Initial Condition ◽

Canopy Interception ◽

Rainfall Events ◽

Sloping Surface

This study provides an exploration of matric suction influenced by tree canopy interception on a single rainfall event. A field monitoring was carried out to measure matric suction at slope with two conditions; at toe of slope without tree and with a tree at toe of slope on a tropical residual soil. The variation in matric suction values and matric suction profiles response to the rainfall events on slope with and without a tree at toe were analysed to reveal the effect of the tree canopy. At initial condition, the matric suction was significantly higher at vicinity of tree compared to that of area without tree at toe of slope. However, a typical short and intense tropical rainfall has caused the matric suction to drop dramatically to a minimum value on slope without tree. This condition did not occur on slope with tree. Although, both slopes (with and without tree at toe) received the same amount of precipitation rainfall but the different responses in matric suction valueswere clearly shown at slope with tree at the slope toe. The short and intense rainfalls appeared to be the dominant factor to the suction variation at slope without tree, but not at slope with the tree. The tree canopy can be a factor to influence the suction variation at slope with tree as canopy interception reduced the amount of precipitation to the ground/sloping surface

Download Full-text

Monitoring mass changes in the Volta River basin using GRACE satellite gravity and TRMM precipitation

Boletim de Ciências Geodésicas ◽

10.1590/s1982-21702012000400003 ◽

2012 ◽

Vol 18 (4) ◽

pp. 549-563 ◽

Cited By ~ 12

Author(s):

Vagner G. Ferreira ◽

Zheng Gong ◽

Samuel A. Andam-Akorful

Keyword(s):

River Basin ◽

Gravity Data ◽

West African ◽

Rainfall Time Series ◽

Tropical Rainfall Measurement Mission ◽

Satellite Gravity ◽

Rainfall Events ◽

The North ◽

Trmm Precipitation ◽

Grace Satellite

GRACE satellite gravity data was used to estimate mass changes within the Volta River basin in West African for the period of January, 2005 to December, 2010. We also used the precipitation data from the Tropical Rainfall Measurement Mission (TRMM) to determine relative contributions source to the seasonal hydrological balance within the Volta River basin. We found out that the seasonal mass change tends to be detected by GRACE for periods from 1 month in the south to 4 months in the north of the basin after the rainfall events. The results suggested a significant gain in water storage in the basin at reference epoch 2007.5 and a dominant annual cycle for the period under consideration for both in the mass changes and rainfall time series. However, there was a low correlation between mass changes and rainfall implying that there must be other processes which cause mass changes without rainfall in the upstream of the Volta River basin.

Download Full-text