scholarly journals Revisiting the limnology of Lake Río Cuarto, Costa Rica, thirty-five years later

2018 ◽  
Vol 66 (1-1) ◽  
pp. 42
Author(s):  
Gerardo Umaña-Villalobos ◽  
Aldo Farah-Pérez
Keyword(s):  
Land Use ◽  
Costa Rica ◽  
Global Climate ◽  
Land Use Changes ◽  
Secchi Depth ◽  
Aerial Photographs ◽  
Tree Cover ◽  
Relative Depth ◽  
Oxygen Conductivity ◽  
The North

Lake Río Cuarto is a meromictic lake at low elevation in the North of Costa Rica. It offers an opportunity to compare its present state with the condition it had when first studied in the late 1970’s and occasional samplings since then. This comparison expects to identify changes that could be attributed to incipient effects of global climate change. We studied the limnology and conditions of its drainage area for three years (2013-2016) to compare with previous data. Vertical profiles of temperature, dissolved oxygen, conductivity, pH, chlorophyll a, dissolved H2S were performed several times per year, for a total of 22 samplings. Aerial photographs taken since 1950 were analyzed to describe land use changes. The lake had a shallow Secchi depth (< 5 m) at all times. It was stratified on all occasions, with a thermocline that fluctuated between 10 and 20 m. It has a monimolimnion, with a chemocline at 14 to 22 m. Below the chemocline it was always anoxic, and during annual partial mixing events in the mixolimnion, oxygen levels decreased compared to stratified periods. There was a continuous presence of H2S from 20 m downwards, with annual fluctuations, being lower during partial mixing events. A peak in chlorophyll was detected on all occasions just below the thermocline. Land use around the lake hasn’t changed much since 1952, when only a rim of tree cover was left around the steep margins of the lake. The lake has maintained its limnological characteristics, with the only exception that it didn’t cooled down to historical levels. This limited response could be the result of the high relative depth and steep margins of the lake, which prevent the downward distribution of heat and keeps the lake in a meromictic state, preventing its mixing for long periods of time.

scholarly journals Evolution récente et future des paysages sylvo-pastoraux du Jura vaudois

2012 ◽  
Vol 163 (12) ◽  
pp. 469-480
Author(s):  
Alexandre Buttler ◽  
Thomas Spiegelberger ◽  
Joël Chételat ◽  
Michael Kalbermatten ◽  
Katy Lannas ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Changes ◽  
Aerial Photographs ◽  
Tree Cover ◽  
General Tendency ◽  
Future Evolution ◽  
Goods And Services ◽  
Long Run ◽  
Cover Density

Recent and future evolution of the silvopastoral landscape in the Jura vaudois Land-use management in silvopastoral landscapes is particularly complex because such ecosystems depend on a subtle equilibrium in the management scheme which aims to provide various ecological goods and services such as fodder, timber and biodiversity, as well as areas for leisure and attractive scenery. In this study we investigated land-use changes in the Parc naturel régional Jura vaudois, and the changes in tree cover density in two pastures using land-use statistics and aerial photographs. A prospective modelling approach was also undertaken on one pasture to assess changes in the landscape structure under two climate scenarios. A general tendency towards segregation between closed forests and open pastures was observed. The agriculture policy has markedly influenced the dynamics of tree cover density, but this effect depended very much on the local situation, for example, the proximity of a village, which allows a better optimization of farm management. The simulation of future development of these landscapes suggests that one might expect large changes in the structure and composition of the vegetation because of climate change. In the long run, areas of high tree densities will expand, and spruce will give way to beech and pine, depending on the warming intensity. Nevertheless, adaptation to new environmental conditions for sustaining ecological goods and services will call for management measures appropriate to the intensity of climate change. Furthermore, an active adaptive management based on experimentation and innovation, as well as allowing collaboration between scientists and land managers will be required to face and mitigate the ecological problems associated with climate change.

scholarly journals Correction to: The impacts of agricultural and urban land-use changes on plant and bird biodiversity in Costa Rica (1986–2014)

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Andrea Montero ◽  
Joan Marull ◽  
Enric Tello ◽  
Claudio Cattaneo ◽  
Francesc Coll ◽  
...  
Keyword(s):  
Land Use ◽  
Costa Rica ◽  
Land Use Changes ◽  
Urban Land ◽  
Urban Land Use

scholarly journals Assessment of the soil loss caused by riverbank erosion in Serbia

2021 ◽  
Vol 101 (1) ◽  
pp. 31-47
Author(s):  
Marko Langovic ◽  
Slavoljub Dragicevic ◽  
Ivan Novkovic ◽  
Nenad Zivkovic ◽  
Radislav Tosic ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Loss ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Land Use Changes ◽  
Arable Land ◽  
Aerial Photographs ◽  
Lateral Migration ◽  
Channel Migration ◽  
Riverbank Erosion

Riverbank erosion and lateral channel migration are important geomorphological processes which cause various landscape, socio-economic, and environmental consequences. Although those processes are present on the territory of Serbia, there is no available data about the soil loss caused by riverbank erosion for the entire country. In this study, the spatial and temporal dynamics of the riverbank erosion for the largest internal rivers in Serbia (Velika Morava, Zapadna Morava, Juzna Morava, Pek, Mlava, Veliki Timok, Kolubara) was assessed using remote sensing and GIS. The aim of this paper is to determine the total and average soil loss over large-scale periods (1923-2020), comparing data from the available sources (aerial photographs, satellite images, and different scale paper maps). Results indicated that lateral migration caused significant problems through land loss (approximately 2,561 ha), especially arable land, and land use changes in river basins, but also economic loss due to the reduction of agricultural production. Total and average soil loss was calculated for five most representative meanders on all studied rivers, and on the basis of the obtained values, certain regularities about further development and dynamics of riverbank movement are presented. A better understanding of river channel migration in this area will be of a great importance for practical issues such as predicting channel migration rates for river engineering and planning purposes, soil and water management and land use changes, environment protection.

scholarly journals Landscape Ecological Structure in the Eastern Part of the North Vidzeme Biosphere Reserve, Latvia

2008 ◽  
Vol 62 (1-2) ◽  
pp. 63-70
Author(s):  
Aivars Tērauds ◽  
Oļgerts Nikodemus ◽  
Inga Rasa ◽  
Simons Bells
Keyword(s):  
Land Use ◽  
Landscape Structure ◽  
Land Use Changes ◽  
Biosphere Reserve ◽  
Forest Area ◽  
Forest Patches ◽  
Ecological Structure ◽  
The North ◽  
Landscape Units ◽  
Landscape Ecological

Landscape Ecological Structure in the Eastern Part of the North Vidzeme Biosphere Reserve, Latvia Latvia is a country where the forest area has increased and habitat fragmentation has reversed compared with many other European countries. In order to examine the effect of this expansion on biodiversity, vegetation maps dating from 2002 and the years 1930-1936 were used for comparative landscape structure analyses while archive materials from forest plans, and data from the national forest management database were used for land use analysis. Four landscape ecoregions in the eastern side of the North Vidzeme Biosphere Reserve were selected for analysis. Landscape structure indicators derived from landscape ecology were used for the ecological assessment of land use changes. The total number of forest patches had decreased over the study period, but mean patch size had increased for all types of landscape element. This general change was found to vary between different landscape units in the study area. The biggest change in the area of forest patches occurred in the Rūjiena drumlin field, where the amount of forest patches decreased least and forest area increased the most. This study showed that the internal structure of the forest matrix changed substantially. This finding has implications for biodiversity protection if this trend of land use change continues.

Land Planning, Agro-forest Systems, and Implications for Ecosystem Services: Insights from Northern Italy

2021 ◽  
Author(s):  
Antonio Tomao ◽  
Barbara Ermini ◽  
Marcela Prokopov ◽  
Adriano Conte
Keyword(s):  
Land Use ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Value Added ◽  
Temporal Analysis ◽  
Land Use Land Cover ◽  
Development Patterns ◽  
The North ◽  
Multi Temporal ◽  
Potential Impact

Negative environmental changes generally addressed as ‘syndromes’ are evaluated in the context of Soil Degradation (SD) and interpreted by using a ‘Land-Use/Land Cover Changes’ (LULCCs) framework in order to disentangle ‘past trajectories’, ‘present patterns’, and ‘future changes’. This approach allows to discuss the potential impact on SD processes and it represents an informed basis for identifying measurable outcomes of SD. This study focuses on the case of Emilia Romagna, a region located in the North of Italy with high-value added agricultural productions. A multi-temporal analysis of land-use changes between 1954 and 2008 has been proposed, discussing the evolution of associated SD syndromes in Emilia Romagna. The contributing information have been used as a baseline for Sustainable Land Management (SLM) strategies. This framework of analysis provides useful tools to investigate and to monitor the effects of SD in the Mediterranean basin where several regions underwent common development patterns yelding global pathological symptoms of environmental degradation.

scholarly journals Runoff processes and land use changes in the upper reaches of the Krupá river catchment during the last 70 years

2008 ◽  
Vol 2 (No. 3) ◽  
pp. 77-84
Author(s):  
R. Pavelková Chmelová ◽  
B. Šarapatka ◽  
M. Dumbrovský ◽  
P. Pavka
Keyword(s):  
Land Use ◽  
River Basin ◽  
Hydrological Model ◽  
Land Use Changes ◽  
Aerial Photographs ◽  
Historical Maps ◽  
River Catchment ◽  
Cadastral Maps ◽  
Left Tributary ◽  
Morava River

In this paper, the authors summarise the land use changes in the upper reaches of the Krup&aacute; river catchment, which is a left tributary of the Morava River. During last 70 years, the catchment was exposed to many important historical events that have been inscribed in the physique of the landscape in a very interesting way. The land use changes, which occurred during the last eight decades in the subcatchment of the Krup&aacute; river basin, have been analysed using historical maps, cadastral maps, and both historical and recent aerial photographs of the area. The next step is to estimate, through the CN method and DesQ hydrological model, how the runoff processes in the Krup&aacute; River catchment could be influenced by the land use changes.

scholarly journals Reconstructing long-term gully dynamics in Mediterranean agricultural areas

2017 ◽  
Vol 21 (1) ◽  
pp. 235-249 ◽  
Author(s):  
Antonio Hayas ◽  
Tom Vanwalleghem ◽  
Ana Laguna ◽  
Adolfo Peña ◽  
Juan V. Giráldez
Keyword(s):  
Land Use ◽  
Temporal Resolution ◽  
Land Use Changes ◽  
Mediterranean Area ◽  
Gully Erosion ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Erosion Rates ◽  
Erosion Processes

Abstract. Gully erosion is an important erosive process in Mediterranean basins. However, the long-term dynamics of gully networks and the variations in sediment production in gullies are not well known. Available studies are often conducted only over a few years, while many gully networks form, grow, and change in response to environmental and land use or management changes over a long period. In order to clarify the effect of these changes, it is important to analyse the evolution of the gully network with a high temporal resolution. This study aims at analysing gully morphodynamics over a long timescale (1956–2013) in a large Mediterranean area in order to quantify gully erosion processes and their contribution to overall sediment dynamics. A gully network of 20 km2 located in southwestern Spain has been analysed using a sequence of 10 aerial photographs in the period 1956–2013. The extension of the gully network both increased and decreased in the study period. Gully drainage density varied between 1.93 km km−2 in 1956, a minimum of 1.37 km km−2 in 1980, and a maximum of 5.40 km km−2 in 2013. The main controlling factor of gully activity appeared to be rainfall. Land use changes were found to have only a secondary effect. A new Monte Carlo-based approach was proposed to reconstruct gully erosion rates from orthophotos. Gully erosion rates were found to be relatively stable between 1956 and 2009, with a mean value of 11.2 t ha−1 yr−1. In the period 2009–2011, characterized by severe winter rainfalls, this value increased significantly to 591 t ha−1 yr−1. These results show that gully erosion rates are highly variable and that a simple interpolation between the starting and ending dates greatly underestimates gully contribution during certain years, such as, for example, between 2009 and 2011. This illustrates the importance of the methodology applied using a high temporal resolution of orthophotos.

scholarly journals The Importance of Environmental Factors for the Development of Water Erosion of Soil in Agricultural Land: The Southern Part of Hronská Pahorkatina Hill Land, Slovakia

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1234
Author(s):  
Viera Petlušová ◽  
Peter Petluš ◽  
Michal Ševčík ◽  
Juraj Hreško
Keyword(s):  
Land Use ◽  
Environmental Factors ◽  
Geographical Information Systems ◽  
Agricultural Land ◽  
Land Use Changes ◽  
Water Erosion ◽  
Geographical Information ◽  
Aerial Photographs ◽  
Slope Length ◽  
Erosion Processes

The water erosion research was carried out in the lowland type of hilly landscape. The aim was to monitor and evaluate the importance of environmental factors (steepness of slope, relief shapes, aspect, slope length, combination slope length (L) and slope (S)—LS factor, types of land use changes) for the development of water erosion. We focused on the identification of areas threatened by erosion by interpreting aerial photographs from several time periods. This was followed by verification of erosion using soil probes. We identified 408.44 ha of areas affected by erosion, and measured the depth of soil and “A” horizons thickness. The environmental factors were modeled in geographical information systems by tools for spatially oriented data. Subsequently, the influence and significance of individual environmental factors were compared, and the probability of erosion was statistically estimated. The decisive factors in the formation of erosive surfaces are the LS factor and the slope. We also consider the factor of the relief shape to be important. The shape did not appear to be very significant as a separately evaluated factor, but all convex parts correlate with the identified erosion surfaces. The susceptibility of erosion related to the aspect of the slopes to the cardinal directions has not been confirmed. Types of land use changes with the most significant relation of erosion were confirmed in areas of strong intensification. We confirmed the importance of factors and land use for the development of erosion processes.

Simulation of Nitrate Concentration Affected from Land Use Changes in the Lower Part of Yom River Basin,Thailand: A Preliminary Study

2014 ◽  
Vol 931-932 ◽  
pp. 738-743
Author(s):  
Satika Boonkaewwan ◽  
Srilert Chotpantarat
Keyword(s):  
Land Use ◽  
River Basin ◽  
Swat Model ◽  
Land Use Changes ◽  
Sediment Concentration ◽  
Model Parameters ◽  
The North ◽  
Optimal Values ◽  
Preliminary Study ◽  
Year 2000

The Lower Yom River Basin is located in the north of Thailand. This study carried out to calibrate and validate using SWAT model in terms of streamflow and sediment concentration hydrographs (Year 2000-2012) for 3 RID streamflow gauging stations (the Royal Irrigation Department). The nitrates concentrations simulate have been influenced of land use changes during last ten years. Optimal values of model parameters derived from calibration and validation processes, which showed well fitted between observed and simulated results. In the last decade, particular in Lower Yom River, the land use change gradually transformed to be more paddy field and has been increased 127.48 km2 (approx. 0.87% increase), followed by urban area, which has been increased 196.66 km2 (approx. 1.35% increase), respectively. Average monthly concentration of nitrate increased 38.28 mg/l (approx.13.40 % increase), 43.17 mg/l (approx.12.00% increase), 43.02 mg/l (approx. 8.60% increase) at station Y.6, Y.4 and Y.17, respectively. Accordingly, on the basis of the results presented in this study, land use changes can significantly affect on concentrations of nitrate.

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