scholarly journals Catchment based hydrology under post farmland abandonment scenarios

2018 ◽  
Vol 44 (2) ◽  
pp. 503 ◽  
Author(s):  
N. Lana-Renault ◽  
M. López-Vicente ◽  
E. Nadal-Romero ◽  
R. Ojanguren ◽  
J.A. Llorente ◽  
...  
Keyword(s):  
Land Cover ◽  
Natural Forest ◽  
Land Abandonment ◽  
Hydrological Connectivity ◽  
Hydrological Response ◽  
Farmland Abandonment ◽  
Rainfall Events ◽  
Hydrological Responses ◽  
Dry Conditions ◽  
Terraced Fields

Vegetation expansion following farmland abandonment is a complex process that depends on multiple natural and human-induced factors, resulting in differences in the evolution of land cover on former cultivated fields, with various environmental implications. To assess the complexity of the hydrogeomorphological consequences of farmland abandonment, the Instituto Pirenaico de Ecología (CSIC) and the University of La Rioja monitored three small catchments, representative of different post land abandonment scenarios, in the Pyrenees and Iberian Range respectively. In the Pyrenees, a fourth small catchment, covered by natural forest, was monitored as a reference for an undisturbed environment. This study describes the evolution of land use in the abandoned catchments and examines its implications on catchment hydrological connectivity. It also analyses the hydrological responses of the three abandoned scenarios to similar rainfall events, and compares them to that of natural forested areas. .Vegetation tended to increase in the three catchments, but there were important differences in the characteristics of the current land cover. Arnás, the catchment left to a process of natural revegetation, contained a mosaic of shrubs (64%) and forest (27%) at different stages of succession, largely conditioned by the topography and soil properties. Araguás_afforestation was extensively afforested in the 1960s, with 75% of this catchment currently covered by forest, most of it planted artificially. In Munilla, occupied by terraced fields, vegetation recovery was partly restrained by the introduction of cattle, and 80% of the catchment was covered by sparse shrubs. Land abandonment resulted in a general reduction in computed hydrological connectivity in the three studied catchments, except in localized areas close to the main channel, new forest roads and trails, and upstream of terrace wall collapses, all areas of increased hydrological connectivity. The decrease in hydrological connectivity was much lower in Munilla, characterized by an absence of dense vegetation and still dominated by a terraced topography. The hydrological responses of the catchments to similar rainfall events differed significantly, showing the influence of not only vegetation cover but of the properties of soil remaining after previous agricultural activities. Significant storm-flow discharge was observed in Arnás, even under dry conditions, with high peakflows and fast responses. Lower streamflow response was observed in Araguás_Afforestation under dry conditions; however, once the soils were wet the hydrological response was notable and was characterized by high peakflow. The response under afforested trees differed greatly from that of a catchment covered by natural forest, with the latter characterized by gentler hydrographs. The hydrological response in Munilla was the lowest, with long response times and recessions, associated with the thick soils of the terraced fields. These results demonstrated the large variability of post land abandonment scenarios and associated hydrological implications, and highlighted the need to consider these differences to reduce future uncertainties in forecasting water resources and soil conservation.

scholarly journals Hydrological Responses to Land Use Land Cover Changes in the Fincha’a Watershed, Ethiopia

Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 916
Author(s):  
Urgessa Kenea ◽  
Dereje Adeba ◽  
Motuma Shiferaw Regasa ◽  
Michael Nones
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Local Governments ◽  
Swat Model ◽  
Landsat 8 ◽  
Land Use Land Cover ◽  
Hydrological Response ◽  
African Countries ◽  
Hydrological Responses ◽  
Basin Scale

Land use land cover (LULC) changes are highly pronounced in African countries, as they are characterized by an agriculture-based economy and a rapidly growing population. Understanding how land use/cover changes (LULCC) influence watershed hydrology will enable local governments and policymakers to formulate and implement effective and appropriate response strategies to minimize the undesirable effects of future land use/cover change or modification and sustain the local socio-economic situation. The hydrological response of the Ethiopia Fincha’a watershed to LULCC that happened during 25 years was investigated, comparing the situation in three reference years: 1994, 2004, and 2018. The information was derived from Landsat sensors, respectively Landsat 5 TM, Landsat 7 ETM, and Landsat 8 OLI/TIRS. The various LULC classes were derived via ArcGIS using a supervised classification system, and the accuracy assessment was done using confusion matrixes. For all the years investigated, the overall accuracies and the kappa coefficients were higher than 80%, with 2018 as the more accurate year. The analysis of LULCC revealed that forest decreased by 20.0% between the years 1994–2004, and it decreased by 11.8% in the following period 2004–2018. Such decline in areas covered by forest is correlated to an expansion of cultivated land by 16.4% and 10.81%, respectively. After having evaluated the LULCC at the basin scale, the watershed was divided into 18 sub-watersheds, which contained 176 hydrologic response units (HRUs), having a specific LULC. Accounting for such a detailed subdivision of the Fincha’a watershed, the SWAT model was firstly calibrated and validated on past data, and then applied to infer information on the hydrological response of each HRU on LULCC. The modelling results pointed out a general increase of average water flow, both during dry and wet periods, as a consequence of a shift of land coverage from forest and grass towards settlements and build-up areas. The present analysis pointed out the need of accounting for past and future LULCC in modelling the hydrological responses of rivers at the watershed scale.

scholarly journals Structural changes to forests during regeneration affect water flux partitioning, water ages and hydrological connectivity: Insights from tracer-aided ecohydrological modelling

2021 ◽  
Vol 25 (9) ◽  
pp. 4861-4886
Author(s):  
Aaron J. Neill ◽  
Christian Birkel ◽  
Marco P. Maneta ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Forest Regeneration ◽  
Structural Changes ◽  
Water Flux ◽  
Natural Forest ◽  
Hydrological Connectivity ◽  
Area Index ◽  
Flux Partitioning ◽  
Natural Forest Regeneration

Abstract. Increasing rates of biodiversity loss are adding momentum to efforts seeking to restore or rewild degraded landscapes. Here, we investigated the effects of natural forest regeneration on water flux partitioning, water ages and hydrological connectivity, using the tracer-aided ecohydrological model EcH2O-iso. The model was calibrated using ∼ 3.5 years of diverse ecohydrological and isotope data available for a catchment in the Scottish Highlands, an area where impetus for native pinewood regeneration is growing. We then simulated two land cover change scenarios that incorporated forests at early (dense thicket) and late (old open forest) stages of regeneration, respectively. Changes to forest structure (proportional vegetation cover, vegetation heights and leaf area index of pine trees) were modelled for each stage. The scenarios were then compared to a present-day baseline simulation. Establishment of thicket forest had substantial ecohydrological consequences for the catchment. Specifically, increased losses to transpiration and, in particular, interception evaporation drove reductions in below-canopy fluxes (soil evaporation, groundwater (GW) recharge and streamflow) and generally slower rates of water turnover. The greatest reductions in streamflow and connectivity were simulated for summer baseflows and small to moderate events during summer and the autumn/winter rewetting period. This resulted from the effect of local changes to flux partitioning in regenerating areas on the hillslopes extending to the wider catchment by reducing downslope GW subsidies that help sustain summer baseflows and saturation in the valley bottom. Meanwhile, higher flows were relatively less affected, especially in winter. Despite the generally drier state of the catchment, simulated water ages suggested that the increased transpiration demands of the thicket forest could be satisfied by moisture carried over from previous seasons. The more open nature of the old forest generally resulted in water fluxes, water ages and connectivity returning towards baseline conditions. Our work implies that the ecohydrological consequences of natural forest regeneration depend on the structural characteristics of the forest at different stages of development. Consequently, future land cover change investigations need to move beyond consideration of simple forest vs. non-forest scenarios to inform sustainable landscape restoration efforts.

scholarly journals Anthropogenic Land Use/Cover Change Detection And Its Impacts On Hydrological Responses of Genale Catchment, Ethiopia

2021 ◽  
Author(s):  
Tufa Feyissa Negewo ◽  
Arup Kumar Sarma
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Change Detection ◽  
Water Body ◽  
Land Development ◽  
Geographical Information ◽  
Hydrological Response ◽  
Runoff Water ◽  
Lulc Change ◽  
Hydrological Responses

Abstract Change in land use land-cover (LULC) is a paramount dynamic present-day challenging landscape process capable of altering the hydrological responses in the catchment. As the land use planners require updated and high-resolution land resources information, understanding land cover change-induced status due to anthropogenic activities is significant. In this study, multitemporal cloud-free satellite imageries for periods (1990, 2002, and 2013) were used to quantify the spatiotemporal dynamics of land-use change detection and examine the effect on hydrological response using Geographical Information System (GIS) and Soil and Water Assessment Tool (SWAT) model in the Genale watershed, Ethiopia. The model performance was evaluated through sensitivity, uncertainty analysis, calibration, and validation process. The analysis of LULC change patterns for the area under study over 24 years showed that most parts of the green forest, barren land, and range shrubs were changed into agriculture, built up, wetlands, and water body with an increase of agriculture by 60%, built up 68%, pasture 37%, range shrubs 9%, and water body 57% over (1990 to 2013), which increased surface runoff, water yield, and sediment yield in the catchment. Significant changes in hydrological elements were observed at the sub-basins scale, mainly associated with the uneven spatial distribution of LULC changes compared to the whole watershed. The impacts of individual LULC change on hydrological response show a good correlation matrix. The regional government needs to modify land development policies and sustainable plans for examining LULC change detection using satellite imagery to avoid illegal land expansion activities.

scholarly journals Structural changes to forests during regeneration affect water flux partitioning, water ages and hydrological connectivity: Insights from tracer-aided ecohydrological modelling

2021 ◽  
Author(s):  
Aaron J. Neill ◽  
Christian Birkel ◽  
Marco P. Maneta ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Forest Regeneration ◽  
Structural Changes ◽  
Water Flux ◽  
Natural Forest ◽  
Hydrological Connectivity ◽  
Area Index ◽  
Flux Partitioning ◽  
Natural Forest Regeneration

Abstract. Increasing rates of biodiversity loss are adding momentum to efforts seeking to restore or rewild degraded landscapes. Here, we investigated the effects of natural forest regeneration on water flux partitioning, water ages and hydrological connectivity, using the tracer-aided ecohydrological model EcH2O-iso. The model was calibrated using ~3.5 years of diverse ecohydrological and isotope datasets available for a catchment in the Scottish Highlands, an area where the impetus for regeneration of native pinewoods is growing. We then simulated two land cover change scenarios that incorporated forests at early (thicket) and late (old-open forest) stages of regeneration, respectively, and compared these to a present-day baseline simulation. Changes to forest structure (proportional vegetation cover, vegetation heights and leaf area index of pine trees) were modelled for each stage. Establishment of thicket forest had the greatest effect on water partitioning/ages and connectivity, with increased losses to interception evaporation driving reductions in below-canopy fluxes (soil evaporation, groundwater recharge and streamflow) and generally slower rates of water turnover. Effects on streamflow were most evident for low and moderate summer flows rather than winter high flows. Whilst full forest regeneration was limited to hillslopes, resultant changes to the spatial dynamics of flux partitioning could also cause drying out of the valley bottom. The more open nature of the older forest generally resulted in water fluxes, ages and connectivity characteristics returning towards baseline conditions. Our work implies that the ecohydrological consequences of natural forest regeneration on degraded land depend on the structural characteristics of the forest at different stages of development. Consequently, future land cover change investigations need to move beyond consideration of simple forest vs. non-forest scenarios to inform management that effectively balances landscape restoration with demand for ecosystem services. Tracer-aided ecohydrological models were also shown to be useful tools for land cover change simulations and further potential of such models was highlighted.

scholarly journals Hydrological Responses to Land Use Land Cover Change in the Fincha’a Watershed, Ethiopia

2021 ◽  
Author(s):  
Urgessa Kenea ◽  
Dereje Adeba ◽  
Motuma Shiferaw Regasa ◽  
Michael Nones
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Local Governments ◽  
Swat Model ◽  
Landsat 8 ◽  
Land Use Land Cover ◽  
Hydrological Response ◽  
African Countries ◽  
Hydrological Responses ◽  
Basin Scale

Land use land cover (LULC) changes are highly pronounced in African countries, as they are characterized by an agriculture-based economy and a rapidly growing population. Understanding how land use/cover change (LULCC) influence watershed hydrology will enable local governments and policymakers to formulate and implement effective and appropriate response strategies to minimize the undesirable effects of future land use/cover change or modification and sustain the local socio-economic situation. The hydrological response of the Ethiopia Fincha’a watershed to LULCC happened during the last 30 years was investigated comparing the situation in three reference years: 1994, 2004 and 2018. The information was derived from Landsat sensors, respectively Landsat 5 TM, Landsat 7 ETM and Landsat 8 OLI/TIRS. The various LULC classes were derived via ArcGIS using a supervised classification system, and the accuracy assessment was done using confusion matrixes. For all the years investigated the overall accuracies and the kappa coefficients were higher than 80%, with 2018 as the more accurate year. The analysis of LULCC revealed that forest decreased by 19.99% between the years 1994-2004, and it decreased by 11.85% in the following period 2004-2018. Such decline in areas covered by forest is correlated to an expansion of cultivated land by 16.4% and 10.81%, respectively. After having evaluated the LULCC at the basin scale, the watershed was divided into 18 sub-watersheds, which contained 176 Hydrologic Response Units (HRUs), having a specific LULC. Accounting for such a detailed subdivision of the Fincha’a watershed, the SWAT model was firstly calibrated and validated on past data, and then applied to infer information on the hydrological response of each HRU on LULCC. The modelling results pointed out a general increase of average water flow, both during dry and wet periods, as a consequence of a shift of land coverage from forest and grass towards settlements and build-up areas. The present analysis pointed out the need of accounting for past and future LULCC in modelling the hydrological responses of rivers at the watershed scale.

Heterogeneity in soil hydrological response from different land cover types in southern Spain

CATENA ◽  
2008 ◽  
Vol 74 (2) ◽  
pp. 137-143 ◽  
Author(s):  
Antonio Jordán ◽  
Lorena Martínez-Zavala ◽  
Nicolás Bellinfante
Keyword(s):  
Land Cover ◽  
Southern Spain ◽  
Hydrological Response ◽  
Land Cover Types

scholarly journals Effects of land cover type on carabid beetles (Coleoptera: Carabidae) of the Canterbury foothills, New Zealand

2019 ◽  
Vol 49 ◽  
Author(s):  
Lisa A. Berndt ◽  
Eckehard G. Brockerhoff
Keyword(s):  
New Zealand ◽  
Land Cover ◽  
Natural Forest ◽  
Carabid Beetle ◽  
Carabid Beetles ◽  
Native Forest ◽  
Potential Contribution ◽  
Pine Plantation ◽  
Plantation Forest ◽  
Beetle Assemblages

Background: Land cover changes during the recent history of New Zealand have had a major impact on its largely endemic and iconic biodiversity. As in many other countries, large areas of native forest have been replaced by other land cover and are now in exotic pasture grassland or plantation forest. Ground beetles (Carabidae) are often used as ecological indicators, they provide ecosystem services such as pest control, and some species are endangered. However, few studies in New Zealand have assessed the habitat value for carabid beetles of natural forest, managed regenerating natural forest, pine plantation forest and pasture. Methods: We compared the carabid beetle assemblages of natural forest of Nothofagus solandri var solandri (also known as Fuscospora solandri or black beech), regenerating N. solandri forest managed for timber production, exotic pine plantation forest and exotic pasture, using pitfall traps. The study was conducted at Woodside Forest in the foothills of the Southern Alps, North Canterbury, New Zealand, close to an area where the critically endangered carabid Holcaspis brevicula was found. Results: A total of 1192 carabid individuals from 23 species were caught during the study. All but two species were native to New Zealand, with the exotic species present only in low numbers and one of these only in the pasture habitat. Carabid relative abundance and the number of species was highest in the pine plantation, where a total of 15 species were caught; however, rarefied species richness did not differ significantly between habitats. The sampled carabid beetle assemblages were similar across the three forested habitat types but differed significantly from the pasture assemblages based on unconstrained and canonical analyses of principal coordinates. Holcaspis brevicula was not detected in this area. Conclusions: Our results show that managed or exotic habitats may provide habitat to species-rich carabid assemblages although some native species occur only in natural, undisturbed vegetation. Nevertheless, it is important to acknowledge the potential contribution of these land uses and land cover types to the conservation of native biodiversity and to consider how these can be managed to maximise conservation opportunities.

Understanding the role of different geographical features in the hydrological response of humid mountainous areas through a stepwise clustering scheme

2021 ◽  
Author(s):  
Yaqian Yang ◽  
Jintao Liu
Keyword(s):  
Bulk Density ◽  
Optimal Parameter ◽  
Soil Bulk Density ◽  
Model Parameters ◽  
Hydrological Response ◽  
Runoff Generation ◽  
Explanatory Variables ◽  
Hydrological Responses ◽  
Rainfall Patterns

<p>In the mountainous basins with less anthropogenic influence, the hydrological function is mainly affected by climate and landscape, which makes it possible to measure hydrological similarity indirectly by geographical features. Due to the mechanisms of runoff generation can vary geographically, in this study, a simple stepwise clustering scheme was proposed to explore the role of geographical features at different spatial hierarchy in indicating hydrological response. Research methods mainly include (1) Stepwise regression was used to quantitatively show the correlation between 35 geographical features and 35 flow features and identify the important explanatory variables for hydrological response; (2) 64 basins were divided by stepwise clustering scheme, and the overall ability of the scheme to capture hydrological similarity was tested by comparing the optimal parameters; (3) The hydrological similarity of basin groups was measured by the leave-one cross validation of hydrological model parameters. The results showed that: (1) Rainfall features, elevation, slope and soil bulk density are the main explanatory variables. (2) The NSE of basin groups based on stepwise clustering is 0.64, reaches 80% of the optimal parameter sets (NSE=0.80). The NSE of 90% basins is greater than 0.5, 80% is greater than 0.6, and 49% is greater than 0.7. (3) In humid areas, the hydrological responses of the basins with more uniform monthly rainfall and more abundant summer rainfall are more similar, e.g., the NSE of Class 4 is 0.77. Under similar rainfall patterns, the hydrological responses of the basins with higher average altitude, greater slope, more convergent of shape and richer vegetation are more similar, e.g., the NSE of Class 3-2 is 0.72 and that of Class 1-2 is 0.70. In the case of similar rainfall patterns and landforms, the hydrological responses of the basins with smaller soil bulk density are more similar, e.g., the NSE of Class 3-2-2 is 0.80. In conclusion, the stepwise clustering enhances the interpretability of basin classification, and the effect of different geographical features on hydrological response can show the applicability of hydrological simulation in ungauged basins.</p>

scholarly journals Impact of Farmland Abandonment on Water Resources and Soil Conservation in Citrus Plantations in Eastern Spain

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 824 ◽  
Author(s):  
Artemi Cerdà ◽  
Oren Ackermann ◽  
Enric Terol ◽  
Jesús Rodrigo-Comino
Keyword(s):  
Water Resources ◽  
Plant Cover ◽  
Land Abandonment ◽  
Rainfall Simulation ◽  
Runoff Generation ◽  
Farmland Abandonment ◽  
Water Losses ◽  
Erosion Rates ◽  
Soil Losses ◽  
Soil And Water

Due to the reduction in the prices of oranges on the market and social changes such as the ageing of the population, traditional orange plantation abandonment in the Mediterranean is taking place. Previous research on land abandonment impact on soil and water resources has focused on rainfed agriculture abandonment, but there is no research on irrigated land abandonment. In the Valencia Region—the largest producer of oranges in Europe—abandonment is resulting in a quick vegetation recovery and changes in soil properties, and then in water erosion. Therefore, we performed rainfall simulation experiments (0.28 m2; 38.8 mm h−1) to determine the soil losses in naveline orange plantations with different ages of abandonment (1, 2, 3, 5, 7 and 10 years of abandonment) which will allow for an understanding of the temporal changes in soil and water losses after abandonment. Moreover, these results were also compared with an active plantation (0). The results show that the soils of the active orange plantations have higher runoff discharges and higher erosion rates due to the use of herbicides than the plots after abandonment. Once the soil is abandoned for one year, the plant recovery reaches 33% of the cover and the erosion rate drops one order of magnitude. This is related to the delay in the runoff generation and the increase in infiltration rates. After 2, 3, 5, 7 and 10 years, the soil reduced bulk density, increase in organic matter, plant cover, and soil erosion rates were found negligible. We conclude that the abandonment of orange plantations reduces soil and water losses and can serve as a nature-based solution to restore the soil services, goods, and resources. The reduction in the soil losses was exponential (from 607.4 g m−2 in the active plot to 7.1 g m−2 in the 10-year abandoned one) but the water losses were linear (from 77.2 in active plantations till 12.8% in the 10-year abandoned ones).

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