scholarly journals Identification of glacial meltwater runoff in a karstic environment and its implication for present and future water availability

2013 ◽  
Vol 17 (8) ◽  
pp. 3261-3277 ◽  
Author(s):  
D. Finger ◽  
A. Hugentobler ◽  
M. Huss ◽  
A. Voinesco ◽  
H. Wernli ◽  
...  

Abstract. Glaciers all over the world are expected to continue to retreat due to the global warming throughout the 21st century. Consequently, future seasonal water availability might become scarce once glacier areas have declined below a certain threshold affecting future water management strategies. Particular attention should be paid to glaciers located in a karstic environment, as parts of the meltwater can be drained by underlying karst systems, making it difficult to assess water availability. In this study tracer experiments, karst modeling and glacier melt modeling are combined in order to identify flow paths in a high alpine, glacierized, karstic environment (Glacier de la Plaine Morte, Switzerland) and to investigate current and predict future downstream water availability. Flow paths through the karst underground were determined with natural and fluorescent tracers. Subsequently, geologic information and the findings from tracer experiments were assembled in a karst model. Finally, glacier melt projections driven with a climate scenario were performed to discuss future water availability in the area surrounding the glacier. The results suggest that during late summer glacier meltwater is rapidly drained through well-developed channels at the glacier bottom to the north of the glacier, while during low flow season meltwater enters into the karst and is drained to the south. Climate change projections with the glacier melt model reveal that by the end of the century glacier melt will be significantly reduced in the summer, jeopardizing water availability in glacier-fed karst springs.

2013 ◽  
Vol 10 (3) ◽  
pp. 2743-2788 ◽  
Author(s):  
D. Finger ◽  
A. Hugentobler ◽  
M. Huss ◽  
A. Voinesco ◽  
H. Wernli ◽  
...  

Abstract. Glaciers all over the world are expected to continue to retreat due to the global warming throughout the 21st century. Consequently, future seasonal water availability might become scarce once glacier areas have declined below a certain threshold affecting future water management strategies. Particular attention should be paid to glaciers located in a karstic environment, as parts of the melt water can be drained by souterrain karst systems. In this study tracer experiments, karst modeling and glacier melt modeling are combined in order to identify flow paths in a high alpine, glacierized, karstic environment (Glacier de la Plaine Morte, Switzerland) and to investigate current and predict future downstream water availability. Flow paths through the karst underground were determined with natural and fluorescent tracers. Subsequently, tracer results and geologic information were assembled in a karst model. Finally, glacier melt projections driven with a climate scenario were performed to discuss future water availability in the area surrounding the glacier. The results suggest that during late summer glacier melt water is rapidly drained through well-developed channels at the glacier bottom to the north of the glacier, while during low flow season melt water enters into the karst and is drained to the south. Climate change projections reveal that by the end of the century glacier melt will be significantly reduced in the summer, jeopardizing water availability in glacier-fed karst springs.


2018 ◽  
Vol 8 (4) ◽  
pp. 3234-3237
Author(s):  
A. N. Laghari ◽  
G. D. Walasai ◽  
A. R. Jatoi ◽  
D. K. Bangwar ◽  
A. H. Shaikh

The Alps play a vital role in the water supply of the region through the rivers Danube, Rhine, Po and Rhone while they are crucial to the ecosystem. Over the past two centuries, we witnessed the temperature to increase by +2 degrees, which is approximately three times higher than the global average. Under this study, the Alps are analyzed using regional climatic models for possible projections in order to understand the climatic changes impact on the water cycle, particularly on runoff. The scenario is based on assumptions of future greenhouse gases emissions. The regional model results show the consistent warming trend in the last 30-year span: temperature in winter may increase by 3 to 4.5°C and summers by 4 to 5.5°C. The precipitation regime may also be altered: increasing about 10-50% in winter and decreasing about 30-60% in summer. The changes in the amount of precipitation are not uninformed. Differences are observed particularly between the North West and South East part of the Alps. Due to the projected changes in alpine rainfall and temperature patterns, the seasonality of alpine flow regime will also be altered: massive rise will occur in winter and a significant reduction in summer. The typical low flow period during winter will also be shifted to late summer and autumn.


2022 ◽  
Vol 2 ◽  
Author(s):  
Shannon M. Healy ◽  
Alia L. Khan

The glaciers of the North Cascades have experienced mass loss and terminus retreat due to climate change. The meltwater from these glaciers provides a flux of cold glacier meltwater into the river systems, which supports salmon spawning during the late summer dry season. The Nooksack Indian Tribe monitors the outlet flow of the Sholes Glacier within the North Cascades range with the goal of understanding the health of the glacier and the ability of the Tribe to continue to harvest sustainable populations of salmon. This study compares the UAV derived glacier ablation with the discharge data collected by the Tribe. We surveyed the Sholes Glacier twice throughout the 2020 melt season and, using Structure-from-Motion technology, generated high resolution multispectral orthomosaics and Digital Elevation Models (DEMs) of the glacier on each of the survey dates. The DEMs were differenced to reveal the surface height change of the glacier. The spectral data of the orthomosaics were used to conduct IsoData unsupervised classification. This process divided the survey area into Snow, Ice, and Rock classes that were then used to attribute the surface height changes of the DEMs to either snow or ice melt. The analysis revealed the glacier lost an average thickness of −0.132 m per day (m d−1) with snow and ice losing thickness at similar rates, −0.130 m d−1 and −0.132 m d−1 respectively. DEM differencing reveals that a total of −550,161 ± 45,206 m3 water equivalent (w.e.) was discharged into Wells Creek between the survey dates whereas the stream gauge station measured a total discharge of 350,023 m3. This study demonstrates the ability to spectrally classify the UAV data and derive discharge measurements while evaluating the small-scale spatial variability of glacier melt. Assessing ablation in small alpine glaciers is of great importance to downstream communities, like the Nooksack Indian Tribe who seek to understand the magnitude and timing of glacier melt in order to better protect their salmon populations. With this paper, we provide a baseline for future glacier monitoring and the potential to connect the snow surface properties with the rate of snow melt into a warming future.


Author(s):  
W.N. Reynolds

Following the 2007/08 drought, we experienced poor pasture production and persistence on our dairy farm in north Waikato, leading to decreased milksolids production and a greater reliance on bought-in feed. It is estimated that the cost of this to our farming operation was about $1300 per hectare per year in lost operating profit. While climate and black beetle were factors, they did not explain everything, and other factors were also involved. In the last 3 years we have changed our management strategies to better withstand dry summers, the catalyst for which was becoming the DairyNZ Pasture Improvement Focus Farm for the north Waikato. The major changes we made were to reduce stocking rate, actively manage pastures in summer to reduce over-grazing, and pay more attention to detail in our pasture renewal programme. To date the result has been a reduced need for pasture renewal, a lift in whole farm performance and increased profitability. Keywords: Focus farm, over-grazing, pasture management, pasture persistence, profitability


1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.


1991 ◽  
Vol 23 (1-3) ◽  
pp. 49-55
Author(s):  
E. H. baron van Tuyll van Serooskerken

An inventory is made of the effects of sea level rise and expected climatic change on the level of the district water authorities in the Netherlands and especially the “hoogheemraadschap” of Rhineland in the next 100-200 years. Special attention is paid to the effects on land utilization, coastal defence and water control. The first is hard to describe by lack of research, the second can already be determined in terms of cost; the third can be described in its effects on brackishness and water provision with indication of policies and measures to be taken. Preliminary conclusions are that larger efforts on coastal defence - even with present techniques - will be a realistic answer in terms of cost. The foreseen increase of brackishness in area and salt concentration, will give a significant extra need for fresh water. High cost and even higher risks have to be expected with regard to measures to neutralize the effects of a water surplus in winter and a growing water shortage in (late) summer, while the cost will further grow. Because of the effect a larger area must be drained off and water has to be raised higher as the Netherlands will sink in relation to the North Sea.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 425
Author(s):  
Rodrigue Vivien Cao Diogo ◽  
Luc Hippolyte Dossa ◽  
Sèyi Fridaïus Ulrich Vanvanhossou ◽  
Badirou Dine Abdoulaye ◽  
Kossi Hélliot Dosseh ◽  
...  

The sustainable use of rangelands in pastoral areas requires the inclusion of all stakeholders to develop sound management strategies. However, the role of these actors in the sustainable management of natural resources is still poorly understood. The present study aims to (i) assess the perception of farmers and herders of the risks and opportunities of transhumance on rangeland resource use and management, and to (ii) generate useful knowledge for the design and implementation of policies that favor the coexistence of these actors and reduce competition over rangeland resources use in Benin. To this end, interviews were conducted with 240 crop farmers and herders using a semi-structured questionnaire in two contrasting agroecological zones in the northern (Kandi) and the southern (Kétou) part of the country. Among the respondents, 64% of farmers in the North were agro-pastoralists (owning 10.6 ha of land and 10.7 cattle) and 36% were herders (keeping 45.8 cattle and cultivating about 3.7 ha of land). They perceived that communal rangelands were entirely degraded. In the South, 36% of respondents were agro-pastoralists (with 0.3 cattle and farming 4 ha of land) and 64% cattle herders (raising 45.3 cattle and farming 0.9 ha of land only). Of the herders, 50% kept cattle for more than 20 years, while agro-pastoralists had no previous experience in cattle herding. Cultivation practices among crop farmers, such as high use of mineral fertilization (23.8%) and bush fires for land clearing (22.5%), were reported in Kandi (North) and Kétou (South) as factors that might contribute to land degradation. However, these farmers perceived transhumance as a threat to the sustainable use of natural resources. In contrast, herders perceived transhumance as an opportunity to valorize unused land and increase the availability of manure to cropland. The prevalent negative attitude of crop farmers regarding transhumant herders increases the vulnerability of cattle herding in both regions. There is an urgent need of raising awareness concerning the mutual benefits provided by the coexistence of crop farmers with herders to promote participative rangeland management strategies. This may contribute towards coping with the current challenges of food insecurity and increasing climate variability as well as to reducing recurrent conflicts in the region.


2014 ◽  
Vol 41 (7) ◽  
pp. 545 ◽  
Author(s):  
Britney Niedzielski ◽  
Jeff Bowman

Context In an era of rapid environmental change, many species are shifting their distributions. As temperate-zone species’ expand their ranges north, different and potentially severe limiting factors may begin to affect their ability to survive and reproduce. The wild turkey (Meleagris gallopavo) is one example of a species undergoing rapid northern expansion. Aims An improved understanding of wild turkey demography at the species’ northern range periphery would facilitate effective management of this important game species. Therefore, we undertook a study to evaluate survival, causes of mortality, and behavioural strategies that may govern survival of female wild turkeys. Methods We captured 53 female wild turkeys, and used backpack transmitters to monitor their individual fates during 2012–13. Key results The annual survival estimate was 0.37 (95% CI: 0.25–0.55), with the lowest seasonal survival in the winter. The most frequent cause of mortality was mammalian predation, predominately by coyotes (Canis latrans). Age, proximity to supplemental food, and habitat use did not affect risk of mortality. Conclusions Northern wild turkeys in our study exhibited lower survival and suffered higher predation than did populations in the species’ historic range. Despite our findings, the wild turkey has expanded its range northwards and continues to exist in these peripheral areas. This may be due to high productivity or a source–sink dynamic, whereby high mortality is offset by immigration from the south. Implications The low survival and high predation of wild turkeys in the north must be considered when developing management strategies, particularly if interest exists in translocating turkeys farther north. Further research is needed to better understand whether northern turkey populations persist as sinks.


2012 ◽  
Vol 39 (4) ◽  
pp. 332 ◽  
Author(s):  
David A. Ramírez ◽  
Antonio Parra ◽  
Víctor Resco de Dios ◽  
José M. Moreno

Understanding the mechanisms underlying the response of different plant functional types to current and projected changes in rainfall is particularly important in drought-prone areas like the Mediterranean. Here, we report the responses of two species with contrasting leaf characteristics and post-fire regeneration strategies (Cistus ladanifer L., malacophyllous, seeder; Erica arborea L., sclerophyllous, resprouter) to a manipulative field experiment that simulated a severe drought (45% reduction of historical average rainfall). We measured monthly changes in relative growth rate (RGR), specific leaf area (SLA), bulk leaf carbon isotope composition (δ13C), predawn water potential (Ψpd), photosynthetic gas exchange, bulk modulus of elasticity and osmotic potential at maximum turgor (π). Temporal (monthly) changes in RGR of C. ladanifer were correlated with all measured leaf traits (except π) and followed Ψpd variation. However, the temporal pattern of RGR in E. arborea was largely unrelated to water availability. SLA monthly variation reflected RGR variation reasonably well in C. ladanifer, but not in E. arborea, in which shoot growth and δ13C increased at the time of maximum water stress in late summer. The relationship between water availability, and RGR and carbon assimilation in C. ladanifer, and the lack of any relationship in E. arborea suggest that the former has an enhanced capacity to harness unpredictable rainfall pulses compared with the latter. These contrasting responses to water availability indicate that the projected changes in rainfall with global warming could alter the competitive ability of these two species, and contribute to changes in plant dominance in Mediterranean shrublands.


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