scholarly journals Riparian Land Cover, Water Temperature Variability, and Thermal Stress for Aquatic Species in Urban Streams

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2732
Author(s):  
Anne Timm ◽  
Valerie Ouellet ◽  
Melinda Daniels
Keyword(s):  
Thermal Stress ◽  
Land Cover ◽  
Water Temperature ◽  
Urban Streams ◽  
Temperature Variability ◽  
Tree Canopy ◽  
Aquatic Species ◽  
Thermal Dynamics ◽  
Riparian Area ◽  
Total Length

Thermal regime warming and increased variability can result in human developed watersheds due to runoff over impervious surfaces and influence of stormwater pipes. This study quantified relationships between tree canopy, impervious surface, and water temperature in stream sites with 4 to 62% impervious land cover in their “loggersheds” to predict water temperature metrics relevant to aquatic species thermal stress thresholds. This study identified significant (≥0.7, p < 0.05) negative correlations between water temperature and percent tree canopy in the 5 m riparian area and positive correlations between water temperature and total length of stormwater pipe in the loggershed. Mixed-effects models predicted that tree canopy cover in the 5 m riparian area would reduce water temperatures 0.01 to 6 °C and total length of stormwater pipes in the loggershed would increase water temperatures 0.01 to 2.6 °C. To our knowledge, this is the first time that the relationship between stormwater pipes and water temperature metrics has been explored to better understand thermal dynamics in urban watersheds. The results highlight important aspects of thermal habitat quality and water temperature variability for aquatic species living in urban streams based on thermal thresholds relevant to species metabolism, growth, and life history.

scholarly journals Integrating structure and function: mapping the hierarchical spatial heterogeneity of urban landscapes

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuguo Qian ◽  
Weiqi Zhou ◽  
Steward T. A. Pickett ◽  
Wenjuan Yu ◽  
Dingpeng Xiong ◽  
...  
Keyword(s):  
Land Cover ◽  
Spatial Heterogeneity ◽  
Urban Ecosystem ◽  
Tree Canopy ◽  
Urban Landscapes ◽  
Shenzhen City ◽  
Object Based ◽  
Level 3 ◽  
Industrial Zones ◽  
Level 2

Abstract Background Cities are social-ecological systems characterized by remarkably high spatial and temporal heterogeneity, which are closely related to myriad urban problems. However, the tools to map and quantify this heterogeneity are lacking. We here developed a new three-level classification scheme, by considering ecosystem types (level 1), urban function zones (level 2), and land cover elements (level 3), to map and quantify the hierarchical spatial heterogeneity of urban landscapes. Methods We applied the scheme using an object-based approach for classification using very high spatial resolution imagery and a vector layer of building location and characteristics. We used a top-down classification procedure by conducting the classification in the order of ecosystem types, function zones, and land cover elements. The classification of the lower level was based on the results of the higher level. We used an object-based methodology to carry out the three-level classification. Results We found that the urban ecosystem type accounted for 45.3% of the land within the Shenzhen city administrative boundary. Within the urban ecosystem type, residential and industrial zones were the main zones, accounting for 38.4% and 33.8%, respectively. Tree canopy was the dominant element in Shenzhen city, accounting for 55.6% over all ecosystem types, which includes agricultural and forest. However, in the urban ecosystem type, the proportion of tree canopy was only 22.6% because most trees were distributed in the forest ecosystem type. The proportion of trees was 23.2% in industrial zones, 2.2% higher than that in residential zones. That information “hidden” in the usual statistical summaries scaled to the entire administrative unit of Shenzhen has great potential for improving urban management. Conclusions This paper has taken the theoretical understanding of urban spatial heterogeneity and used it to generate a classification scheme that exploits remotely sensed imagery, infrastructural data available at a municipal level, and object-based spatial analysis. For effective planning and management, the hierarchical levels of landscape classification (level 1), the analysis of use and cover by urban zones (level 2), and the fundamental elements of land cover (level 3), each exposes different respects relevant to city plans and management.

scholarly journals Linking Urban Tree Cover Change and Local History in a Post-Industrial City

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 403
Author(s):  
Lara A. Roman ◽  
Indigo J. Catton ◽  
Eric J. Greenfield ◽  
Hamil Pearsall ◽  
Theodore S. Eisenman ◽  
...  
Keyword(s):  
Land Cover ◽  
Low Income ◽  
Historical Context ◽  
Local History ◽  
Tree Canopy ◽  
Tree Cover ◽  
Open Spaces ◽  
Urban Tree ◽  
Suburban Areas ◽  
Post Industrial

Municipal leaders are pursuing ambitious goals to increase urban tree canopy (UTC), but there is little understanding of the pace and socioecological drivers of UTC change. We analyzed land cover change in Philadelphia, Pennsylvania (United States) from 1970–2010 to examine the impacts of post-industrial processes on UTC. We interpreted land cover classes using aerial imagery and assessed historical context using archival newspapers, agency reports, and local historical scholarship. There was a citywide UTC increase of +4.3 percentage points. Substantial UTC gains occurred in protected open spaces related to both purposeful planting and unintentional forest emergence due to lack of maintenance, with the latter phenomenon well-documented in other cities located in forested biomes. Compared to developed lands, UTC was more persistent in protected open spaces. Some neighborhoods experienced substantial UTC gains, including quasi-suburban areas and depopulated low-income communities; the latter also experienced decreasing building cover. We identified key processes that drove UTC increases, and which imposed legacies on current UTC patterns: urban renewal, urban greening initiatives, quasi-suburban developments, and (dis)investments in parks. Our study demonstrates the socioecological dynamism of intra-city land cover changes at multi-decadal time scales and the crucial role of local historical context in the interpretation of UTC change.

scholarly journals Exploring and Quantifying River Thermal Response to Heatwaves

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1098 ◽  
Author(s):  
Sebastiano Piccolroaz ◽  
Marco Toffolon ◽  
Christopher Robinson ◽  
Annunziato Siviglia
Keyword(s):  
Water Temperature ◽  
River Water ◽  
Thermal Response ◽  
Hydrological Regime ◽  
Management Policy ◽  
Extreme Weather Events ◽  
Thermal Dynamics ◽  
Depth Analysis ◽  
River Water Temperature

Most of the existing literature on river water temperature focuseds on river thermal sensitivity to long-term trends of climate variables, whereas how river water temperature responds to extreme weather events, such as heatwaves, still requires in-depth analysis. Research in this direction is particularly relevant in that heatwaves are expected to increase in intensity, frequency, and duration in the coming decades, with likely consequences on river thermal regimes and ecology. In this study we analyzed the long-term temperature and streamflow series of 19 Swiss rivers with different hydrological regime (regulated, low-land, and snow-fed), and characterized how concurrent changes in air temperature and streamflow concurred to affect their thermal dynamics. We focused on quantifying the thermal response to the three most significant heatwave events that occurred in Central Europe since 1950 (July–August 2003, July 2006, and July 2015). We found that the thermal response of the analyzed rivers contrasted strongly depending on the river hydrological regime, confirming the behavior observed under typical weather conditions. Low-land rivers were extremely sensitive to heatwaves. In sharp contrast, high-altitude snow-fed rivers and regulated rivers receiving cold water from higher altitude hydropower reservoirs or diversions showed a damped thermal response. The results presented in this study suggest that water resource managers should be aware of the multiple consequences of heatwave events on river water temperature and incorporate expected thermal responses in adaptive management policy. In this respect, additional efforts and dedicated studies are required to deepen our knowledge on how extreme heatwave events can affect river ecosystems.

Land Cover Change: Does it affect temperature variability?

2021 ◽  
Author(s):  
Aristoklis Lagos ◽  
Stavroula Sigourou ◽  
Panayiotis Dimitriadis ◽  
Theano Iliopoulou ◽  
Demetris Koutsoyiannis
Keyword(s):  
Land Cover ◽  
Land Cover Change ◽  
Urban Areas ◽  
Temperature Increase ◽  
Temperature Variability ◽  
Land Cover Changes ◽  
The Earth ◽  
Different Types ◽  
General Dynamics ◽  
Global Datasets

&lt;p&gt;Changes in the land cover occur all the time at the surface of the Earth both naturally and anthropogenically. In the last decades, certain types of land cover change, including urbanization, have been correlated to local temperature increase, but the general dynamics of this relationship are still not well understood. This work examines whether land cover is a parameter affecting temperature increase by employing global datasets of land cover change, i.e. the Historical Land-Cover Change Global Dataset, and daily temperature from the NOAA database. We thoroughly investigate the temperature variability and its possible correlation to the different types of land-cover changes. A comparison is specifically made between the rate of temperature increase measured in urban areas, and the same rate measured in nearby non-urban areas.&lt;/p&gt;

scholarly journals Assessment of Water Quality and Thermal Stress for an Artificial Fish Shelter in an Urban Small Pond during Early Summer

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 139
Author(s):  
Chang Hyuk Ahn ◽  
Saeromi Lee ◽  
Ho Myeon Song ◽  
Jae Roh Park ◽  
Jin Chul Joo
Keyword(s):  
Water Quality ◽  
Thermal Stress ◽  
Water Temperature ◽  
Open Space ◽  
Phenomenological Study ◽  
Quality Parameters ◽  
Early Summer ◽  
Freshwater Ecosystem ◽  
Artificial Wetlands ◽  
Forced Circulation

: This study evaluated water quality variations in an artificial deep pool (ADP), which is an underground artificial structure built in a shallow pond as a fish shelter. The water temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC) were measured on an hourly basis in the open space and inside the ADP, and a phenomenological study was performed, dividing seasons into normal and rainy seasons and environments into stagnant and circulating conditions. The results showed that the water quality parameters inside the ADP exhibit lower fluctuations and diurnal variations compared with the open space. On average, the water temperature inside the ADP is lower than outside it by 1.7–3.7 °C in stagnant conditions, and by 0.6–0.7 °C in circulating conditions during early summer. Thermal stratification occurs inside the ADP but is temporarily disturbed due to the mixing from the forced circulation and the rainwater input through rainfall events. The ADP provided a constant and optimal water temperature for living and spawning for bitterling (i.e., 15.0–21.0 °C), which dominated in experimental pond during spring to summer. Most importantly, the ADP was able to significantly reduce the thermal stress of the fish in the study site, and as a result, the bitterling, a cool water fish species, could successfully become dominant. Finally, the deployment of the ADP appears to provide a practical alternative for effective fishery resources management to improve species diversity and fish communities in an artificial freshwater ecosystem (garden pond, park pond, other artificial wetlands, etc.).

Role of Greenland Sea Gyre Circulation on Atlantic Water Temperature Variability in the Fram Strait

2018 ◽  
Vol 45 (16) ◽  
pp. 8399-8406 ◽  
Author(s):  
Sourav Chatterjee ◽  
Roshin P. Raj ◽  
L. Bertino ◽  
Ø. Skagseth ◽  
M. Ravichandran ◽  
...  
Keyword(s):  
Water Temperature ◽  
Atlantic Water ◽  
Temperature Variability ◽  
Fram Strait ◽  
Greenland Sea ◽  
Gyre Circulation

TWO-DIMENSIONAL FINITE ELEMENT MODEL TO STUDY THERMO BIOMECHANICS IN PERIPHERAL REGIONS OF HUMAN LIMBS DUE TO EXERCISE IN COLD CLIMATE

2017 ◽  
Vol 17 (01) ◽  
pp. 1750002 ◽  
Author(s):  
BABITA KUMARI ◽  
NEERU ADLAKHA
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Physical Exercise ◽  
Peripheral Region ◽  
Cold Climate ◽  
Two Dimensional ◽  
Human Beings ◽  
Thermal Dynamics ◽  
Thermal Injuries ◽  
The Impact

Human beings are equipped with thermo sensitivity, thermoregulation and thermo protection for maintaining the structure and function of their body organs. The thermoregulatory responses and disturbances caused by physical activity in thermo biomechanics of human body organs are not well understood. The mechanism of thermoregulation exhibits a beautiful coordination of biophysical process in order to balance distribution caused by a biothermal system due to physical exercise and other abnormal conditions. In view of above, a model has been developed to study the thermal dynamics in peripheral region of human limbs immediately after exercise under cold climatic conditions. The human limb is assumed to be of cylindrical shape. The peripheral region of limb is divided into three natural components namely epidermis, dermis and subdermal tissues. Appropriate boundary conditions have been framed based on the physical condition of the problem. Finite difference has been employed for time variable and the finite element method is employed along radial and angular direction. The numerical results have been used to obtain temperature profiles in the peripheral region immediately after continuous exercise for a two-dimensional unsteady state case. These results have been used to analyze the thermal disturbances caused by the different intensities of physical exercise in the peripheral region of human limbs. Such a model can be developed to study the generated thermal information which can be useful to biomedical science to analyze the impact of thermal stress on mechanism of thermoregulation causing thermal injuries like heat cramps, heat exhaustion and heat stroke. The results give the idea about the capacity of biothermo mechanisms of human limbs in counting balance. The thermal stress is caused by different intensities of physical exercise. These results can be useful for the biomedical scientists to understand the thermal discomfort caused by different intensities of physical exercise and the time period of rest required to overcome discomfort. Further, the result can be useful to biomedical scientists for developing protocols for physical exercise and rest required by the subject for different intensities of physical exercise and prevent thermal injuries in the workers and sportsmen.

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