scholarly journals “ The future of revegetation technology in cold regions with snowfall ” Relation between soil freezing and vegetation in forest with Sasa-type undergrowth

2016 ◽  
Vol 42 (4) ◽  
pp. 516-519
Author(s):  
Taizo UCHIDA ◽  
Natsuko YAMAZATO (née SAKAMOTO)
Keyword(s):  
Soil Freezing ◽  
Cold Regions ◽  
The Future

scholarly journals Impact of Winter Soil Processes on Nutrient Leaching in Cold Region Agroecosystems

2021 ◽  
Author(s):  
Konrad Krogstad ◽  
Grant Jensen ◽  
Mehdi Gharasoo ◽  
Laura Hug ◽  
David Rudolph ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Flow Reactor ◽  
Soil Column ◽  
Growing Season ◽  
Soil Freezing ◽  
Soil Processes ◽  
Soil Columns ◽  
Cold Regions ◽  
Freeze Thaw ◽  
Biogeochemical Models

<p>High-latitude cold regions are warming more than twice as fast as the rest of the planet, with the greatest warming occurring during the winter. Warmer winters are associated with shorter periods of snow cover, resulting in more frequent and extensive soil freezing and thawing. Freeze-thaw cycles influence soil chemical, biological, and physical properties and any changes to winter soil processes may impact carbon and nutrients export from affected soils, possibly altering soil health and nearby water quality. These impacts are relevant for agricultural soils and practices in cold regions as they are critical in governing water flows and quality within agroecosystems. In this study, a soil column experiment was conducted to assess the leaching of nutrients from fertilized agricultural soil during the non-growing season. Four soil columns were exposed to a non-growing season temperature and precipitation model and fertilizer amendments were made to two of the columns to determine the efficacy of fall-applied fertilizers and compared to other two unfertilized control columns. Leachates from the soil columns were collected and analyzed for cations and anions. The experiment results showed that a transition from a freeze period to a thaw period resulted in significant loss of chloride (Cl-), sulfate (SO42-) and nitrate (NO3-). Even with low NO3- concentrations in the applied artificial rainwater and fertilizer, high NO3- concentrations (~150 mg l-1) were observed in fertilized column leachates. Simple plug flow reactor model results indicate the high NO3- leachates are found to be due to active nitrification occurring in the upper oxidized portion of the soil columns mimicking overwinter NO3- losses via nitrification in agricultural fields. The low NO3- leachates in unfertilized columns suggest that freeze-thaw cycling had little effect on N mineralization in soil. Findings from this study will ultimately be used to bolster winter soil biogeochemical models by elucidating nutrient fluxes over changing winter conditions to refine best management practices for fertilizer application.</p>

The Future of a Cold Regions Deltaic Ecosystem Influenced by Multiple Hydrological Stressors

2021 ◽  
Author(s):  
Daniel Peters ◽  
Wendy Monk ◽  
Donald Baird
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Aquatic Ecology ◽  
World Heritage ◽  
Environmental Flow ◽  
World Heritage Site ◽  
Management Options ◽  
Unesco World Heritage ◽  
Cold Regions ◽  
The Future

<p>The Peace-Athabasca Delta (PAD) in one of the largest (~6000 km<sup>2</sup>) freshwater deltaic ecosystem in the world.  This low relief, deltaic floodplain formed at the confluence of the Peace-Athabasca-Birch rivers the west end of Lake Athabasca in northwestern Canada.  Small changes in water level/depth have important implications for surface water connectivity and associated habitat quality The floodplains contain more than 1000 wetland-lake basins with varying degrees of connectivity to the main flow system.  Hydroperiod is influenced by occasional ice-jam and open-water inundations that recharge wetland basins.  This culturally important and biologically rich delta is a Ramsar Convention Wetland Site of International Importance, and is a key feature of the Wood Buffalo National Park (WBNP) that is listed as a UNESCO World Heritage Site.  The PAD ecosystem is influenced by contributing basin and local scale hydrological stressors from flow regulation (eg, hydroelectric dam, weirs), water and land use (eg, oil sands mining) and climate change.</p><p>Growing concern regarding increased cumulative effects on the delta led Indigenous Peoples petitioning UNESCO World Heritage Committee (WNC) to reassess the protection status of the park. The WBNP Action Plan was developed to address 17 UNESCO WHC recommendations to ensure maintenance of Outstanding Universal Value of the Park.  One key set of recommendations is to: 1) Conduct environmental flows assessments, to the highest international standard, in order to identify water flows needed to sustain the ecological functioning of the PAD under current and projected development and climate change; 2) Establish adequate baseline hydrological information for PAD assessments.</p><p>A significant scientific effort has been invested in the last four decades, particularly since 2010, in improving our understanding the relationship between streamflow, landscape controls and aquatic ecology in this cold-regions delta.  This information is key to assess historical and present states, learn from past development to inform planned development, and prepare for anticipated future hydro-ecological changes.  However, several key questions arise regarding what is the best approach to preparing for the future and managing such a complex system, what management options are possible within an environmental flow framework given known hydrological stressors, and what future ecosystem state does society want for the delta.  The goal of this presentation focused on the PAD is threefold:  i)  Provide an overview of major hydro-ecological research and water management;  ii)  Assess the potential applicability of riverine environmental flow frameworks to deltaic floodplain environments; and iii)  Explore the development of an environmental flow/water level framework and tools necessary to assess and manage changes to the aquatic ecology of this internationally important deltaic ecosystem.</p>

scholarly journals Extension of the Representative Elementary Watershed approach for cold regions: constitutive relationships and an application

2008 ◽  
Vol 12 (2) ◽  
pp. 565-585 ◽  
Author(s):  
L. Mou ◽  
F. Tian ◽  
H. Hu ◽  
M. Sivapalan
Keyword(s):  
Energy Balance ◽  
Soil Freezing ◽  
Western China ◽  
Unfrozen Water ◽  
Balance Equations ◽  
Freezing And Thawing ◽  
Modeling Framework ◽  
Cold Regions ◽  
Constitutive Relationships ◽  
Unfrozen Water Content

Abstract. The Representative Elementary Watershed (REW) approach proposed by Reggiani et al. (1998, 1999) represents an attempt to develop a scale adaptable modeling framework for the hydrological research community. Tian et al. (2006) extended the original REW theory for cold regions through explicit treatment of energy balance equations to incorporate associated cold regions processes, such as snow and glacier melting/accumulation, and soil freezing/thawing. However, constitutive relationships for the cold regions processes needed to complete these new balance equations have been left unspecified in this derivation. In this paper we propose a set of closure schemes for cold regions processes within the extended framework. An energy balance method is proposed to close the balance equations of melting/accumulation processes as well as the widely-used and conceptual degree-day method, whereas the closure schemes for soil freezing and thawing are based on the maximum unfrozen-water content model. The proposed closure schemes are coupled to the previously derived balance equations and implemented within the Thermodynamic Watershed Hydrological Model (THModel, Tian, 2006) and then applied to the headwaters of the Urumqi River in Western China. The results of the 5-year calibration and 3-year validation analyses show that THModel can indeed simulate runoff processes in this glacier and snow-dominated catchment reasonably well, which shows the prospects of the REW approach and the developed closure schemes for cold regions processes.

scholarly journals Implementation of salt-induced freezing point depression function into CoupModel_v5 for improvement of modelling seasonally frozen soils

2018 ◽  
Author(s):  
Mousong Wu ◽  
Per-Erik Jansson ◽  
Jingwei Wu ◽  
Xiao Tan ◽  
Kang Wang ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Soil Water ◽  
Field Experiments ◽  
Freezing Point ◽  
Numerical Models ◽  
Soil Freezing ◽  
Freezing Point Depression ◽  
Soil Hydrology ◽  
Cold Regions ◽  
New Model

Abstract. Soil freezing/thawing is important for soil hydrology and water management in cold regions. Salt in agricultural field impacts soil freezing/thawing characteristics and therefore soil hydrologic process. In this context, we conducted field experiments on soil water, heat and salt dynamics in two seasonally frozen agricultural regions of northern China to understand influences of salt on cold regions hydrology. We developed CoupModel by implementing impacts of salt on freezing point depression. We employed a Monte-Carlo sampling method to calibrate the new model with field observations. The new model improved soil temperature mean error (ME) by 16 % to 77 % when new freezing point equations were implemented into CoupModel. Nevertheless, we found that parameters related to energy balance and soil freezing characteristics in the new model were sensitive to soil heat and water transport at both sites. However, a systematic model sensitivity and calibration has shown to be able to improve model performance, with mean values of R2 from behavioral simulations for soil temperature at 5 cm depth as high as 0.87 and 0.90, and mean value of R2 for simulated soil water (liquid or total water contents at 5 cm depth) of 0.31 and 0.80 at site Qianguo and site Yonglian, respectively. This study provided a new approach considering influences of salt on soil freezing/thawing in numerical models and highlighted the importance of salt in soil hydrology of seasonally frozen agricultural soils.

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