scholarly journals Canal blocking optimization in restoration of drained peatlands

2020 ◽  
Author(s):  
Iñaki Urzainki ◽  
Ari Laurén ◽  
Marjo Palviainen ◽  
Kersti Haahti ◽  
Arif Budiman ◽  
...  

Abstract. Drained peatlands are one of the main sources of carbon dioxide (CO2) emissions globally. Emission reduction and, more generally, ecosystem restoration can be achieved by raising the water table using canal or drain blocks. When restoring large areas, the number of blocks becomes limited by the available resources, which raises the following question: in which exact positions should a given number of blocks be placed in order to maximize the water table raise throughout the area? There is neither a simple nor an analytic answer. The water table response is a complex phenomenon that depends on several factors, such as the topology of the canal network, site topography, peat hydraulic properties, vegetation characteristics and meteorological conditions. We developed a new method to position the canal blocks based on the combination of a hydrological model and heuristic optimization algorithms. We applied this approach to a large drained peatland area (931 km2) in Sumatra, Indonesia. Our solution consistently improved the performance of traditional block locating methods, indicating that drained peatland restoration can be made more effective at the same cost by selecting the positions of the blocks using the presented scheme.

2020 ◽  
Author(s):  
Iñaki Urzainqui ◽  
Ari Laurén ◽  
Marjo Palviainen ◽  
Hannu Hökkä

<p><span>Building canal or drain blocks is a powerful tool to raise the water table of a drained peatland and to enhance ecosystem restoration. When restoring large areas, the number of blocks becomes limited by the available resources, which raises the following question: in which exact positions should a given number of blocks be placed in order to maximize the water table raise? There is neither a simple nor an analytic answer. The water table response is a complex phenomenon that depends on several factors, such as the topology of the canal network, site topography, peat hydraulic properties, vegetation and meteorological conditions. We developed a new method to position the canal blocks which is based on the combination of a hydrological model and heuristic optimization algorithms. We applied this approach to a large drained peatland area (1100 km</span><sup><span>2</span></sup><span>) in Indonesia. Our solution consistently improved the performance of traditional block locating methods, indicating that drained peatland restoration can be made more effective at the same cost by selecting the positions of the blocks using a numerical approach.</span></p>


2020 ◽  
Vol 17 (19) ◽  
pp. 4769-4784
Author(s):  
Iñaki Urzainki ◽  
Ari Laurén ◽  
Marjo Palviainen ◽  
Kersti Haahti ◽  
Arif Budiman ◽  
...  

Abstract. Drained peatlands are one of the main sources of carbon dioxide (CO2) emissions globally. Emission reduction and, more generally, ecosystem restoration can be enhanced by raising the water table using canal or drain blocks. When restoring large areas, the number of blocks becomes limited by the available resources, which raises the following question: in which exact positions should a given number of blocks be placed in order to maximize the water table rise throughout the area? There is neither a simple nor an analytic answer. The water table response is a complex phenomenon that depends on several factors, such as the topology of the canal network, site topography, peat hydraulic properties, vegetation characteristics and meteorological conditions. We developed a new method to position the canal blocks based on the combination of a hydrological model and heuristic optimization algorithms. We simulated 3 d dry downs from a water saturated initial state for different block positions using the Boussinesq equation, and the block configurations maximizing water table rise were searched for by means of genetic algorithm and simulated annealing. We applied this approach to a large drained peatland area (931 km2) in Sumatra, Indonesia. Our solution consistently outperformed traditional block locating methods, indicating that drained peatland restoration can be made more effective at the same cost by selecting the positions of the blocks using the presented scheme.


2013 ◽  
Vol 10 (11) ◽  
pp. 7623-7630 ◽  
Author(s):  
R. R. E. Artz ◽  
S. J. Chapman ◽  
M. Saunders ◽  
C. D. Evans ◽  
R. B. Matthews

Abstract. Yamulki and co-authors address in their recent publication the important issue of net emissions of greenhouse gases (GHGs) from peatlands where land use conversion has taken place. In their case, they studied conversion to forestry versus peatland restoration after a first rotation of plantation forestry. They monitored soil-derived fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) using opaque chamber measurements on planted and unplanted control treatments (with or without drainage), and an unplanted plot within a restored (felled) block on former lowland raised bog. They propose that their measurements of greenhouse gas (GHG) emissions at these sites suggest that the total net GHG emissions, in 100 yr carbon dioxide equivalents, of the restored peat bog would be higher than that of the peat bog with trees. We believe there are a number of issues with the measurement, calculation and comparison of these greenhouse budgets that may invalidate this conclusion.


Botany ◽  
2018 ◽  
Vol 96 (11) ◽  
pp. 779-791 ◽  
Author(s):  
Félix Gagnon ◽  
Line Rochefort ◽  
Claude Lavoie

There are very few studies on the spontaneous revegetation of cutover fens or bogs from which peat has been extracted to the minerotrophic layers. Most peatlands with fen-type residual peat have problems regenerating a plant cover satisfactorily from a restoration point of view. We nevertheless found a site (Moss Spur, Manitoba, Canada) presenting a substantial and diversified spontaneous plant cover. We estimated that the site would provide insights about natural revegetation processes operating in peatlands. Vegetation assemblages and environmental conditions were surveyed 19 years after extraction activities ceased. Moss Spur has densely revegetated (163 plant species, vegetation cover of 94%) with minimal human assistance. However, the composition of plant assemblages varies considerably across the site, depending on certain abiotic variables, particularly water pH, water table level, and the thickness of the residual peat layer. Moss Spur was remarkably wet considering the past peat extraction activities and the absence of active rewetting procedures. The high water table level may in part explain the successful revegetation. However, plant assemblages were not of equal quality from a restoration perspective. Some assemblages were highly diversified, and especially those dominated by Scirpus cyperinus, a species that should be further considered in peatland restoration projects to direct the recovery of the peatland towards a natural fen species composition.


2018 ◽  
Vol 195 ◽  
pp. 03016
Author(s):  
Henny Herawati ◽  
Aji Ali Akbar ◽  
Dwi Farastika ◽  
Azmeri

Creating canal network is the first step to do agricultural practice in wetlands that aims to make the wetland dry. The existence of canal network affects the hydrological function of peat ecosystem in West Kalimantan which leads to drought and peatland fires during dry season. Canal network on peatlands causes the previously stagnant water to flow out easily through the canal. Therefore, a repressive effort is required to maintain water table in peatland. A countermeasure that has been applied to restore peat is by constructing canal blocks on the established canals. The objective of this study was to assess and evaluate changes in water table in peatlands after the construction of a canal block in Wajok Hilir Village, Mempawah Regency, West Kalimantan. Based on the water table evaluation result on peatland with and without blocked canal, it is identified that peatland surrounding blocked canal had smaller water table fluctuation than the peatland surrounding unblocked canal during 1 tidal period. This research concludes that the construction of canal block helps retain water longer in peatland so that water table can be maintained in short term and is expected to restore hydrological function of peatland in the long term.


2016 ◽  
Author(s):  
Sung Ching Lee ◽  
Andreas Christen ◽  
Andy T. Black ◽  
Mark S. Johnson ◽  
Rachhpal S. Jassal ◽  
...  

Abstract. Many peatlands have been drained and harvested for peat mining, which has turned them from carbon (C) sinks into C emitters. Rewetting of disturbed peatlands facilitates their ecological recovery, and may help them revert to carbon dioxide (CO2) sinks. However, rewetting may also cause substantial emissions of the more potent greenhouse gas (GHG) methane (CH4). Our knowledge on the exchange of CO2 and CH4 following rewetting during restoration of disturbed peatlands is currently limited. This study quantifies annual fluxes of CO2 and CH4 in a disturbed and rewetted area located in the Burns Bog Ecological Conservancy Area in Delta, BC, Canada. Burns Bog is recognized as the largest raised bog ecosystem on North America's West Coast. Burns Bog was substantially reduced in size and degraded by peat mining and agriculture. Since 2005, the bog has been declared a conservancy area, with restoration efforts focusing on rewetting disturbed ecosystems to recover Sphagnum and suppress fires. Using the eddy-covariance (EC) technique, we measured year-round (16th June 2015 to 15th June 2016) turbulent fluxes of CO2 and CH4 from a tower platform in an area rewetted for the last 8 years. The study area, dominated by sedges and Sphagnum, experienced a varying water table position that ranged between 7.7 (inundation) and −26.5 cm from the surface during the study year. The annual CO2 budget of the rewetted area was −179 g CO2-C m−2 year−1 (CO2 sink) and the annual CH4 budget was 16 g CH4-C m−2 year−1 (CH4 source). Gross ecosystem productivity (GEP) exceeded ecosystem respiration (Re) during summer months (June–August), causing a net CO2 uptake. In summer, high CH4 emissions (121 mg CH4-C m−2 day−1) were measured. In winter (December–February), while roughly equal magnitudes of GEP and Re made the study area CO2 neutral, very low CH4 emissions (9 mg CH4-C m−2 day−1) were observed. The key environmental factors controlling the seasonality of these exchanges were downwelling photosynthetically active radiation and 5-cm soil temperature. It appears that the high water table caused by ditch blocking which suppresses Re. With low temperatures in winter, CH4 emission was more suppressed than Re. Annual net GHG flux from CO2 and CH4 expressed in terms of CO2 equivalents (CO2e) during the study period totaled to −55 g CO2e m−2 year−1 (net CO2e sink) and 1147 g CO2e m−2 year−1 (net CO2e source) by using 100-year and 20-year global warming potential values, respectively. Consequently, the ecosystem was almost CO2e neutral during the study period expressed on a 100-year time horizon but was a significant CO2e source on a 20-year time horizon.


2017 ◽  
Vol 9 (2) ◽  
pp. 127-130
Author(s):  
MA Islam ◽  
M Mano ◽  
MS Hossen ◽  
A Miyata ◽  
MA Baten

An experiment was conducted to measure carbon dioxide (CO2) flux by using the eddy covariance technique over rice paddy field at Mymensingh flux study site at Bangladesh Agricultural University, Mymensingh at three growing stage in Aman season in 2015. The variation of CO2 flux in the experimental period displayed distinct diurnal variations as influenced by rice growth and development. The diurnal pattern of CO2 flux showed broad peak at flowering stage of Aman rice at DOY 285 due to photosynthesis. The diurnal pattern of CO2 flux showed also higher broad peak at 1500 hour in DOY 272 at vegetative stage and lower broad peak at 1300 hour in DOY 330 ripening stage of Aman rice due to photosynthesis, meteorological conditions and field management activities.J. Environ. Sci. & Natural Resources, 9(2): 127-130 2016


2016 ◽  
Vol 20 (7) ◽  
pp. 2827-2840 ◽  
Author(s):  
Delphine J. Leroux ◽  
Thierry Pellarin ◽  
Théo Vischel ◽  
Jean-Martial Cohard ◽  
Tania Gascon ◽  
...  

Abstract. Precipitation forcing is usually the main source of uncertainty in hydrology. It is of crucial importance to use accurate forcing in order to obtain a good distribution of the water throughout the basin. For real-time applications, satellite observations allow quasi-real-time precipitation monitoring like the products PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks, TRMM (Tropical Rainfall Measuring Mission) or CMORPH (CPC (Climate Prediction Center) MORPHing). However, especially in West Africa, these precipitation satellite products are highly inaccurate and the water amount can vary by a factor of 2. A post-adjusted version of these products exists but is available with a 2 to 3 month delay, which is not suitable for real-time hydrologic applications. The purpose of this work is to show the possible synergy between quasi-real-time satellite precipitation and soil moisture by assimilating the latter into a hydrological model. Soil Moisture Ocean Salinity (SMOS) soil moisture is assimilated into the Distributed Hydrology Soil Vegetation Model (DHSVM) model. By adjusting the soil water content, water table depth and streamflow simulations are much improved compared to real-time precipitation without assimilation: soil moisture bias is decreased even at deeper soil layers, correlation of the water table depth is improved from 0.09–0.70 to 0.82–0.87, and the Nash coefficients of the streamflow go from negative to positive. Overall, the statistics tend to get closer to those from the reanalyzed precipitation. Soil moisture assimilation represents a fair alternative to reanalyzed rainfall products, which can take several months before being available, which could lead to a better management of available water resources and extreme events.


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