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BACKGROUND AND OBJECTIVES: To minimize the potential risk of land fires, climate monitoring and hydrology characterization are crucial factors in managing peatlands. Therefore, this study aimed to investigate the relation between climate variability and water dynamics to develop a peatland fire early warning model.METHODS: This research was conducted in an oil palm plantation located in Pangkalan Pisang village, Koto Gasib subdistrict, Siak district, Riau province, Indonesia. Herein, the observed parameters were climate and dynamics of ground water level and soil moisture, which were monitored using data loggers installed on predefined representative locations and distributed over three blocks of 30 hectares in the palm oil plantation research site. Thus, the peat fire early warning model was developed based on the relation between peat water dynamics and the recorded history of peat fire events.FINDINGS: Herein, a recession curve analysis of soil moisture and ground water level revealed the relation between soil water dynamics and local climate. Consequently, this study found that soil moisture was the suitable parameter to estimate peat fire risk owing to its predictability. Furthermore, this study has identified a threshold of low and high peat fire risk in the area with less than 104 percent and 129 percent dry weight of soil moisture content, respectively. Afterward, this soil moisture criterion was transferred into precipitation value to develop a peat fire early warning model for estimating the days left before a high peat fire risk status was attained based on the latest daily rainfall rates.CONCLUSION: This study has developed a simple peat fire early warning model using daily precipitation data. The accurate estimation of countdown days to peat fire susceptibility status in an area would enhance fire mitigation strategies in peatlands.

Predicting groundwater levels is challenging, especially in regions of water scarcity where data availability is often limited. However, these regions have substantial water needs and require cost-effective groundwater utilization strategies. This study uses artificial intelligence to predict groundwater levels to provide guidance for drilling shallow boreholes for subsistence irrigation. The Bilate watershed, located 80 km north of Arba Minch in southern Ethiopia and covering just over 5250 km2, was selected as the study area. Bilate is typical of areas in Africa with high demand for water and limited availability of well data. Using a non-time series database of 75 boreholes, machine learning models, including multiple linear regression, multivariate adaptive regression splines, artificial neural networks, random forest regression, and gradient boosting regression (GBR), were constructed to predict the depth to the water table. The study considered 20 independent variables, including elevation, soil type, and seasonal data (spanning three seasons) for precipitation, specific humidity, wind speed, land surface temperature during day and night, and Normalized Difference Vegetation Index (NDVI). GBR performed the best of the approaches, with an average 0.77 R-squared value and a 19 m median absolute error on testing data. Finally, a map of predicted water levels in the Bilate watershed was created based on the best model, with water levels ranging from 1.6 to 245.9 m. With the limited set of borehole data, the results show a clear signal that can provide guidance for borehole drilling decisions for sustainable irrigation with additional implications for drinking water. [ABSTRACT FROM AUTHOR]

Surface waves typically constitute the dominant component of the seismic record, thus yielding the highest signal-to-noise ratio. Their propagation velocities are closely linked to the shear-wave velocity of the medium. In this study, we provide a review of the basics of surface wave analysis, focusing on Multichannel Analysis of Surface Waves (MASW). We illustrate this approach through four case studies representing common geophysical tasks. By incorporating basic surface wave dispersion analysis into standard refraction surveys, we aim to reduce solution ambiguity and enhance knowledge without incurring additional costs. In Case Study 1, we address the topic of vertical geophone natural frequencies and compare data acquired simultaneously, concluding that even with 10 Hz geophones, surface wave dispersion analysis can yield satisfactory results. Case Study 2 demonstrates that MASW analysis can successfully supplement the standard traveltime tomography and help define geological interfaces. In Case Study 3, we demonstrate that obtaining P-wave and S-wave velocities from a single acquisition setup can aid in determining groundwater level. Case Study 4 showcases an example of joint passive and active MASW analysis, resulting in an extended shear wave velocity model. As our four case studies illustrate, when used appropriately and with an understanding of its limitations, MASW can serve as a powerful tool for subsurface investigation across various geological and geotechnical settings, significantly augmenting the knowledge derived from refraction data. [ABSTRACT FROM AUTHOR]

After reclamation of the Isahaya Bay polder, a conserved area is covered with naturally developed vegetation under high groundwater level conditions. This study investigated how alluvial deposits transform into soil without utilizing artificial water drainage systems for agricultural land uses. Soils were surveyed under four vegetation compositions, including those dominated by goldenrods (GR), occupied by high-grown reeds (HRD), covered with low-grown reeds (LRD), or a mixture of goldenrods and reeds (MIX). The microtopography of the polder differentiated the research site with a higher elevation at the GR location, followed by a MIX, HRD, and a lower elevation at the LRD location. The soils were characterized by their physicochemical properties and ionic composition of the soil water. Electrical conductivity (EC), which can be an indicator of residual seawater, was lowest in the GR, followed by the MIX, HRD, and LRD. The soil moisture regimes affected by microtopography led to different frequencies of wet-dry cycles in the soil, resulting in a developing sequence of soil structure from LRD to GR with decreasing EC. The ionic composition of soil water varied with elevation and soil depth. The residual seawater still influenced the ionic composition of deeper soil horizons at lower elevations, while specifically high rates of Ca2+ and SO42− were observed in GR. The oxidation of pyrite is stimulated by soil aeration with lowering water level, resulting in soil acidification and the simultaneous dissolution of calcium carbonate from seashells. The sequential changes in soil properties with elevation indicated the effects of microtopography on soil moisture dynamics, which led to variations in soil formation and vegetation in the conserved area. [ABSTRACT FROM AUTHOR]

The present study proposes an integrated simulation–optimization framework to assess environmental flow by mitigating environmental impacts on the surface and ground water resources. The model satisfies water demand using surface water resources (rivers) and ground water resources (wells). The outputs of the ecological simulation blocks of river ecosystem and the ground water level simulation were utilized in a multiobjective optimization model in which six objectives were considered in the optimization model including (1) minimizing losses of water supply (2) minimizing physical fish habitat losses simulated by fuzzy approach (3) minimizing spawning habitat losses (4) minimizing ground water level deterioration simulated by adaptive neuro fuzzy inference system(ANFIS) (5) maximizing macroinvertebrates population simulated by ANFIS (6) minimizing physical macrophytes habitat losses. Based on the results in the case study, ANFIS-based model is robust for simulating key factors such as water quality and macroinvertebrate's population. The results demonstrate the reliability and robustness of the proposed method to balance environmental requirements and water supply. The optimization model increased the percentage of environmental flow in the drought years considerably. It supplies 69% of water demand in normal years, while the environmental impacts on the river ecosystem are minimized. The proposed model balances the portion of using surface water and ground water in water supply considering environmental impacts on both sources. Using the proposed method is recommendable for optimal environmental management of surface water and ground water in river basin scale. [ABSTRACT FROM AUTHOR]

One of the most important issues that has been considered by many researchers in recent years is the study of the phenomenon of land subsidence. The purpose of studying subsidence is to examine the risks and consequences that can result from it over many years. In their research, most researchers considered the occurrence of earthquakes and excessive abstraction of groundwater aquifers due to the drilling of a large number of illegal wells as the most important causes of subsidence. The aim of this study was to obtain a statistical relationship between groundwater level changes and the rate of vertical movement of the earth's surface using linear regression and grade 3 models and using InSAR radar interferometry technique in Varamin plain between 2014 and 2019. Most of the surface of Varamin plain is covered by agricultural lands and therefore it can be said that the uncontrolled abstraction of groundwater is considered as the main cause of vertical movements of the earth. In order to analyze the subsidence that occurred in this plain, Snap software was used and by applying the desired filters to eliminate the noise in the initial images, surface displacement maps were obtained in Varamin plain. The images used for the surface of the earth from 2014 to 2019 were obtained by Sentinel-1 satellite SAR sensor as ascending, and finally, by comparing the obtained statistical models from the fluctuation of the aquifer and the ground, it was found that the linear regression model has a better predictive power than the 3rd degree regression model.

The size of peat subsidence at Solec peatland (Poland) over 50 years was determined. The field values for subsidence and mineralization were compared with estimates using 20 equations. The subsidence values derived from equations and field measurements were compared to rank the equations. The equations that include a temporal factor (time) were used to forecast subsidence (for the 20, 30 and 40 years after 2016) assuming stable climate conditions and water regime. The annual rate of subsidence ranged from 0.08 to 2.2 cm year−1 (average 1.02 cm year −1). Equation proposed by Jurczuk produced the closest-matching figure (1.03 cm year−1). Applying the same equation to calculate future trends indicates that the rate of soil subsidence will slow down by about 20% to 0.82 cm year−1 in 2056. With the measured peat subsidence rate, the groundwater level (57–72 cm) was estimated and fed into equations to determine the contribution of chemical processes to the total size of subsidence. The applied equations produced identical results, attributing 46% of peat subsidence to chemical (organic matter mineralization) processes and 54%—to physical processes (shrinkage, organic matter consolidation). The belowground changes in soil in relation to groundwater level have been neglected lately, with GHGs emissions being the main focus. [ABSTRACT FROM AUTHOR]

A multitude of research has been rising for predicting the behavior of different real-world problems through machine learning models. An erratic nature occurs due to the augmented behavior and inadequacy of the prerequisite dataset for the prediction of water level over different fundamental models that show flat or low-set accuracy. In this paper, a powerful scaling strategy is proposed for improvised back-propagation algorithm using parallel computing for groundwater level prediction on graphical processing unit (GPU) for the Faridabad region, Haryana, India. This paper aims to propose the new streamlined form of a back-propagation algorithm for heterogeneous computing and to examine the coalescence of artificial neural network (ANN) with GPU for predicting the groundwater level. twenty years of data set from 2001-2020 has been taken into consideration for three input parameters namely, temperature, rainfall, and water level for predicting the groundwater level using parallelized backpropagation algorithm on compute unified device architecture (CUDA). This employs the back-propagation algorithm to be best suited to reinforce learning and performance by providing more accurate and fast results for water level predictions on GPUs as compared to sequential ones on central processing units (CPUs) alone. [ABSTRACT FROM AUTHOR]

The relevance of the research consists in studying the change of the level, chemical content, conditions of formation, regime of groundwater and salinity of soils under the influence of anthropogenic factors over a long period of time and in this background the formation of hydrogeological-meliorative conditions. The main aim is to study the change of the hydrogeological-meliorative conditions under the anthropogenic influence in the territories of its effect zone after putting into operation Verkhne-Shirvan canal. Objects of the research are the effect zone of the Verkhne-Shirvan canal of Shirvan plain of the Republic of Azerbaijan. Methods. Based on the results of research conducted by the author on the level, mineralization degree of groundwater and salinity of soils over a long period of time and the data collected the hydrogeological-meliorative division into districts was carried out. Results. Due to the operation of the Verkhne-Shirvan canal, the level of groundwater, the degree of mineralization, the chemical content and the salinity and chemical content of the salts have changed in its effect zone. From 1958 to 2018 groundwater in this area rose by more than 4,0 m due to irrigation reclamation, and their mineralization degree decreased by 16,0 g/l due to infiltration of surface water and removal of mineralized water through drainage. The groundwater regime in the whole is formed by irrigation of lands and drainage. Hydrogeological-meliorative zoning of the area was carried out based on the results of research on changes in the level of subsoil water,chemical composition and salinity of soils and analysis of collected archival materials. A province-the Kur synclinorium,one zone, semi-steppe with temperate-hot climate and dry-steppe with dry climate, three districts and four sub-districts are allocated. The first region covers the ends of the cones of river networks. The filtering coefficient of the rocks of the water-bearing horizons is 4-10 m/day, the degree of mineralization of groundwater is 1-5 g/l, their slope depth is 6-10 m. The second area covers the middle parts of the cones of the rivers, the filtering coefficient of proluvial sediments varies in the range of 3-5 m/day, the degree of mineralization of groundwater is 5-6 g/l their slope depth is 1,5-6,0 m. The third region covers the alluvial plain of the Kura River. The filtering coefficient of the rocks where the water is located reaches 1-10 m/day, the degree of mineralization of groundwater increases to 1-50 g/l, the slope depth is 1-3 m.

Abstract We analyze temporal variations in the travel times of both P and S waves (Vp and Vs) for 14 months at Toyohashi (central Japan) with a continuously operating vibration source that could efficiently produce both P and S waves. Seismic waves produced by the source, which is called the accurately controlled routinely operated signal system (ACROSS), are recorded by three nearby seismic stations, and the travel time variation at each station is estimated using the transfer function calculated from the recorded data. Long-term variations in Vp and Vs are observed and can be interpreted by the change in fluid saturation and crack density of the subsurface rocks. The variation in fluid saturation and crack density are consistent with that in the groundwater level, which is measured at the station nearest to the ACROSS. Short-term responses to rainfalls are observed at the station nearest to the ACROSS system; the interpretation of the changes in crack density and saturation is inconsistent with the ground water observation, partly owing to the initial response to rainfall. This can be interpreted as an air–water mixture within pores or cracks on a fine scale.

Abstract The present study was performed in order to determine the engineering geology and geotechnical details of soils and rocks along Tabriz Metro Line 2(TML2) by using the information and raw data which were acquired by borehole drilling and all field and laboratory tests in the study area. The minimum and maximum depths of the boreholes were 15 and 40 m, respectively. The results of their analysis revealed that geologically, the areas of metro route, mainly formed by alternating layers of claystone, siltstone, marl, and conglomerate, covered mainly by the alluvial deposits and in addition to older, dextral, strike-slip North Tabriz Fault (NTF) which is a major and most important geological structure of Tabriz area, there are also many minor and generally young and seismically active faults. The results of investigation on the groundwater depth in boreholes of TML2 also indicated that the groundwater depth varies between 1.5 and 30 m, along the route of metro. Eventually, based on the standard penetration test values (N-SPT), it was revealed that soils of the western parts of TML2 are in the group of dense to very dense, the central parts are in the group of very dense (Bazaar area) and dense (Fahmideh area), and the eastern parts are very dense. And finally the results achieved from determining groundwater sulfate values according to Concrete Code of Iran (CCI) indicated that the amount of soluble sulfate in the soil is mild to extremely high. Accordingly, the amount of sulfate increases from the western to the eastern parts. So that, this value is between 200 and 26,500 ppm. Based on these studies, the average of sulfate in the western, central and eastern parts is, respectively, 1118, 1275 and 4840 ppm. Thus, the groundwater in the east part is highly aggressive, and deterioration of concrete lining of the tunnel is expected in the near future.

Determination of the fluctuations in groundwater level (GWL) in terms of planning and operating their resources is important. In Turkey, many basins are experiencing problems in terms of the potential of groundwater. Increasing water demand, adverse conditions created by climate change and lack of planning related to underground water management in the basin have increased these problems. As a field of application, it was applied for General Directorate of State Hydraulic Works (DSI) well of Hatay province in Turkey. In the study, GWL predictions were evaluated using data mining approaches such as Radial Basis Neural Network (RBNN) and Support Vector Machines (SVM) methods. Monthly data sets between 2002 and 2015, including hydrological parameters predict the GWL used. According to comparison results, it was observed that the data mining models gave good results for observation in test phase.

Ozegahara Mire is the largest alpine mire in Japan. The mire has been preserved as the precious peatland ecosystem with high ecological diversity. After the late 20th century, the mire has been exposed to ecosystem disturbance by mire flooding due to heavy rain as well as invaded Sika deer. Especially, browsing and digging of the mire vegetation by invaded Sika deer have caused considerable impacts on not only vegetation but also physicochemical properties of the mire peat soil. Little information has been published on the effect of flooding and Sika deer disturbance on greenhouse gas emission from the mire. This study aims to provide investigation about the effects of Sika deer disturbance on the soil physicochemical properties and the emission of carbon dioxide (CO2) and methane (CH4) from Ozegahara Mire. Soil and gas samples were collected at 14 fixed plots on 5 sites with and without mire disturbance by Sika deer at eastern Naka-tashiro of Ozegahara Mire through 5 months of 2019 (June to October). Groundwater levels at the study sites were measured each month using hand measurements and continuously using water level loggers. Soil samples were collected with a trowel and gas samples were collected in cylindrical polyvinyl chloride chambers installed on the study sites. Subsequent physicochemical analysis of the soil samples and the gas chromatographic analysis of the gas samples were conducted at the laboratory. Groundwater level displayed similar seasonal change in two sites, being affected by precipitation. The concentrations of NH4+ nitrogen in the disturbed sites were higher than those in the undisturbed sites. Mechanical disturbance of the peat soils by deer resulted in mineralization of organic matter. CO2 and CH4 fluxes from the disturbed sites were lower than those from the undisturbed sites where highest fluxes were recorded in August. Negative correlation was found between CO2 and groundwater level (r = −0.327, p < 0.05), suggesting the importance of groundwater level in greenhouse gas flux. These results indicate the marked influences of the mire disturbance by Sika deer on physicochemical properties of the peat soils and greenhouse gas fluxes at Ozegahara Mire. [ABSTRACT FROM AUTHOR]

The analysis of long-term observations in the Kamennaya Steppe (over 125 years) for climatic parameters (air temperature and precipitation), ground water level, vegetation species composition revealed the main trends in their variability. Since 1969 there has been an increase in temperature and a reduction in temperature fluctuation during the year. Over the last 30 years, the difference has reached 1.90, and over the last decade it has grown by 0.40 due to the cold season. The amount of precipitation over the same 50-year period has not changed much. In total, an increase of 45 mm was observed over the decade (1999-2008). In the XXI century, there has been registered an increase in the amount of precipitation in the cold season by 12.7% and a decrease in the warm season, which creates certain prerequisites for climate continentality mitigation during the annual cycle. During the first 70 years of observations, the groundwater level in the well No. 1 was on average at the depth of 6.5 m (5.7-7.3 m). At the end of the XX century and at the beginning of the XXI century, there was marked a pronounced rise in the ground water level, the average depth was 3.8 m, which coincided with the growth of average annual temperature and an increase in total rainfall. In this period changes in the long-term regime of ground and surface soil moisture resultedin expanding the area of wetlands and hydromorphic soils on the territory of the steppe. The period of 2009-2018 is characterized by a continued increase in average annual temperatures and a decrease in precipitation, which may lead to a seasonal change in temperature and precipitation to milder and wetter winters and warmer and drier summers. Transformation of vegetation for 100 years of observations had several stages with a general trend to change the steppe grasslands to meadow-steppe, shrubs and woody species.

Peatlands rewetting for hydrological restoration plays an important role in fire prevention and peatland restoration of degraded peatland. One of the methods for the rewetting is canal blocking. The impact of canal blocking for peatland rewetting is further analyzed in this research. This study focused in Pulau Tebing Tinggi peatland hydrological unit (PHU), which is located in Kepulauan Meranti Regency, Riau Province. To analysis the rewetting impact, 15 dipwells were installed with the distance of 1 m, 51 m, 101 m, 201 and 301 m from the canal for each transect of the three transects. A transect was set in the downstream and two transects were set in the upstream of canal block. The ground water level (GWL) in the 15 dipwells was recorded using water-loggers for one year. This research found that canal blocking has a good effect on maintaining groundwater levels and keeping peatlands in always wet or humid conditions up to a distance of 201 m perpendicular to the canal if the rise in water level in the canal due to canal blocking is more than 0.6 m. It is able to maintain the ground water depth in peatlands around 0.4 m, where the peatlands become low risk to the fire, emission rates and subsidence.

Aim of the study: The aim of the work was to develop methods for calculating water consumption of plants and vertical moisture exchange, paying attention to the influence of meteorological factors in the agricultural conditions of reclaimed soils. Material and methods: The methods of Shebeko, Rogotskiy and Pylenok, which are commonly used in Russia, were taken as the basis of the study. The researches were carried out on an ecological landfill created in the Oka river basin near Riazań (central part of the Russian Plain). The empirical data of agro-climatologic, radiation, lysimetric and soil moisture measurements in the period from the beginning of May to the end of September during the years 1981-2018 were taken into account in the conducted analyses. Processing of research materials was carried out using such methods as analysis of variance, calculation of statistical characteristics of the sample, linear correlation. The analysis of the influence of meteorological factors on the water balance of soil with three agricultural crops: lupine, potatoes, oats, was given in the following 16 weeks from the time of field crops sowing (planting). Results and conclusions: Such investigated temporal dynamics of water consumption has pointed to strong correlations of this consumption with radiation balance, saturation deficit and bioclimatic coefficients of the agricultural crops. The new coefficients, more precision than earlier in Russia conducted, for used methods of calculating water consumption and vertical moisture exchange were proposed.. They are need in calculating the optimal irrigation regime of drained soils and in planning of its regime for complex land reclamation including technologically contaminated lands.

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In recent years, the high development of high-speed railway lines cross through areas with poor geological conditions, such as soft soil, offshore and low-lying marsh areas, resulting geotechnical problems, such as large settlements and reduction of bearing capacity. As a new soil reinforcement method in high speed railway lines, the piled raft structure has been used to improve soil conditions and control excess settlement. In order to study the dynamic behavior of piled raft supported ballastless track system in soft soil, an experimental study on vibration velocities of piled raft supported embankment and foundations is presented in soft soil with different underground water levels. Vibration velocities at specified positions of the piled raft supported embankment and foundations are obtained and discussed. The vibration velocity curves on various testing locations of piled raft foundations are clearly visible and have sharp impulse and relaxation pattern, corresponding to loading from train wheels, bogies, and passages. Vibration velocity distribution in the horizontal direction at three train speeds clearly follows an exponential curves. Most of the power spectrums of vibration velocity at various locations are mainly concentrated at harmonic frequencies. The change in water level has slight impaction on the peak spectrum of vibration velocity at harmonic frequencies. The vibration power induced by train loads are transmitted, absorbed, and weakened to a certain extent through embankment and piled raft structure. The dynamic response character of embankments are affected by their self-vibration characteristics and the dynamic bearing capacity of the piled raft structure.

We analyze temporal variations in the travel times of both P and S waves (Vp and Vs) for 14 months at Toyohashi (central Japan) with a continuously operating vibration source that could efficiently produce both P and S waves. Seismic waves produced by the source, which is called the accurately controlled routinely operated signal system (ACROSS), are recorded by three nearby seismic stations, and the travel time variation at each station is estimated using the transfer function calculated from the recorded data. Long-term variations in Vp and Vs are observed and can be interpreted by the change in fluid saturation and crack density of the subsurface rocks. The variation in fluid saturation and crack density are consistent with that in the groundwater level, which is measured at the station nearest to the ACROSS. Short-term responses to rainfalls are observed at the station nearest to the ACROSS system; the interpretation of the changes in crack density and saturation is inconsistent with the ground water observation, partly owing to the initial response to rainfall. This can be interpreted as an air–water mixture within pores or cracks on a fine scale. [ABSTRACT FROM AUTHOR]

This study coupled the Soil and Water Assessment Tool (SWAT) with a ground water finite element model (FEM) with the enhancements of multiple interface conversions and management practices. The coupled model, SWAT_FEM was applied to assess the hydrology of the Chennai River basin in India, a coastal zone with significant irrigation. The SWAT_FEM enhanced the predictions of stream flows and ground water levels (R2:0.69,0.81; Nash Sutcliffe Efficiency (NSE):0.64,0.74) compared to the standalone model, SWAT (R2:0.64,0.66; NSE:0.60,0.63) respectively. The coupled model produced an all-inclusive representation of the impacts of management practices on the hydrological processes and generated insights into the spatiotemporal patterns of the surface water and ground water interactions in the study area. The results showed that the interactions of surface water and ground water were significant in the mainstream of Chennai River basin. The seasonal ground water levels obtained with the SWAT_FEM model reinforced the increases in exorbitant ground water abstraction rates (9%-44%) with the introduction of management practices including reservoirs, pond irrigation, and agricultural water use. The results emphasized that if the ground water demand continued to increase, accelerated and unregulated ground water extraction is bound to happen shortly to suffice the water use, which can bring about environmental problems to this basin. Overall, this study demonstrated the applicability of the SWAT_FEM model and its value to the water resources management in irrigated areas with management practices. The developed model can be utilized in water resources assessment tools for effective predictions of ground water contributions in river basins. [ABSTRACT FROM AUTHOR]

Determination of the fluctuations in groundwater level (GWL) in terms of planning and operating their resources is important. In Turkey, many basins are experiencing problems in terms of the potential of groundwater. Increasing water demand, adverse conditions created by climate change and lack of planning related to underground water management in the basin have increased these problems. As a field of application, it was applied for General Directorate of State Hydraulic Works (DSI) well of Hatay province in Turkey. In the study, GWL predictions were evaluated using data mining approaches such as Radial Basis Neural Network (RBNN) and Support Vector Machines (SVM) methods. Monthly data sets between 2002 and 2015, including hydrological parameters predict the GWL used. According to comparison results, it was observed that the data mining models gave good results for observation in test phase. [ABSTRACT FROM AUTHOR]

Changes in land use of tropical peat will lead to the release of carbon (C) on the condition that initially stabilized, and resulting in land subsidence. Peatland clearance which is preceded by the construction of the canals will cause the ground water table in peatlands fell. Along with that, the subsidence occurs, which at the beginning of peatland reclamation rate of decline very fast and gradually slow down over time with reduction of organic materials that decompose or burn. Therefore, knowledge of the rate of subsidence is very important to plan drainage and optimal use of peat land in order to preserve the peat. The method or scientific approach used is the assessment directly, include: measurement of the location of groundwater levels, land subsidence at various existing condition of land in different locations, peat soil sampling and calculation with the empirical formula. The calculation of land subsidence using average data groundwater levels during the dry season, in addition to the types of land cover took into account as well. This paper presented the results of the analysis of land subsidence and the projected decline in the next 50 years peatlands in Sei Ahaz, Kapuas, Central Kalimantan and Sungai Buluh, Tanjung Jabung, Jambi and comparative results between the two locations. The implications of this study indicate that the regulation of groundwater levels will control land subsidence.

For the sustainable restoration of wet farm land degraded by the climate change-induced rise of ground water level (GWL) and soil salinity etc., the sheet pipe system is one of the most useful technologies which reduces cultivation obstacles due to the poor drainage by controlling the rapid drainage function and enabling farmers to produce profitable crops. This system is characterized mainly as a perforated polyethylene rolled-band sheet 180 mm in width and 1 mm thick which is drawn into the subsurface layer while transforming a drainage pipe with φ = 50 mm. The major advantage of this system is that since the sheet pipe is installed without trenching, the disturbance of land is minimized and the construction period can be shortened to about 1/4 (which reduces the cost approximately by 50%). In this study, by using the sheet pipe installed miniature-type model soil box, the drainage capacity of the sheet pipe was confirmed as being the same as the pipe-shaped standard drainage pipes. Based on the observations of the saturated–unsaturated flow and the maximum lowering rate of GWL was predicted. Finally, at the farm land wherein the free board of the adjoining canal was limited, the effectiveness of the sheet-pipe system was confirmed.

The estimation of greenhouse gas emissions was carried out by using model calculations of the dynamics of organic matter in organic soils and emissions of greenhouse gases (PEAT-GHG-MODEL). Emissions of CO2, CH4, N2O, NO and carbon accumulation in drained organic soil in reclamation «Kryukovo» system located in the Chernihiv province in the period 2000–2011 were modeled. The lot with vegetation type Community of Cārex humīlis / Cārex rhizīna was studied. The average rate of above-ground dry matter is 125–325 g/m2, the content of organic matter in dry matter of the plant is 45.5– 47.8 %. The average annual rates of CO2, CH4, N2O, NO emissions for the period 2000–2011 are 6.718 tons of CO2 – C ha–1 ∙ y–1; 2.960 kg of CH4 – C ha–1 ∙ y–1; 5.583 kg N2O and NO – N ha–1 ∙ y–1 respectively. The carbon accumulation in the soil varied from year to year, from 0.439 to 0.836 tons C ha–1 ∙ y–1. The estimations of annual variability of CO2, CH4, N2O and NO fluxes for the two contrasting GWL dynamics 2006 and 2010 years were given.

Aim of the work - to study influence of closed potters drainage on regime of ground waters' level and humidity of sandy soils; estimation of dynamics of producing moisture storage in 1 meter soil layer in different lands. Observation on ground water level (GWL) was conducted with data holes placed 2.0…2.3 m deeps in the middle of a line between interceptors. Soil humidity was estimated by weight method till 1 m deep in 10 cm layers. Drainage flow was detected in data holes with volume method. Perennial variation (1983-2014 gg.) in GWL was governed with climatic factors mainly with dynamics of atmospheric precipitations. During seasonal variation there were spring and autumn rising, summer and winter recessions of the GWL. Till winter it was on the depth more than 1 meter but in spring rises up to plough-layer for a little time. In humid years GWL of growth season was changed within 84…100 cm, in arid years - within 149…174 cm, and in average years - within 116…128 cm. Possibility of rising of perched groundwater into plough-layer is about five times every 20 years. It was some higher in lowering sites than in slopes or plain Arable land has higher GWL than forest. Humidity of drained soil varies within broad limits - from full moisture capacity in early spring, fall and at intensive precipitations till wilting humidity in arid periods. Soil humidity was close to optimal one in humid and average humid years. Water supply of cultivated plants was governed with amount of precipitation. Increase in humidity along with soil depth was pointed out in timothy field. The highest level of humidity was in layers 60…80 and 80…100 cm in all periods of observation. Water storages reset in October-November and in period of spring melting of snow. At these times they exceed field moisture capacity. Forest soil humidity is much lower than arable soil humidity under perennial grasses and in pure fallow land.

In drained forest sites, ditch cleaning (DC) may be needed to restore the drainage function of ditches and maintain favourable growing conditions. The main aims of this study were (i) to estimate the growth responses of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst) stands following DC, and (ii) to test the hypothesis that stand stocking should be less than 150 m3 ha−1 at DC to obtain a growth response. This survey included 14 ditched stands in Sweden on both mineral and peat soils. The methodology was based on evaluating growth rates before and after the DC operation (growth ratio), reconstructing the growth by taking increment cores from the tree trunks. The measured growth was related to growth derived using a growth simulator as if DC had not been conducted. The results showed an average growth increase of 1.6 m3 ha−1 yr−1 for about 25 years after DC in the stands containing 50–200 m3 ha−1. The growth response appeared to be positively related to stand age, trees ha−1 and site index, and negatively related to stand volume, supporting the hypothesis that stand stocking is an important factor to consider when assessing the need for DC. [ABSTRACT FROM AUTHOR]

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An integrated observation system so-called SEnsory data transmission Service Assisted by Midori Engineering laboratory (SESAME) has been deployed in the peatland area of the South Sumatera Province, Indonesia since June 2017. The system directly measures and records the groundwater level, soil moisture, skin temperature and rainfall in the peatland area. In this study, we used data recorded at four locations, two sensors located at the Peatland Hydrological Unit (PHU) of the Saleh River and the other two are located at the PHU of the Lumpur River. Data for a period of 17 June 2017 to 31 March 2018 were used to evaluate the characteristics of hydrology and climatology of the peatland in the South Sumatera. It was found that a high rainfall is associated with low skin temperature, high soil moisture, and shallow groundwater level. Furthermore, it was found that the observed groundwater level is significantly correlated with the observed rainfall. Interestingly, the adjusted groundwater level from TRMM rainfall shows a significant correlation with the number of hotspots during dry-season (July-October). Therefore, we may use the observed rainfall for peat fire early morning. [ABSTRACT FROM AUTHOR]

Persistent agricultural irrigation makes loess terrace prone to landslide hazards. Therefore， it is necessary to identify and monitor the potential landslides with effective ways. In this paper，the time series interferometric synthetic aperture radar (InSAR) analysis technique is utilized to analyze both descending and ascending Sentinel-1 data stacks covering the period from January 2016 to August 2018. Active slopes on the Heifangtai terrace and surrounding area in northwest China are identified. Comparison between time series InSAR measurements and GPS measurements is carried out. Time series displacement analysis reveals that agricultural irrigation poses a great threat to the stability of slopes at the terrace edge. Meanwhile，temperature variation related displacements are also identified on bridges across the Yellow River with high correlation. Our study confirms the effectiveness of time series InSAR method, which can play a significant role in the identification and prevention of loess landslides. [ABSTRACT FROM AUTHOR]

Restoration of deforested and drained tropical peat swamp forests is globally relevant in the context of reducing emissions from deforestation and forest degradation. The seasonal flux of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in a restoration concession in Central Kalimantan, Indonesia, was measured in the two contrasting land covers: shrubs and secondary forests growing on peatlands. We found that land covers had high, but insignificantly different, soil carbon stocks of 949 + 56 and 1126 + 147 Mg ha−1, respectively. The mean annual CO2 flux from the soil of shrub areas was 52.4 ± 4.1 Mg ha−1 year−1, and from secondary peat swamp forests was 42.9 ± 3.6 Mg ha−1 year−1. The significant difference in mean soil temperature in the shrubs (31.2 °C) and secondary peat swamp forests (26.3 °C) was responsible for the difference in total CO2 fluxes of these sites. We also found the mean annual total soil respiration was almost equally partitioned between heterotrophic respiration (20.8 + 1.3 Mg ha−1 year−1) and autotrophic respiration (22.6 + 1.5 Mg ha−1 year−1). Lowered ground water level up to − 40 cm in both land covers caused the increase of CO2 fluxes to 40-75%. These numbers contribute to the provision of emission factors for rewetted organic soils required in the national reporting using the 2013 Supplement of the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for wetlands as part of the obligation under the United Nations Framework Convention on Climate Change (UNFCCC). [ABSTRACT FROM AUTHOR]

Abstract Due to the fluctuating nature of ground water level, it becomes impossible to operate submersible pumps in the designed head and discharge. As a result, these pumps are running at lower efficiency (about 18% to 35%) compared to standard laboratory efficiency 64% around the year. This deficiency in efficiencies causes huge consumption of energy and corresponding costs. The total operating head of the submersible pumps includes a parameter known as "drawdown" which is the difference between pumping level and static water level. The drawdown parameter has a significant effect on pump performance. In the present work, the drawdown characteristics of a 3HP submersible pump have been studied in laboratory scale by varying the filter length and well diameter. The pump characteristic curves are plotted and compared for various well and filter arrangement. The maximum pump efficiency was 38% in 0.15m well diameter and 0.90 m filter length with 42 m head and discharge about 138 liter/min. It has observed that the amount of drawdown decreases significantly with increasing well diameter and filter length. However, beyond 0.90 m filter length, the drawdown starts decreasing and energy consumption increases. A specific arrangement of pump and well is suggested which will provide maximum efficiency under specific operating condition. A mathematical relation has also been developed by multiple regression model to account the effect of filter length and well diameter in submersible pump performance. [ABSTRACT FROM AUTHOR]

Aim. The aim is to select the crops to reclaim the highly saline soils of the plains of Dagestan.Materials and Methods. We made an analysis of the literature sources; applied the field experiment methods using standard techniques, instruments and equipment along with processing of experimental data and mathematical statistics methods.Results. According to the results of the research held in agricultural production cooperative "Novaya Zhizn" of Kazbekski district, wheatgrass (Elytrigia elongata) formed higher rates of leaf area, photosynthetic potential of crops and net photosynthetic productivity. In the year of planting alfalfa, the yield amounted to 11.8; 14.0 and 11.7 t / ha which is less than the Elytrigia elongata for 22.8; 7.8 and 15.4%. A similar situation occurred in the second and third years of growth of perennial grasses. On average, during the years of research, productivity of Elytrigia elongate was higher compared with alfalfa respectively by 36.8; 20.1 and 40.7%.Conclusion. These studies indicate the effectiveness of growing Elytrigia elongata as a phytomeliorant on saline soils, as compared with alfalfa. Growing Elytrigia elongata on highly saline meadow soils is an effective technique to improve its structure.

A simple model was developed to describe the dependence of net CO2 exchange in a sphagnum peat bog as a function of incoming solar radiation, air temperature, and soil moisture. It was parameterized using the field measurement data from two neighboring sites in an undisturbed peat bog (the pine mire with shrub and sphagnum and the shrub-sphagnum mire with rare pine) in Moscow Region. Measurements were conducted during the second part of the growing season, when the groundwater level was below 30 cm. It was shown that is a key parameter influencing the photosynthesis and respiration rates of a sphagnum moss and peat soil. The developed model allows to explain from 71 % to 74 % of the variation of CO2 exchange in the peat bog.