Experienced Land Subsidence Research Articles

Analysis Of Presumed Land Subsidence In The Cities Of Lampung Province Using InSAR And GNSS Data

Land subsidence is a naturally occurring phenomenon that has become a growing concern in various regions, including Lampung Province. In this study, we investigate land subsidence in various cities within Lampung Province, Indonesia, utilizing Sentinel-1A using Sentinel-1A satellite image data from the period 2014 to 2022. The cities of Lampung Province analyzed in this study were Liwa, Kota Agung, Kalianda, Sukadana, Bandar Lampung and Krui. The method used is Interferometric Synthetic Aperture Radar (InSAR) with the Small Baseline Area Subset (SBAS) technique. Furthermore, to validate and improve the accuracy of land subsidence measurements, the Global Navigation Satellite System (GNSS) velocities were utilized. The land subsidence result obtained in this study is presumed land subsidence. The cities that experienced land subsidence was Kalianda, Sukadana, Bandar Lampung and Krui ranging from ~3 mm/yr to ~15 mm/yr. Meanwhile, the areas that experienced an uplift were the Liwa and Kota Agung cities.

Mapping of Land Surface Deformation Using Ps-Insar for Disaster Risk Management in the Future

DKI Jakarta is experiencing land subsidence due to overexploitation of its use and the increasing population. It is feared that this decline or deformation will occur in the location of the new national capital. The research objective is "Mapping of Land Surface Deformation using PS-InSAR for Disaster Risk Management in the Future." Quantitative and qualitative research and data collection methods use secondary and primary data. Secondary data in the form of Permanent Scatterers Interferometry Synthetic Aperture Radar (PS-InSAR) Sentinel-1A images to determine soil deformation. Primary data uses a questionnaire to assess disaster risk management. Data analysis uses spatial and statistical analysis. Spatial analysis for land deformation mapping and statistical analysis for risk management. The results showed that the pattern of land deformation before the determination of the location of the capital city of Indonesia was random. On the other hand, after decision-making, it appears to be more systematic and homogeneous in adjacent areas with a decreasing range of about 5 cm per year. Other findings show that disaster risk management carried out by several agencies, especially the problem of land deformation in East Kalimantan, is still far from expectations and very minimal. The findings can be used for future disaster risk management to minimize negative impacts and reduce disaster risk.Keywords: PS-INSAR; Land Deformation; Capital City; Disaster Risk Management

Assessments of Land Subsidence in the Tehran Metropolitan Using Satellite Radar Interferometry Technique

Background and objective Many cities in the world have land subsidence problems because of environmental issues related to urban development. The arid and semi-arid climatic conditions prevailing in most of the interior regions of Iran and the need for the increasing industrial, agricultural, and drinking water exploitation from underground water resources, as well as urban development, have increased the occurrence of land subsidence in Iran, especially in the metropolis of Tehran. This study aims to assess land subsidence in Tehran, Iran, using the satellite radar interferometry (InSAR) technique. Method In this research, 31 images of Sentinel-1 were processed using the time series of persistent scatter interferometry (PSI) in 2022, and a map of the average annual rate of land subsidence in Tehran metropolis was prepared. Finally, after validating the results of interferometry with GPS station observations, the relationship between land subsidence and exploitation of underground water resources was examined as the most important factor in ground surface changes in the study area. Results The findings showed a decreasing trend in land subsidence from plain to urban areas. The highest land subsidence, with a rate of -43 mm per year occurred in the southern and southwestern parts of Tehran. Districts 10, 11, 12, 16, 17, 18, 19, and 20, which comprise about 26% of Tehran’s population, were experiencing land subsidence. The drop in the water level of observation wells was considerable in the areas where the highest rate of land subsidence occurred. Another finding of the research was the decrease of the underground water level from the north to the south of Tehran, indicating that the water depth in the southern areas of Tehran decreased due to human activities such as water pumping. Conclusion There is an increasing pressure in the aquifer through pumping water from wells in the study area for various industrial, agricultural and drinking water uses which has led to the increase in the occurrence of land subsidence.

Assessing land subsidence and analyzing tidal flooding in Tangerang, Banten

The increase in ocean temperature causes the expansion of seawater volume, resulting in an increase in sea level rise. The phenomenon of land subsidence also exacerbates the occurrence of tidal floods in coastal areas of Indonesia. This has prompted the need for a study of land subsidence and the distribution of tidal floods in Tangerang as a basis for taking anticipatory steps to reduce the negative impacts. The methods used for estimating land subsidence involved the SAR Sentinel-1A. The research utilized a total of 170 data points, spanning from 2017 until 2022. Data processing was carried out using the Parallel Small Baseline Subset method. The supporting data used in this study included SRTM data, tidal range, rainfall data, wind speed and direction. The results of this study reveal that the city of Tangerang has a maximum deformation value of -10.8 cm per year in the Periuk Sub District. Meanwhile, Tangerang Regency experienced land subsidence at a rate of -8.6 cm per year in Kosambi Sub District. Significant subsidence deformations occurred on the northeast side of Tangerang District and the southeast side of Tangerang City. Based on data analysis, it is evident that the total area inundated by tidal floods in Tangerang covers 33.267 hectares, with the largest affected area being in Pakuhaji District, spanning 9,262 hectares.

A Fusion of Geothermal and InSAR Data with Machine Learning for Enhanced Deformation Forecasting at the Geysers

The Geysers geothermal field in California is experiencing land subsidence due to the seismic and geothermal activities taking place. This poses a risk not only to the underlying infrastructure but also to the groundwater level which would reduce the water availability for the local community. Because of this, it is crucial to monitor and assess the surface deformation occurring and adjust geothermal operations accordingly. In this study, we examine the correlation between the geothermal injection and production rates as well as the seismic activity in the area, and we show the high correlation between the injection rate and the number of earthquakes. This motivates the use of this data in a machine learning model that would predict future deformation maps. First, we build a model that uses interferometric synthetic aperture radar (InSAR) images that have been processed and turned into a deformation time series using LiCSBAS, an open-source InSAR time series package, and evaluate the performance against a linear baseline model. The model includes both convolutional neural network (CNN) layers as well as long short-term memory (LSTM) layers and is able to improve upon the baseline model based on a mean squared error metric. Then, after getting preprocessed, we incorporate the geothermal data by adding them as additional inputs to the model. This new model was able to outperform both the baseline and the previous version of the model that uses only InSAR data, motivating the use of machine learning models as well as geothermal data in assessing and predicting future deformation at The Geysers as part of hazard mitigation models which would then be used as fundamental tools for informed decision making when it comes to adjusting geothermal operations.

Analisis Deformasi Jalan Penghubung Antara Kelurahan Sanga-Sanga Dalam dan Kelurahan Pendingin Tahun 2015 dan 2021 Menggunakan Metode Interferometry Synthetic Aperture Radar

The rise of coal mining in the East Kalimantan area which is close to public road access is thought to affect the quality and sustainability of surrounding public road access. The aim of this research is to determine the use of remote sensing data to analyze land subsidence or deformation that occurs on the connecting road between Sanga-Sanga Dalam Village and Pendingin Village, Sanga-Sanga District, Kutai Kartanegara Regency. The method used in this research is quantitative descriptive, namely determining ground deformation on roads obtained by analyzing Sentinel-1 imagery in 2015 and Sentinel-1 imagery in 2021. Ground deformation can be identified using a satellite-based remote sensing method through interferometry of two SAR images (interferometry synthetic aperture radar or InSAR) uses the Sentinel application platform (SNAP) which is an open source software (FOSS) application. Interferometry can represent changes in the line of sight between the ground and satellites in general. Changes in line of sight can be interpreted as signals of ground deformation. The results of this research can provide adequate information regarding comparative data on land elevation on the Sanga-Sanga Dalam - Pendingin road from several points experiencing land subsidence or deformation on average of 161.3 cm with an average land subsidence rate of 23.04 cm/year . Thus, remote sensing technology using the InSAR technique can be used to determine changes that occur in a short time and at low cost.

Monitoring Land Subsidence and its Effect on Surabaya Coastal Inundation by Utilizing GPS Campaigns Data

Land subsidence is a process of land movement based on a certain datum (geodetic reference frame) in which there are various variables causing it. This phenomenon occurs in many big cities in Indonesia, which is the city of Surabaya. The Surabaya city has a type of soil in the form of alluvial soil which is prone to movement. The accumulation of land subsidence that occurs will certainly cause its own losses. As a result, it can damage urban infrastructure so that in the future it can cause disruption to the environment, economic activities, and social life in the region. In addition, the Surabaya area is also a coastal area. Coastal areas have characteristics where this area will be strongly influenced by natural events. One of the natural events that affect the oceans and coastal areas is global temperature changes. The phenomenon of global temperature changes can affect sea level rise. If sea level rise occurs accompanied by an increase in the rate of land subsidence, this can result in flooding or inundation in coastal areas. Considering that the city of Surabaya is a metropolitan city that has a high population density and a continuous level of development, mitigation efforts are important in following up on land subsidence in this area. One of the efforts that can be applied is by conducting GPS observations. The outcomes of the GPS observations were then processed using scientific software in the form of GAMIT/GLOBK. According to the study’s findings indicated that Surabaya is experiencing land subsidence in the northern and eastern coastal areas with a range of 0.2 – 83.3 mm/year. The point that experienced a significant decline was in the border area of Tandes and Asemrowo, namely station BM35. Furthermore, land subsidence conditions influence the extent of tidal inundation, where in 2032 tidal inundation will inundate 105.411 km2.

New Preconsolidation Heads Following the Long-Term Hydraulic-Head Decline and Recovery in Houston, Texas.

The Houston area in Texas, United States, has been experiencing land subsidence for a century from the 1920s to 2010s. A substantial portion of the Houston area had finished a consolidation cycle following the long-term hydraulic head decline and recovery. A new "maximum effective stress" (preconsolidation stress) was preserved in the memory of the aquitards. For an aquifer system comprising aquifers and aquitards, the preconsolidation stress is corresponding to the lowest hydraulic head in the aquitards, not in the aquifers. Preconsolidation head is generally regarded as a groundwater-level threshold below which inelastic compaction begins. The preconsolidation head finalized after the long-term hydraulic head decline and recovery is called new preconsolidation head. This study has developed an empirical equation for projecting the new preconsolidation head. According to this study, the new preconsolidation heads in the primary aquifers (lower Chicot and Evangeline) are local specific: varying from about 30 m below land surface (-30 m) in the south to -50 m in the north of the Harris-Galveston Subsidence District (HGSD) Regulatory Area 1, from -60 m in the east to -80 m in the west of Area 2, and from -70 m in the south to -100 m in the center of Area 3. In Areas 1 and 2, the current hydraulic heads are about 10m to 20 m higher than the local new preconsolidation heads; thus, remarkable land subsidence (>1cm/year) would not be reinitiated unless the hydraulic heads are to fall below the local new preconsolidation head.

Thirty years of change of Pekalongan coastline based on Landsat imagery

The northern coastal area of Java Island is where many economic and industrial centers are located. Many big cities are located in this area, such as Jakarta, Semarang, and Surabaya. One of the problems in this area is the occurrence of tidal flooding. One of those affected by the tidal flood is Pekalongan, where the city also experienced land subsidence which is more severe than other big cities in Indonesia. One of the impacts of tidal flooding is the occurrence of coastal abrasion, where land areas are increasingly disappearing. This research objective is to see how big the coastline changes occurred in the Pekalongan area for 30 years through remote sensing data. Landsat image was used to see changes in coastlines from 1988 to 2021 on an annual basis. NDWI (Normalized Difference Water Index) was used to clarify the difference between land and water areas. Moreover, to reduce subjectivity, Otsu’s method was used for thresholding. The results show that most Pekalongan area is subject to abrasion, with the most severe conditions up to around 232 m. In addition, there are also problems related to tidal flooding, whose conditions are increasingly widespread every year.

Use of InSAR data for measuring land subsidence induced by groundwater withdrawal and climate change in Ardabil Plain, Iran

The Ardabil plain, with an approximate area of 1097.2 km2 in northwestern Iran, has experienced land subsidence due to intensive groundwater withdrawal and long seasons of drought in recent years. Different techniques have been used to investigate and evaluate subsidence in this region including: Global Positioning Systems (GPS), Levelling, and Geotechnical methods. These methods are typically expensive, time-consuming, and identify only a small fraction of the areas prone to subsidence. This study employs an Interferometric Synthetic Aperture Radar (InSAR) technique to measure the long-term subsidence of the plain. An open-source SAR interferometry time series analysis package, LiCSBAS, that integrates with the automated Sentinel-1 InSAR processor (COMET-LiCSAR) is used to analyze Sentinel-1 satellite images from October 2014 to January 2021. Processing of Sentinel-1 images shows that the Ardabil plain has been facing rapid subsidence due to groundwater pumping and reduced rainfall, especially between May 2018 to January 2019. The maximum subsidence rate was 45 mm/yr, measured at the southeastern part of the plain. While providing significant advantages (less processing time and disk space) over other InSAR processing packages, implementation of the LiCSBAS processing package and its accuracy for land subsidence measurements at different scales needs further evaluation. This study provides a procedure for evaluating its efficiency and accuracy for land subsidence measurements by comparing its measurements with the results of the GMTSAR and geotechnical numerical modeling. The results of geotechnical numerical modeling showed land subsidence with an average annual rate of 38 mm between 2006 and 2020, which was close to measurements using the InSAR technique. Comparison of the subsidence measurements of the Ardabil plain using the LiCSBAS package with results obtained from other techniques shows that LiCSBAS is able to accurately detect land deformation at large scales (~ km). However, they may not be optimized for more local deformations such as infrastructure monitoring.

Planning methods for conjunctive use of urban water resources based on quantitative water demand estimation models and groundwater regulation index in Yangon City, Myanmar

Although planned and regulated conjunctive use of surface water and groundwater could help alleviate water shortages in developing countries, unregulated conjunctive use is common due to the lack of water consumption data and management plans. This study aimed to establish planning methods for conjunctive use of urban water resources in Yangon City, Myanmar, for which only limited data on water resources and consumption are available. To obtain accurate operational times for groundwater pumps, vibration loggers were attached to discharge pipes of the groundwater pumps owned by Yangon City Development Committee and households, and the water consumption of residents without piped water supply was estimated based on their housing types. Subsequently, the groundwater consumption by residential and commercial users was estimated from the water mass balance for Yangon City. It was found that the actual groundwater abstraction and consumption in Yangon City is far greater than the amounts reported in the Water Supply Master Plan of 2014. Groundwater abstraction per area (APA) was proposed as an index to prevent land subsidence, and the calculated values of APA for each township of Yangon City were very high compared with those of other Asian cities that have experienced land subsidence. Based on the APAs estimated for three future scenarios with two future water demands, this study calls for immediate regulation of industrial water to minimize the risk of land subsidence in Yangon City. The planning methods for conjunctive use proposed herein could be useful for other cities in developing countries where unplanned conjunctive use is prevalent.

Spatial Modeling of Environmental Quality Change Based on Geographic Information System

A coastal area is prone to decrease of environmental quality due to coastal land abrasion and inundation/tidal flood. Several studies have shown that the coastline of Sayung District, Demak Regency, is moving toward the mainland for 6.8 mm/year and the surrounding area is experiencing land subsidence for 5-7 cm/year. These phenomena have consequences to the environmental quality in the area. In this case, this research aims to develop a spatial model using a Geographical Information System (GIS) in describing and predicting changes of environmental quality in Sayung District, Demak Regency. Four variables in a Risk-Screening Ecological Index (RSEI) approach, namely (1) vegetation density, (2) soil moisture, (3) soil quality, and (4) built space and surface temperature were used as indicators of the environmental quality. A raster calculator and Spatial Principal Component Analysis (SPCA) were then used to calculate total value of the environmental quality. This research results that the environmental quality of the study area is decreasing which indicated by the RSEI value of 0.614 (1999), 0.4749 (2009), and 0.3933 (2019). The environmental quality in the study area is also worsened by waterbody expansion.

Spatial modeling of susceptibility to subsidence using machine learning techniques

Land subsidence is a hazard that results from conditioning factors that cause environmental change and generate social and economic impacts. Some of these factors may increase dissolution of calcareous stones, change groundwater storage, or stem from mining, faulting, and seismic activity. Semnan Plain, Iran is experiencing land subsidence that, along with secondary impacts like surface fissures, is becoming increasingly troublesome. This study modeled land subsidence and created a susceptibility map using multivariate adaptive regression spline (MARS), mixture discriminant analysis (MDA), and boosted regression tree (BRT) machine-learning methods. Analysis of satellite imagery, documents reporting past subsidence, and a contemporary field survey identified 65 sinkholes on Semnan Plain. Twelve conditioning factors were selected for analysis from a review of the scholarly literature, field investigation, and data availability. The three methods were used to model subsidence from a training subset of the known sites. The models were validated with the remaining subset of subsidence locations. Finally, susceptibility maps were used to predict other sites that are highly likely to see subsidence. Receiver operating characteristic curves and the area under the curves (AUC) were applied to assess the accuracies of the maps. AUC values (0.637, 0.783, and 0.712 for the BRT, MARS, and MDA models respectively) showed that MARS generated the most accurate model, MDA generated the second most accurate, and BRT’s was the least accurate model. Subsidence susceptibility maps as produced here can be useful, meaningful, and functional tools for local and regional planners and policy makers involved in land use planning, resource management, and hazard mitigation.

Measuring land subsidence of buildings in Semarang Chinatown

There are not many studies that discuss land subsidence and try to measure it in historic areas. This paper will take an inventory of historical areas that have existed since the early growth of cities such as Semarang Chinatown, which has existed since the 17th century. This paper is part of the results of research on land subsidence in coastal cities in Java, which have left many historical areas. Semarang City is one of the case studies because it has a high land subsidence rate of around 20 cm/year in the North Semarang area. Indeed, this area in the past was an ocean. However, due to sedimentation, on the old 1700s map, this area has become a marsh. After becoming mainland, several historical areas stood on young alluvial land. The purpose of this paper is to make an inventory of old buildings in the historic area of Chinatown. On the map from 1695 to now, after 305 years, the area has experienced land subsidence, which can be seen visually in several buildings. The research method used old photos, old maps, and field surveys by taking samples of several old residences that still exist. To strengthen the data, the use of Google street view is very helpful in seeing conditions in the field. The recommendation of this research is to provide directions for an inventory of the list of buildings that need to be conserved due to the hazard of subsidence, which is currently not being felt by the local community.

REVIEW OF THE LAND SUBSIDENCE HAZARD IN PEKALONGAN DELTA, CENTRAL JAVA: INSIGHTS FROM THE SUBSURFACE

Land subsidence is a global threat to coastal areas worldwide, including the North Java coastal area. Of many areas experiencing land subsidence in North Java, the rate of land subsidence in Pekalongan has matched the high subsidence rates usually found in big cities. The rate of land subsidence in Pekalongan far exceeds the sea-level rise, resulting in a looming threat of land loss. The devastating impacts of land subsidence are the manifestation of its subsurface movement. Therefore, it is essential to understand the subsurface to elucidate the mechanism of land subsidence. Previous studies on land subsidence in Pekalongan are mainly related to subsidence rate monitoring and have not elaborated on the subsurface condition. This paper reviews the Pekalongan subsurface geology based on available literature to provide insight into the land subsidence problem. The results revealed that the land subsidence occurs in the recent alluvial plain of Pekalongan, consisting of a 30-70 m thick compressible deposit. Possible mechanisms of land subsidence arise from natural compaction, over-exploitation of confined groundwater, and increased built areas. As the seismicity of the study area is low, tectonic influence on land subsidence is considered negligible. It is expected that the offshore, nearshore, and swamp deposits are still naturally compacting. As the surface water supply is minimal, over-exploitation of groundwater resources from the deltaic and Damar Formation aquifers occurs. In the end, future research direction is proposed to reduce the impacts of the subsidence hazard.

Inventory of old buildings and land subsidence in Semarang Old Colonial City

There have been many researches on the conservation efforts of historical cities. The building inventory stage is the first step in conservation efforts to protect buildings from the past in order to have benefits in the present. This paper provides some data on buildings that undergo land subsidence in historical areas. Semarang Old City is a historical area built by the Colonial government in the 17th century. After nearly 320 years, some of these buildings have been damaged. This research, which focuses on buildings damaged by land subsidence will collect data from 245 existing buildings in 40 ha area. The approach method uses historical buildings, photos of old buildings, and field surveys. Several old buildings have been detected to be decreased in height due to land subsidence. This can be seen by comparing photos of old buildings from the past and the present. The research analysis uses sketches and photoshop to provide information on how much the height is decreased visually. This inventory results will be able to give advice to the government regarding the appropriate conservation actions to take in an area experiencing land subsidence. This research will also help preserve buildings and environment according to current and future needs in order to preserve their cultural meaning.

LAND SUBSIDENCE MONITORING ON THE UNDERGROUND MRT CONSTRUCTION AREA IN JAKARTA, INDONESIA

Space utilization for measurement of the changes of Earth’s surface is an alternative monitoring technique. Covering a large area with better spatial resolution, comparable accuracy and costly low compared with conventional measurement have made SAR technology more popular in monitoring the subsidence. Land subsidence is the vertical movement of the land surface mainly triggered by fluid extraction, load of construction, geological condition, natural compaction or tectonic activity. Previous researchers have found that Jakarta has experienced land subsidence for decades. On the other hand, rapid urban growth and severe congestion problem in Jakarta are also crucial issues. By providing the first MRT subway, it is expected to be solved the congestion problem. Persistent Scatterer Interferometry Synthetic Aperture Radar (PSInSAR) is one of method to identify the deformation with millimeter accuracy. It was perfectly useful for studied on the land subsidence in consequence of the first MRT subway project in Jakarta. The land displacement monitoring along MRT subway trajectory has been acquired by processing Sentinel 1 and ALOS PALSAR-2. This study was able to investigate the land subsidence by using SARPROZ. Finally, the results of this study indicated that land subsidence occurred in the construction area with the lowest land subsidence rate of -0.6 cm/year and the highest land subsidence rate was -7.3 cm/year.
 Keywords: PSInSAR; subway; land subsidence; MRT.

Mapping and predicting subsidence from spatio-temporal regression models of groundwater-drawdown and subsidence observations

Many regions of the earth are experiencing land subsidence owing to aquifer-system compaction, a consequence of groundwater depletion manifesting as excessive groundwater drawdown. The relation between groundwater drawdown and land subsidence caused by aquifer-system compaction is nonstationary in space and time due to the highly heterogeneous aquifer material, hydraulic and mechanical properties, and spatio-temporal variations in aquifer recharge and groundwater extraction. Annual land subsidence maps are developed using geographical time-slice weighted regression (GTSWR) and geographical temporal weighted regression (GTWR). Considering these spatiotemporal regressions, groundwater drawdown is used as the input parameter to estimate spatial and temporal patterns of land subsidence in both Changhua and Yunlin counties, Taiwan, for an 8-year period. Results indicate that the GTSWR or GTWR models yield greater accuracy with a lower root mean square error (RMSE) than linear regression (LR). The correlation between the predicted and observed data for LR, GTSWR and GTWR is 0.31, 0.93 and 0.94, respectively. In the spatiotemporal models, areas with smaller model coefficients represent over-consolidated sediments, whereas the areas with larger coefficients represent where sediments are normally consolidated. Normally consolidated sediments tend to produce the greatest amount of land subsidence. Annual subsidence patterns reveal that greater levels of subsidence are progressing inland. The greatest level of subsidence occurs in central Yunlin (7 cm/year) due to groundwater extraction. The spatio-temporal regression model is used to predict the effects of reduced groundwater extraction for different areas based on two scenarios of 30 and 50% reductions in groundwater drawdown.

Population dynamics of Hippophae rhamnoides shrub in response of sea-level rise and insect outbreaks.

The coastal vegetation of islands is expected to be affected by future sea-level rise and other anthropogenic impacts. The biodiverse coastal vegetation on the eastern part of the Dutch Wadden Island of Ameland has experienced land subsidence caused by gas extraction since 1986. This subsidence mimics future sea-level rising through increased flooding and raising groundwater levels. We studied the effects of this relative sea-level rise and other environmental factors (i.e. insect outbreaks, temperature and precipitation) on the population dynamics (i.e. cover and age structure and annual growth) of the shrub sea-buckthorn (Hippophae rhamnoides L.) in young (formed after 1950) and old (formed before 1950) dune areas over a period of 56 years (1959–2015). We found an increase in sea-buckthorn cover in the young dune areas since 1959, while over time the population in the old dunes decreased due to successional replacement by other species. With the increasing age of the young dunes, we found also a decrease in sea-buckthorn after 2009. However the sharp decrease indicated that other environmental factors were also involved. The most important determinant of annual shrub growth appeared to be five outbreaks of the brown-tail moth (Euproctis chrysorrhoea L.), in the last decade. Relative sea-level rise caused more frequent flooding and reduced growth at lower elevations due to inundation or soil water saturation. This study clearly indicates that sea-buckthorn is affected by relative sea-level rise, but that other ecological events better explain its variation in growth. Although shrub distribution and growth can be monitored with robust methods, future predictions of vegetation dynamics are complicated by unpredictable extreme events caused by (a)biotic stressors such as insect outbreaks.

Spatio-Temporal Visualization of Peatlands Changes

Increased deforestation and draining of peatlands with the started of the drainage occurs quickly makes the availability of peatlands as carbon storage is even more alarming. The presence of peat land conversion greatly affect the hydrological balance of the ecosystem. The conversion of peatland have the massive effect with the increase of drainage constructions for land cultivation needs. This makes the neighborhood unity peat hydrology (KHG) which is wet into dry so prone to burning and experiencing land subsidence. Information of peatland degradation is presented in the spatio - temporal visualization using Space Time Cube (STC). The usability in order to determine the extent of the spatio - temporal visualization can be used by users to obtaining information peatland degradation in terms of effectiveness, efficiency and satisfaction for users. Drainage density built on KHG getting bigger every year with the index of medium density classification. Increasing the number of long-drainage occurs at 119.4934 km per year from 2000 to 2008 and 148.6954 km per year from 2008 to 2012. Based on observations in 12 years has increased the number of distribution Hotspot significantly in February. In May and September the spread of hotspots increased by the average number of hotspots at 15 points per month. The drainage development’s and distribution of hotspot has dominant occurs at the HTI in the KHG Peatland degradation is presented in Visualization spatio-temporal, which visualization is very effective, fairly efficient, and give satisfaction to the users in displaying information peatland degradation in time series.