Satellite-based Monitoring System Research Articles

Toward a satellite-based monitoring system for urban CO2 emissions in support of global collective climate mitigation actions

Toward a satellite-based monitoring system for urban CO2 emissions in support of global collective climate mitigation actions

A simplified approach to satellite-based monitoring system of sugarcane plantation to manage yield decline at Wonji-Shoa Sugar Estate, central Ethiopia

Drastic and continuous decline in cane yields has become a major threat to sustainable sugarcane production in Ethiopia. Among the causes for the decline are the inefficient and ineffective system of monitoring sugarcane plantations. Adopting satellite-based crop monitoring through the Landviewer platform may circumvent this problem. However, the reliability of vegetation indexes calculated by the platform is unknown and thus requires evaluation. Accordingly, we tested the accuracy of selected Landviewer Calculated Vegetation Indexes (LCVIs) on three major sugarcane varieties and two cropping types. The goodness-of-fit of the sigmoid curve to the LCVIs profile of sugarcane was evaluated. The correlations between LCVIs and yield components, LCVIs and fractional green canopy cover (FGCC), as well as the time-serious Normalized Difference Vegetation Index (NDVI) and yields, were also analysed. We found that the goodness-of-fit of the sigmoid curve was significant (p < 0.001), with 84%–95% accuracy in all the indexes. The majority of LCVIs showed significant (p < 0.05) relationships with yield components and FGCC. The time-series NDVI also demonstrated a significant relationship with cane yield (R2 = 0.73–0.85) at the age of 10 months and above. The accuracy level of LCVIs varies with varieties and crop types, but the Normalized Difference Phenology Index (NDPI), Soil Adjusted Vegetation Index (SAVI), and NDVI were identified as the most consistent and effective LCVIs for sugarcane monitoring. Therefore, the accuracy of LCVIs was dependable and can be used effectively in monitoring sugarcane plantations to tackle the problem of continuous decline in the yield of the crop.

A satellite-based monitoring system for quantifying surface water and mesic vegetation dynamics in a semi-arid region

Semi-arid and arid systems cover one third of the earth’s land surface, and are becoming increasingly drier, but existing datasets do not capture all of the types of water resources that sustain these systems. In semi-arid environments, small surface water bodies and areas of mesic vegetation (wetlands, wet meadows, riparian zones) function as critical water resources. However, the most commonly-used maps of water resources are derived from the Landsat time series or single date aerial photographs, and are too coarse either spatially or temporally to effectively monitor water resource dynamics. In this study, we produced a Sentinel Fusion (SF) water resources product for a semi-arid mountainous region of the western United States, which includes monthly maps of both a) surface water and b) mesic vegetation at 10 m spatial resolution using freely available Earth observation data on an open access platform. We applied random forest classifiers to optical data from the Sentinel-2 time series, synthetic aperture radar (SAR) data from the Sentinel-1 time series, and topographic variables. We compared our SF product with three commonly used and publicly available datasets in the western U.S. We found that our surface water class contained fewer omission errors than a leading global surface water product (94 % producer’s accuracy (PA) vs 84 %) and comparable user’s accuracy (UA) (91 % vs 97 %) with commission errors occurring largely in mixed water pixels. Our mesic vegetation class had up to 43 % higher PAs compared to the National Wetlands Inventory (NWI) estimates and up to 78 % higher UAs over the Sage Grouse Initiative mesic resources maps during the most critical part of the water year. We found that while inclusion of SAR data from the C-band Sentinel-1 sensor consistently improved estimates of water resources in each of the last four months of the 2021 water year when compared to optical-only + topographic variables, only in September did those improvements lie outside of the 95 % confidence interval. With nine times finer spatial resolution and more frequent image collection, our SF maps characterize intra-annual dynamics of smaller water bodies (<30 m wide) and mesic vegetation integral to ecosystem functioning in semi-arid systems compared to leading Landsat-derived products. Further, our workflow is easily reproducible using freely available data on an open access platform, and can be adopted to help guide land use decisions related to water resources by farmers, ranchers, and conservationists in semi-arid environments.

A Simplified Approach to Satellite-Based Monitoring System of Sugarcane Plantation to Manage Yield Decline at Wonji-Shoa Sugar Estate, Central Ethiopia

A Simplified Approach to Satellite-Based Monitoring System of Sugarcane Plantation to Manage Yield Decline at Wonji-Shoa Sugar Estate, Central Ethiopia

Evaluation of Pre-Earthquake Anomalies of Borehole Strain Network by Using Receiver Operating Characteristic Curve

In order to monitor temporal and spatial crustal activities associated with earthquakes, ground- and satellite-based monitoring systems have been installed in China since the 1990s. In recent years, the correlation between monitoring strain anomalies and local major earthquakes has been verified. In this study, we further evaluate the possibility of strain anomalies containing earthquake precursors by using Receiver Operating Characteristic (ROC) prediction. First, strain network anomalies were extracted in the borehole strain data recorded in Western China during 2010–2017. Then, we proposed a new prediction strategy characterized by the number of network anomalies in an anomaly window, Nano, and the length of alarm window, Talm. We assumed that clusters of network anomalies indicate a probability increase of an impending earthquake, and consequently, the alarm window would be the duration during which a possible earthquake would occur. The Area Under the ROC Curve (AUC) between true predicted rate, tpr, and false alarm rate, fpr, is measured to evaluate the efficiency of the prediction strategies. We found that the optimal strategy of short-term forecasts was established by setting the number of anomalies greater than 7 within 14 days and the alarm window at one day. The results further show the prediction strategy performs significantly better when there are frequent enhanced network anomalies prior to the larger earthquakes surrounding the strain network region. The ROC detection indicates that strain data possibly contain the precursory information associated with major earthquakes and highlights the potential for short-term earthquake forecasting.

Convergent Validity of Satellite and Secchi Disk Measures of Water Clarity in Hedonic Models

Budget-constrained environmental agencies across the United States are limited in their ability to monitor water quality changes using traditional in situ sampling. Satellite-based monitoring systems represent a lower-cost alternative. It is unclear, however, how this transition will impact nonmarket valuation estimates of perceived water quality. To answer this question, we merge housing information with Secchi depth and satellite estimates of water clarity from over 100 lakes in Wisconsin. A comparison of hedonic price functions reveals satellite estimates of water clarity provide a stronger statistical fit of housing price and produce implicit prices up to 11% larger in magnitude.

Persistent Scatterers continuous streaming for landslide monitoring and mapping: the case of the Tuscany region (Italy)

The results of the continuous monitoring of ground deformation throughout the Tuscany region using radar images acquired by the Sentinel-1 satellite constellation of the European Space Agency (ESA) are presented here. This new monitoring approach, based on systematic imagery processing and analysis of deformation time series, is discussed at regional (for the entire Tuscany) and at local scale in the context of a case study of the Carpineta landslide, which is a large, active earth slide in the Northern Apennines (Pistoia province). The landslide registered an acceleration during the winter and spring of 2018 as a direct consequence of rainfall and snow melt. The increase in the deformation rate of the landslide, which led to the damage of several buildings, was promptly detected and monitored due to the enhanced temporal repetitiveness offered by the Sentinel-1 constellation. The results demonstrate that advances in satellite sensors, increases in computing capacity and the refinement of processing approaches and data screening tools can contribute to the development of new paradigms in satellite-based monitoring systems. Sentinel-1 data, which are systematically acquired with short revisiting times and then promptly processed, can now be used as a tool for the systematic tracking of ground deformation at the regional scale and for the continuous monitoring of slow and very slow landslides.

Satellite-based monitoring of contrasting characteristics of suspended sediment discharged from the Red and the Ma river systems along the northern coast of Vietnam

The northern coast of Vietnam has accumulated a significant amount of sediment discharged from the multiple distributaries of rivers such as the Red River and Ma River. While recent decreases of the sediment supply appears to have a significant impact on coastal erosion, the complex network of these distributaries makes it difficult to determine the overall spatiotemporal characteristics of sediment discharges and related topographic changes. The goal of the current study is to develop a satellite-based monitoring system for observation of turbidity discharged from the multiple rivers and to investigate the applicability of the developed monitoring system through a case study on the northern coast of Vietnam. Based on the in-situ observed data, a formula was determined for estimation of the surface water turbidity as a function of the red band reflectance of Moderate Resolution Imaging Spectro-radiometer (MODIS) images. The formula was then combined with a newly determined threshold for cloud-masking to obtain maps of the nearshore turbidity patterns. These maps capture the spatiotemporal water surface turbidity along the entire coast of the Red River Delta and the coast around the Ma River mouth over the past sixteen years with frequency of twice a day. Finally, long-term trends of the turbidity patterns from multiple rivers were compared with the in-situ observation data and it was found that the Red River and the Ma River showed clearly contrasting characteristics, which reasonably explain the recent coastal shoreline changes and characteristics of sediment sampled along the coast.

The materiality of data transparency and the (re)configuration of environmental activism in the Brazilian Amazon

This article examines the relation between data transparency and environmental activism in the Amazon rainforest. For this purpose, we analyze the history of PRODES and DETER, two satellite-based monitoring systems developed by the Brazilian Institute for Space Research (INPE). We discuss its role in environmental activism and the formulation of policy toward the Amazon over the last three decades. Based on this analysis, we argue that the level of aggregation (e.g. regional figures vs. individual events) and temporality (e.g. yearly consolidations vs. near real-time releases) of open data configure different ways of performing environmental activism. Aggregated figures tend to have wider policy significance due to their simplicity and scale, yet allow very little room for reinterpretation, contribution from environmental activists, and direct use in policy implementation. Disaggregated data, while allowing more forms of (unexpected) reinterpretations and additions via the overlay of different data-sets, also require the intervention of environmental activists and other info-mediators in order to acquire meaning for the broader public. Similarly, while consolidated data-sets have the advantage of allowing more time for the creation of higher quality data, they are often published at a point in the policy-making cycle in which the negative effects of current choices are irreversible. At the same time, while more frequent data releases may lead to more responsive policies, they also place governmental agencies in a more vulnerable position since near real-time data are more prone to contain errors. Based on these considerations we conclude that monitoring data do not simply represent deforestation in the Amazon. Instead, different publics and data configurations (i.e. spatial and temporal aggregation levels) produce different objects (e.g. a threatened Amazon, a successful policy) and subjects (e.g. knowledgeable environmental activists, an unresponsive government).

Toward a Satellite-Based Monitoring System for Water Quality

Water Quality Workshop for End Users; Greenbelt, Maryland, 27 September 2017

Satellite-based Monitoring of Behavior of Fine Sediment Discharged from Rivers

This paper evaluates the fine sediment discharge patterns of rivers in the northern part of Vietnam and the Enshu-nada coast in Japan. The monitoring system was developed based on the MODIS satellite data which has archives for the last 16 years. The system enabled us to capture the different patterns of fine sediment discharge with its relative magnitudes and we found through the monitoring that the amount of turbid discharge in the rivers of the Red River system was reduced while that of the Ma River system tended to be increased. The results of the satellite-based monitoring system present the discharge pattern on a daily, monthly and yearly basis. The daily basis results support the feasibility of the use of the present MODIS-based monitoring system for the investigation of turbidity patterns which may be affected by daily factors such as tides and winds. Monthly or yearly averaged turbidity patterns along the coasts provide us with the additional information of the long-term trends of sediment discharge and the behavior of littoral movement. The results of suspended sediment patterns and their magnitudes are further discussed from a previous study around the Ma river study site. For instance, the decreasing trend of the Red River discharge and increasing trend of the Ma river discharge surely corresponded to the estimated littoral drift based on the analysis of thermoluminescence.

THE EUROPEAN CONTROLLING SYSTEM TO REDUCE OIL DISCHARGES IN THE SEA

Ship-origin operational discharges of oil mainly include the discharge of bilge water from motor rooms, fuel oil sludge and oily ballast water from fuel tanks. Also, various tankers can illegally discharge of tank-washing residues. Accidental discharges can appear when ship collide or come in distress at sea (e.g. engine breakdown, fire, explosion, pipeline breaks). There is necessity of continuous inspection of marine shipping routes, especially in environmentally sensitive areas (e.g. whole Baltic Sea). If protection against oil pollution is considered - the coastal nations of the North Sea are formed in the Bonn Agreement, whereas coastal nations of the Baltic Sea are formed in the HELCOM convention. Both organizations carrying out the international aerial surveillances and manage international oil-combat systems. Unfortunately, air surveillance can operate mainly in good weather, good visibility and in daylight. The surface of the whole world is observed independently on the time of day and weather by antennas of Synthetic Aperture Radars (SAR) of dozen military satellites with resolution of several meters. Some civil satellites equipped with SAR, supply every few days a set of signals which in ground-based centres are transformed to image of a define area of the sea surface. In these images, the shapes of places, which can be interpreted as polluted by an oil film, are shown. The system is introduced after EU directive and managed by European Maritime Safety Agency (EMSA). EMSA has developed the CleanSeaNet service - a satellite based monitoring system for marine oil spill detection. Advantages and limitations of the SAR-methods are discussed in this study. Physical, meteorological and hydrological as well as organizational conditions for effective use of this system are considered.

Satellite-based water quality monitoring for improved spatial and temporal retrieval of chlorophyll-a in coastal waters

The coastal zones are the most inhabited areas of the world and are therefore strongly affected by humans, leading to undesirable environmental changes that may alter the ecosystems, such as eutrophication. In order to evaluate changes in the environment an effective water quality monitoring system for the coastal zones must be in place. The chlorophyll-a concentration is commonly used as a proxy for phytoplankton biomass and as indicator for eutrophication and it can be retrieved from ocean colour remote sensing data. Several operational monitoring systems based on remote sensing are in place to monitor the open sea and, to some extent, the coastal zones. However, evaluations of coastal monitoring systems based on satellite data are scarce. This paper compares the chlorophyll-a concentrations retrieved from an operational satellite system based on MERIS (Medium Resolution Imaging Spectrophotometer) data with ship-based monitoring for the productive seasons in 2008 and 2010, in a coastal area in the Baltic Sea. The comparisons showed that the satellite-based monitoring system is reliable and that the estimations of chlorophyll-a concentration are comparable to in situ measurements in terms of accuracy and quantitative retrieval. A very strong correlation was found between measurements from satellite-derived chlorophyll-a compared to in situ measurements taken close in time (0–3days), with RMSE of 64% and a MNB of 17%. The comparison of the monthly means showed improved RMSE and a MNB of only 8%. Furthermore, this study shows that MERIS is better at capturing spatial dynamics and the extent of phytoplankton blooms than ship-based monitoring, since it has a synoptic view and higher temporal resolution. Satellite-based monitoring also increases the frequency of chlorophyll-a observations considerably, where the degree of improvement is dependent on the sampling frequency of the respective monitoring programme. Our results show that ocean colour remote sensing can, when combined with field sampling, provide an improved basis for more effective monitoring and management of the coastal zone. These results are important for eutrophication assessment and status classifications of water basins and can be applied to a larger extent within national and international agreements considering the coastal zones, e.g. the European Commission's Water Framework Directive.

Satellite-based monitoring system for assessment of vegetation vulnerability to locust hazard in the River Ili delta (Lake Balkhash, Kazakhstan)

The study investigates the overall vulnerability of vegetation in the River Ili delta (Lake Balkhash, Southern Kazakhstan) to locust hazards using correlation between the normalized difference vegetation index data from advanced very high resolution radiometer and the TOPEX/POSEIDON/JASON-1 satellite altimetry derived water level of Lake Balkhash. The study develops a new monitoring and evaluation system to detect the annual vegetated areas infested by locusts and to quantify the overall recurrence of locust damage in these areas throughout the period 1992 to 2006. The monitoring system-based annual estimations of locust-affected areas were validated against ground survey data. The validation reveals a good correspondence of the estimations with the information from ground truth. The results of the overall vulnerability assessment showed that, for the River Ili delta vegetative land, ∼17% of the total area was characterized by moderate and high vulnerability of vegetation to locust hazards, whereas ∼3% showed low vulnerability. Most parts of the Ili delta area are not sensitive to locust hazard.

Real-Time Loss Estimation as an Emergency Response Decision Support System: The Early Post-Earthquake Damage Assessment Tool (EPEDAT)

At the time of the Northridge earthquake, a number of new technologies, including real-time availability of earthquake source data, improved loss estimation techniques, Geographic Information Systems and various satellite-based monitoring systems, were either available or under consideration as emergency management resources. The potential benefits from these technologies for earthquake hazard mitigation, response and recovery, however, were largely conceptual. One of the major lessons learned from the January 17, 1994 earthquake was that these technologies could confer significant advantages in understanding and managing a major disaster, and that their integration would contribute a significant additional increment of utility. In the two and half years since the Northridge earthquake, important strides have been taken toward the integration of relatively discrete technologies in a system which provides real-time estimates of regional damage, losses and population impacts. This paper will describe the development, operation and application of the first real-time loss estimation system to be utilized by an emergency services organization.