Magaly Koch

• PhD in Geology
• Professor (Associate) at Boston University

There is a lack of datasets to study the climate and human outcomes nexus. There are many flood data portals due to recent improvements in flood identification using satellites, providing opportunities to study the human impacts. The development of these portals is rapid and there is currently no standard for evaluating their usability for interdis...

It is unknown how recurring flooding impacts household diet in Central Java. We aimed to assess how recurrent flooding influenced household food access over 22 years in Central Java by linking the Global Surface Water dataset (GSW) to the Indonesian Family Life Survey. We examined linear and nonlinear relationships and joint effects with indicators...

This paper analyzed the quality of the xBD image-training dataset for identifying building damage across a variety of natural hazards using deep learning convolutional neural networks. Specifically, we evaluated the pros and cons of combining training datasets across multiple natural hazards and provided recommendations on using the provided traini...

Landslides, often occurring in mountainous regions and triggered by earthquakes or heavy rainfall, are a major natural disaster. Traditionally, identifying landslides involves manually analyzing optical remote sensing imagery, a process that is both slow and labor-intensive. This study proposes an automatic landslide detection method using advanced...

This study explores a new method to identify and map soil liquefaction areas from aerial images after earthquake events. Traditionally, liquefaction is recorded through field visits as geographic points, leading to incomplete data. Comprehensive mapping of affected areas is crucial for developing accurate prediction models. The research introduces...

Landslides are major natural disasters in mountainous areas, often caused by earthquakes and heavy rainfalls. Traditional manual delineation methods for identifying landslide features using optical imagery are inefficient, highlighting the need for automated detection techniques. Deep Convolutional Neural Networks (CNNs) have emerged as advanced so...

A series of earthquakes occurred in Kumamoto, Japan, in April 2016, which caused numerous landslides. In this study, high-resolution pre-event and post-event optical imagery, plus bi-temporal Synthetic Aperture Radar (SAR) data are paired with geospatial data to train a pixel-based machine learning classification algorithm using logistic regression...

Soil liquefaction often occurs as a secondary hazard during earthquakes and can lead to significant structural and infrastructure damage. Liquefaction is most often documented through field reconnaissance and recorded as point locations. Complete liquefaction inventories across the impacted area are rare but valuable for developing empirical liquef...

Ecosystem destruction and biodiversity loss are now widespread, extremely rapid, and among the top global anthropogenic risks both in terms of likelihood and overall impact. Thorough impact evaluation of these environmental abuses—essential for conservation and future project planning—requires good analysis of local ecological and environmental dat...

Central Java, Indonesia, is prone to river and coastal flooding due to climate changes and geological factors. Migration is one possible adaptation to flooding, but research is limited due to lack of longitudinal spatially granular datasets on migration and metrics to identify flood-affected households. The available literature indicates social and...

A series of earthquakes, with 7.3 Mw highest intensity, hit Kumamoto, Japan, over a period of two days in April 2016. The earthquakes caused numerous landslides and surface ruptures in the steep volcanic geological environment. In this study, pre- and post-event sets of high-resolution aerial (Geospatial Information Authority of Japan) and satellit...

Geospatial ground failure models are routinely implemented as part of the Ground Failure tab of the USGS Event page. After the February 2023 Earthquake sequence in Turkey, ground failure maps were disseminated for the Mw7.8 and Mw7.5 events. In addition to the Zhu et al. (2015) and Zhu et al. (2017) models, the authors have an updated geospatial li...

Changes in total suspended solids (TSS) concentrations provide information to determine the quality of the carrying capacity of waters as marine resources. This research aims to analyze the concentration and distribution of TSS in marine waters due to anthropogenic impacts on land. The concentration and distribution changes of TSS were analyzed usi...

Public climatic data are rapidly growing in volume and complexity at a global and national scales but these data remain underutilized for vulnerability assessment. We aim to explore how flood records from Dartmouth Flood Observatory, a global flood monitoring database, can be linked with a national disaster database maintained by the Indonesian Nat...

The purpose of his study is to propose a fast pixel-based classification technique based on Logistic Regression algorithm, and to evaluate addition of geospatial and temporal change information to the color imagery in order to increase the classification accuracy in earthquake-induced landslide mapping. Datasets from the 2016 Kumamoto Earthquake in...

Groundwater exploration is the most promising way to overcome water scarcity in hyper-arid regions around the world. Due to the scarcity of hydrogeological information in these regions, groundwater exploration is a challenging issue requiring the joint application of satellite and land-based information to delineate the groundwater aquifers in such...

Natural and anthropogenic disasters can cause significant damage to urban infrastructure, landscape, and loss of human life. Satellite based remote sensing plays a key role in rapid damage assessment, post-disaster reconnaissance and recovery. In this study, we aim to assess the performance of Sentinel-1 and Sentinel-2 data for building damage asse...

Land Use and Land Cover Changes (LULCC) are occurring rapidly around the globe, particularly in developing island nations. We use the lens of the United Nations’ Sustainable Development Goals (SDG) to determine potential policies to address LULCC due to increasing population, suburbia, and rubber plantations in Semarang, Indonesia between 2006 and...

Objectives We examine the utility and quality of IFLS – a longitudinal health and economic survey of Indonesian households – for studying the relationship between recurrent flooding and household diet-related food access. Methods We reviewed IFLS documentation and modules for availability, alignment, completeness, variety, continuity, and compatib...

In the aftermath of an earthquake, data collection is an important part of the response and is used for both loss assessment and data curation for model development. For liquefaction impacts, post-earthquake data collection often relies on field investigations, which are usually spatially limited and incomplete. Field investigations may capture liq...

A series of subsequent earthquakes, with the highest intensity of 7.0 Mw, hit Kumamoto, Japan, continuously over a period of two days in April 2016. The earthquakes caused numerous landslides and surface ruptures in the steep volcanic geological environment, some of them very large in size. In this study, pre- and post-event sets of high-resolution...

In the 20th century, climate change caused an increase in temperature that accelerated the rate of sea level. Sea level rise and land subsidence threaten densely populated coastal areas as well as lowlands because they will cause tidal flooding. Tidal floods occur every year due to an increase in sea level rise and land subsidence. Lack of informat...

Accurate and timely damage assessment is important after any natural disaster event. Accurate damage assessments enhance the efficient distribution of resources. Building damage levels are an important outcome of damage assessment, especially in urban areas. Although at present most building damage assessments are collected manually from post-disas...

Monitoring sources of environmental risks from rising groundwater levels and associated soil degradation is a substantial challenge in coastal regions of the world. The integration of remote sensing and subsurface data, followed by field geophysical surveys, provided an innovative approach for identifying sites susceptible to environmental risks fr...

Collapsed buildings are usually linked with the highest number of human casualties reported after a natural disaster; therefore, quickly finding collapsed buildings can expedite rescue operations and save human lives. Recently, many researchers and agencies have tried to integrate satellite imagery into rapid response. The U.S. Defense Innovation U...

Recently, the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique is widely used for quantifying the land surface deformation, which is very important to assess the potential impact on social and economic activities. Radar satellites operate in different wavelengths and each provides different levels of vertical displacement ac...

Mapping of seismic-induced soil liquefaction is a common practice after earthquakes to help local authorities devise better disaster preparedness plans after a seismic event and to provide data for the research community. Many of those reports provide limited and inconsistent geographic information. Some of the reconnaissance reports provide coordi...

Crop yield maps are valuable for many applications in precision agriculture, but are often inaccessible to growers and researchers wishing to better understand yield determinants and improve site-specific management strategies. A method for mapping sub-field crop yields from remote sensing imagery could increase the availability of crop yield maps....

The integrated use of remote sensing imagery and hydro-geophysical field surveys is a well-established approach to map the hydrogeological framework, and thus explore and evaluate the groundwater potentiality of desert lands, where groundwater is considered as the main source of freshwater. This study uses such integrated approach to map the ground...

he integrated use of remote sensing imagery and hydro-geophysical field surveys is a well-established approach to map the hydrogeological framework, and thus explore and evaluate the groundwater potentiality of desert lands, where groundwater is considered as the main source of freshwater. This study uses such integrated approach to map the groundw...

With the world population projected to grow significantly over the next few decades, and in the presence of additional stress caused by climate change and urbanization, securing the essential resources of food, energy, and water is one of the most pressing challenges that the world faces today. There is an increasing priority placed by the United N...

The short-lived events of high SST are called hot events (HEs) and can only be generated under the conditions of large daily heat gain due to strong solar radiation and weak wind. We investigated the thermal structure below HEs in the western equatorial Pacific by using in situ data obtained from TAO/TRITON buoys. We found that the occurrence of HE...

Using automated supervised methods with satellite and aerial imageries for liquefaction mapping is a promising step in providing detailed and region-scale maps of liquefaction extent immediately after an earthquake. The accuracy of these methods depends on the quantity and quality of training samples and the number of available spectral bands. Digi...

Menier, D.; Mathew, M.; Cherfils J.-B.; Ramkumar, M.; Estournès, G.; Koch, M.; Guillocheau F.; Sedrati, M.; Goubert, E.; Gensac, E.; Le-Gall, R., and Novico, F., 2019. Holocene sediment mobilization in the inner continental shelf of the Bay of Biscay: Implications for regional sediment budget offshore to onshore. Sediment mobilization, especially f...

Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environment...

Water scarcity is a widespread problem in arid and semi-arid regions such as the western Mediterranean coastal areas. The irregularity of the precipitation generates frequent droughts that exacerbate the conflicts among agriculture, water supply and water demands for ecosystems maintenance. Besides, global climate models predict that climate change...

Presents corrections to the paper, “Distinct characteristics of SST variabilities in the Sulawesi sea and the northern part of the Maluku sea during the southeast monsoon,” (Wirasatriua, A., et al), IEEE J. Sel. Topics Appl. Earth Observ. Remote Sens., to be published.

The Sulawesi Sea and the northern part of the Maluku Sea belong to the western equatorial Pacific that is influenced by the Mindanao Current. During the southeast (SE) monsoon, contrasting sea surface temperature (SST) distributions occur between these two seas. The purpose of this research is to investigate the mechanisms of contrasting SST distri...

Background Schistosomiasis is a water-related neglected tropical disease. In many endemic low- and middle-income countries, insufficient surveillance and reporting lead to poor characterization of the demographic and geographic distribution of schistosomiasis cases. Hence, modeling is relied upon to predict areas of high transmission and to inform...

Data processing steps. (TIF)

Sentinel-2 blue band reflectance values. (TIF)

Sentinel-2 green band reflectance values. (TIF)

Sentinel-2 NDWI values. (TIF)

Data analysis steps. (TIF)

Sentinel-2 short wavelength infrared band reflectance values. (TIF)

Landsat 8 land surface temperature values. (TIF)

Sentinel-2 NDVI values. (TIF)

Sentinel-2 EVI values. (TIF)

Sentinel-2 SAVI values. (TIF)

Sentinel-2 MSAVI values. (TIF)

Interpolated total dissolved solids (TDS) concentration values (in mg/L) derived in ArcGIS from field data. (TIF)

Interpolated iron concentration values (in mg/l) derived in ArcGIS from field data. (TIF)

Scatter plots of model predicted (x-axis) vs. observed (y-axis) prevalence values as compared to the line of equality [left]; variable importance values [right] for random forest models conducted with environmental variables from Landsat 8 and topographic variables from GDEM. (TIF)

Scatter plots of model predicted (x-axis) vs. observed (y-axis) prevalence values as compared to the line of equality [left]; variable importance values [right] for random forest models conducted with environmental variables from Sentinel-2 and topographic variables from GDEM. (TIF)

Predicted prevalence values using Landsat 8 data (mask 1). (TIF)

Spearman’s rank correlations among six environmental indices (all are statistically significant; p < 0.05); Sentinel-2 values are shown in top and Landsat 8 in bottom of the matrix. (XLSX)

Sentinel-2 red band reflectance values. (TIF)

Sentinel-2 MNDWI values. (TIF)

Slope values (in degrees) derived from GDEM. (TIF)

Functional improved water source (FIWS) access values derived in ArcGIS from field data. (TIF)

Perennial surface water source (SWAP) access values derived in ArcGIS from field data. (TIF)

Predicted prevalence values using Sentinel-2 data (mask 1). (TIF)

Predicted prevalence values using Landsat 8 data (mask 2). (TIF)

Predicted prevalence values using Landsat 8 data (mask 6). (TIF)

Microhematuria prevalence survey results. (XLSX)

Sentinel-2 near infrared band reflectance values. (TIF)

Elevation values (in meters) derived from GDEM. (TIF)

Slope values derived from GDEM. (TIF)

Predicted prevalence values using Sentinel-2 data (mask 2). (TIF)

Predicted prevalence values using Landsat 8 data (mask 4). (TIF)

Predicted prevalence values using Sentinel-2 data (mask 4). (TIF)

Predicted prevalence values using Sentinel-2 data (mask 6). (TIF)

Predicted prevalence values using Landsat 8 data (mask 5). (TIF)

Predicted prevalence values using Sentinel-2 data (mask 5). (TIF)

The purpose of this study is to investigate the variation of diurnal SST amplitude (∆SST) in the seas west of the Tsugaru Strait, Japan, which exhibit complex topography that affects the wind pattern during “Yamase” season, when cold easterly winds blow around northeastern Japan. We used infrared based satellite SSTs to obtain strong ∆SST signals....

Despite the fact that the Sahara is considered the most arid region on Earth, it has witnessed prolonged fluvial and aeolian depositional history, and might harbor substantial fresh groundwater resources. Its ancient fluvial surfaces are, however, often concealed by aeolian deposits, inhibiting the discovery and mapping of potential groundwater rec...

Near real-time building damage mapping is an indispensable prerequisite for governments to make decisions for disaster relief. With high-resolution synthetic aperture radar (SAR) systems, such as TerraSAR-X, the provision of such products in a fast and effective way becomes possible. In this letter, a deep learning-based framework for rapid regiona...

The accurate detection of land subsidence rates in urban areas is important to identify damage-prone areas and provide decision-makers with useful information. Meanwhile, no precise measurements of land subsidence have been undertaken within the coastal Port-Said City in Egypt to evaluate its hazard in relationship to sea-level rise. In order to ad...

Satellite-borne Synthetic Aperture Radar (SAR) has been used for characterizing and mapping in two relevant ice-free areas in the South Shetland Islands. The objective has been to identify and characterize land surface covers that mainly include periglacial and glacial landforms, using fully polarimetric SAR C band RADARSAT-2 data, on Fildes Penins...

The study employs a Fourier transform analysis approach to assess the land-cover changes in a mountainous Mediterranean protected area using multi-temporal satellite images. Harmonic analysis was applied to a time series of Landsat satellite images acquired from 1984 to 2008 to extract information about land cover status with a vegetation spectral...

90% of the worldwide schistosomiasis burden falls on sub-Saharan Africa. Control efforts are often based on infrequent, small-scale health surveys, which are expensive and logistically difficult to conduct. Use of satellite imagery to predictively model infectious disease transmission has great potential for public health applications. Transmission...

Drylands regions of the world face difficult issues in maintaining water resources to meet current demands which will intensify in the future with population increases, infrastructure development, increased agricultural water demands, and climate change impacts on the hydrologic system. New water resources evaluation and management methods will be...

Mapping and characterizing surface sediment of desert environments in terms of surface texture and grain sizes provide important information on the geomorphology and depositional history to assess their potential for economic development. Accurate maps of surface sediment are often not available at the desired scales using conventional field survey...