I am currently @ Stockholm Resilience Center, Stockholm University, Kräftriket 2B, SE-10691 Stockholm, Sweden

Research & Projects

Research Interests

  • Spatiotemporal Statistics
  • Geographic Information Science and Systems
  • Earth System Dynamics
  • Climate
  • Eco(toxico)logy
  • Ecohydrology


Current Projects

1. Mapping human risk from exposure to contaminants via different pathways in developing countries

Exposure to contaminants, e.g. trace metals, organic pollutants, is one of the major causes of mortality, cardiovascular and skeletal diseases in developing countries. These contaminants originate in environment via different pathways through several geogenic and anthropogenic processes. However, due to resource constraints, environmental monitoring activities have been limited to a few administrative areas and a nationwide human risk assessment from exposure to contaminants is often lacking for developing countries. In this project, we calculate nationwide human risk maps for developing countries, i.e. initially for Pakistan and Bangladesh, by generating databases through field monitoring, as well as by predicting the concentration of contaminants in different sources, e.g. inland water and dusts, using GIS coupled methods and comparing them to guideline values. The results can inform disease mitigation and environmental management regarding potential hot spots.

Collaborators

  • Ralf B. Schäfer, Junior-Professor for Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany

  • Syed Ali Musstjab Akber Shah Eqani, Assistant professor on Environmental Toxicology, Department of Bio Sciences, COMSATS Institute of Information and Technology, Pakistan

  • Heqing Shen, Professor, Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, China

  • Ioannis Katsoyiannis, Lecturer, Department of Chemistry, Division of Chemical Technology, Aristotle University of Thessaloniki, Greece

  • Habib Bokhari, Professor, Public Health and Environment Division, Department of Biosciences, COMSATS Institute of Information Technology, Pakistan

  • Nadeem Ali, Assistant Professor, Center of Excellence in Environmental Studies, King Abdulaziz University, KSA

Important publications from the project

2. Climate change impacts on the trait composition and community structure of stream organisms in Germany

Climate is the predominant environmental driver of the community patterns and trait compositions of freshwater organisms on large spatial scales. Since considerable changes in several climatic aspects have been predicted for Germany in the coming decades, we predict the associated changes in the spatial distribution of stream macroinvertebrates in this project. This is achieved by analyzing the spatial relationships between macroinvertebrate community trait compositions and climate, and the effects of extreme weather events on macroinvertebrate taxa pool. We use long term stream biomonitoring data and apply spatial statistical methods for the purpose. The findings contribute to the understanding of ecological effects of climate change and support the development of trait-based metrics to predict and detect climate-related changes of stream macroinvertebrate communities.

Collaborators

  • Gunnar Oehmichen, Ph.D. Candidate, Bioenergy research group, Division of Environmental Technology, The Helmholtz Centre for Environmental Research - UFZ, Germany

  • Eduard Szöcs, Ph.D. Candidate, Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany.</li>

  • Ralf B. Schäfer, Junior-Professor for Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany

Important publications from the project

3. Effects of landuse on the energy transfer across the freshwater-land interface

Freshwater ecosystems subsidize adjacent terrestrial ecosystem through emerging aquatic, i.e. merolimnic, insects. While recent studies have established catchment and riparian land use as important predictors of aquatic population and community endpoints, the relevance of land use for cross-system fluxes remains open. In this project, the influences of landuse on merolimnic insect biomass are evaluated and the energy transfer to land is estimated at four different scales – the catchment scale and three riparian corridors. The results will contribute to the identification of anthropogenic land use change effects on coupled ecosystems.

Collaborators

  • Ralf B. Schäfer, Junior-Professor for Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany

  • Shree Varma Kakarlapudi, Master’s candidate, Master of Science in Ecotoxicology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany


Completed Projects

1. Development of automated, objective and open-source tools for stream extraction and riparian corridor delineation

The extraction of stream networks from digital elevation models and delineation of upstream riparian corridors for stream sampling points are frequently used techniques in freshwater and environmental research, although are often done manually. A few available available algorithms for automated accumulation threshold selection for stream extraction were developed on proprietary software and only tested on small scale, i.e. catchment. In this project, we developed two algorithms by co-interfacing the open source software packages R and GRASS GIS, which allow for automated accumulation selection and upstream riparian corridor delineation. The algorithms showed similar or better performance than available algorithms and were capable of stream network extraction and upstream riparian corridor delineation on large scales, i.e. state. They improve the extraction of stream networks and the assessment of magnitude and scale of effects from riparian stressors (e.g. landuse) on freshwater ecosystems.

The algorithms are freely available from an online repository with detailed documentation and example data. They are currently being used by the Amazon Conservation Team in Columbia for assessing the impacts of deforestation on stream communities. The algorithms are under continuous development and version update. Moreover, an R package for stream network and upstream riparian corridor extraction, and a model for stream network extraction in unmapped regions based on climatic parameters are currently under development.

Collaborators

  • Ralf B. Schäfer, Junior-Professor for Quantitative Landscape Ecology, Institute for Environmental Sciences, University of Koblenz-Landau, Germany

  • Markus Metz, GIS and Remote Sensing Platform, Biodiversity and Molecular Ecology Department, Research and Innovation Centre - Fondazione Edmund Mach, Italy

Important publications from the project

2. Evaluation of spacetime geostatistical techniques for mapping climate variables with low sample density

Accuracy and precision of geostatistical interpolation techniques are highly influenced by sample density in a region. Variograms for the regions with low sample density are often imprecise and gridded climate surfaces are erratic. In this project, we analyzed the impact of sample density on the performance of spatiotemporal geostatistical interpolation of climate variables. The available spatiotemporal interpolation techniques were evaluated for regions with low sample density and novel methods were developed to improve accuracy and precision of spatiotemporal interpolation in data scarce regions. Thus, climatic trends and variability over space and time were quantified and impacts on agricultural production were also assessed.

The project contributed with a novel pooled within-time series variogram computation tool that spatializes temporal data points and entail higher precision for variogram estimation than the available methods. The tool is freely available from an online repository.

Collaborators

  • Ana Cristina Costa, Assistant Professor, Instituto Superior de Estatística e Gestão de Informação, Universidade NOVA de Lisboa, Portugal

  • Pedro Cabral, Assistant Professor, Instituto Superior de Estatística e Gestão de Informação, Universidade NOVA de Lisboa, Portugal

  • Jorge Mateu, Full Professor of Statistics, Departamento de Matemáticas, Universitat Jaume I, Castellón, Spain

  • Edzer Pebesma, Professor and Director, Institute for Geoinformatics (ifgi), University of Münster, Germany

Important publications from the project

3. Quantifying impacts of cyclone Sidr on the Sundarbans floristic diversity using remote sensing techniques

The Sundarbans - the world’s largest single block of tidal halophytic mangrove forest situated at the southwest of Bangladesh, plays a vital role in maintaining environmental sustainability of the country and the world in general. This project identified and quantified the extent and degree of damage caused to the floristic diversity of the Sundarbans by the tropical cyclone Sidr in 15 November 2007 using freely available remotely sensed imageries. It also quantified the extent and rate of the post-cyclone regeneration in the damaged flora. The results were in line with the ground-based studies and thus demonstrated potentials of remote sensing in early detection of natural perturbation effects.

Collaborators

  • Pedro Cabral, Assistant Professor, Instituto Superior de Estatística e Gestão de Informação, Universidade NOVA de Lisboa, Portugal

  • René de Groot, Geographic Information Analyst, Utrecht Province, Netherlands

Important publications from the project

4. Relocation of Hazaribagh Tanneries: myth or reality?

Leather industry is one of the most important export oriented industries of Bangladesh. The main tannery area situated at Hazaribagh in the capital has been causing severe environmental degradation because of the unavailability of precautionary and protective measures. Consequently, the government has launched a relocation project of tannery industries from Hazaribagh to the outskirt of the city that has been failing after multiple trials. In this project, we critically reviewed the Bangladesh leather processing industries’ relocation plan and identified the reasons for the failure of its implementation. A questionnaire survey was conducted for the purpose among the leather industry owners and the original project documents were reviewed. The geographic suitability of the new location and Hazaribagh as well as the redevelopment options for Hazaribagh area and environmental sustainability issues were assessed. The results contribute to the development of policies for sustainable urbanization.

Collaborators

  • Mohammad Shakil Akther, Professor, Department of Urban & Regional Planning, Bangladesh University of Engineering & Technology

  • M. Samiul Islam, Relationship Manager, IDLC Finance Limited, Bangladesh

Important publications from the project