Lisa-Maria Rebelo

Digital Earth Africa

Wetlands are among the most vulnerable, threatened, valuable, diverse, and heterogeneous ecosystems existing on our planet. While they provide invaluable ecosystem services to our society, they have been declining globally for many centuries. Monitoring of these changes is necessary for implementing efficient conservation policies and sustainable m...

Mangroves are a globally important ecosystem that provides a wide range of ecosystem system services, such as carbon capture and storage, coastal protection and fisheries enhancement. Mangroves have significantly reduced in global extent over the last 50 years, primarily as a result of deforestation caused by the expansion of agriculture and aquacu...

Producing more food for a growing population requires sustainable crop intensification and diversification, particularly in high-potential areas such as the seasonal floodplain wetlands of sub-Saharan Africa (SSA). With emerging water shortages and concerns for conserving these multi-functional wetlands, a further expansion of the cropland area mus...

Producing more food for a growing population requires sustainable crop intensification and diversification, particularly in high-potential areas such as the seasonal floodplain wetlands of sub-Saharan Africa (SSA). With emerging water shortages and concerns for conserving these multi-functional wetlands, a further expansion of the cropland area mus...

Maintaining healthy, productive ecosystems in the face of pervasive and accelerating human impacts including climate change requires globally coordinated and sustained observations of marine biodiversity. Global coordination is predicated on an understanding of the scope and capacity of existing monitoring programs, and the extent to which they use...

This report describes the Water Accounting and Water Productivity methodology. The analyses contributed to various ADB funded projects in six countries (Cambodia, India, Kazakhstan, Mongolia, Philippines and Sri Lanka). The focus of the analyses was on using remote sensing information to assess the water resources situation at basin level (Water Ac...

Coordinating the Implementation of Mangrove and Seagrass Essential Observations: A joint GOOS/MBON community outreach workshop to implement EOV/EBVs (Sea Plants Workshop), Consortium for Ocean Leadership; Washington, D.C., 10–11 June 2019

Development of global ocean observing capacity for the biological EOVs is on the cusp of a step-change. Current capacity to automate data collection and processing and to integrate the resulting data streams with complementary data, openly available as FAIR data, is certain to dramatically increase the amount and quality of information and knowledg...

This study presents a new global baseline of mangrove extent for 2010 and has been released as the first output of the Global Mangrove Watch (GMW) initiative. This is the first study to apply a globally consistent and automated method for mapping mangroves, identifying a global extent of 137,600 km 2 . The overall accuracy for mangrove extent was 9...

There is a growing awareness that data obtained from Earth Observation (EO) has the potential to provide the information needed for accurate wetland inventory, assessment and monitoring, and for updating a number of data fields in the Ramsar Sites Information Sheets (RIS). The latter includes: the physical features of the wetland, the presence and...

Measurements of the status and trends of key indicators for the ocean and marine life are required to inform policy and management in the context of growing human uses of marine resources, coastal development, and climate change. Two synergistic efforts identify specific priority variables for monitoring: Essential Ocean Variables (EOVs) through th...

Mangroves are characteristics of coastlines and occur primarily in the tropics and subtropical but extend to temperate regions. Remote sensing radar and optical and lidar data can be used to provide information on mangrove extent and also biophysical characteristics. Optical data are the most useful for differentiating species type, while radar and...

While many wetlands are still observed in their natural state, humans have exerted a considerable influence on their extent, condition, and dynamics. This section focuses on remote sensing techniques that have been used to characterize, map, and monitor these impacts which arise from agricultural production, aquaculture, dam and reservoir construct...

This study focuses on Laos, a landlocked nation located in Southeast Asia with subtropical climate and highly seasonal rainfall distribution. Laos is one of the world's least developed countries, and currently witnesses an unprecedented level of development that is highly reliant on its natural resources, including groundwater. There is currently v...

The Dabus Wetland complex in the highlands of Ethiopia is within the headwaters of the Nile Basin and is home to significant ecological communities and rare or endangered species. Its many interrelated wetland types undergo seasonal and longer-term changes due to weather and climate variations as well as anthropogenic land use such as grazing and b...

The Agenda 2030 on Sustainable Development Goals has produced a step-by-step method for Indicator 6.6.1 on water-related ecosystems. This guideline gives support to that method by providing greater context and detali.

The characterization, mapping, and monitoring of mangroves based on remote sensing data has proved challenging as the prevalence of cloud cover in many areas they inhabit limits observations by optical sensors, diurnal changes in tidal inundation lead to variability in their appearance, and similarities with other proximal vegetation types often co...

Agricultural Water Productivity (AWP) is often simplified as the ‘crop per drop’, described as the output in terms of yield or biomass per unit of water input. This purely physical measure of Water Productivity (WP) using only a single factor input (water) does not consider: (1) the level of other inputs used in conjunction with water, (2) the oppo...

The Nile, the World’s longest river, is well endowed with wetlands, including the Sudd, one of the World’s largest. The wetlands are not only biodiversity hotspots but also vital for the livelihoods and wellbeing of people. In total there are 14 Ramsar Sites in the basin and thousands of smaller, lesser-known wetlands. Many of these wetlands sustai...

The Sudd is one of the largest floodplains in Africa and one of the largest tropical wetlands in the world. It is located in South Sudan, and forms part of the White Nile, or Bahr el Jebel river system, which originates in the African Lakes Plateau. Derived from an Arabic word meaning obstacle or blockage of river channels, the Sudd is composed of...

Earth observation from satellites offers potential for aquaculture applications, including the selection of sites, management of aquaculture ponds, and assessment of impacts. While there are many forms of aquaculture in coastal areas as well as in many inland lakes and wetlands, here the focus is on shrimp farming in ponds. Mangroves are commonly r...

In developing countries millions of people live a life of subsistence agriculture, mired in poverty, with limited access to basic human needs, such as food and water. Under such circumstances wetlands, through the provision of a range of direct and indirect ecosystem services, play a vital role in supporting and sustaining peoples’ livelihoods and...

In the Blue Nile Basin of Ethiopian highlands, rainfall distribution is extremely uneven both spatially and temporally. Drought frequently results in crop failure, while high rainfall intensities result in low infiltration and high runoff causing soil erosion and land degradation. These combined factors contribute to low agricultural productivity a...

Study region Increasing demographic pressure and economic development in the Mekong Basin result in greater dependency on river water resources and increased vulnerability to streamflow variations. Study focus Improved knowledge of flow variability is therefore paramount, especially in remote catchments, rarely gauged, and inhabited by vulnerable...

The increasing competition for water resources requires a better understanding of flows, fluxes, stocks, and the services and benefits related to water consumption. This paper explains how public domain Earth Observation data based on Moderate Resolution Imaging Spectroradiometer (MODIS), Second Generation Meteosat (MSG), Tropical Rainfall Measurem...

Across Africa and Asia water resources are being affected by a complex mixture of social, economic, and environmental factors. These include climate change and population growth, food prices, oil prices, financial disruptions, and political fluctuations. The need to produce more food will have one of the largest impacts on water and will continue t...

Information on the status of and changes in mangroves is required for national and international policy development, implementation and evaluation. To support these requirements, a component of the Japan Aerospace Exploration Agency's (JAXA) Kyoto and Carbon (K&C) initiative has been to design and develop capability for a Global Mangrove Watch (GMW...

Summary Agriculture is the main sector of the Ethiopian economy, as is the case in many sub-Saharan African countries. In this region, rainfall distribution is extremely uneven both spatially and temporally. Drought frequently results in crop failure, while high rainfall intensities result in low infiltration and high runoff, causing soil erosion a...

The abundance of groundwater resources of Sub-Saharan Africa is generally well recognized, but quantitative estimates of their potential for irrigation development are lacking. This study derives estimates using a simple and generic water balance approach and data from secondary sources for 13 countries. Even with conservative assumptions and accou...

The conversion of wetlands to agriculture through drainage and flooding, and the burning of wetland areas for agriculture have important implications for greenhouse gas (GHG) production and changing carbon stocks. However, the estimation of net GHG changes from mitigation practices in agricultural wetlands is complex compared to dryland crops. Agri...

By mitigating the vagaries of climatic variability, agricultural water storage is widely anticipated to make a key contribution to climate change (CC) adaptation, particularly in Africa. However, if the planning of water storage is not improved, it is likely that many investments will fail to deliver intended benefits. This report describes differe...

Located on the Bahr el Jebel in South Sudan, the Sudd is one of the largest floodplain wetlands in the world. Seasonal inundation drives the hydrologic, geomorphological, and ecological processes, and the annual flood pulse is essential to the functioning of the Sudd. Despite the importance of the flood pulse, various hydrological interventions are...

Wetlands, which occupy a considerable proportion of Malawi, are an important resource for the rural-poor. In regions of low and erratic rainfall, they provide important opportunities for agriculture and fisheries and are often vital for food security. However, overutilization and some farming practices can result in environmental degradation and th...

The GaMampa wetland, a palustrine wetland, comprises less than 1% of the catchment but is widely believed to make a significant contribution to dry-season river flow in the Mohlapitsi River, a tributary of the Olifants River, in South Africa. The contribution of the GaMampa wetland to dry-season flow in the Mohlapitsi River and the impact of increa...

Wetlands contribute in diverse ways to the livelihoods of millions of people. They are often inextricably linked to agricultural production systems. In many places, growing population, in conjunction with efforts to increase food security, is escalating pressure to expand agriculture within wetlands. The environmental impact of wetland agriculture...

Maps describing the eco-hydrology of inland wetland systems in Africa are needed to identify and implement appropriate adaptive management plans related to land use and land cover. Many African countries lack regional baseline information on the temporal extent, distribution and characteristics of wetlands. This information is provided here in the...

Wetlands of International Importance, as listed by the Ramsar Convention, can provide valuable opportunities to conserve otter species worldwide. Adopted in 1971, the Convention originally focused on protecting habitats for waterfowl. Since then the convention has broadened its scope to cover all aspects of wetland conservation and wise use, recogn...

This paper provides an overview of poverty levels, hydrology, agricultural production systems and water productivity in the Nile Basin. There are opportunities to manage water better in the basin for use in agriculture to improve food security, livelihoods and economic growth by taking into account not only the water in the river, but also by impro...

Wetlands contribute in diverse ways to the livelihoods of millions of people in Sub-Saharan Africa. In many places they are inextricably linked to cropping and livestock management systems. At the same time, increasing population in conjunction with efforts to increase food security is escalating pressure to expand agriculture within wetlands. The...

Over one hundred wetland specialists and Earth Observation experts from around the world gathered at the European Space Agency's ‘GlobWetland Symposium: Looking at wetlands from space’ in Frascati, Italy, from 19 to 20 October, 2006. The aim of the Symposium was to stimulate discussion between the two communities by reviewing the latest development...

A multiple purpose wetland inventory is being developed and promoted through partnerships and specific analyses at different scales in response to past uncertainties and gaps in inventory coverage. A partnership approach is being promoted through the Ramsar Convention on Wetlands to enable a global inventory database to be compiled from individual...

A comprehensive, multiple purpose and multiple-scale wetland inventory is being developed and promoted through partnerships and specific analyses at different scales. These include an analysis of the distribution of Ramsar sites and their importance for agriculture and the role of agriculture in wetland degradation. At a regional scale wetlands use...

.........GWIM will address the major causes of wetland loss and in particular investigate the role of agriculture and fisheries which have been identified as being amongst the most important drivers of past and current loss and degradation. The project will specifically seek to develop image-based automated techniques to describe the ecological cha...

1] Southern African wildfires are a globally significant source of trace gases and aerosols. Estimates of southern African wildfire fuel consumption have varied from hundreds to thousands of teragrams (Tg), and better-constrained estimates are required to properly assess the effects of the pollutant emissions. A new approach for providing such esti...

Conference code: 65467, Export Date: 17 January 2013, Source: Scopus, CODEN: ESPUD, Language of Original Document: English, Correspondence Address: Lewis, P.E.; NERC Centre for Terrestrial Carbon Dynamics, Department of Geography, University College London, 26 Bedford Way, London, WC1H 0AP, United Kingdom; email: plewis@geog.ucl.ac.uk, References:...

Remote Sensing provides the only practical means to monitor changes over large areas. This paper describes the development of a generic algorithm designed to map the temporal occurrence and spatial extent of areas exhibiting sudden change. The algorithm is demonstrated here applied to the problem of mapping fire-affected areas. The research further...

A new generic approach to change detection is presented. Applicable to high temporal and moderate spatial resolution satellite data, the method identifies the location, the start and the duration of surface change. The algorithm described exploits the information content of the remote sensing signal as a result of angular variations, and employs a...

A range of spaceborne radar images are acquired over a tropical catchment containing a large floodplain wetland in Cat Tien National Park, Vietnam. The images, which are a combination of ERS and JERS SAR over the period 1992 to 2000, are focussed on the wet season in each year while more frequent sampling is available throughout 1999-2000. These da...

Inland wetlands occur extensively across Sub- Saharan Africa. These ecosystems typically play a vital role in supporting rural populations and their sustainable management is thus critical. In order to prevent depletion of resources and ecosystem services provided by these wetlands, a balance is required between ecological and socio-economic factor...