– Siberia could hold clues as to how ecosystems will adapt to future climate change.

– More than twenty years after intense fire scorched Yellowstone National Park, the ecosystem is still recovering. More frequent fires in a warmer climate could force the ecosystem to change altogether.

Screenshot of MappingForRights.org.

MappingForRights.org is a new participatory mapping website produced by The Rainforest Foundation UK.

MappingForRights supports Foundation’s goal of promoting community rights over rainforest lands, and builds a knowledge base of the Congo Basin’s inhabitants and how resources are used within these mapped forest regions.

Built on an interactive and free, open-source software platform, MappingforRights offers access to detailed digital maps and provides users with the locations of forest communities, and how and where forest resources are used.

According to The Rainforest Foundation UK, the website also provides details on protected forest areas, as well as the current state of degraded forest areas due to factors such as logging.

It also contains interactive features such as photos, videos, and music, providing insight on important cultural activities and background on the communities’ livelihoods.

The website is a culmination of years of work in mapping forest communities in the Congo Basin, with many of the digital maps produced by trained local forest communities supported by The Rainforest Foundation UK and other organizations.

According to the Foundation, training community members in remote locations can be implemented at a cost of less than $1 per hectare of forest mapped.

Since 2001, The Rainforest Foundation UK has mapped forest communities in Cameroon and has expanded to the Central African Republic, Republic of Congo, Democratic Republic of Congo, and Gabon.

Viewing portions of the website’s community map databases requires permission from the Rainforest Foundation UK, due to the sensitivity of some of the data. Potential users are required to submit an online application form.

MappingForRights promotes community-based mapping, incorporating locals’ expert knowledge of their land, boundaries, and natural resource management practices, thus contributing to the organization’s recognition of the importance of local decision-making and resource planning.

See also “Interactive Map Viewer Launched to Monitor Congo Forests”

The tremendous importance of water in society and nature underscores the necessity of understanding how a change in global climate is affecting the availability and variability of regional water resources. Lake Chad for instance, located in one of the poorest and most drought-prone regions of the world – the Sahel region of sub Saharan Africa – has shrunk from around 25,000 square-kilometers in the early 1960s to less than 2,000 square kilometers today (Grove, 1996). The Sahel region today may receive just enough precipitation. The lessons from the current drought in Horn of Africa, however, is a reminder of the potential threat facing the more than 30 million inhabitants of the Lake Chad Basin (LCB).

The United Nations estimates that 12 million people have been affected in East Africa by the worst drought in more than half a century. The urgency of the humanitarian assistance needed to save more than 3 million internally displaced and starving populations (UN, 2011) has raised the question of reliability of early warning mechanisms and water question in drought prone regions of Africa.

Unlike Somalia, will an effective mechanism be put in place to detect onset of drought in LCB? Most importantly, what needs to be done to minimize adverse effects of drought in LCB? In this essay, scientific perspectives will be applied to explain and compare the complex nature of the current drought in Somalia and Lake Chad Basin (LCB). The similarities between hydro-meteorological variables in both cases were analyzed. The objective of the study is to provide a comparative analysis of spatial and temporal variability of drought indices in Somalia and LCB with the view to identifying trends and onset of drought. The result from this comparison will hopefully serve as timely input for policy makers in LCB and international organizations for sustainable water resources development and management in LCB

The similarities

Figure 1: Mean annual precipitation (mm) – 1961 to 1990: (a) Somalia (b) Lake Chad Basin: data from (CRU CL 1.0) of Climate Research Unit (CRU) of the University of East Anglia (UEA).

The third is the insurgence by Islamic militants that tend to capture the attention of the rest of the world much more than the threat of drought and famine. In Somalia, there is the Al-Shabab with links to al-Qaida while the Boko Haram operate in the southeast of LCB (Maiduguri, Nigeria) and are also linked with al-Qaida. The activities of these militants have captured the attention of international communities in the global fight against terrorism. The danger is that the socio-economic issues like the present drought in the Horn of Africa are getting secondary attention as a result. The question then is, like in Somalia, will the local policy makers in LCB and international community fail to detect onset of drought in LCB?

Figure 2: Study area showing perennial (dark blue) and intermittent (sky blue) rivers in (a) Lake Chad Basin (b) Somali (c) Africa.

The difficulty in developing a definition to describe drought and an index to measure it is due to its diverse geographical and temporal distribution, the many scales drought operates in and the variety of disciples it affects. Despite these difficulties, McKee et al., (1993) developed an effective drought index – the Standardized Precipitation Index (SPI) – which facilitates temporal analysis of drought. In contrast to complex drought indices like the Palmer Drought Severity Index (PDSI; Palmer, 1965), SPI has the advantage of requiring only precipitation data and is not affected by geographical differences (Lana et al., 2001). Palmer’s indices, on the other hand, are water balance indices that consider water supply (precipitation), demand (evapotranspiration) and loss (runoff).

From the understanding of the science of drought in LCB based on the similarities and differences of locational attributes of temporal and spatial drought data, the following action plan is advised:

• A preliminary early warning alert may be issued in LCB for SPI values less than -1;
• A further decline in SPI value below -1.5 may serve as threshold at which a drought watch alert should be issued basin wide.

In effect, it will be safe to say there is an effective scientific tool for early drought detection and monitoring. The rest of what is needed in early drought mechanism implementation is political. This is where lessons from the current drought in the Horn of Africa are vital for LCB. The close hydro meteorological similarities should also serve as timely scientific insight for policy makers in LCB

Policy perspective and recommendations

Expert value judgment about potential risks from drought and what should be done is the role of policy makers and not scientists. Yet, it is the scientists that will help policy makers evaluate what ‘critical’ drought entails by laying out the element of risk. It is apparently clear that even if the element of risk of the current drought in Somalia was made available to relevant government agencies, the financial, administrative and political structure to fully take necessary action was not in place. Moreso, the organs of the United Nations that ordinarily would have filled this gap were slow to act because the attention of the world was on Islamic insurgence operating in Somalia. From socio-policy perspective, therefore, the activities of Islamic insurgence linked with al-Qaida diverted attention away from the threat of drought.

Had attention been paid to a drought early warning mechanism and action taken in time; a fraction of the millions of dollars currently being raised to save the starving population in the Horn of Africa would have been enough to adequately coordinate resettlement away from the worst-hit areas. This would have enabled relevant authorities and agencies to start making financial and logistical arrangements to accommodate the large population of human beings and animals that will be displaced as they move south in search of water resources. Unlike Somalia, it is hoped that the activities of Boko Haram around the Lake Chad will not take attention away from the potential threat of drought in LCB.

The lesson from Somalia is that just as animals cannot survive when disconnected with their habitats; neither can humans live disconnected from the water cycle that has evolved to maintain it. The challenge to international organizations, developed countries and individual African countries is to ensure effective implementation of an early drought warning mechanism in LCB and other drought prone regions of Africa on a more sustainable basis for all users. The urgent need to move from analysis to action also underscores the need to have trained scientists proactively communicating the policy-usefulness of research findings to relevant governments and agencies.

References

IPCC 2001, Climate change. 2001. Synthesis report. A contribution of working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, 398 pp.
New, M., Hulme, M. and Jones, P.D., 1999: Representing twentieth century space-time climate variability. Part 1: development of a 1961-90 mean monthly terrestrial climatology. Journal of Climate 12, 829-856

United Nations 2011, On eve of Horn of Africa pledging conference, UN calls for generous donations. http://www.un.org/apps/news/story.asp?NewsID=39374&Cr=horn+of+africa&Cr1=Accessed August 25th 2011.

McKee TN, Doesken J, and Kleist J, (1993). The relationship of drought frequency and duration to time scales. Eight Conf. on Applied Climatology, Anaheim, CA, Amer. Meteor. Soc., pp179-184

Palmer WC, (1965). Meteorological Drought, US. Department of Commerce Weather Bureau Research Paper 45, 58pp

Grove, AT (1996) African river discharge and the lake levels in twentieth century, In The Limnology, Climatology and Paleoclimatology of the East African Lakes: edited by T.C. Johnson and E. Odada, pp. 95-100, Gordon and Breach, Newark, N.J., 1996

Okonkwo, CO A Comparison of the Spatial and Temporal Variability of Drought Indices in Somalia and Lake Chad Basin, African Journal of Environmental Science and Technology.

Churchill Okonkwo is research assistant at Beltsville Center for Climate System Observation (BCCSO), Howard University, Washington, D.C. His current research is on improving the understanding of biophysical and hydrological aspects of Land Surface Models in simulating the impacts of land-cover change on Lake Chad in the Sahel region of sub Saharan Africa. The primary tools for his research are GIS technology and variety of climate models including CWRF. He has a special interest in educating the public on the emerging issues of sustainable environment and development in Africa.

– A report says that the population of endangered delta smelt in the Sacramento-San Joaquin River delta has increased 10-fold since last year.

– Gray wolves were returned to Yellowstone 15 years ago. Amid controversy, scientists say they are keeping elk at bay and helping ecosystems flourish.

(1) Department of Remote Sensing, University of Würzburg, Würzburg, Germany; now at Institute of Geography, Department of Earth Observation, Friedrich-Schiller-University Jena, Germany

(2) Department of Remote Sensing, University of Würzburg, Würzburg, Germany; now at Institute of Photogrammetry and Remote Sensing, Vienna University of Technology, Vienna, Austria

(3) German Remote Sensing Data Center, German Aerospace Center, Oberpfaffenhofen, Germany

(4) Jena-Optronik GmbH, Jena, Germany

(5) La Tour du Valat, Research centre for the conservation of Mediterranean wetlands, Arles, France

(6) The Goulandris Natural History Museum Greek Biotope Wetland Centre (EKBY), Thessaloniki, Greece

(7) European Space Agency (ESA), Frascati, Italy

Abstract – The monitoring and assessment of the status and trends of wetlands is of major concern for long-term biodiversity conservation initiatives. In particular, the coastal wetlands in the Mediterranean have undergone considerable land use and land cover changes in recent decades, by way of urban growth and increasing tourism infrastructure. A rise in sea level would result in a major ecological pressure for natural and human-made wetlands in deltas and coastal lagoons. Satellite observation techniques allow for an objective monitoring of the Earth on large scales. Aiming at the demonstration of the current capabilities of satellite Earth observation applications to support inventorying, monitoring, and assessment of wetland ecosystems, the GlobWetland-II project makes use of the 35 years of Landsat archives for a basic identification and delineation of wetlands during1975, 1990, and 2005. We present results of wetland identification and delineation mapping from 1975 to 2002, for the test sites of the Menderes Delta and Güllük Bay. Methodically, a decision tree approach is used integrating multi-temporal spectral (Landsat MSS, TM, ETM+) and topographic (SRTM) satellite-based indicators for the occurrence of wetlands. While comparing the spatial distribution of wetlands over 27 years, a remarkable decrease of natural wetlands became obvious, particularly at the expense of increasing agricultural land use, artificial areas, or dam constructions. The detected land change processes show the capabilities of satellite-based Earth observation time series. In particular, the potential of the freely available Landsat archives for the quantification of the status and trends of Mediterranean wetlands in the framework of the RAMSAR Convention on Wetlands is demonstrated.

1 Spatial information needs for wetland monitoring

Wetlands serve as important resources for water supply, water quality, recharge of groundwater aquifers, and flood and shoreline protection, and provide a number of important ecosystem services. Wetlands are biodiversity hotspots, hosting large numbers of threatened species [1] and play an important role in regional economics through things like reed production, fishing, and tourism [2] [3]. Beside those provisioning ecosystem services, coastal and inland aquatic ecosystems provide a number of important regulating services, such as climate regulation , water runoff and erosion regulation, water purification, and pollination [4].

Despite the economical and ecological importance of wetland systems, they are being affected by distinct change processes triggered by global climate change (e.g. global sea level rise, droughts, and flooding) and human-induced land use pressure, mainly through the intensification of agriculture and urban growth. Wetlands have a high degree of bio-complexity, making them vulnerable to human induced climate and land use change. Most conversions of coastal and inland wetlands,with increasing trends, were due to habitat changes which had the highest impact on biodiversity in the last century [5].

The standardized and continuous monitoring of wetlands is essential for understanding the status and trends of the direct drivers of change, such as changes in local land use and land cover, species migration, external inputs due to agriculture, and harvesting. Satellite-based Earth observation technologies have been well recognized as a method for mapping and monitoring wetland ecosystems. Recent developments of satellite data policies of the national space agencies increased the availability of multi-scale Earth observation data and lead to the situation that the remote sensing community lives in a data-rich world. Because historical data archives, such as the Landsat data archive [6], are freely available for scientific purposes, it significantly increases the role of satellite-based Earth observation data for ecosystem monitoring and nature conservation purposes [7]. As recently stated by MacKay [8], Earth observation techniques are essential for standardized wetland monitoring mechanisms, and cover the information needs for managing wetlands in the context of the Ramsar Convention.

2 The GlobWetland-II Project

Spatial information needs are addressed during several reporting mechanisms as a base for management planning and implementing policy responses concerning sustainable management and nature protection. Spatial information is necessary for baseline and status assessments and for deriving trends in several kinds of inventories and monitoring tasks.

Fitoka & Keramitsoglou [4] pointed at the capabilities of satellite-based wetland observation initiatives to derive spatially explicit information on the status and dynamics of wetlands.

A number of projects and programs cover wetland monitoring tasks using Earth observation techniques in the Mediterranean, such as the Pan-Mediterranean Wetland Inventory (PMWI), the Land and Ecosystem Accounting (LEAC) of the European Environmental Agency (EEA), the Mediterranean Wetland Observatory (MWO) and the GlobWetland initiative. Within GlobWetland, the European Space Agency (ESA) in 2003 launched a joint wetland monitoring project in collaboration with the Ramsar Secretariat aiming at the demonstration of Earth observation capabilities for supporting inventorying, monitoring, and assessment of 50 selected wetland test sites on the globe[9]. ESA continues supporting this effort in close collaboration with the Ramsar Secretariat, its Scientific and Technical Review Panel, and the Mediterranean Wetlands initiative. The first and major continuation of GlobWetland-I is the GlobWetland-II project,a regional pilot project of the Ramsar Convention on Wetlands. GlobWetland-II aims at developing a Global Wetland Observation System (G-WOS), with about 200 test sites throughout Africa and the Middle East. All test sites will be located less than 100 kilometers from the Mediterranean coast.

This pilot information system, also called the GlobWetland-II information system, includes maps and system software. The GlobWetland-II system software consists of three components: A remote sensing component for tasks like satellite image pre-processing, land use and land cover classification and change detection; a Geographic Information System (GIS) component for the wetland indicator computation,describing the status and trends of wetlands; and an online GIS component providing permanent access to the maps and information data produced during the project or provided by users and partners [10]. The GlobWetland-II geo-information maps will be produced to highlight 1975-1976, 1990-1991, and 2005-2006, on the 200 wetland sites, at a geographical scale of 1 to 50,000 to 1 to100,000 in the Mediterranean, taking full advantage of the time series of Landsat data (MSS, TM and ETM). Besides these main components, a demonstration task in GlobWetland-II is to cover the inventory and delineation of wetland areas in catchment and sub-catchment areas in the Eastern Mediterranean, especially in Turkey and Egypt.

3 Wetland Inventory and Delineation Mapping: Examples from GlobWetland-II

This article aims at the presentation of the methodological framework of the GlobWetland-II wetland inventory and delineation mapping approach. First results are demonstrated on the Turkish test sites of the Menderes Delta and Güllük Bay region, located at the Turkish west coast of the Aegean Sea.

Figure 1: Time series of the normalized difference vegetation index (NDVI) indicate different coastal Mediterranean wetland types derived from nine Landsat ETM+ acquisitions from September 2001 to January 2003, over the study area of the Menderes Delta, Turkey.

3.1 Data and Methods

Multi-temporal Landsat acquisitions for 1975, 1990, and 2002 were achieved from the ESA and USGS data archives covering the hydrological cycle of coastal Mediterranean wetland systems. Different water cycle regimes become apparent by incorporating multi-temporal acquisition dates. Time series of the normalized difference vegetation index (NDVI) capture the temporal characteristics of the Ramsar wetland types, as shown in Figure 1 of the Ramsar classes of coastal lagoons, marshland, and seasonal flooded marshland. Flooding events within the marshlands are indicated by decreasing NDVI values caused by increasing absorption rates in the near infrared band. The temporal dimension, and the availability of multi-temporal imagery are mandatory for the spectral discrimination of natural and human-made wetlands from the surrounding land cover.

Figure 2: Process workflow for the derivation of the Globwetland-II Wetland Identification and Delineation Maps.

The classification process itself consists of a simple rule- and knowledge-based decision tree classification. The composition of a set of multi-temporal spectral and topographic features combines key parameters indicating a wetland, the main one of which is a distinct hydrological cycle caused by alternating wet winter and spring conditions, and hot and dry summers in the coastal Mediterranean region. A very low NIR mean threshold indicates the occurrence of open water bodies or wet soils such as mud flats where high variations indicate seasonally flooded marshlands or Ramsar-type natural wetlands, and irrigated agricultural lands , or Ramsar-type human-made wetlands. Low elevation and slope thresholds are applied to delimit wetlands to be detected to the flat areas of river deltas, coastal lagoons or other depressions.

Figure 3: Multi-temporal Wetland Identification and Delineation products (1975, 1990, and 2002) for exemplary sites between Izmir and Bodrum (upper part: region around Tahtali Dam; lower part: Bodrum airport area).

3.2 Results and Discussion

Exemplary results of the spatiotemporal dynamics of coastal wetlands in western Turkey between Izmir and Bodrum are shown in Figure 3. The mapping results show the basic wetland delineation 1975, 1990, and 2002, in shades of green over a false-color composite of the original Landsat image, showing green vegetation in red, with forest and shrub lands in dark red, and agricultural lands in brown-beige and red.

While comparing the spatial distribution of wetlands over a period of 27 years, a remarkable decrease of natural wetlands became obvious, particularly at the expense of increasing agricultural land use, artificial areas, and dam constructions. The first example shows different land use pressures on natural wetlands. The situation in the 1970s shows a more natural and intact wetland system that decreases in its areal extent through agricultural intensification in the hinterland and coastal lagoon of the river delta. The wetland map of 2002 shows that the entire geo-ecosystem has changed by the dam construction. The Tahtali dam is now an important water reservoir for the nearby city of Izmir. However, the inland wetlands and coastal lagoons have significantly decreased. The second example shows a similar land change process of an airport construction (the airport of Bodrum) in a former wetland area of Güllük Bay south of Izmir. The wetland area decreased by 729.38 km² between 1975 and 2002 (7.3 percent of the study area). The two examples demonstrate that besides agricultural intensification, urban sprawl and growing demands of artificial areas for tourism, second housing and infrastructure as shown in Figure 4 are the major land-use modification processes affecting the decrease and ongoing pollution of coastal wetland systems.

Figure 4: Decreasing trends of Mediterranean wetlands near Davutlar (western Turkey) between 1975 and 2002. In particular, wetlands close to the coast (a) disappeared within the monitoring frame of 27 years. Examples of second housing areas built in former wetlands in the Güzelcamli und Davutlar area are shown in (b) and (c) {12}. Photos were taken by Julia Reschke during an intensive field campaign in February 2009.

4 Conclusions

The detected decreasing trends in natural and semi-natural wetland areas were demonstrated at exemplary GlobWetland-II test sites in western Turkey. Retrieving reliable wetland delineation results with a simple decision tree classifier shows the capabilities of high resolution Landsat time series for longer-term monitoring purposes. In particular, the potential of the freely available Landsat archives for the quantification of the status and trends of Mediterranean wetlands in the framework of the Ramsar Convention of Wetlands is demonstrated, showing high potential for the implementation of the Ramsar Convention. Area-wide wetland identification maps of past time imagery bares high potential for the support of local scale wetland protection planning, keeping in mind that the procurement of historic land cover and land use data and the analyses of former ecosystem conditions is challenging.

This study has been conducted by DLR and the University of Würzburg in preparation of the GlobWetland-II project. The application of a threshold-based mapping framework covers both the detection of wetland geo-ecosystems with acceptable mapping accuracies, and a comprehensible method which can be used by local wetland managers and local administrative staff. The method is already being applied in the project.

The consistent temporal tracking of coastal Mediterranean wetlands is of major importance for all water-related ecosystem services affecting both land and sea ecosystems. A standardized wall-to-wall monitoring of the coastal geo-ecosystems of the Mediterranean Sea is still outstanding. Coastal wetlands affect an important buffer zone function in terms of water de-pollution, storage, and biodiversity balancing. The cross-border identification of land cover impact, including land cover and land use types and processes, on semi-natural wetlands, is of major concern and a basic parameter for the quantification of the Ramsar indicators like the status and trends of wetland extent. The combination of deriving large-area Earth observation products (1:90.000) of Wetland Identification and Delineation Maps and regional scale (1:50.000) land cover and Ramsar wetland typology maps at three points in time will be the basic spatial information products to derive the Ramsar indicators of effectiveness as defined by the Scientific and Technical Review Panel (STRP) and the Mediterranean Wetlands Observatory (MWO). The most important Earth observation-derived indicators are change in wetland area, inundation in the ecosystem, and change in wetland area due to urbanization. Within Globwetland-II, the capabilities and technical limitations of Earth observation for the Ramsar reporting mechanisms are being evaluated. Recent results highlight the needs to make a bigger picture of the ecological state of Mediterranean coastal wetlands.

References

[1] BirdLife International, Important Bird Areas and potential Ramsar Sites. 2001.

[2] E. B. Barbier, J. C. Burgess, and C. Folke, Paradise lost?: the ecological economics of biodiversity. Earthscan, 1995, p. XVI, 267 p.

[3] D. Dudgeon et al., “Freshwater biodiversity: importance, threats, status and conservation challenges.,” Biological Reviews of the Cambridge Philosophical Society, vol. 81, no. 2, pp. 163-182, 2006.

[4] E. Fitoka and I. Keramitsoglou, Inventory, assessment and monitoring of Mediterranean Wetlands: Mapping wetlands using Earth Observation techniques. 2008, p. 140.

[5] Millenium-Ecosystem-Assessment, Ecosystems and human wellbeing:Wetlands and Water Synthesis. Washington: , 2005, p. 80.

[6] J. Ju and D. P. Roy, “The availability of cloud-free Landsat ETM+ data over the conterminous United States and globally,” Remote Sensing of Environment, vol. 112, no. 3, pp. 1196-1211, Mar. 2008.

[7] P. Leimgruber, C. A. Christen, and A. Laborderie, “The Impact of Landsat Satellite Monitoring on Conservation Biology,” Environmental Monitoring and Assessment, vol. 106, no. 1-3, pp. 81-101, Jul. 2005.

[8] H. MacKay, C. M. Finlayson, N. Davidson, D. Pritchard, and L.-M. Rebelo, “The role of Earth Observation ( EO ) technologies in supporting implementation of the Ramsar Convention on Wetlands,” Journal of Environmental Management, vol. 90, no. 7, pp. 2234-2242, 2009.

[9] K. Jones, Y. Lanthier, P. van der Voet, E. van Valkengoed, D. Taylor, and D. Fernández-Prieto, “Monitoring and assessment of wetlands using Earth Observation: the GlobWetland project.,” Journal of environmental management, vol. 90, no. 7, pp. 2154-69, 2009.

[10] K. Weise, E. Fitoka, H. Hansen, and M. Paganini, “Executive Summary of the GlobWetland-II Project,” 2010. [Online]. Available: www.globwetland.org.

[11] P. Reinartz, “The CATENA Processing Chain – Multi-Sensor Pre-processing: Orthorectification, Atmospheric Correction, Future Aspects,” in Geoland Forum 6, 24 -25 March 2010, Toulouse, France, 2010.

[12] G. Sarigül, “Personal communication,” 2009.

– New research shows shrubs and other plants infiltrating the countryside and advancing northward in Quebec.

– Linear dunes dominate the landscape of eastern Namibia. Part of the Kalahari Desert, the dunes likely formed more than 10,000 years ago.