Date : 12 April 2011 EO Information Services in support of Zambezi River Basin Mapping Corné van der Sande, NEO BV Steef Peters, Water Insight BV World Bank HQ, Washington DC

Introduction : NEO BV - Dutch Earth Observation independent services company established in Amersfoort: 17 specialists and >10 part time workers - India: >20 specialists - Monitoring infrastructure and environment using EO - Using change detection for management information and updating maps - 80% of work in Netherlands (municipalities, provinces, ministries and EU)

Background : Zambezi River Basin Mapping Project Context: - Zambezi River basin requires substantial support in using modern information products to improve watershed planning and management. - Focus on the countries of Malawi, Zambia, and Zimbabwe where the World Bank already is involved in several water related development activities. Information requirements: - 1 For the development of market-oriented smallholder irrigation, small scale water resources will be monitored in time for water availability. - 2 For Lake Malawi standard EO products from ESA satellites will be delivered in time related to water quality, water temperature and water surface height. - 3 Already started projects in the Shire Sub basin in Malawi related to risk reduction will be strengthened with information on erosion hazards due to land use changes. Driver: improve watershed planning and management for (irrigated) farming and fishing

The EO Information Products : What they are, bring and examples Small Reservoirs Map - Mapping small reservoir well established technique - Provides comprehensive overview of water stored over time - Based on Envisat ASAR dual-pol images - Not hindered by cloud cover - Twice monthly coverage of reservoir areas in area of interest (>0.5 ha accuracy). - Automated procedure and validated through NEO’s SignalEyes Benefits: - Present distribution of small reservoirs - Planning of small reservoirs - Functionality of small reservoirs over time Limitations: - Ideally, regional area/volume curves would be established - Method well described and can be performed by University of Zambia Impact: - Better planning of village-based irrigation - NRT information on water availability / food production Users: - Ghana, Burkina Faso, Zimbabwe, Brazil

The EO Information Products : What they are, bring and examples - Not hindered by cloud cover - High accuracy (0.1 m) - Fast delivery of information - Good correlation with in situ data Benefits: - Long-term monitoring - NRT Level Lake Malawi - Consistent time series development is valuable to assess climate impact on lake Limitations - Dependence on continuation Lake & River Impact - Faster assessment of hydrological impacts on Lake Malawi Users - Volta basin Authority in Ghana uses it for inventory and hydrological monitoring Lake Malawi water level using ESA River & Lake product

The EO Information Products : What they are, bring and examples Land use and soil erosion Context: Already started WB projects in the Shire Sub basin in Malawi related to erosion hazards due to land use changes EO Products: - Land use maps of 2005 and 2010, 10 meter resolution SPOT5 data. (see example Congo River Basin) For validation we use KOMPSAT-2 data of 1 meter resolution - Land use change map - Erosion hazard map based on Elevation model and land use For AOI of 10,000km2 to be determined Benefits: - Fulfill the need of the World Bank and its partners for updated information on soil erosion and areas of risk. - EO gives information of a large area Limitations - The soil loss method used is not developed for Malawi - Information on erosion potential in a relative scale Impact: Up to date information on land use, land use change and erosion potential Users: Institute for Environmental Security, Dutch Government Congo River Basin AOI: 21,000km2 Institute for Environmental Security Land use 2002 Land use 2008 Land use change Erosion in Southern Limburg, the Netherlands: Catchment of 42 hectares, slopes % Loess soils, highly erodible Agricultural land use types: orchard, arable land Increased erosion risk, due to: intensification re-allotment change of crop types Soil erosion hazard map

Introduction : Water Insight BV Water Insight bv - Located in Wageningen (The Netherlands); Spin-off of Free University Amsterdam - Exists 5 years; 8 employees - Specializes in remote sensing of water quality in optically complex waters (coastal waters, lakes, reservoirs, etc.) Offers: 1) Satellite services: monitoring of water quality & water temperature for: -early detection of (potentially harmful) algae blooms -Monitoring of dredging activities -Environmental impact assessments (e.g. Before or during drilling and dredging) -Information support services to aquaculture, fisheries, recreation, management etc. 2) Services based on dedicated hand held or fixed position spectrometer for close range water quality measures (ideal for reference measurements or local monitoring) Examples: Daily Algae bloom monitoring North Sea Environmental impact assessment Caspian Sea Monitoring Mussels banks Monitoring cyanobacteria blooms in lakes Clients: Dutch Government, European Commission, Oil Companies, Aquaculture companies, Local water management boards

The EO Information Products : What they are Chlorophyll-a (Chl-a) Total Suspended Matter (TSM) Coloured Dissolved Organic Matter (CDOM) Products are resampled to 1 km (RR) or 300 m (FR) Missions: ENVISAT-MERIS and AATSR; MODIS Timeliness: 24 hours after receipt of images + 2 x per week detailed bulletins Geometric accuracy : MERIS + AATSR about 1 km Thematic accuracies will be illustrated by standard error products; Chl-a error is usually smaller than 10%; Lake Malawi water quality and temperature Example: North Sea Algae bloom Monitoring + validation Validation of North Sea Chlorophyll-a (based on MERIS) gives at 19 stations an R2 value of 0.948! Currently the reduction of regular stations is considered Lake Malawi is 580 km long and 75 km at it’s widest: too big to monitor by in-situ techniques The lake seems to gradually move towards a situation with more nutrients, which is probably due to an influx of phosphorous rich sediment during high river run-off episodes.

The EO Information Products : What they bring Benefits / Advantages It was concluded by a large customer of Water Insight that the Chl-a and TSM products are of the same accuracy as the in-situ samples Satellite mapping allows the gathering of information in areas that are not easy to reach or in areas where some stakeholders wish to conceal information The combined optical water parameters give a remarkable good insight in the ecological status of the lake Some parameters (such as the concentration of cyanobacteria) is difficult to measure in the lab; it is often not measured at all: so cases of intoxification remain unnoticed Satellite monitoring offers the possibility of high frequency monitoring providing synoptically information (no in-situ technique could ever approach the spatial resolution and coverage of satellite images) Where in-situ samples have to be taken to the lab and analyzed in batches (usually taking weeks to months); satellites provide information within 24 hours Since all information is digital from the start, communication over internet to decision makers is inherently efficient

Limitations / Constraints Water quality and water temperature measurements from space are obstructed by cloudiness Unknown atmospheric conditions (e.g. Specific dust storms) can cause unwanted artefacts Unknown Specific Optical properties (what type of algae, which pigments etc) can cause some uncertainty in the results Additional info/measurements In-situ spectral measurement are a great help to validate the remote sensing results and to help calibrating the atmospheric correction Local knowledge, Photographs and visual evaluations can provide also relevant information Impact Improved insights in spatial and temporal distribution nutrients and sediments inputs into the lake Improved insights in the exposure risks of vulnerable sub-ecosystems Management info: where and when to apply erosion control Management info: do measures work or is the situation worsening Possibly: information on the presence of potentially toxic species The EO Information Products : What they bring

Date : 12 April 2011 Thank you Questions & Discussion