Centro di Ricerca Progetto San Marco

Project details - 2

AERONET (AErosol RObotic NETwork)

The AERONET program is an inclusive federation of ground-based remote sensing aerosol networks established by AERONET and PHOTONS and greatly expanded by AEROCAN and other agency, institute, and university partners.

The goal is to assess aerosol optical properties and validate satellite retrievals of aerosol optical properties. The network imposes standardization of instruments, calibration, and processing. Data from this collaboration provides globally distributed observations of spectral aerosol optical depths, inversion products, and precipitable water in geographically diverse aerosol regimes.

Three levels of data are available from this website: Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (Cloud-screened and quality-assured). Descriptions may be found of program objectives, affiliations, the instrumentation, operational issues, data products, database browser, research activities, at website:

http://aeronet.gsfc.nasa.gov/.

AERONET is an optical ground based aerosol monitoring network and data archive supported by NASA's Earth Observing System and expanded by federation with many non-NASA institutions.

The network hardware consists of identical automatic sun-sky scanning spectral radiometers owned by national agencies and universities. Data from this collaboration provides globally distributed near real time observations of aerosol spectral optical depths, aerosol size distributions, and precipitable water in diverse aerosol regimes.

The data undergo preliminary processing (real time data), reprocessing (final calibration ~6 mo. after data collection), quality assurance, archiving and distribution from NASA's Goddard Space Flight Center master archive and several identical data bases maintained globally.

The data provide algorithm validation of satellite aerosol retrievals and as well as characterization of aerosol properties that are unavailable from satellite sensors.

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LAKE VICTORIA

The Lake Victoria (Kenya) is a very big Lake (third largest in size in the world). The importance of this natural resource cannot be overemphasised. It provides key services that include transport & navigation, water for human use, an important fisheries plus recreation (aesthetic value). The lake has an overall annual gross product of US$ 3 to 4 million. It supports 25 million people in East Africa with annual incomes in the range US$ 90 to 270 per annum. Annual fish production on the Kenyan part was estimated at 175 000 tons.

Over time, the Lake Victoria, Kenya has experienced a host of problems including some water pollution from effluents and untreated waste from the nearby town (Kisumu), sediment loads from riparian and catchment areas, algal blooms, eutrophication pesticides from agricultural areas in the catchments, and fish species introductions that have interfered with the fisheries ecosystem. But the most severe of the problems has been the invasive weed water hyacinth.

An activity of monitoring of the Lake based on satellite images, supported by ground based measurements has been started by CRPSM in 2004, with the aim to investigate, and produce information for management.

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DESERTIFICATION

A greater region of the Kenian country lies within the eastern end of the Sudan-Sahelian belt, a region often affected by drought and desertification in Africa.

Like many other countries of the world, Kenya is one of the developing countries threatened by desertification. Past land degradation and desertification is as evident in Kenya as elsewhere, and its imprints often persist to the present despite great effort to revert the problem.

Availability and access to information and technology is the main challenge in the development and management of natural resources in dry lands. Notable environmental monitoring programmes which have been on going in Kenya are: Wildlife and livestock and their ecological environment using aerial survey, drought and famine using meteorological data and NOAA-AVHRR and rangeland biomass using NOAA-AVHRR.

Current desertification monitoring programmes are mainly localized and ground based. Ground monitoring has limitations due to the costs involved to carry out such programmes and thus have a likelihood of discontinuity. Remote sensing programmes to complement the ground surveys provides a solution to long term monitoring programmes.

Estimate of change for 1985-1991 in Kenya dry land environment was that its state was worsening while recent reports have reported accelerating degradation.

The main aim of this research is to integrate remote sensing; field and ancillary data, and using Geographic information system (GIS) determine the status of desertification in the dry lands of Kenya by accomplishing the following objectives:

• Assess current extent and trend of desertification;
• Identify areas at risk (hot spots) by modelling degradation/desertification using remote sensing and other spatial entities;
• Search for a methodology for calibrating arid and semi arid NDVI;
• Start a spectral library of semi arid and arid environments of Kenya.

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