Evaluating the feasibility of systematic inland water quality monitoring with satellite remote sensing

[摘要] The National Plan for Environmental Information (NPEI) initiative is the first step towards a long-term commitment to reform Australia’s environmental information base and build critical infrastructure for the future. The NPEI ‘Inland Water Quality Monitoring with Synoptic Remote Sensing’ project was initiated to assess the feasibility of using remote sensing for water quality monitoring for improved information for the purpose of reporting processes such as Australia’s five yearly State of the Environment Report (under the EPBC Act) andthe bi-annual Bureau-led National Water Quality Assessment Report.The advent of new operational remote sensing platforms and supporting infrastructure such as the Terrestrial Ecosystems Research Network (TERN) for medium to high spatial resolution satellite imagery and Integrated Marine Observing System (IMOS) for coarse spatial resolution satellite imagery provides new opportunities for developing an operational inland water quality monitoring capability for Australia.This study examines the feasibility, resource requirements and potential of current and new satellite platforms for developing an Australian inland water monitoring capability. Based on the policy, legislative, climate change and other environmental drivers there is a strong case for investing in the operationalisation of inland and estuarine water quality using earth observation. Earth observation for environmental monitoring is especially relevant to Australia as it is a continent with large areas of sparse population and limited infrastructure access facing, increasing pressure from mining, urbanisation, irrigation, environmental flows and climate change.Existing water quality information may be sparse, difficult to obtain and variable in information content and accuracy. In situ data is difficult to collect systematically, expensive, and therefore existing water quality information is sparse and variable in information content and accuracy.The case studies illustrate earth observation is sufficiently developed to produce water quality information at multiple spatial and spectral scales, temporal frequency and varying costs.The synoptic view of earth observation and the retrospective processing capability allow the assessment of water quality in areas of Australia that have never been sampled, back to 1984 at 30 m resolution and 1973 at 80 m resolution using Landsat data at 16 day revisit frequency and since 1998 possible on a daily basis using low spatial resolution daily images by SeaWiFS, MODIS and MERIS.Earth observation derived water quality information may contribute to 1)providing information on changes in water availability and quality unobtainable with in situ methods2)highlight patterns, trends and anomalies in water quantity, quality and land use at local to national scales and over time scales of months to decades from 1984 onwards; 3)monitoring water and water constituentflows –especially during extreme events.4)statistics for key reference sites (irrespective of whether the key reference site has an ongoing in situ monitoring program)5)provide spatially and temporally explicit analysis outputs as image based maps, graphs, figures and tables.Systematic earth observation provided water quality information across national and state scales would be conducive to systematic and long term relevant SoE and NWQA type reporting, independent of seasonal, yearly or decadal environmental variability. From a catchment and inland water quality modelling point of view it is important to know how water constituent concentration varies with land cover (as a function of land use) as well as with base flow and under extreme event (high flow and flood) conditions. Often catchment run-off and inland water quality models applied in relatively data poor areas end up using data from elsewhere for parameterisation or validation. Having access to earth observation based synoptic water quality

[发布日期] 2012-05-17 [发布机构] CSIRO

[学科分类] 地球科学(综合)