A novel framework for the use of remote sensing for monitoring catchments at continental scales

Abstract

Historical ecology can teach us valuable lessons on the processes and drivers of environmental change that can inform future monitoring priorities and management strategies. Environmental data to study environmental history, however, is often absent or of low quality. Even when studying changes occurring during the last few decades, monitoring efforts are scarce due to logistical and cost limitations, leaving large areas unassessed. The aim of this study is to evaluate the use of estuarine water colour as an indicator of historical environmental change in catchments. Water colour change was assessed in estuaries in Australia from 1987 to 2015 using satellite remote sensing. Random points were selected for each estuary and applied to the Australian Geoscience Data Cube (based on Landsat images) to obtain reflectance data through time. We propose a framework where (i) water colour is used to detect historical changes in catchments using generalised additive models, (ii) possible stressors and pressures driving those changes are evaluated using other available historical data, and (iii) lessons learned inform appropriate monitoring and management actions. This framework represents a novel approach to generate historical data for large-scale assessments of environmental change at catchment level, even in poorly studied areas.

Ecological health assessment of the Ousteri wetland in India through synthesizing remote sensing and inventory data

“…Quantitative analysis of the water balance utilizing data derived from remote sensing and meteorological data is in conformity with literature reports (Bugnot et al, 2018;Eslamian, 2016;Garg & Eslamian, 2017). Mohebzadeh and Fallah (2019), for example, reported Urmia Lake was exhibiting a negative water balance.…”

“…Accurate quantification of water balance components in large lakes is fundamental for assessing the changes in hydrological components, and subsequent variations in a lake's water balance. Quantitative analysis of the water balance utilizing data derived from remote sensing and meteorological data is in conformity with literature reports (Bugnot et al, ; Eslamian, ; Garg & Eslamian, ). Mohebzadeh and Fallah (), for example, reported Urmia Lake was exhibiting a negative water balance.…”

Climate change rapidly warms and acidifies Australian estuaries

“…Australian air and sea temperatures have increased by~1°C since 1910 21 ; however, eastern Australia is warming faster than the rest of the continent. Over the last decade, summer air temperatures in eastern Australia have generally increased by 1.5°C, and sea surface temperatures have increased by~1°C compared with the 1961-1990 average 20 . Our findings show that overall, estuaries are warming generally faster than these temperatures, with much of the warming concentrated in lagoons and rivers, with less change in lakes and creeks.…”

“…The diversity, complexity and generally small size of Australia's non-tropical estuaries, hinder the use of remote sensing to monitor change 20 , and current large-scale oceanic or atmospheric models are limited in their capacity to predict change. Therefore, current ocean and atmosphere modelling provides very little insight into how shallow estuaries are affected by climatic warming, either on Australia's eastern coast or worldwide.…”

Classification of Australian Waterbodies across a Wide Range of Optical Water Types

“…Retrieval of water quality information from EO data can provide an improved understanding of the spatial and temporal variability within water bodies for the resource managers by filling temporal gaps between periodic in situ observations. Freely available, medium resolution EO data, such as from the Landsat suite of sensors and Sentinel-2 provide a useful platform in which to investigate temporal changes in water quality across wide geographic scales, e.g., [11,[17][18][19][20][21].…”