Wetlands are of great importance for providing the appropriate conditions for the diversity of species and inhabitants living in these ecosystems and for a wide range of public goods and services (fresh water, air filtering, recreational and tourism opportunities). However, despite their importance, wetlands are continuously degraded due to various human activities at an alarming rate worldwide. In the context of this study and considering the rational management of wetlands and the inevitable impact of climate change, a wetland, spatiotemporal monitoring system is proposed, implemented in the karst wetland of Almyros Stream (Heraklion, Crete, Greece). The implementation of this system is based on robust techniques from the allied fields of chemistry, earth and ecology assisted by GIS techniques. Our results indicate that this Mediterranean karst wetland of great ecological importance is under pressure because of pollution, climate change and land change. This argument is supported by (a) the high concentrations of water photosynthetic pigments and nutrients at certain times of the year, both provided by chemical analysis and partially verified by geophysical monitoring (spectral induced polarization) and (b) the high values of soil magnetic susceptibility at sites close to human infrastructures that is an indicator of heavy metals concentrations.
The overall health of streams, including their surrounding urban or agricultural areas, is inextricably linked to general ecological balance and public health (physical and mental well-being). This study aims to contribute to the monitoring of rural or suburban areas adjacent to streams. Specifically, low-cost and rapid ground and Earth observation techniques were used to (a) obtain a rapid assessment of stream soil and water patterns, (b) create a database of selected parameters for the study area that can be used for future comparisons, and (c) identify soil variability in agricultural fields adjacent to streams and determine soil zones that will enable the rational use of inputs (water, fertilisers, and pesticides). Robust techniques from related fields of topography, geology, geophysics, and remote sensing were combined using GIS for two selected areas (I and II) in Heraklion, central Crete (Greece) in the eastern Mediterranean. Our results indicate that area I (east of Heraklion) is under pressure only in its coastal part, most probably due to urbanisation (land change). The agricultural fields of area II (west of Heraklion) show normal values for the distribution of electrical conductivity and magnetic susceptibility and present spatial variability indicating intra-parcel zones. Intra-parcel variability of the conductivity and magnetic susceptibility should be considered in future cropping and environmental management.
Urban streams undergo significant ecological alterations due to urbanization, including hydrological changes, water contamination, and biodiversity loss. This research employs a combination of satellite and drone imagery alongside traditional chemical and geophysical methods, facilitating a multi-dimensional assessment of Almyros and Gazanos urban stream health in Heraklion (Crete, Greece). The satellite imagery, obtained from the Copernicus program, allows for monitoring land use and impervious surface density around the streams, while drone surveys capture high-resolution images and calculate various water quality indices. In addition, chemical analyses of water samples for pollutants, as well as geophysical measurements using spectral induced polarization (SIP) and electromagnetic scanning (GEM-2), provide insight into the integrity of aquatic and riparian ecosystems. The study reflects on the different types of anthropogenic pressure faced by these two ecosystems. Almyros stream exhibits signs of eutrophication, characterized by elevated levels of chlorophyll and the presence of algal blooms, possibly due to runoff from adjacent agricultural activities. Conversely, the Gazanos stream shows signs of pollution mostly related to urbanization. The findings emphasize that both streams are under increasing anthropogenic pressure, thus highlighting the importance of employing comprehensive methods for effective stream management and policy implementation. This study ultimately advocates for ongoing monitoring initiatives that embrace technological advancements to safeguard urban water ecosystems.
The objective of this study is to demonstrate the effective use of remote sensing and ground-based techniques in conjunction with geographic information systems (GIS) to achieve two important goals: (a) to conduct a rapid and comprehensive assessment of soil and water quality in urban streams and (b) to emphasise the critical importance of continuous monitoring of environmental indicators. This approach ensures the ecological integrity of the fragile ecosystems in urban streams and emphasises their important role in human mental and physical health. It also emphasises the interdependence of the environment and human well-being.
Wetlands, including associated waterbody types such as riverine wetlands, are highly vulnerable to pollution and ecological degradation driven by surrounding land-use activities. This study presents a risk-mapping methodology designed to predict where such impacts are most likely to occur. This approach uses high-resolution land-cover data to identify land-use types within 200 m and 400 m buffer zones surrounding each waterbody. Each land-use category within these buffers is assigned an impact score that reflects known stressor effects of different land-covers on wetlands. These scores are combined into a risk index (risk = probability × severity × consequence) calculated for each riverine wetland. The resulting maps highlight areas where adjacent land-uses threaten wetlands’ integrity. Overall, this methodology serves as an early warning tool to support the prioritization of monitoring, mitigation and conservation efforts in vulnerable aquatic ecosystems.
The general condition of urban watercourses is inextricably linked to ecological balance and public health (physical and mental well-being). Given the vulnerability of these systems to climate change and human pollution, this work aims to demonstrate the effective use of environmental indicators to: a) rapidly assess soil and water conditions near urban streams and b) highlight the importance of geoinformatics and earth observation supported by ground-based techniques. There is a great need for new technology and methods for spatial and temporal monitoring and further quantification of environmental quality in urban streams and the land surrounding them to sensitize policymakers and the public to the environmental degradation of these exceptional habitats and to further protect people’s mental health.