Image-driven hydrological parameter coupled identification of flood plain wetland conservation and restoration sites

Examining the landscape transformation and temperature dynamics in Pakistan

This study aims to examine the landscape transformation and temperature dynamics using multiple spectral indices. The processes of temporal fluctuations in the land surface temperature is strongly related to the morphological features of the area in which the temperature is determined, and the given factors significantly affect the thermal properties of the surface. This research is being conducted in Pakistan to identify the vegetation cover, water bodies, impervious surfaces, and land surface temperature using decadal remote sensing data with four intervals during 1993-2023 in the Mardan division, Khyber Pakhtunkhwa. To analyze the landscape transformation and temperature dynamics, the study used spectral indices including Land Surface Temperature, Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Built-up Index, and Normalized Difference Bareness Index by employing Google Earth Engine cloud computing platform. The results suggest that there are differences in the type of land surface temperature, ranging from 15.58 °C to 43.71 °C during the study period. Nevertheless, larger fluctuations in land surface temperature were found in the cover and protective forests of the study area, especially in the northwestern and southeastern parts of the system. These results highlighted the complexity of the relationship between land surface temperature and spectral indices regarding the need for spectral indices.

Effect of channel morphological changes on wetland transformation

Keeping aside the traditional approaches to investigating floodplain wetland transformation, the current study investigated various aspects of it through changes in river channel morphology and drainage pattern. The study analyzed wetland transformation using satellite image-based machine learning and intensive fieldwork. Ordinary Least Square (OLS) regression was applied to identify dominant influencing factors among 24 contributing factors under six clusters to eight dependent phenomena of transformation. The result showed that 57 % of wetland area lost since 1991, and existing wetland has also experiencing hydrological scarcity. From 1991 to 2021, the area under low water depth (<1 m.) inflated from 18.55 % to 50.54 %, the hydro-period narrowed down, and the appearance of water become inconsistent. The OLS result showed that changes in channel morphology (bottle neck channel, embankment-driven carrying capacity enhancement, etc.), interruptions in river and wetland connecting channels (source closure, breaching the continuity, conversion in to agricultural land, etc.), and changes in flood ambience (regulated by dam construction, erection of embankments, etc.) majorly contributed to wetland transformation. Very high explainability was found in the cases of rate of wetland loss, decreasing water depth under greater depth, narrowing hydro-period (R2 > 0.9). The findings of this work would be a good policy document for floodplain wetland management.

Biodiversity conservation and management of lake wetlands based on the spatiotemporal evolution patterns of crane habitats

The typical lake wetlands in the middle and lower reaches of the Yangtze River are important wintering sites of cranes in China. The spatiotemporal evolution of crane populations and their habitats has great value in clarifying the pivotal role of regional lake wetlands in biodiversity conservation. Therefore, 2562 data points of four crane species were selected in this study. The data reflected the distributional position of the cranes over the period 2000-2020. Twelve surrounding environmental factors were selected to investigate the spatiotemporal evolution in the study area by using the MaxEnt model. The Jackknife method was used to identify the main environmental factors affecting the choice of crane habitats. The results indicated that: (1) Developed land in the study area increased by 42,795.81 hm2. The crane populations were mainly distributed in the farmland and mudflat, and their number decreased yearly. (2) From 2000 to 2020, the area of suitable crane habitat experienced an overall decrease. Specifically, the mid-suitable area dwindled by 6234.23 hm2, marking a substantial reduction of 52.05 %. Similarly, the most suitable area saw a decline of 786.41 hm2, representing a noteworthy decrease of 71.09 %. (3) The findings from the analysis of influencing factors revealed a dynamic pattern over the years. Habitat type, water density, and distance to water were the main influencing factors in the study area from 2000 to 2020. This study provides a new perspective on the conservation and structural habitat restoration of crane populations in the middle and lower reaches of the Yangtze River.

How geographical factors and decision-makers' perceptions influence the prioritization of ecosystem services: Analysis in the Spanish rice field areas in RAMSAR Mediterranean wetlands

Mediterranean wetlands provide many ecosystem services to humans and other organisms. However, these services are being increasingly damaged. The prioritization of ecosystem services is essential to start a decision-making process focused on environmental policies, highlighting the necessity of equilibrium between sustainability and human well-being. This study analyzes the similarities and differences among the ecosystem services provided by the Spanish RAMSAR Mediterranean wetlands, where rice production is the main economic activity. These areas are the Ebro Delta, the Albufera Natural Park and the Guadalquivir Marshes (Doñana Biosphere Reserve). Despite being different areas, environmental and agricultural policies sometimes treat their characteristics without distinction since they are conceptually englobed in the same category. This analysis aims to study whether geographical and sociocultural factors could influence the prioritization of ecosystem services. The prioritization of the three study areas was conducted using the Analytic Network Process (ANP), a multi-criteria decision-making method which allows decision-makers to manage the ecosystem's complexity. The results are helpful for future policies and in understanding the complex network of interconnections among ecosystem services. Additionally, results show that there are statistically significant differences in priorities among the three study areas due to geographical and cultural reasons. Moreover, results have also shown that decision-makers' judgements influenced the priorities depending on their background and personal or professional preferences. It emphasizes the necessity of implementing environmental policies from a theoretical and global scale to a participatory and local one, considering a broader range of stakeholders' perceptions to reflect the complexity of the ecosystem services network.

Linking river flow modification with wetland hydrological instability, habitat condition, and ecological responses

Flow modification pursuing dams is widely found. Some works also focused on its impact on floodplain wetland hydrology. However, how this change can pose an impact on habitat conditions, ecological conditions, and trophic state is also a matter of investigation. The very least attention has been paid to this so far. Therefore, the present study focused on these, taking the dam-induced Lower Tangon river basin of India and Bangladesh as a case. The degree of flow alteration in the river was presented in a heat map. Multi-parametric machine learning (ML) approaches were applied to model hydrological instability and habitat condition. The ecological consequences like evaluating eco-deficit using flow duration curve (FDC) approach, trophic state using trophic state index (TSI), fish habitat zone using image-based hydrological parameters, etc. were measured. The study exhibited that after damming, the degree of river flow modification was about 41%. Consequently, the wetland hydrological instability and habitat conditions were degraded. In the post-dam period, > 50% of wetland area was lost, and hydrological instability was enhanced considerably over wider parts of the wetland. Habitat conditions of the existing wetland also witnessed fragility (poor and very poor areas increased by about 22.23 and 9.34%). As a result of this, adverse ecological responses were found. For instance, the eco-deficit area was increased by 36.19%, a good proportion (100%) of wetlands was witnessed the transformation of TSI from oligotrophic to mesotrophic state, and optimum fish habitat area was declined. The ecological strength map integrating all the cause-effect model parameters showed that good ecological strength was reduced from 49 to 2% in the post-dam. The result of the study would be very useful for wetland restoration for ecological and human well-being.