Indian coastal regions have often been affected by frequent climate-induced natural disasters such as cyclones, floods, droughts and other related hazards in recent decades. Existing literature was not sufficient to fully understand these event trends from diverse perspectives in a systematised manner at current scenarios. Therefore, a systematic approach has been employed to assess the climate change and cyclone trends of nine Indian coastal states by using various geographical information system (GIS) tools for 2006–2020. The results showed that 61 cyclones occurred in nine coastal states from 2006 to 2020; the highest numbers were recorded in Odisha (20), West Bengal (14) and Andhra Pradesh (11). Accordingly, these three coastal states emerged as the most vulnerable for high-intensity cyclones. The results also identified that the highest average temperature (29.3 °C) was recorded at Tamil Nadu and Gujarat, and the lowest temperature (26.7 °C) was recorded in West Bengal and Odisha. Most of the coastal states showed fluctuations in temperatures during the study period. At the same time, Kerala and Karnataka states recorded the highest average rainfall (2341 mm and 2261 mm) and highest relative humidity (78.11% and 76.57%). Conversely, the Gujarat and West Bengal states recorded the lowest relative humidity at 59.65% and 70.78%. Based on these results, the current study generated GIS vulnerability maps for climate change and cyclone activity, allowing one to rank each state’s vulnerability. Cumulatively, these results and maps assist in understanding the driving mechanisms of climate change, cyclones and will contribute towards more effective and efficient sustainable disaster management in the future.

The present study analyzed the river morphometric characteristics of the Moyar river basin, which consists of seven sub-watersheds (SWS), located in the upper Bhavani River basin in South India. The morphometric appraisal was carried out based upon the digital elevation model using the geographical information system (GIS). The study area comprises the seven SWS. River morphometric parameters have been classified based upon the characteristics i.e., linear, areal, and relief aspects. The drainage patterns clearly exposed effective regional tectonics, and the stream orders of the basin are primarily controlled by physiographic and tectonic structure in the study area. The bifurcation ratio was recorded from 3.8 to 6.2, and the higher values of the mean bifurcation of the all stream orders revealed that the geological and tectonic control of the river basin i.e., SW1, SW2, and SW3. Likewise, the result exhibited that the priorities level of each and every SWS will assist the priority rank such as highest priority was given to SW3 (with a compound value of 2.40), and SW4 (compound value of 5.60) is the lowest priority in the Moyar river basin. Furthermore, the novelty of the study revealed that the three SWS (SWS3, SWS7, and SWS6) are highly susceptible and it requires appropriate sustainable soil and water conservation.

The industrial revolution and the rapid increase in population growth have led to water pollution. Among the various types of pollutants, industrial dyes pose a serious threat to public health. Hence, remediation of these toxic dyes from water sources has become highly essential in terms of public health. The present study focused on the use of nanoparticles synthesized using plant sources for the remediation of azo dyes such as Methyl orange (MO) Congo red (CR), Malachite Green (MG), Eriochrome Black T (EBT) under direct solar radiation. The fabrication of Zinc oxide nanoparticles (ZnO-NPs) was mediated by aqueous flower extract of Cassia alata. The synthesized nanoparticles exhibited a surface plasmon resonance (SPR) vibration at wavelength 372 nm. The FTIR analysis revealed aromatic amines and alcohols coating the surface of ZnO-NPs. The XRD analysis showed that the synthesized nanoparticles are highly crystalline and possess hexagonal wurtzite structures. The particle size measured with maximum diffraction peak using Scherrer’s equation was 9.93 nm. The SEM images showed spherical morphology. The particle size determined with Dynamic Light Scattering (DLS) was 78.18 nm and the zeta potential analysis showed that the ZnO-NPs was -14.6 mV, indicating good dispersion and stability. The C.alata mediated ZnO-NPs exhibited excellent Photocatalytic degradation of azo dyes. Degradation efficiency of Methyl orange, Malachite green and Eriochrome black T are 76.65%, 65.07%, 60% respectively at 150 min. But Congo red is 72.76% at 120 min, because the Congo red was completely degraded at 120min. The study shows that green mediated ZnO-NPs could be effectively used as an eco-friendly alternative for the remediation of chemical pollutants from water.

In the current scenario, environmental friendly methods of synthesizing nanoparticles and their composites have become a desirable trend. Phytochemicals derived from plant extracts are now being employed as a distinctive method for synthesizing nanoparticles due to their ability to serve as both reducing and capping agents. In present study, copper oxide nanoparticles (CuO NPs), zinc oxide nanoparticles (ZnO NPs) and their mixed composites (CuO/ZnO) were synthesized using the flower extract of plant Cassia alata. The synthesis of nanoparticles was confirmed by observing the colour change of the reaction mixture and was determined by detecting the surface plasmon resonance band at 280, 320 and 359 nm for CuO, ZnO and CuO/ZnO, respectively. The antioxidant activity of nanoparticles was characterized for DPPH, ABTS, NO and iron reducing power method. In addition, the antibacterial properties of these bioactive nanoparticles were also investigated. The CuO/ZnO nanocomposites showed superior antioxidant and antibacterial activity than CuO and ZnO nanoparticles.