Zoning areas prone to fire occurrences in the forest ecosystems of North Zagros (Case study: Sardasht forests in West Azarbaijan)

The ecological balance in nature is integrated with forest safety. Wildfire causes irreparable effects on the ecological functions of the forest and disrupts the production of oxygen and carbon sequestration, reducing biodiversity, expanding pests and diseases, and eventually breaking the balance of nature, which is the unique role of the forest. The purpose of this study was to identify the factors affecting the occurrence and zoning of fire hazards in Sardasht forests in the area of 1784.8 hectares to achieve control and counteraction strategies. At first, layers of elevation, slope, aspect, precipitation, temperature, organic carbon, soil texture, and vegetation cover were mapped for the study area. AHP was used for prioritization, evaluation criteria, and weighting of the layers. Finally, the classifications of the layer were done using GIS, and hazard scores were classified at four classes included; Safe, low risk, medium risk, and high risk. The results showed that 12.7% of the study area is at high risk, 39.9% has moderate risk, 31.9% is in the low-risk area and 15.5% is located in the safe area. Also, the Angstrom index was showed that wildfire occurring has maximum possibility between June to September. It was also found that the north-east of the study area is more at risk of fire due to the denser vegetation than other areas. The minimum fire hazard was observed in the north, part in the south, and the narrow strip in the central regions of the study area

Effect of Land-Use Change on Runoff in Hyrcania

Population growth and human activities have resulted in drastic changes in land use in many areas of the world, including the Hyrcania region in northern Iran. Land-use changes affect the hydrological processes of water basins. This study evaluated the effect of land-use changes on runoff over 15 years in the Haraz River basin located in Hyrcania using remote sensing data and GIS analyses. The annual precipitation of the region is 66.5 cm. Two Landsat images were used to develop land-use maps for 1996 and 2011. Original image features, their principal components, and vegetation indices were used to classify the two Landsat images into different land-use categories. Runoff was predicted from precipitation, land use, and hydrological soil groups, using the SCS-CN model (the “curve number” approach). During the 15 years, 62.4% of the area remained unchanged and 37.6% had undergone a land-use change. The highest average runoffs were obtained for bare land (14.1–14.5 cm/year) and residential land (10.4–11.4 cm/year), and the lowest for dense forest (2.5–2.6 cm/year) and first-grade rangeland (2.8–3.1 cm/year). The volume of annual runoff increased by 9% during 1996–2011 due to land-use changes. Runoff was estimated at 9.4% of precipitation in 1996, and 9.6% of precipitation in 2011. Most of the increase was related to the increased area of bare land and decreased area of rangeland. The study indicated that combined use of the SCS-CN approach, remote sensing data, and GIS tools allow cost-effective runoff estimation, helping watershed management. The results on the effect of land-use change on runoff can be seen as a warning for land-use managers and policymakers, who should aim at stopping and reversing the current land-use trends of the Haraz River basin

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population