Journal of Nature and Spatial Sciences
Volume:3 Issue: 2, Summer and Fall 2023

 The research was conducted to the relationship review of LST and NDVI of the Mashhad and Gorgan cities of Iran using the GEE system based on the Landsat 8 OLI and Sentinel 5P images from the period between 1/1/2021 and 1/1/2022. The purpose of this research was to compare the relationship between the temperature of the earth's surface and changes in the vegetation index and its possible relationship with air pollution.

  For this purpose, first, the date of certain images and then the desired bands for calculating three variables, earth surface temperature, vegetation index, and air pollution were introduced to it. In the end, a normalized vegetation difference index or NDVI was obtained to calculate surface emissivity and LST land surface temperature map, and an air pollutants map (SO2, NO2, HCHO, CO, Aerosol) was prepared and produced.

 The results showed that the highest average temperature for the cities of Mashhad and Gorgan is 42 and 35 degrees Celsius, and the lowest average temperature is 27 and 17 degrees Celsius, respectively. It can also be seen that the relationship between the temperature of the earth's surface and the amount of vegetation has an inverse relationship. Thus, the lowest temperature is related to the areas with the most vegetation and the highest temperature is related to the barren lands and built areas. By superimposing the surface temperature map and the air pollution map, it was found that high temperature brings more pollution.

Spatiotemporal maps are suitable tools to convey information to the interested audience. The aim of this paper is to create continent-wide spatiotemporal maps regarding the role of agriculture on CO2-eq production in the period between 1990 and 2019 using the t-map package of R software.

  Initial data were obtained from the Internet resources (the FAO, and ARCGIS websites), and after performing some adjustments and modifications i.e. deletion of unnecessary data and matching of the contents of the FAO and ARCGIS data files, as well as combining data files, final data were uploaded to the R software to convert to spatiotemporal maps using the t-map package.

The results showed a decreasing trend of the share of agriculture in total CO2-eq production from 1990 to 2019. At the same time, the amount of agriculture-induced CO2-eq has increased very gradually. On the other hand, the amount of total CO2-eq produced has grown considerably from 1990 to 2019; therefore, it can be concluded that the growth of CO2-eq production in the other economic sectors is higher than that of agriculture. Thus, the first priority should be to curb the growth of CO2-eq production in all economic sectors, especially non-agricultural ones.

 Assessing the suitability and capability of land is a guarantee of sustainable production and preservation of valuable soil and water resources in any country, and paying attention to it is an undeniable necessity for the sustainable management of water and soil resources.

In this research, the land use map of 1381 and the land capability map of 1360 of Urmia Lake catchment area were used using the INTERSECT tool in the geographic information system environment, and the land capability codes, each of which represents its land, were used with the land use of the studied area Matched.

 The results of this research showed that about 76.27% of the codes that had the capability of agricultural land on low slopes have been converted to urban land and 10.17% of the codes that were related to pasture use have been converted to agriculture and rain fields and also on slopes of 8 to 40%, the codes that had pasture and grazing capacity, about 3.9% of it became rainfed and agricultural lands, and finally in the slope above 40%, which includes the smallest area of the lake's catchment area, both in terms of the slope and the land capability map, which is specific to the land They are pastures, nearly 1% of it has been converted into wetlands. Although this amount is less, it is very influential on the flooding of the studied area. In a general summary, it can be said that the land suitability of the study area is not well respected and this can be one of the important factors threatening the saline lake of the study area in the coming years.

In recent years, we have witnessed the growth of forest fires due to severe climate changes and increased human activities. These fires impose many destructive effects on the environment and human health. Therefore, it is necessary to identify and measure the intensity of forest fires and plan for the revitalization of vegetation.

This study aims to investigate the intensity of the fire in the forest areas of northern Ukraine using Sentinel 2 satellite images and using the indicators of different normalized burn ratios (dNBR), relatively different normalized burn ratios (RdNBR), and relativized burn ratio ( RBR) in the Google Earth Engine (GEE) cloud platform and comparing the results of the extent of the fire area extracted from the indicators with the data available by the European Forest Fire Information System (EFFIS). Also, the Normalized Difference Vegetation Index (NDVI) was used to investigate the process of forest cover restoration.

The results showed that the RBR and RdNBR indices in study areas A and B have been able to estimate the fire extent with 1.43% and 5.96% differences compared to EFFIS data. Also, the results of the NDVI index showed that after two years of the fire, in study areas A and B, 76.06% and 58.86% of the damaged forest cover improved, respectively.

Watershed implementation projects represent crucial infrastructure endeavors in many countries, demonstrating positive impacts in virtually all pilot regions. Each implementation project comprises planning, execution, monitoring, and assessment phases. In this context, the overarching goal of project planning is to enhance performance. However, there is no consensus on the best approach to project planning. Consequently, this study conducts a descriptive comparison of two methods the Logical Framework Approach (LFA) and the Participatory Rural Appraisal (PRA). The aim is to assist planners in selecting the most suitable method according to their specific needs.

Modern research and the examination of various methodologies have provided the means to plan projects for optimal performance. In this regard, a comprehensive analysis of the strengths and weaknesses of both LFA and PRA methods was conducted, drawing from an extensive body of literature.

In essence, there is no significant disparity between these two methods. The primary contrast between LFA and PRA lies in the fact that LFA anticipates external factors that may influence project success or failure. Furthermore, all stakeholders impacting the project play a role in pivotal decisions. Hence, it can be argued that LFA addresses the deficiencies and limitations of PRA, presenting itself as an ideal model for optimal decision-making. Consequently, it is recommended that this method be utilized in future research endeavors, particularly in assessing country watersheds.

Subsidence is a crisis that modern societies are currently facing. It has the potential to inflict irreparable damage to the lives and properties of residents, as well as disrupt urban infrastructure, including water, oil, and gas transmission lines. While horizontal displacement is also possible, its extent is typically minor. Subsidence results in the formation of cracks and fissures in the ground, alterations in underground water quality, changes to the Earth's surface topography, and other related issues.

In this study, using the multi-criteria decision-making approach, the seven criteria have been taken into account to produce subsidence risk map. At first, expert opinion on this issue have been used to investigate the effect of different criteria on subsidence. Then the weight of each criterion was obtained using the geometric mean method. Then to combine the layers, VIKOR and TOPSIS fusion techniques were used. To evaluate the implemented method, Sentinel 1 radar images were used to prepare a subsidence map, and a comparison between the two maps has been made.

The analysis indicated that land use, underground water, and rainfall had the most significant influence on subsidence, with weights of 0.4292, 0.2699, and 0.1473, respectively. In contrast, slope and elevation had the least impact, with weights of 0.0220 and 0.0375, respectively. A subsidence map was successfully produced using Sentinel-1 images and Differential Interferometric Synthetic-Aperture Radar (DInSAR) techniques, and this map was compared to those obtained through VIKOR and TOPSIS methods, demonstrating a favorable level of compatibility.