Journal of RS and GIS for Natural Resources
Year:2013 | Volume:4 | Issue:1|Papers Count:8

Land use management based on its capabilities and production capacity, as an indispensable factor, plays an important role in maintaining irreparable natural resources such as water and soil. To determine optimum land utilizations according to natural ability and also to improve current management methods, land use planning can be implemented effectively using different methods and tools within GIS. In the present study, ecological capability and land use planning in Cheragh Vei’s watershed were determined. For these purposes, two methods of land assessment and land use planning, Systematic and Multi-objective land use allocation methods were used and compared. After evaluation and determination of land capabilities, the obtained maps were merged. Prioritization land uses showed two priorities for plan preparation. In order to compare the efficiency of the two methods, sediment and erosion of the watershed were evaluated using the obtained plans. The results acquired through the EPM erosion model showed that the sediment production in the current situation can be around 44495.32 tons, and in the future according to methodical and multi-objective land allocation can be around 81341.73 and 72973.41 tons respectively. We found that the map obtained from multiobjective land allocation was better in terms of land use allocation and also for reducing erosion and sediment production when compared with that of the systematic method.

The purpose of this study was to have a quantitative evaluation of current desertification status in Segzi plain of Isfahan using MEDALUS model. To achieve this purpose 6 important criteria, which were effective on desertification have been selected. These criteria are: soil quality, climate, vegetation, underground water, erosion, management and policy. Each one of these criteria has numerous indicators. Each indicator data after statistical analyses and normality test with the Kolmogorov-Smirnov test has been imported to ArcGIS®9.3 and interpolated with IDW and normal and discrete kriging methods to produce their maps. Methods with highest accuracy have been selected. Then, the maps scored by MEDALUS approach and final map of each criterion have been created from the geometrical mean of its indicators. Finally current desertification status in Segzi plain of Isfahan has been created from the geometrical mean of all 6 criteria. The results showed that 81299 ha of the region classified in severe desertification class and 30868 ha classified as a very severe desertification class. Weighted average of the quantity desertification (current desertification) for the Segzi plain is equal DS=153.32 ha classified as a severe desertification class. The results also showed that climate and plant cover criteria are the most important criteria of desertification in the study area and erosion criterion (wind and water erosion) has the minimum importance.

Human activity over recent years has led to land use and cover changes. These changes bring about alterations in ecosystem structure and function and are consequently affecting ecosystem goods and services. Today, application of remote sensing due to ease of data availability as well as saving time and cost is considered as an appropriate tool for Valuation of ecosystem goods and services. The purpose of this study is to estimate changes in ecosystem service value of water resources using remote sensing techniques. In order to estimate the damage caused by the land use change on water resource ecological service, first LandSat satellite imagery, ETM+ and TM sensors in the three time period (1987, 2000, 2008) have been georeferenced, classified and were interpreted with application of ENVI®4.8 software. In order to estimate the missing values serve to protect water resources, Hydrological situation within the region, precipitation, evaporation, runoff volume and infiltration of water in the soil ecosystem and forest ecosystem were Examined by Justin’s method. After determining the contribution of forests in water conservation, the value of this service was obtained using Replacement Cost Method approach. The results of this study estimated the number of 1 billion Rials loss per 620 hectares of Chalu’s forest loss.

One of the most critical problems in human societies is the production of different types of waste in different quantity and quality that must be disposed. Piling up the waste material in a flat area and incineration is the first solution that comes into the mind. Problems of the unsanitary disposal of solid wastes such as smoke and smell, insidious organisms, combustion waste, contaminated surface water and ground water has changed this idea and has forced the decision-makers to convert the solid waste dump area into the sanitary landfills. For these reasons, Ramhormoz city in the East of Khuzestan province was considered. In this city, the generated per capita of municipal and household solid waste is 800 grams (person/day). The current waste disposal site is in the hilly area, 30 km far from Ramhormoz. The site has been used without any environmental considerations, since 2006. In the current study, landfill selection was achieved through a geographic information system (GIS) and Fuzzy-AHP logic, using Expert®choice software. For this purpose, twelve layers were provided input to GIS, including: Distance to residential areas and waste generation source, Distance to Surface water, Distance to groundwater (well, spring), Distance to main road, Distance to Major infrastructure systems (electrical transmission lines, oil pipelines), Land use, dominant wind direction, Soil characteristics, Depth of groundwater, rain, Land slope. Four zones were selected as the suitable area for landfill through this methodology. Then, the best alternative was chosen based on the field visit. Field investigation, Surface soil samples, geological maps and geoelectric catheter verified the usefulness of the proposed methodology.

Nowadays, land use change detection needs the fastest and best method for collecting information and overlay layers. Data extracted from satellite images and combine them with field data can accurate and better information for decision making in the multiple factors are involved, provide. In this study, MSS (Multi Spectral System) of images in 1976, TM (Thematic Mapper) in 1987 and ETM+ (Enhancment Thematic Mapper) in years 2000 and 2005 were used, and processing operations was performed using ENVI®4.3 software. For preparing the land use/cover map of supervised classification method was used and ultimately, five type’s user identified. Results showed that, land changes form to convert barren lands and Sediment lands are not cultivated, to garden land and residential areas and industrial. Such that the area of garden land within 29 years, 2893.5 hectare has been added, in contrast the area of the barren land (desert) 1572.7 hectares has been reduced. Furthermore, extent residential areas and industrial areas have increased, if this trend increase can cause negative effects on the environment. The results indicate that the efficiency of satellite images for obtained from land use/cover maps and the changes; to facilitate planning environmental resource management is essential.

In this study, the role of vegetation covers in the plain land degradation and prepare severity land degradation mapping based upon three criteria; vegetation cover’s condition, vegetation cover utility and regeneration of vegetation were investigated by geographic Information System (GIS). A comprehensive model entitled Iranian Model of Desertification Potential Assessment has been prepared in Iran. In this research, among different existing methods IMDPA (Iranian Model of Desertification Potential Assessment) was selected and desertification intensity was evaluated based on vegetation cover criterion and three indices, including: vegetation condition, utilization of vegetation and the revitalization of vegetation. Each criterion was assessed based on the selected indices which result in a qualitative mapping of each criterion cased on geometrical average of the indices. Finally, sensitive map to the region was extracted using the geometrical average of all criteria. Thematic databases, with a scale of 1:50000 were integrated and elaborated in ILWIS. Among the whole study area, 53.06% were found to be in medium class, and about 46.94% are in very high class of degradation.

The aim of this study was the evaluation of potential of the land around Qeshm Island for mangrove forest development using Analytic Hierarchy Process (AHP). For this purpose, at the first, the most important effective criteria and indicators in evaluating of the potential for the area were determined. The criteria and indicators based on the additional study in this respect, natural conditions of the area, existing data and expert opinions were assigned. Questionnaires were provided based on Delphi method and were distributed among experts. The experts expressed their preferential judgments about the amount of importance of any criteria and indicator in pairwise comparisons by using of ratio scale from 1 to 9. Then, the final weights of the criteria in each questionnaire were calculated by Expert®Choice software, and the inconsistency rate on expert judgments was investigated. By using of weighted linear combination method, each of the provided maps with its special weight was integrated into the GIS environment. The final extracted map was classified into five classes (excellent, good, fair, poor and unsuitable). The results showed that about 1348.41 ha, which is equal to 5.27 percent of the total study area has the best water and edaphic conditions for the development of mangrove forest around the Qeshm Island.