Remote Sensing

Human activities such as development of urban area and reducing vegetation cause dramatic changes in surface runoff generation. In the present study effects of Land use and Land cover (LU/LC) changes on surface runoff in Siahroud watershed in north of Iran has been assessed. LU/LC was derived from an Aster imagery (acquired in 2002) and a Landsat 8 imagery (acquired in 2013) for two different periods using object-oriented classification. For this purpose preprocessing and Image enhancement on remotely sensed data were applied. The images were segmented to objects and then objects assigned into 5 classes based on spectral features and physical characteristics such as texture and size of the segmented objects. Accuracy assessment of Classifications was computed by calculation of total accuracy for each classification, user, producer`s accuracy for individual classes and also KAPPA index. In order to determine the average Curve Number for each year, LULC maps were combined with Soil Hydrologic Groups map of study area in ArcGIS. The surface runoff was calculated for 7 events in each year using SCS-CN method. Finally direct runoff has been calculated from the same rainfall for both years. Results showed that urban area has increased during the last 11 year resulting in 5to 40 percent increase in surface runoff.

The present study area (Cauvery river basin) lies between 77o 43’ 54’’ E to 79o 35’ 55’’ E longititude and Latitude 10o 10’ 0’’ N to 11o 10’ 6’’ N. The basin area is demarcated from the survey of Indian topographical map No.58 I/2 (1:50,000,1972) and it covers the area about 3397 sqkms. Morphometric analysis and their relative parameters have been quantitatively carried out for the Cauvery basin, Salem district, Tamilnadu, India. Digital elevation model (DEM) is used to determine the features of drainage networks and slope of drainage network and to determine the characteristics of basins. The foregoing analysis clearly indicates some relations among the various attributes of the morphometric aspects of the basin helps to understand their role in sculpturing the surface of the region.

This paper investigates the effects of extra-terrestrial impact cratering of Silali Basin on the environment of the area. The Silali Basin is located in Turkana East /Pokot East regions of Kenya. The basin is a depression suspected to be an extra-terrestrial impact crater (ETIC). The objective of the study was to document the effect that the cratering of Silali had on the environment of the area. To answer the study research question, remote sensing was utilized to map the Silali basin. Satellite images were used to identify the nature of the crater and characterize it, since most large terrestrial impact craters are not identifiable from the surface of the earth. The study established that the effects of Silali’s impact cratering on the environment of the area include formation of physical features and minerals. The crater’s potential economic and social significance has also been cited and include tourism, paragliding, quarrying of breccias and geothermal power harvesting. Being a pioneer study in the investigation of ETICs in Kenya, the study may form a basis for further research on ETICs in the country, besides enhancing knowledge on Extra-terrestrial impact cratering in Kenya and its environmental significance. It is also hoped that the study will enhance the economic utilization of Silali basin.

The study aimed at estimating the crop water requirements under climatic and geographical conditions of Armenia with the help of FAO-56 methods to improve irrigation. To calculate the evapotranspiration at 5, 25, 50, 75 and 95 % probability using 10 years’ meteorological data of 24 meteorological stations the Republic territory was conditionally divided into six irrigation zones. The comprehensive analysis show that by the end of this century the air temperature increases by 20 C degrees and precipitation decreases by 10 %, thus the crop water requirements increases resulting in irrigation water consumption change. The Republic irrigated land area will increase by 25-50 % over the existing one. The resulting evapotranspiration patterns before and after the climatic changes were mapped with the use of GIS technology.

Land use and land cover change play a pivotal role in global environmental change. They contribute significantly to earth-atmosphere interactions and biodiversity loss, are major factors in sustainable development and human responses to global change, and are important for integrated modeling and assessment of environmental issues in general The land cover map and land use map can be produced by field research and observation and interpretation of the large scale aerial pictures, but both of them are time and cost consuming. The main advantage of satellite images is that the classification is able to be repeatedly performed by simultaneous usage of multiple images during a short time. Applying the satellite data is a proper way in order to producing the land cover map and monitoring it especially in the vast geographical regions. The iterative self organizing data analysis technique (isodata) method used a set of rule-of-thumb procedures. Many of the steps used in the algorithm are based on the experience obtained through experimentation. According to evaluate signature file the optimal number of classes is 11.after determining of best classified NDVI map processed of spot NDVI maps for a new set of the hyper temporal. Drawinggraphs of mean digital number help to us for determined kind of classes. According to the graph of the spectral behavior of each class and fieldwork were determined land covers types. The optimum numbers of classes are 11 classes in the case study region based on the divergence of a minimum of separability. Spectral behavior shows the highest mean digital number in 11th class that starts in the spring season and finish in winter. First to fifth class has spectral behavior to each other. Mean of digital number of different years not same each other years and have different actions.

The present study focuses on the role of remote sensing and geographic information system (GIS) in assessment of changes in vegetation cover, between 1973 and 2010, in the Salem revenue division, Salem district of Tamilnadu, India. The trend of vegetal cover changes over the time span of 37 years, was precisely analysed using Satellite images. The study revealed that the vegetal cover was 1325.99 and 1199.04 sqkm in 1973 and 2010 respectively. It was noticed that vegetal cover has decreased in 2010, because of the urban expansion led deforestation. It also revealed that the vegetal cover loss is due to expansion of cultivation and human interference. It is envisaged that the study would prove the usefulness of Remote Sensing and GIS in forest restoration planning.

Sorghum (Sorghum bicolor) is an important African cereal crop and is listed among Africa’s lost crops but is now gaining popularity as other cereals are declining in production due to climatic change. To promote food security, many researchers and policy makers are shifting the focus on production of sorghum. In Kenya, sorghum is primarily grown in ASALs whose suitability is climatic factors but the extent is not known. This paper modeled the potential sorghum suitable areas of current and the years 2050 and 2080 climatic periods. The sorghum location data were downloaded from GENESYS and Kenya Agricultural Research Institute while climate data was from world climate database website. Analysis was done using Maxent and DIVA-GIS softwares. The model generated an excellent AUC of 0.97 and the suitable areas in the future are shown to expand in both 2050 and 2080 climatic periods though not in same magnitude. The main variables contributing more than 10 % of change in suitability areas in decreasing order are precipitation of wettest period, temperature seasonality (STD * 100), precipitation of warmest quarter, and precipitation of driest month. The generated information will guide the policy makers and stakeholders in making informed decisions with regard to the efforts of re-introduction and promotion of sorghum production in ASALs.

Now a day, global warming has induced changes in precipitation in different regions of the world. Bangladesh is recently experiencing climate change impact related to hazards like cyclone, flood, draught etc. Climate variable like rainfall is the most important parameter which is linked with agricultural aspects too. Most of the rain occurred during monsoon period in Bangladesh. The study on rainfall trend over the country has done using observed station data of Rainfall (In-situ) collected from Bangladesh Meteorological Department (BMD) .These data have been analyzed based on annual and seasonal variation in Bangladesh for last 6 decades. A set of analysis has been carried out for this study. Linear trend lines show the rainfall trend over Bangladesh which is not very significant. The annual and monsoon rainfall is found in decreasing trend in recent times (1981-2010) whereas in increasing trend during the period of 1951-2011. The time series statistical analysis of this study will provide information about annual and seasonal mean total rainfall and rainfall variation over the country for different decades, as well as the rainfall trend in different divisions of Bangladesh in different times. The result of this study will help the policy makers to take necessary steps and measure in different sectors like disaster management, agricultural production, drought mitigation, flood control etc. and to act against the adverse impact of climate change. In this paper, annual, seasonal and divisional rainfall variability and trend analysis over Bangladesh will be discussed.

More than 75 percent of Iran is located in arid and semi-arid and faces many hydrological constraints that often are attributed to the lack of rainfall and rainfall distribution. This issue is locating suitable areas for rain water harvestingin Birj and plain however it ismore importance in poor farming communities that are dependent on rain-fed cultivation. To determine the areas those are prone to runoff collection used from a Decision Support System (DSS) and Geographic Information System (GIS)to identify a logical process in relation to harvesting the rainfall and Within this system utilization from Model Builder in Arc GIS 9.3 software. The process defined in this paper uses from runoff capacity for decision and some information such as runoff potential map, distances from residential areas map, irrigated cultivation map and rain-fed cultivation map is inputting in the system. With combination of these maps makes the rain water harvesting prone areas map. The result shows that more than 40 present is in medium class and 32 present is in good class.

It could be stated that using GIS and linear assignment for analyzing position data and choosing optimized location, has unique performance, so it is suggested that fire fighting organizations use these software applications to create database. It is suggested that fire fighting organization and safety services, create reasonable relationship with urban service centers to enhance their performance, and equip these centers to safety tools before the incident. The purpose of this study is Study of locating Fire stations using ELECTRE method. ELECTRE method is one of the Multi criteria decision making which can compound the quantitative and qualitative criteria, weight each criterion based on its importance and help decision makers to select the best option at the same time. Electrical method is one of the available methods in compensatory methods. In this method, all options are analyzed and evaluated by non-ranked comparisons. Whole stages of this method are based on coordinated and uncoordinated sets and thus it is called ‘‘coordination analysis’’. The results and findings show that zone (3) dominated (5) times and defeated (1) time, so it is located in the first rank with (4) points and is the most suitable zone for Fire stations. In contrast, zone (4) defeated (5) time and dominated (1) time, therefore it is located in the last rank with (-5) points and is not the most suitable zone for Fire stations. And, zones (2, 5, 1) dominated (4, 3, 2) times and defeated (2, 3, 4) and located in other ranks with (2, 0, -2) points respectively. Also, zones (4,1) should be omitted because their defeated times are more than dominated times.