عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Modeling land cover changes in the rural of Isfahan Province by using GWT-test
Management and regional planning need accurate and timely spatial information on Land cover and its pattern changes. Observation and discovery of these patterns provide the required Information about the current state of development and the nature of the changes in order to accurate planning for planners and decision- makers. Land cover, dynamics and its changes are important variables that have serious effects on the environment and environmental processes. Population growth and the development of human activities in the last few decades have influenced the Earth's surface significantly. Timely and accurate information regarding the land use and land cover are needed for decision-makers and researchers at all levels. Satellite data have the current high ability for mapping land use and land cover in particular geographic areas. Addition information on the importance of land cover, Knowledge of its changes Over a period of time is very important for planners and managers. With knowledge of the proportion of land use changes in time, we can predict future changes and perform the appropriate actions. For this reason, it seems that the change detection methods are necessary to determine the trends of the time. Accurate and timely detection of the changes, postal and altitude, provides a basis for a better understanding of the relationships and interactions between human and natural phenomena in order to management and better use of resources. And generally it is one of the basic needs in the management and assessment of natural resources. The extensive research for mapping land cover classification using remote sensing and GIS methods is performed.Because of this, in the present research, we seek to explore the spatial patterns of the spatial - temporal land cover over a period of 10 years in the rural districts of Isfahan.
To achieve this purpose, land cover map of Esfahan that was classified by the supervised classification method by using the algorithm of maximum likelihood was prepared. This map was obtained from Landsat satellite images of Landsat and 8 Landsat were prepared for 2002 to 2015 and the classes in it are vegetation, water, barren lands and settlements. Then in order to test the spatial-temporal variations at the local level is used of GWT-test.
The basic advantage of this approach is that every Spatial unit are measured with itself around units. Spatial and temporal variations in the period 2002 to 2015 can be measured using hypothesis testing and the GWt-test also a good way to check the statistical significance of the issue.
3-The research process:
1- Determine the area of the land use map
2- Classification of satellite images.
To perform this step , four operations were performed on satellite images which they are:
b)Implementation of training samples in Area image
d)The process after classification)
3-To make the geographical weight matrix
GWt-test - 4
Expansion GWt-test model:
The proposed model is an innovative model Based upon Geographically weighted matrix.
In this model For expansion GWt-test model, Spatial weight matrix is added to T standard equation.
For this purpose, Computational steps are as follows:
1- Calculate the weighted average of the geographical
2- Calculate the weighted variance of geographical
3- Calculate the weighted t of geographical
4- Geographically weighted average equality hypothesis test at 2 periods
Results and discussion
In Iran, In recent decades the process of land degradation is almost 6 thousand hectares per year that this is except for land use in the cities, service and industries. In general , Statistics show after 1978 Land and natural resources of the country have Land use change. This Statistic are generally and they can not show changes in space – time. On the other hand, the information provided space for the units must be placed evaluated using scientific methods.
In this study, to create a map land cover in Esfahan province have been used changes processing and classification of satellite images of 2002 and 2015. Analysis and hypothesis testing is used to test GWt-test. With the help of hypothesis testing spatial and temporal changes during the period 1381 to 1393 were identified and then these changes were modeled.
The results showed that the lands of the Isfahan in the years 2002 to 2015, in four categories: vegetation, water settlements (urban and rural) and barren lands, have spatial variant. For irrigated farms, all rural districts, except Jarghoye Middle has changed at a %99 confidence interval level. The assumption changes have been confirmed in the case the bare land for 124 rural districts, about the land settlements for 118 rural districts, and about the land vegetation for more than half of the district. The present study seeks to explore the spatial variation of land in the Isfahan’s rural district. Research in this area and examine the causes of the emergence of these changes is needed for deeper investigation with approach to land use planning.
The extensive research in the field of mapping and classification of different land cover using remote sensing and GIS done. In this paper, in addition to preparation of the land cover map of the district of province, we tried to use the GWT-test in modeling and spatial temporal of land use. Since in this method each spatial unit is measured with its surrounding and also due to specific local circumstances modeling change spatial - temporal will have results. For this reason, We can say that GWt-tes is a good method to check the significance test.
The results show great spatial variations with the spatial differences in land use in the Isfahan's rural. These results also indicated classes that have the most of land use variation are, respectively, with classes of water, settlements, bare land and vegetation.