Enfoque integrado de SIG y herramientas de teledetección para la gestión de las zonas periféricas en las ciudades del Magreb desde 1988 hasta 2005. Caso de estudio: el Gran Agadir (Marruecos) y la ciudad de Argel (Argelia)

More than one-third of the land worldwide is located in areas with arid and semiarid climates. Desertification has been increased in these areas during the recent decades. About 80% of that of Iran is located in the arid and semiarid areas. Sand dunes, as an indicator of desert land, cover an area of about 32 million hectares, out of which 12 million hectares have not been stabilized yet. Advancing sand dunes have resulted in much more damage to the agricultural products and urban areas of the region. In this survey, satellite images and aerial photos were employed to evaluate the role of land use changes on desertification within the years 1955, 1997 and 2002. Therefore, IRS (International Revenue Service) images of 2002 and available aerials photos of 1955 and 1997 were used. After making the aerial photos mosaic, processing was dose using ILWIS software. The needed data were completed by field surveying and the land use map was produce for two decades. To produce the land use map using digital processing methods, 10 sample sets (training points) were selected uniformly in the area. After preprocessing including geometric correction, image enhancement and band composition, image classification was done by maximum likelihood method and the land use map was produced. In this phase, the obtained land use map corresponded to the ground truth map, which was achieved using field surveying and recording of the coordinates of the points with GPS pixel to pixel, and accuracy obtained from the numerical classification was estimated to be 0.3%. Then, due to the obtained low accuracy, the visual interpretation method was used to produce the land use map, so the accuracy of 78.5% was achieved. Finally, the area of each land use and the rate of changes were calculated. The results indicated a decrease of 2000 ha in the desert area from 1955 to 1997 and of 160 ha from 1997 to 2002 as well as an increase in the area of the other land uses. The results showed no desertification in the study area, even though land degradation could obviously be identify in the area, resulting from the changes of gardens and agricultural land uses to industrial and urban areas. Key words: Desertification, land use, remote sensing, IRS images, Ardakan, Iran.

Land use analysis from spatial and field data capture in southern Burkina Faso, West Africa

Abstract. The mountain watershed of Nepal is highly rugged, inaccessible and difficult for acquiring field data. The application of ETM sensor Data Sat satellite image of 30 meter pixel resolutions has been used for land use and land cover classification of Tamakoshi River Basin (TRB) of Nepal. The paper tries to examine the strength of image classification methods in derivation of land use and land classification. Supervised digital image classification techniques was used for examination the thematic classification. Field verification, Google earth image, aerial photographs, topographical sheet and GPS locations were used for land use and land cover type classification, selecting training samples and assessing accuracy of classification results. Six major land use and land cover types: forest land, water bodies, bush/grass land, barren land, snow land and agricultural land was extracted using the method. Moreover, there is spatial variation of statistics of classified land uses and land cover types depending upon the classification methods. The image data revealed that the major portion of the surface area is covered by unclassified bush and grass land covering 34.62 per cent followed by barren land (28 per cent). The knowledge derived from supervised classification was applied for the study. The result based on the field survey of the area during July 2014 also verifies the same result. So image classification is found more reliable in land use and land cover classification of mountain watershed of Nepal.

This study focuses on detecting, mapping and analyzing the conversion of forests into agricultural uses and agricultural uses into urban/peri-urban uses in Nzega district, Tabora Region - Tanzania over a period of 28 years since 1978. Land use classes were from multitemporal and multi-sensor satellite images and aerial photographs. Topographical maps at a scale of 1:50000 and onsite information gathered in the field were used for interpretation and ground truthing purposes. Land use changes were detected using land use change matrices and land use change maps. Four land use maps were compiled from Aerial photographs dated 1978, Landsat TM satellite imagery dated 1986, Landsat ETM+ satellite imagery dated 2000 and IRS satellite imagery dated 2006. The maps show agricultural areas are concentrated along road networks generally expanding towards neighboring grasslands and unprotected forested areas. Land use changes were detected from land use maps for three change periods: 1978 - 1986, 1986 - 2000 and 2000 - 2006, with emphasis on agricultural and forest land uses. The change maps and change matrices show that despite abandoned farms agricultural land increases with time. Change in the opposite direction was also common where abandoned agricultural land gradually regenerated back to grasslands and forests. An average of 16% of agricultural land has been maintained during the 1978 - 2006 period compared to 67% of forests that have been maintained in the same period of time.

Discrepant impacts of land use and land cover on urban heat islands: A case study of Shanghai, China

Some Techniques For Analysis Of Land Use Patterns in Northern Florida Raymond A. Peterson University of Florida Those geographers interested in analyzing land use changes are finding it increasingly necessary to utilize modern techniques and to be cognizant of the contributions and limitations of aerial photographs and topographic and other maps. It is the purpose of this paper to comment on the extent to which aerial photographs and topographic maps may be used in the study of present and historical patterns of land use in the northern Florida area. Naturally, these are best employed in conjunction with observation and enumeration techniques. In addition, experience with four sampling procedures used in the field is evaluated. Aerial photographs of the northern Florida area are available for the years 1937, 1949, 1955, and 1961. These photos can be used for making historical comparisons of land use, although the number of categories is limited. The 1961 air photos were used to prepare base maps. Although much time was saved through the use of these air photos, one must recognize some of the shortcomings of aerial photography in a situation such as that existing in northern Florida. The first limitation of accuracy in land use mapping and coding on aerial photos becomes evident when field work is done by observation alone. While it is easy to differentiate corn, Pensacola bahia grass, and planted pines by observation, it is more difficult to ascertain, for example, whether the Pensacola bahia is in the Feed Grain Program and thus not actually used for unlimited grazing, or whether the planted pines are in the Soil Bank Program and thus a part of a farm unit or a part of a corporate plantation. Additional inaccuracies may result in land use mapping when crops with limited acreages or crops of a seasonal nature are considered, such as tobacco and truck crops. These crops may be practically surrounded in the field by other crops, out of view because of topography, or the land may appear idle even though it may have been used for a fall or spring planting. As a consequence, tobacco may be mapped as corn, and cropland may be mapped as idle land instead of seasonally idle cropland. ( 1 ) Such problems or hazards provide a good reason for combining field observation with enumeration techniques. (2) By the latter is meant interviewing the occupants of rural land and asking them to name the use of each parcel. By using both procedures a more satisfactory portrayal of present land use can be drawn, and the data can be much more useful for historical and comparative analyses. 34The Southeastern Geographer A few problems in interpretation arise when using photos from earlier flights. It is almost impossible to differentiate some categories of cropland from some categories of grazing land on these early pictures, and it is equally difficult to subdivide forest and woodland into "grazed" and "not grazed." Since flights are normally made during the winter months, little can be done to sub-categorize cropland. As a consequence, only three categories can be used, namely, (1) cropland and grazing land, (2) forest and woodland, and (3) other land. However, within these limitations land use maps can be drawn for each flight to analyze change over time. Government programs are factors which aid in explaining the present land use pattern. Unawareness of the content and extent of influence of these programs on the present land use structure might lead to gross misrepresentation , and improper analytical conclusions and historical comparisons . This is particularly true for land which may be mapped as idle. Idle land should be mapped as idle cropland, idle pasture, idle forest land, and so forth. (3) This type of mapping is quite feasible for the field worker who has acquainted himself with government programs, and uses the observation and enumeration method. After the land use has been mapped accurately, exact acreages of land in government programs can be obtained from the county office of the Agricultural Stabilization and Conservation Service. Topographic maps at a scale of 1:24,000 are companion tools to aerial photographs. The topographic map, provided it is of recent date, has several uses in land use mapping. It...

Water Accounting Plus for Water Resources Reporting and River Basin Planning

Kortlægning af marksystemer fra jernalderen – En kildekritisk vurdering af luftfotografiers anvendelighed

In recent years, GIS and Remote Sensing technology has played a vital role in studying urban growth and development. This study is aimed to assess the effects of urban expansion on the surrounding land uses using GIS and Remote Sensing in Debre Tabor Town. Remote sensing data or products such as Aerial photograph (1984), Quick Bird Satellite Image (2000), and Aerial photograph (2016) were used to compute spatial or temporal changes of land use land cover due to urban expansion. ERDAS Imagine and Arc GIS software were used to analyze, model and map the data. The study revealed a significant change in urban boundary and urban land-use land cover between 1984 and 2016. The urban boundary expansion rate between the years 1984 and 2000 was 69.06%, higher than the rate experienced thereafter to the year 2016 (18.86%). However, for the last thirty-two years, between 1984 and 2016, the overall boundary increasement of almost eighty one percent (81.4) was very magnificent. The study also indicated that the area experiencing rapid increase in built-up areas (80.93 %), and agricultural land (23.81%). However, sharp decrease of forest by 36.07%, and open land by 65.02% was seen in the same periods of years. Built-up area expansion was found to have increased by expanding the urban boundary at the expense of open land, agricultural land, and forests. Therefore, integrating GIS and remote sensing technology for urban expansion mapping is a worthy method. Hence, it is recommended that it will be cost effective if the results of this study will be incorporated into ongoing urban planning and land use by concerned bodies.

Dynamic land use and land cover changes and their effect on forest resources in a coastal village of Matemwe, Zanzibar, Tanzania

Watamu Mida creek coastal areas, mainly the shoreline, the mangroves and the general environment have been changing due to the impact of land use change, shoreline erosion, human population pressure and the expansion of tourism sector. This research assesses the impact of land use change on mangrove dynamics and shoreline erosion as well as the main driving factors that cause these changes in Watamu Midacreek. This study uses old aerial photographs (1969 and 1989), current high resolution satellite images World view (2010) and ground truthing in combination with information from the local community to analyze the impact of change in land use from 1969-2010. Land use and cover types were visually interpreted, digitized and delineated using aerial photographs of 1969, 1989 and 2010 satellite images in ArcGIS.9.3.1 and ERDAS IMAGINE 2014 software. The results of the land use change between 1969 and 1989 showed a decline of scrub land, miscellaneous coastal vegetation, coastal bush, thicket with trees and mangroves, whereas new types of land use which emerged during this period were town and barren land. The greatest land use change rate observed between 1969 and 1989 was in miscellaneous coastal vegetation at 2.5%, while coastal bush experienced a significant negative change rate of 6.5%. The main land use changes observed between 1989 and 2010 were increasing coastal bush, an expansion of town and urban areas, hotels and private holiday houses. Encroachments into the mangrove forest have been observed both by local people and foreign private holiday house owners. The change in land use had an impact on shoreline changes as well. Areas mainly covered by old trees, and coastal bushes which protected the shoreline from erosion currently have been converted into very big hotels and several private holiday house complexes. The main drivers of land use change were human population growth and policy (through weakness of law enforcement). Policies and regulations which are not currently implemented need to be updated based on the current pressure-state situation, and there should be strong law enforcement and strict regulation to control any unplanned developments along the coast and in the neighboring hinterland.

Land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. Decreasing of forest area in the North of Iran is one of the critical problems in recent years. The aims of this study are to detect land use changes between 1967 to 2002 using satellite images of Land Sat 7 ETM+ (2002), aerial photos and digital topographic maps (1967 and 1994) and to investigate the effect of some physical and socio economical factors on land use dynamic. The forest maps of 1967 and 1994 were collected from 1:25000 digital maps in Micro Station and then Arc/View 3.2 software. The interpretation of the maps of other land uses were derived using aerial photos. ETM+ satellite data were used to generate land use map dated 2002. The images quality assessment and georeferencing were performed on images. Different suitable spectral transformations such as rationing, PCA, Tasseled Cap transformation and data fusion were performed on the images in ENVI and IDRISI software. Image classification was done using supervised classification maximum likelihood and minimum distance classifier utilizing original and synthetic bands resulted from diverse spectral transformation and the forest area was separated from non forest area. Unsupervised classification was used to separate other types of land use. Change detection has shown that the forest area decreased between 1967 and 2002 by 2.99% from 7322.22 to 6947.23 ha. Also, the area with irrigated land farms have been increased to 202.01 ha (1.61%) and the dry land farming area decreased to 9.2%. Overlaying the map of land use change with roads and residential maps showed that by increasing the distance from roads and residential areas and villages, deforestation rate and conversion of forest to arable lands were reduced, but conversion of arable lands to released lands increased. Also, the most quantity of deforestation was observed in lower slope angle, but the dry land farming converted to release lands was observed in higher slope angle.

Humans change the landscapes and especially the coastal zones for their requirements. The aim of the study was to analyse land use changes in the Çeşme coastal zone, Turkey, during a 48‐year period (1957–2005) using remote sensing and GIS. In this study, land use changes in the Çeşme coastal zone were analysed using the four sets of land use maps derived from aerial photographs and classified satellite image taken in the years 1957, 1976, 1995 and 2005. Post‐classification algorithm change detection was applied to observe land use changes during three time periods: Period 1 (1957–1976), Period 2 (1976–1995) and Period 3 (1995–2005). The results showed that natural land cover and agricultural lands decreased and built‐up area increased throughout the study area during the 48‐year period between 1957 and 2005. Furthermore, land use change was successively increased in Period 1, Period 3 and Period 2. Copyright © 2010 John Wiley & Sons, Ltd.

A simple regional downscaling approach for spatially distributing land use types for agricultural land

This study aims to identify the driving forces and implications of the temporal and spatial dynamics of land use and land cover in the Kasso catchment, Bale Mountains (Southeastern Ethiopia). Aerial photographs (1965 and 1973) and satellite image (SPOT5 2007) were interpreted and analyzed using GIS tools. Socio-economic surveys, focus group discussions, and field observations were also used to determine the causes and effects of these land use and land cover dynamics. It was found that agriculture and settlement land had increased by 24%, whereas natural forest, woodland, bush land, and grassland declined by 80.74%, 68.08%, 63.02% and 17.65%, respectively. Agricultural expansion and population growth were the two major driving forces behind the land use and land cover dynamics. Environmental and local livelihood implications included forest cover degradation, soil erosion and fertility decline, stream volume and livestock size decline, and scarcity of firewood and construction materials. These in turn contributed to food insecurity, particularly in some low-income households, as well as hindering the sustainable livelihoods of the study area in general. Therefore, we suggest that there is a need to protect the fragile environment, and to adapt and implement sustainable land management practice to promote sustainable livelihood in the area.