Land use change assessment in coastal mangrove forests of Iran utilizing satellite imagery and CA–Markov algorithms to monitor and predict future change

Mangrove forest stores large organic carbon stocks in a setting that is highly vulnerable to climate change and direct anthropogenic influences. As such there is a need to elucidate the causes and consequences of land use change on these ecosystems that have high value in terms of ecosystem services. We examine the areal pattern of land types in a coastal region located in southern Iran over a period of 14 years to predict future loss and gain in land types to the year 2025. We applied a CA–Markov model to simulate and predict mangrove forest change. Landsat satellite images from 2000 to 2014 were used to analyze the land cover changes between soil, open water and mangroves. Major changes during this period were observed in soil and water which could be attributed to rising sea level. Furthermore, the mangrove area in the more seaward position was converted to open water due to sea-level rise. A cellular automata model was then used to predict the land cover changes that would occur by the year 2025. Results demonstrated that approximately 21 ha of mangrove area will be converted to open water, while mangroves are projected to expand by approximately 28 ha in landward direction. These changes need to be delineated to better inform precise mitigation and adaptation measures.     

Biodiversity and biomass of a natural and degraded mangrove forest of Peninsular Malaysia

Anthropogenic activities have always been the cause of most environmental degradation, and mangrove disappearance is no exception. A comparative assessment on the biodiversity of natural and degraded mangrove forests has been undertaken, looking at the biomass, both above-ground and below-ground. The natural and the degraded mangrove forests were situated at Kuala Selangor and Sungai Haji Dorani, respectively, both on the West coast of Peninsular Malaysia. A random sample scheme with quadrate sample plots (10 m × 10 m) was adopted for the measurement of the diameter at breast height and total height of individual tree species at both forests. Diversity indices and above- and below-ground biomass were estimated from this inventory. Eight mangrove tree species were identified at both study areas, namely: Bruguiera parviflora, Avicennia officinalis, Rhizophora mucronata, Sonneratia alba, Avicennia marina, Bruguiera cylindrica, Xylocarpus mekongensis and Excoecaria agallocha. The mangrove species in Sungai Haji Dorani showed high diversity with a Shannon–Weiner Index (H′) value of 0.91, compared to the natural mangrove of Kuala Selangor which has a lower value, H′ = 0.55. The dominant species in the natural mangrove area was B. parviflora, with the highest Important Value Index (IVI) of 70.96 %, as opposed to A. marina which was the most common species in the degraded mangrove area, with IVI of 49.16 %. An estimate of 305.46 t/ha of above-ground biomass was calculated for the natural mangrove, while 122.78 t/ha was obtained for the degraded mangrove forest. This contrasts with the below-ground biomass estimates, which were 14.09 t/ha for the natural mangrove and 36.35 t/ha for the degraded mangrove.     

Forecasting areas vulnerable to forest conversion using artificial neural network and GIS (case study: northern Ilam forests,Ilam province,Iran)

Forest conversion due to illegal logging and agricultural expansion is a major problem that is hampering biodiversity conservation efforts in the Zagros region. Yet, areas vulnerable to forest conversion are unknown. This study aims to predict the spatial distribution of deforestation in western Iran. Landsat images dated 1988, 2001, and 2007 are classified in order to generate digital deforestation maps which locate deforestation and forest persistence areas. Meanwhile, in order to examine deforestation factors’ investigation, deforestation maps with physiographic and human spatial variables are entered into the model. Areas vulnerable to forest changes in the Zagros forest region are predicted by a multilayer perceptron neural network (MLPNN) with a Markov chain model. The results show that about 19,294 ha forest areas are deforested in the last 19 years. The predictive performance of the model appears successful, which is validated using the actual land cover map of the same year from Landsat data. The validated map is found to be 94 % accurate. The validation is also tested using the relative operating characteristic approach which yielded a value of 0.96. The model is then further extended to predict forest cover losses for 2020. The MLPNN approach was found to have a great potential to predict land use/land cover changes because it permits developing complex, nonlinear models.     

Mangrove Range Expansion Rapidly Increases Coastal Wetland Carbon Storage

The climate change-induced expansion of mangroves into salt marshes could significantly alter the carbon (C) storage capacity of coastal wetlands, which have the highest average C storage per land area among unmanaged terrestrial ecosystems. Mangrove range expansion is occurring globally, but little is known about how these rapid climate-driven shifts may alter ecosystem C storage. Here, we quantify current C stocks in ecotonal wetlands across gradients of marsh- to mangrove-dominance, and use unique chronological maps of vegetation cover to estimate C stock changes from 2003 to 2010 in a 567-km² wildlife refuge in the mangrove-salt marsh ecotone. We report that over the 7-yr. period, total wetland C stocks increased 22 % due to mangrove encroachment into salt marshes. Newly established mangrove stands stored twice as much C on a per area basis as salt marsh primarily due to differences in aboveground biomass, and mangrove cover increased by 69 % during this short time interval. Wetland C storage within the wildlife refuge increased at a rate of 2.7 Mg C ha^?1 yr.^?1, more than doubling the naturally high coastal wetland C sequestration rates. Mangrove expansion could account for a globally significant increase of terrestrial C storage, which may exert a considerable negative feedback on warming.     

Qualitative and Quantitative Characterization of Mangrove Vegetation Structure and Dynamics in a Peri-urban Setting of Douala (Cameroon): An Approach Using Air-Borne Imagery

Qualitative and quantitative characterization of mangrove vegetation structure and dynamics is required for assessment of coastal habitat vulnerability. Changes in mangrove forests around Douala, Cameroon, have been documented using aerial photography between 1974 and 2009. The distribution pattern of tree species was also assessed in 2009 following the point-centered quarter method (PCQM+) protocol. Pristine mangroves observed in 1974 had been disturbed markedly in 2003 and 2009. Some of the pre-existing mangroves were entirely replaced by settlements, road, and crops (maize, bean, banana, oil palm, green vegetables, and sugar cane plantations). From 1974 to 2003, 39.86 % of mangrove forests have disappeared; the net loss of 22.10 % occurred between 2003 and 2009 alone. Mangrove forest area had decreased 53.16 % around Douala over a 35-year period from 1974 to 2009 concurrent with a substantial increase of settlements (60 %), roads (233.33 %), agriculture areas (16 %), non-mangrove areas (193.33 %), and open water (152.94 %). Field survey showed that almost one third of the quadrants in the remaining mangrove forest were empty. The disrupted mangrove forest has an overall mean height, absolute density, and basal area of 19.80 m, 158 trees ha^?1, and 110.44 m² ha^?1, respectively. In comparison with scientific literature on mangrove degradation, this puts the mangroves around Douala at the top of the “peri-urban mangrove degradation” list. In addition, beyond listing of mangrove plants on the Red List of Threatened Species which will seldom lead to widely distributed species being listed, we call for the creation of a Red List of Locally Threatened Ecosystems, which in contrast is likely to list mangroves as an ecosystem under critical risk of (local) extinction in many countries around the globe, in particular, peri-urban sites.     

Appraisal of land use/land cover of mangrove forest ecosystem using support vector machine

Human activities in many parts of the world have greatly changed the natural land cover. This study has been conducted on Pichavaram forest, south east coast of India, famous for its unique mangrove bio-diversity. The main objectives of this study were focused on monitoring land cover changes particularly for the mangrove forest in the Pichavaram area using multi-temporal Landsat images captured in the 1991, 2000, and 2009. The land use/land cover (LULC) estimation was done by a unique hybrid classification approach consisting of unsupervised and support vector machine (SVM)-based supervised classification. Once the vegetation and non-vegetation classes were separated, training site-based classification technology i.e., SVM-based supervised classification technique was used. The agricultural area, forest/plantation, degraded mangrove and mangrove forest layers were separated from the vegetation layer. Mud flat, sand/beach, swamp, sea water/sea, aquaculture pond, and fallow land were separated from non-vegetation layer. Water logged areas were delineated from the area initially considered under swamp and sea water-drowned areas. In this study, the object-based post-classification comparison method was employed for detecting changes. In order to evaluate the performance, an accuracy assessment was carried out using the randomly stratified sampling method, assuring distribution in a rational pattern so that a specific number of observations were assigned to each category on the classified image. The Kappa accuracy of SVM classified image was highest (94.53 %) for the 2000 image and about 94.14 and 89.45 % for the 2009 and 1991 images, respectively. The results indicated that the increased anthropogenic activities in Pichavaram have caused an irreversible loss of forest vegetation. These findings can be used both as a strategic planning tool to address the broad-scale mangrove ecosystem conservation projects and also as a tactical guide to help managers in designing effective restoration measures.     

Land use and land cover change and implication to watershed degradation by using GIS and remote sensing in the Koga watershed,North Western Ethiopia

Information on use/land cover change is important for planners and decision makers to implement sustainable use and management of resources. This study was intended to assess the land use land cover (LULC) change in the Koga watershed. The MSS of 1973, TM images of 1986, 1995 and 2011 were used together with survey and demographic data to detect the drivers of land cover changes. The result revealed that a remarkable LULC change occurred in the study area for the past thirty eight years. The area of cultivated and settlement has increased by 7054.6 ha, while, grass and bush lands decreased by 4846.5 and 3376 ha respectively. Wetland also declined from 580.2 ha to 68.3 ha. The growing demand for cultivable land and fuel wood were the major causes to the deterioration of grass and bush lands. Hence, the appropriate land use policy should be employed to sustain available resource in the watershed.     

Land cover change dynamics mapping and predictions using EO data and a GIS-cellular automata model: the case of Al-Baha region,Kingdom of Saudi Arabia

The present study designed to monitor and predict land cover change (LCC) in addition to characterizing LCC and its dynamics over Al-Baha region, Kingdom of Saudi Arabia, by utilizing remote sensing and GIS-cellular automata model (Markov-CA). Moreover, to determine the effect of rainwater storage reservoirs as a driver to the expansion of irrigated cropland. Eight Landsat 5/7 TM/ETM images from 1975 to 2010 were analyzed and ultimately utilized in categorizing LC. The LC maps classified into four main classes: bare soil, sparsely vegetated, forest and shrub land, and irrigated cropland. The quantification of LCC for the analyzed categories showed that bare soil and sparsely vegetated was the largest classes throughout the study period, followed by forest, shrubland, and irrigated cropland. The processes of LCC in the study area were not constant, and varied from one class to another. There were two stages in bare soil change, an increase stage (1975–1995) and decline stage (1995–2010), and the construction of 25 rainwater-harvesting dams in the region was the turning point in bare soil change. The greatest increase was observed in irrigated cropland after 1995 in the expense of the other three categories as an effect of extensive rainwater harvesting practices. Losses were evident in forest and shrubland and sparsely vegetated land during the first stage (1975–1995) with 5.4 and 25.6 % of total area in 1995, while in 1975, they covered more than 13.8 and 32.7 % of total area. During the second stage (1995–2010), forest and shrubland witnessed a significant increase from 1569.17 km² in 1975 to 1840.87 km² in 2010. Irrigated cropland underwent the greatest growth (from 422.766 km² in 1975 to 1819.931 km² in 2010) during the entire study period, and this agriculture expansion reached its zenith in the 2000s. Markov-CA simulation in 2050 predicts a continuing upward trend in irrigated cropland and forest and shrubland areas, as well as a downward trend in bare soil and sparsely vegetated areas; the spatial distribution prediction indicates that irrigated cropland will expand around reservoirs and the mountain areas. The validation result showed that the model successfully identified the state of land cover in 2010 with 97 % agreement between the actual and projected cover. The output of this study would be useful for decision makers and LC/land use planners in Saudi Arabia and similar arid regions.     

海啸灾害后印度尼西亚班达阿齐市的土地覆盖变化与海岸带区域规划

2004年12月26日,由于欧亚板块的碰撞,40年以来最大的地震灾害发生在印度洋。地震诱发的海啸影响到Nangroe Aceh Darussalam省的许多城市,包括省会城市班达阿齐。在这地区共有超过12万人死亡,100万人无家可归。基于遥感数据的分析表明,有12万亩的土地受到了灾害。在班达阿齐市,鱼塘、住宅用地和保护区的变化是这一地区最显著的土地利用/覆盖变化,受灾前后这些用地类型的面积相应的变化了61.5%、57.8% 和77.6%。目前,印度尼西亚中央政府正在计划一个新的海岸带土地利用规划,在原来密集的海岸带建立一个缓冲区（约距海岸带2 km）。政府已经要求许多海岸带的社区代表与非政府组织参与到决策的过程中。 为了选择并采取最佳的土地利用方式,海啸灾害后的海岸带规划应该包括一些重要的基本要素。本研究主要关注作为该省社会经济活动中心的班达阿齐市。检测了由于海啸灾害造成的土地利用/覆盖变化（包括物理破坏）,特别是农业用地和居住区用地的变化,并且分析了受灾村落的不同类型及灾害对社会经济活动造成的影响。此外,还为政府以及当地居民在灾后的规划中选择更为可持续的空间布局方案提出了建议。     

Effects of land use changes on soil erosion in a fast developing area

Land use changes extensively affect soil erosion, which is a great environmental concern. To evaluate the effect of land use change on soil erosion in fast economic developing areas, we studied land use changes of Guangdong, China, from 2002 to 2009 using remote sensing and estimated soil erosion using the Universal Soil Loss Equation. We calculated the areas and percentage of each land use type under different erosion intensity and analyzed soil erosion changes caused by transitions of land use types. In addition, the impact of land use change on soil erosion in different river catchments was studied. Our results show that forest and wasteland land conversions induce substantial soil erosion, while transition from wasteland to forest retards soil loss. This suggests that vegetation cover changes significantly influence soil erosion. Any conversion to wasteland causes soil erosion, whereas expansion of forests and orchards mitigates it. The most significant increase in soil erosion from 2002 to 2009 was found in the Beijiang catchment corresponding to the transition from forest/orchard to built-up and wasteland. Soil erosion in the Xijiang catchment accelerated in this period due to the enormous reduction in orchard land. In Hanjiang catchment, erosion was alleviated and vegetation coverage greatly expanded owing to considerable transitions from wasteland and cropland to orchards. Field investigations validated our estimations and proved the applicability of this method. Measures including protecting vegetation, strict control of mining as well as reasonable urban planning should be taken to prevent successive soil erosion.     

Assessing land use and land cover change in the Wassa West District of Ghana using remote sensing

Vast tracts of forests are lost globally every year especially in the developing countries of the tropics due to various human activities such as lumbering, farming, bush fires, surface mining and urbanization. The rainforest in Ghana has experienced rapid depletion since the 1980s. The impact of deforestation is widespread, affecting the livelihoods of local people and disrupting the tropical ecosystem. There is a serious concern in the study area about climatic change, soil erosion, siltation of rivers and loss in biodiversity which have an adverse impact on traditional medicinal plants of the local people. The study examined the extent of land cover change through image differencing of Landsat TM 1986 and 2002. The image classification indicated that, vegetative cover from 1986 to 2002 has been reducing whiles land use activities have been increasing. Closed canopy, open canopy and plantation have significantly diminished and land use activities especially built ups, farms, mining and openfields are more than doubled. The driving forces for the change in land cover are population growth, lumbering, socio-economic and cultural practices of the people. Lumbering and mining have been some of the major causes of the changing landscape in primary forest. Also the reliance on wood for domestic energy and the need to increase food productivity to feed growing population have also contributed greatly to the rapid depletion of the vegetative cover.     

Flow discharge simulation based on land use change predictions

Haraz River is one of the most important rivers in Iran, which has been faced with successive inappropriate land use changes and environmental degradation practices in recent decades. In this way, the impact of land use changes on stream flow generation, evaporation and hydrological processes of the Haraz basin has been studied. Land use maps for the years of 1988, 2000 and 2013 were prepared and assessed for any changes in land use using land change modeler and logistic regression methods. GEOMOD method was also used for accuracy tests of models. The calibration periods of 1988–2000, 1988–2013 and also Markov chain with hard prediction model were applied in order to predict the future land use for 2025. Besides, SWAT model was used to evaluate the watershed-scale impacts of land use change. Evaluating the calibration periods using GEOMOD method and some parameters showed a more accurate prediction for the period of 1988–2013 than the 1988–2000 period. Likewise, the results indicated that the rate of changes from 2013 to 2025 will be decreased in terms of forest and range lands (6751.05 and 168,09.01 ha, respectively) and will be increased in terms of residential areas, irrigated farming, gardens and bare lands up to 1567.2, 1405.68, 3039.38 and 174,05.55 ha, respectively. The assessment of model efficiency showed that the SWAT model has acceptable performance to simulate the flow discharge. Overall, the model outcomes indicated that land use changes lead to increase the average runoff in the study area. As a matter of fact, this issue has significant effects on water resources, economic and social situations, and hence, efficient strategies are needed for an integrated management in the Haraz basin.     

Estimating Benefits in a Recovering Estuary: Tampa Bay,Florida

Restoration and preservation of riparian forests and coastal marshes provides nutrient removal and other biochemical and physical functions which may preclude, reduce, or delay the need for additional water treatment, while also protecting human health. We examined the ecosystem goods and related potential cost savings for the Tampa Bay community from seagrass expansion (more than 3,100 ha since 1990), coastal marsh, and mangrove restoration/recovery (more than 600 ha since 1990), and habitat that has been maintained or preserved. Habitats in and around Tampa Bay provide nutrient reductions equivalent to just over US$22 million per year in avoided wastewater treatment plant costs. Future accrual of value associated with maintaining the ecosystem good of usable clean water could rapidly increase to as high as ～US$3 billion per year, when one takes into account the additional costs of water treatment and storm water diversion infrastructure that is likely as the region’s population continues to grow. There is additional value accrual close to a quarter million dollars per year based on avoided social costs to the global community due to greenhouse gases sequestered by bay habitats. Most human beneficiaries associated with the maintenance of usable clean water in Tampa Bay are part of the surrounding regional community. The large current and future cost savings for the community surrounding Tampa Bay and additional benefits for the global community speak to the value of maintaining a healthy bay through past and continued restoration and preservation efforts.     

Spatiotemporal dynamics of land cover and their impacts on potential dust source regions in the Tarim Basin,NW China

Human-driven dynamics of land cover types in the Tarim Basin are able to affect potential dust source regions and provide particles for dust storms. Analyses about dynamics of potential dust source regions are useful for understanding the effects of human activities on the fragile ecosystem in the extremely arid zone and also provide scientific evidence for the rational land development in the future. This paper therefore selected the Tarim Basin, NW China, as a representative study area to reveal spatiotemporal dynamics of land cover and their impacts on potential dust source regions. The results showed that farmland, desert and forest increased by 28.63, 0.64 and 29.27%, while grassland decreased by 10.29% during 1990–2010. The largest reclamation, grassland loss and desertification were 639.17 × 10³, 2350.42 × 10³ and 1605.86 × 10³ ha during 1995–2000. The relationship between reclamation and grassland loss was a positive correlation, while a highly positive correlation was 0.993 between the desertification and grassland loss at different stages. The most serious dust source region was the desertification during 1990–2010 (1614.58 thousand ha), and the serious region was stable desert (40,631.21 thousand ha). The area of the medium and low dust source region was 499.08 × 10³ and 2667.27 × 10³ ha. Dramatic reclamation resulted in the desertification by destroying natural vegetation and breaking the balance of water allocation in various regions.     

Impact of forecasted land use changes on flood risk in the Polish Carpathians

Flooding is a major environmental hazard in Poland with risks that are likely to increase in the future. Land use and land cover (LULC) have a strong influencing on flood risk. In the Polish Carpathians, the two main projected land use change processes are forest expansion and urbanization. These processes have a contradictory impact on flood risk, which makes the future impact of LULC changes on flooding in the Carpathians hard to estimate. In this paper, we investigate the impact of the projected LULC changes on future flood risk in the Polish Carpathians for the test area of Ropa river basin. We used three models of spatially explicit future LULC scenarios for the year 2060. We conduct hydrological simulations for the current state and for the three projected land use scenarios (trend extrapolation, ‘liberalization’ and ‘self-sufficiency’). In addition, we calculated the amount of flood-related monetary losses, based on the current flood plain area and both actual and projected land use maps under each of the three scenarios. The results show that in the Ropa river, depending on scenario, either peak discharge decreases due to the forest expansion or the peak discharge remains constant—the impact of LULC changes on the hydrology of such mountainous basins is relatively low. However, the peak discharges are very diverse across sub-catchments within the modeling area. Despite the overall decrease of peak discharge, there are areas of flow increase and there is a substantial projected increase in flood-related monetary losses within the already flood-prone areas, related to the projected degree of urbanization.     

Managed Retreat of Saline Coastal Wetlands: Challenges and Opportunities Identified from the Hunter River Estuary,Australia

We analyse the potential impacts of sea-level rise on the management of saline coastal wetlands in the Hunter River estuary, NSW, Australia. We model two management options: leaving all floodgates open, facilitating retreat of mangrove and saltmarsh into low-lying coastal lands; and leaving floodgates closed. For both management options we modelled the potential extent of saline coastal wetland to 2100 under a low sea-level rise scenario (based on 5 % minima of SRES B1 emissions scenario) and a high sea-level rise scenario (based on 95 % maxima of SRES A1FI emissions scenario). In both instances we quantified the carbon burial benefits associated with those actions. Using a dynamic elevation model, which factored in the accretion and vertical elevation responses of mangrove and saltmarsh to rising sea levels, we projected the distribution of saline coastal wetlands, and estimated the volume of sediment and carbon burial across the estuary under each scenario. We found that the management of floodgates is the primary determinant of potential saline coastal wetland extent to 2100, with only 33 % of the potential wetland area remaining under the high sea-level rise scenario, with floodgates closed, and with a 127 % expansion of potential wetland extent with floodgates open and levees breached. Carbon burial was an additional benefit of accommodating landward retreat of wetlands, with an additional 280,000 tonnes of carbon buried under the high sea-level rise scenario with floodgates open (775,075 tonnes with floodgates open and 490,280 tonnes with floodgates closed). Nearly all of the Hunter Wetlands National Park, a Ramsar wetland, will be lost under the high sea-level rise scenario, while there is potential for expansion of the wetland area by 35 % under the low sea-level rise scenario, regardless of floodgate management. We recommend that National Parks, Reserves, Ramsar sites and other static conservation mechanisms employed to protect significant coastal wetlands must begin to employ dynamic buffers to accommodate sea-level rise change impacts, which will likely require land purchase or other agreements with private landholders. The costs of facilitating adaptation may be offset by carbon sequestration gains.     

A comparison of brachyuran crab community structure at four mangrove locations under different management systems along the Melaka Straits-Andaman Sea Coast of Malaysia and Thailand

Brachyuran crab community structure was compared between mangrove sites under different management systems from four locations along the Melaka Straits-Andaman Sea Coast. Klong Ngao, a mangrove estuary in Ranong Province of southern Thailand, lies within a Biosphere Reserve designated in 1997. Sites were positioned in plantations at a former charcoal concession forest, a disused tin mine, and an abandoned shrimp pond along this estuary. The Merbok estuary in Kedah, Malaysia, is partially managed: the mangroves are cut for charcoal and poles on a small scale and the forests are left to regenerate naturally. The Matang Mangrove Forest Reserve in Perak, Malaysia, is heavily exploited but well managed, forRhizophora wood to produce charcoal, and has been for 100 years. Sites were positioned in plantations of different ages. Kuala Selangor Nature Park, Selangor, Malaysia, was established as a nature reserve in 1987 and contains mature mangrove forest regenerating naturally from previous selective felling. At Klong Ngao and Matang, mature reserve forest sites were also studied for comparison with plantation sites. The sites included both upstream and downstream locations and were of similar area, minimizing effects from possible species-area relationships. Sites were chosen with similar environmental conditions and with a dominance ofRhizophora spp. At each site per location, the brachyuran crabs were sampled quantitatively in 100 m² quadrats by three independent 15-min timed crab catches. The crab community recorded was analyzed by univariate and multivariate statistical techniques. Management history plays an important role in moderating the crab community structure. The crab community also changes with the age of the mangrove forest stand. Sesarmid crabs consistently dominated in mature forests, whereas young plantations were colonized mainly by ocypodid crabs. The findings show that heavily effected sites—e.g., disused tin mining areas, former concession forests, and abandoned shrimp ponds—can be rehabilitated by planting mangroves and that the crab community is a useful ecological indicator of habitat status.     

Extracting the damaging effects of the 2010 eruption of Merapi volcano in Central Java, Indonesia

This research focuses on providing information related to the damaging effects of the 2010 eruption of Merapi volcano in Central Java, Indonesia. This information will be used to help emergency responders to assess losses more timely and efficiently, and to monitor the progress in emergency response and recovery. The objectives of this research are: (a) to generate a map of pyroclastic deposits based on activities pre- and post-volcano eruption of 2010 in the research area, (b) to investigate the impact of volcano eruption on the environment, and (c) to assess the impact of volcano eruption on landuse. ALOS PALSAR remote sensing data pre- and post-disaster were used in this research for mapping the volcano eruption. Topographic and geomorphological maps were analyzed for profiling and field orientation, which were used to investigate the impact of volcano eruption on the environment. SPOT 4 satellite images were used in this research for updating landuse information from the topographic map. The result of the landuse updated data was used for assessment of the volcano eruption’s impact on landuse with the GIS raster environment. The volcanic eruption that occurred in 2010 is estimated to have an impact of 133.31 ha for settlements, 92.32 ha for paddy fields, 235.60 ha for dry farming, 570.98 ha for plantations, 380.86 ha for bare land, and 0.12 ha for forest areas. An estimate of the number of buildings damaged due to the volcano eruption in 2010 was carried out by overlaying a map of pyroclastic deposits and the information point of the building sites from the topographic map. The total number of buildings damaged is estimated to be around 12,276 units.     

Estimation of soil losses by USLE model using GIS at Mashhad plain, Northeast of Iran

The Universal Soil Loss Equation (USLE) is an erosion estimation model to assess the soil losses that would generally result from splash, sheet, and rill erosion. At the present study, spatial distribution of different erosion prone areas were identified by USLE model to determine the average annual soil losses at Mashhad plain, northeast of Iran. Soil losses were estimated on a 100?×?100 m cell basis resolution by overlaying the five digital parameter layers (R, K, LS, C, P). To determine the critical soil loss regions at the plain, cell-based USLE parameters were multiplied by Arc-GIS ver.9.3. The estimated annual soil losses values were subsequently grouped into five classes ranging from 0 to 0.25 t/h/year around the trough line of the plain at Kashaf-rud River to 2–10 t/ha/year at the hills and pediment plains. Our results indicated a good correlation between land units of hills and pediment plains with the values of soil losses at the study area (R ² ?=?0.72), also the statistical analysis exhibited a high correlation between land use/cover of dry farming and soil losses (R ² ?=?0.78).     

Analysing land and vegetation cover dynamics during last three decades in Katerniaghat wildlife sanctuary,India

The change in the tropical forests could be clearly linked to the expansion of the human population and economies. An understanding of the anthropogenic forcing plays an important role in analyzing the impacts of climate change and the fate of tropical forests in the present and future scenario. In the present study, we analyze the impact of natural and anthropogenic factors in forest dynamics in Katerniaghat wildlife sanctuary situated along the Indo-Nepal border in Uttar Pradesh state, India. The study site is under tremendous pressure due to anthropogenic factors from surrounding areas since last three decades. The vegetation cover of the sanctuary primarily comprised of Shorea robusta forests, Tectona grandis plantation, and mixed deciduous forest; while the land cover comprised of agriculture, barren land, and water bodies. The classification accuracy was 83.5%, 91.5%, and 95.2% with MSS, IKONOS, and Quickbird datasets, respectively. Shorea robusta forests showed an increase of 16 km²; while Tectona grandis increased by 63.01 km² during 1975–2010. The spatial heterogeneity in these tropical vegetation classes surrounded by the human dominated agricultural lands could not be addressed using Landsat MSS data due to coarse spatial resolution; whereas the IKONOS and Quickbird satellite datasets proved to advantageous, thus being able to precisely address the variations within the vegetation classes as well as in the land cover classes and along the edge areas. Massive deforestation during 1970s along the adjoining international boundary with Nepal has led to destruction of the wildlife corridor and has exposed the wildlife sanctuary to human interference like grazing and poaching. Higher rates of forest dynamics during the 25-year period indicate the vulnerability of the ecosystem to the natural and anthropogenic disturbances in the proximity of the sanctuary.