Analyzing and modeling of a large river basin dynamics applying integrated cellular automata and Markov model

Historical and exact information about the land use/land cover change is very important for regional sustainable development. The aim of this paper is to determine the rapid changes in land use/land cover (LULC) pattern due to agriculture expansion, environmental calamities such as flood and government policies over Upper Narmada basin, India. Multi-temporal Landsat satellite images for years 1990, 2000, 2010 and 2015 were used to analyze and monitor the changes in LULC with an overall accuracy of more than 85%. Results revealed a potential decrease in natural vegetation (? 9.52%) due to the expansion of settlement (+ 0.52%) and cropland (+ 9.43%) from 1990 to 2015. In the present study, Cellular Automata and Markov (CA–Markov), an integrated tool was used to project the short-term LULC map of year 2030. The projected LULC (2030) indicated the expansion of built-up area along with the cropland and degradation in the vegetation area. The outcomes from the study can help as a guiding tool for protection of natural vegetation and the management of the built-up area. Additionally, it will help in devising the strategies to utilize every bit of land in the study area for decision makers.     

Land cover and land use change related to shrimp farming in coastal areas of Quang Ninh,Vietnam using remotely sensed data

Rapid development of shrimp farming may lead to unrecognized and undesirable changes of land cover/land use patterns in coastal areas. Of special concern is the loss of mangrove forest in coastal areas such as Quang Ninh, Vietnam, which is adjacent to the World Heritage-listed Ha Long Bay. Understanding the status and changes of land cover/land use for coastal shrimp farms and mangrove forests can support environmental protection and decision-making for sustainable development in coastal areas. Within this context, this paper uses the 1999/2001 Landsat ETM+ and the 2008 ALOS AVNIR-2 imagery to investigate the contraction and expansion of shrimp farms and mangrove forests in coastal areas of Ha Long and Mong Cai, which now have a high concentration of intensive and semi-intensive shrimp farms. Images were separately analyzed and classified before using post-classification comparisons to detect land cover/land use changes in the study area. The results of this study found that the area of mangrove forest has been reduced by an estimated 927.5 ha in Ha Long and 1,144.4 ha in Mong Cai, while shrimp farming areas increased by an estimated 1,195.9 and 1,702.5 ha, respectively, over the same period. The majority of shrimp farms in Mong Cai were established at the expense of mangrove forest (49.4 %) while shrimp farms in Ha Long were mainly constructed on areas previously occupied by bare ground (46.5 %) and a significant proportion also replaced mangroves (23.9 %). The remarkable rate of mangrove loss and shrimp farming expansion detected in this study, over a relatively short time scale indicate that greater awareness of environmental impacts of shrimp farm expansion is required if this industry is to be sustainable, the important estuarine and coastal marine ecosystems are to be protected over the long term, and the capturing and storing of carbon in mangrove systems are to be enhanced for global climate change mitigation and for use as carbon offsets.     

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.     

Use of geoprocessing in the study of land degradation in urban environments: the case of the city of São Carlos,state of São Paulo,Brazil

This paper presents a methodology for the geological engineering survey of land degradation in urban environments using both remote sensing and geoprocessing tools. The area under study was the city of São Carlos, state of São Paulo, Brazil (urban and expansion area). The data presented here were obtained from earlier studies, photointerpretation and geological engineering mapping. The Envi 4.1 software package was used to prepare the digital orthophotos that served as a reference base for the information. Orthorectification of the Ikonos image (PSM, 1 m) was done and compared with other orthophotos from studies of environmental degradation in urban areas. The evolution of land degradation processes was analyzed based on the photointerpretation of aerial photographs taken on different dates and using Ikonos image. This study allowed to conclude that most of the degradation occurring in the city has been caused by unplanned land occupation, in disregard of environmental conditions, resulting in environmental degradation and thus impacting the quality of life of the urban population.     

Land use changes and impact on coral communities along the central Pacific coast of Mexico

The loss of coral coverage from environmental degradation is a progressive phenomenon that occurs in coral communities around the world. However, the consequences of land use changes and its impact on the state of conservation of coral communities are not yet understood. This study compares the impact of coastal land use changes on four coral communities near rural (Isla Faro and El Zapote) and suburban (Caleta de Chon and Playa Manzanillo) sites in the states of Michoacan and Guerrero, along the central Pacific coast of Mexico. Indicators of environmental degradation in coral communities (sediment deposition, water transparency, total suspended solids, and chlorophyll concentration) show that signs of eutrophication are absent from both rural sites in Michoacan. This absence suggests that human impact is not the main cause of the observed degradation (coral Mortality Index MI = 0.85, a high death coral coverage ~42% and the lowest species richness). Instead, the 1997–1998 El Niño-Southern Oscillation (ENSO) event (the strongest in the last decade) appears to be the major factor in this coral cover decline, as it occurred in the eastern Pacific and other regions of the world. In contrast, coral communities near the suburban sites in Guerrero are well developed, and their coral coverage and species richness (up to 67.7% and 7 species, respectively) are comparable to other major coral communities in this region. Nonetheless, indicators of human-derived degradation in the Guerrero coastal zone near Caleta de Chon and Playa Manzanillo, including high sediment deposition up to 1.2 kg m^?2 d^?1, low water transparency <5 m, presence of filamentous algae on dead corals and a coral Mortality Index of MI ~0.6 show that human impact is beginning to affect the conservation state of these coral communities, reducing their species richness and coral coverage. Although the ENSO impact on coral communities could be more drastic than the anthropogenic impact, the current study confirms that increased land use changes and coastal erosion are causing progressive coral community degradation. Therefore, land and coastal changes must be rigorously regulated.     

Spatio-temporal analysis of groundwater levels and projection of future trend of Agra city,Uttar Pradesh,India

Access to water resources is one of the major challenges being faced worldwide. Water scarcity, particularly groundwater resource, is the major ubiquitous concern for the country. Almost half of the country is reeling under severe ground water crisis due to anthropogenic and natural reasons (basalt rock surface). Agra region situated in the western part of Uttar Pradesh state of India has a semi-arid climate. The study area, which has a history of water scarcity since medieval ages, has seen a spurt of acute water shortage in recent times owing to the expansion of a very dense built-up area and excessive haulage accompanied by decline in rainfall. A study was under taken for identifying the trends in pre- and post-monsoon groundwater levels for Agra city, Uttar Pradesh. Pre-monsoon and post-monsoon groundwater depth data of 16 observation wells for the 2007–2016 period were collected and analyzed using ARC GIS 10.2 software. The rainfall trend during the study period was also studied to understand its role in groundwater fluctuation level. Statistical tests like Mann-Kendall, Sen’s slope estimator, and linear regression model were applied to understand the trend and rate of change in groundwater level. The land use/land cover map of the study area was integrated with groundwater map to have a primary understanding of the spatial trend of groundwater scenario of the study area. The result obtained is quite alarming for the city’s groundwater scenario. Results showed that the groundwater levels had significantly declined during 2007–2016. Average rates of water level decline were 0.228 and 0.267 m/year during pre- and post-monsoon seasons, respectively. There was a rapid decline in water level between 2008 and 2009 and between 2013 and 2014. The average rate of decline of pre- and post-monsoon groundwater level in the city during this period is 0.32 and 0.30 m/year, respectively. Significant decrease in groundwater level is found in 84.21% of wells for pre- and post-monsoon as obtained through Mann-Kendall analysis at 95% confidence level. During pre-monsoon season, the rate of decline according to Sen’s slope estimator varied between 0.74 and 2.05 m/year. Almost similar picture of decline is portrayed through linear regression slope wherein the computed rate of decline varied between 0.75 and 2.05 m/year. During post-monsoon, the rate of decline according to Sen’s slope varied between 0.13 and 1.94 m/year. Similar trend statistic is obtained through linear regression method where the declining rate is between 0.14 and 1.91 m/year. Comparison of the three statistical tests indicates similar nature of declining trend. The result of this research raises concern about the future of groundwater resources in Agra city. The findings of this study will assist planners and decision-makers in developing better land use and water resource management.     

Assessment of impervious surface growth in urban environment through remote sensing estimates

The fast growth in population and expansion of urban built area has led to the transformation of the natural landscape into impervious surfaces. Remote sensing-based estimate of impervious surface area (ISA) has emerged as an important indicator for the assessment of water resources depletion in urban areas and developed a correlation between land-use change and their potential impact on urban hydrology. In the present work, a remote sensing-based Impervious Surface Area (ISA) was carried out for New Okhla Industrial Development Authority (NOIDA) city, one of the fastest growing cities in National Capital Region (NCR) of India. The impervious surface area (ISA) of NOIDA was calculated for the years 2001, 2007 and 2014 using multi-temporal LANDSAT thermal data by applying linear spectral mixing analysis (LSMA) techniques to monitor the growth rate of impervious surface. The results observed by analysis of multi-temporal satellite images show an extreme temporal change in the growth of ISA in the city. The ISA observed for the year 2001 is 28 sq.km; in 2007, its increase was 48 sq.km and was 132 in 2014. The results were observed from this work through the use of satellite data which is very important for water resource management, planning and prediction of ISA impact on hydrology.     

Environmental degradation assessment in arid areas: a case study from Basra Province, southern Iraq

Evaluation of recent land degradation affecting Basra Province, Iraq, resulted in the identification of five prominent environmental degradation processes: desertification, secondary salinization, urbanization, vegetation degradation, and loss of wetlands. This analysis was carried out using ‘3S’ technologies [remote sensing, geographic information system (GIS), and global position system], with the layers extracted and manipulated from available topographic, climatic, and soil maps, as well as satellite image (thematic mapping in 1990 and enhanced thematic mapping in 2003) and field survey data analyses. Rates of conversion were calculated and distribution patterns were mapped with the aid of a GIS. The results revealed that land use changes have affected the wider environment and accelerated land degradation, with severe damage located in southwestern Basra Province representing 28.1 % of the total area. Areas of high to moderate degradation characterize the rest of the south, representing 52.7 % of the total area; while the north of the study region is characterized by very low and low degradation levels accounting for 8.5 and 10.7 %, respectively. Iraq faces serious environmental degradation problems that must be addressed immediately; failure to do so will greatly compound the cost and complexity of later remedial efforts, with environmental degradation beginning even now to pose a major threat to human well-being, especially among the poor.     

Sustainable multivariate analysis for land use management in El-Sharkiya,Egypt

In Egypt, major sustainability variables could be identified as scarce of soil and water resources, environmental degradation, rapid population growth, institutional arrangement that includes land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization. The main objective of the current work is to evaluate the sustainable land use management (SLM) model through biophysics and socioeconomic elements for the purpose of combating sustainability constraints that preclude the agricultural development geospatially. In this research, from the geomorphologic point of view, the obtained results showed three main landscapes. They were identified in the study area as: fluviolacustrine plain, Aeolian deposits, and flood plain. The study area was dominated by some physical and chemical degradation processes with different scales breaking down the equilibrium of soil stability. The SLM model was implemented and assessed from multivariate perspective points of productivity, security, protection, economic viability, and social acceptability. Four SLM classes were outlined as follows: class I, land management practices that did meet sustainability requirements with a score ≥0.65, which represented 31.0 % of the considered agricultural study area; class II, land management practices that were marginally above the sustainability threshold and represented 12.6 %; class III, land management practices that were slightly below the threshold of sustainability and represented 8.60 %; class IV, land management practices that did not meet sustainability requirements with index values >0.1 that represented 47.86 %. As a general conclusion, it is found that land management practices tend to be unsustainable in the area under investigation for certain constraints that play motivated roles in lowering the targeted land sustainability.     

S patio-temporal pattern of land use and land cover and its effects on land surface temperature using remote sensing and GIS techniques: a case study of Bhubaneswar city,Eastern India (1991–2021)

Urbanization produces substantial land use changes by causing the construction of different urban infrastructures in the city region for habitation, transportation, industry, and other reasons. As a result, it has a significant impact on Land Surface Temperature (LST) by disrupting the surface energy balance. The objective of this paper is to assess the impact of land-use/land-cover (LU/LC) dynamics on urban land surface temperature (LST) of Bhubaneswar City in Eastern India during 30 years (1991–2021) using Landsat data (TM, ETM + , and OLI/TIRS) and machine learning algorithms (MLA). The finding reveals that the mean LST over the entire study domain grows significantly between 1991 and, 2021due to urbanization (β coefficient 0.400, 0.195, 0.07, and 0.06 in 1991, 2001, 2011, and 2021 respectively) and loss of green space (β coefficient − 0.295, − 0.025, − 0.125 and − 0.065 in 1991, 2001, 2011 and 2021 respectively). The highest class recorded for agricultural land (49.60 km², accounting for 33.94% of the total land area) was in 1991 followed by vegetation (41.27 km², 28.19% of the total land area), and built-up land (27.59 km², 18.84% of the total land area). The sharp decline of vegetation cover will continue until 2021 due to increasing built-up areas (r = − 0.531, − 0.329, − 0.538, and − 0.063 in the 1991, 2001, 2011 and 2021 respectively). Built-up land (62.60 km², accounting for 42.76% of the total land area, an increase of 35.01 km² from 1991) as the highest class followed by water bodies (21.57%, 32.60 km² of the land area), and agricultural land (31.57 km², 21.57% of the land area) in 2021. Remote sensing techniques proved to be an important tool to urban planners and policymakers to take adequate steps to promote sustainable development and minimize urbanization influence on LST. Urban green space (UGS) can help improve the overall liveability and environmental sustainability of Bhubaneswar city.

     

Impact assessment of land cover changes on the runoff changes on the extreme flood events in the Kelantan River basin

In the current years, changing the land cover/land use had serious hydrological impacts affecting the flood events in the Kelantan River basin. The flood events at the east coast of the peninsular Malaysia got highly affected in the recent decades due to several factors like urbanisation, rapid changes in the utilisation of land and lack of meteorological (i.e. change in climate) and developmental monitoring and planning. The Kelantan River basin has been highly influenced due to a rapid change in land use during 1984 to 2013, which occurred in the form of transformation of agricultural area and deforestation (logging activities). In order to evaluate the influence of the modifications in land cover on the flood events, two hydrological regional models of rainfall-induced runoff event, the Hydrologic Engineering Center (HEC)-Hydrologic Modeling System (HMS) model and improved transient rainfall infiltration and grid-based regional model (Improved TRIGRS), were employed in this study. The responses of land cover changes on the peak flow and runoff volume were investigated using 10 days of hourly rainfall events from 20 December to the end of December 2014 at the study area. The usage of two hydrological models defined that the changes in land use/land cover caused momentous changes in hydrological response towards water flow. The outcomes also revealed that the increase of severe water flow at the study area is a function of urbanisation and deforestation, particularly in the conversion of the forest area to the less canopy coverage, for example, oil palm, mixed agriculture and rubber. The monsoon season floods and runoff escalate in the cleared land or low-density vegetation area, while the normal flow gets the contribution from interflow generated from secondary jungle and forested areas.     

Changes of land cover in the Yarlung Tsangpo River basin from 1985 to 2005

Land cover is closely related to environmental changes and socioeconomic development. Land-cover change in the Tibetan Plateau (TP) is different from that in the lowlands; however, a detailed land-cover change in areas such as the Yarlung Tsangpo River (YTR) basin in the TP has not been reported. To fill this gap, the current study explores the land-cover change between 1985 and 2005 in the YTR basin. The results show that only 1 % of the land cover in the YTR basin changed during this time period. The most significant land-cover changes included increases in forest and built-up areas as well as decreases in grassland, water and wetland areas. By percentage, the most rapid land-cover change occurred for built-up areas with an annual variation of 2.07 %. There was an obvious vertical distribution pattern for land-cover types in the YTR basin; from low to high, the average altitudes were forest, farmland, built-up, grassland, water and wetland, and bare land. The average altitude and slope for most land-cover types did not vary over the past 20 years. However, the average altitude and slope of built-up significantly decreased, especially in the zone between 3,500 and 4,000 m. The water and wetland area in altitudes above 4,500 m increased; however, they decreased in the zone between 3,500 and 4,000 m. Natural factors cause most land-cover changes, whereas the increasing intensity of human activities cause some changes to built-up and farmland. Additional attention should be paid to the study of the mechanism of land-cover change in the TP.     

Monitoring land use/land cover change using multi-temporal Landsat satellite images in an arid environment: a case study of El-Arish,Egypt

Environment in arid conditions is dynamic and needs more investigation to understand the complexity of change. This spatiotemporal study will help to assess and monitor the land use and land cover change in the arid region of El-Arish area, where the climate and human activities are the major threats to rural development. In the past 11 years, dramatic changes of environment have been recorded in case studies. The post-classification comparison method was used to observe the changes using multi-temporal satellite images which were captured in the years 1999, 2001, 2005, and 2010. The overall accuracy of the produced thematic images was assessed regarding to the quantity and allocation disagreements. Five classes were defined in this investigation: bare soil, vegetation, urban, sand dunes, and fertile soil. From the year 1999 to 2010, fertile soil was increased by 13 %. Bare soil class occupied more than 50 % of land in the case study during for over a decade. From year 1999 to 2010, vegetation cover witnessed a dramatic increase. Soil and water management are the keys of land development and positive land use and land cover dynamics. Changing agricultural policies of using the available water resources are needed in the case study to prevent severe food shortage in the future.     

Assessment of land-use change and its impact on the environment using GIS techniques: a case of Kolkata Municipal Corporation,West Bengal,India

It is axiomatically true that urbanization in India's metropolises and large cities has been exacerbated since the beginning of the millennium, consuming the natural and semi-natural ecosystem on the outskirts of the city, resulting in a zone with a distinct climate known as urban climate. Such a climate—the result of a built-up environment is distinctly different from the natural climate as the paved surface and concrete skyscrapers not only destroy the natural ecosystem, it peculiarly induce a different kind of insolation, cooling and air drainage were lacking in green space, water bodies and open space cannot accommodate with environmental rhythm properly, resulting into the accumulation of heat, ecological derangement of subsurface soil which can easily be predicted by GIS analysis. This paper is an attempt to measure urban growth and its impact on the environment in the metropolitan city Kolkata. The use of satellite data and GIS techniques to detect urban expansion is a highly scientific strategy. Using geospatial techniques, the current study attempts to examine major urban changes in Kolkata and its surroundings from 1988 to 2021. Landsat 5 TM and Landsat 8 OLI temporal data are used to identify land-use change through unsupervised classification; Spectral Radiance Model and Split Window Algorithm method are used for identifying land surface temperature change. SRTM DEM (30 m) has been used to identify flood risk zones and several spectral indices like Normalized Difference Vegetation Index and Modified Normalized Difference Water Index are a further extension for environmental assessment. By all such suitable methods, a clearer change in an urban environment is detected within the period of 33 years (1988–2021). The result shows that the population changes, vegetation cover and built-up area, and accessibility are at a rapid rate. These changes are causing major environmental degradation in the city. The classification result indicates that appropriate land use planning and environmental monitoring are required for the long-term exploitation of these resources.

     

Land degradation risk assessment in Al-Sawda terraces,Kingdom of Saudi Arabia

Monitoring of soil properties is a significant process and plays an important role about how it can be used sustainably. This study was performed in a local area in Sawda Mountains KSA to map out some soil properties and assess their variability within the area under different land cover. Soil sampling was carried out in four different sites using the grid sampling technique. Ten samples were collected in each location within a 10 by 10 km area; soil was sampled at 0–30-cm depth. The soil samples were air-dried, crushed, and passed through a 2-mm sieve before analyzing it for pH, EC, CaCO₃, organic matter contents, and bulk density. The thematic maps of these characteristics were produced using ArcGIS 10.0 software. Finally, the land degradation was assessed using three factors: soil salinization, compaction, and edibility. The obtained results showed that the high risk of soil compaction, salinization, and erodibility occupied an area 5.6 ha (17.5%), 3.7 ha (11.54%), and 8.1 ha (25.3%), respectively, in the surface soil layer. The land degradation risk in the study area due to salinization was low to high; however, the degree of soil compaction was moderate to very high. The K-factor (soil erodibility) in the area ranged between 0.1 and 0.35 Mg h MJ^?1 mm^?1, and most of the study area was located in moderate to high erodibility classes.     

Assessing the impacts of changing land cover and climate on Hokersar wetland in Indian Himalayas

Monitoring the spatiotemporal changes in wetlands and assessing their causal factors is critical for developing robust strategies for the conservation and restoration of these ecologically important ecosystems. In this study, the spatiotemporal changes in the land cover system within a Himalayan wetland and its catchment were assessed and correlated using a time series of satellite, historical, and field data. Significant changes in the spatial extent, water depth, and the land system of the Hokersar wetland were observed from the spatiotemporal analysis of the data from 1969 to 2008. The wetland area has shrunk from 18.75 km² in 1969 to 13 km² in 2008 with drastic reduction in the water depth of the wetland. The marshy lands, habitat of the migratory birds, have shrunk from 16.3 km² in 1969 to 5.62 km² in 2008 and have been colonized by various other land cover types. The land system and water extent changes within the wetland were related to the spatiotemporal changes in the land cover and hydrometeorological variables at the catchment scale. Significant changes in the forest cover (88.33–55.78 km²), settlement (4.63–15.35 km²), and water bodies (1.75–0.51 km²) were observed in the catchment. It is concluded that the urbanization, deforestation, changes in the hydrologic and climatic conditions, and other land system changes observed in the catchment are the main causes responsible for the depleting wetland extent, water depth, and biodiversity by adversely influencing the hydrologic erosion and other land surface processes in the catchment. All these causes and effects are manifest in the form of deterioration of the water quality, water quantity, the biodiversity changes, and the decreasing migratory bird population in the wetland.     

Assessment of land degradation east of the Nile Delta, Egypt using remote sensing and GIS techniques

Land degradation is one of the most common issues in the eastern part of the Nile Delta area that threatens the ongoing agricultural activities and prohibits further reclamation expansions. The different degradation types and the associated risk assessment of some soils types of western Suez Canal region during the period from 1997 to 2010 is discussed. The assessment of the different degradation degrees in the investigated area has been carried out through integrating remote sensing, GIS and GLASOD approaches. Results revealed that the salinization, alkalization, soil compaction and water logging are the main types of land degradation in the area. The main causative factors of human induced land degradation types are; over irrigation, human intervention in natural drainage, improper time use of heavy machinery and the absence of conservation measurements. Low and moderately clay flats, gypsifferous flats, have high to very high risk in both salinization sodication and physical degradation. Values such as EC, ESP, and ground water level reach 104.0 dS/m, 176? % and 60 cm, respectively. These results will be of great help and be basic sources for the planners and decision makers in sustainable planning. The spatial land degradation model was developed based on integration between remote sensing data, geographic information system, soil characteristics and DEM.     

Assessment of land use/land cover dynamics vis-à-vis hydrometeorological variability in Wular Lake environs Kashmir Valley,India using multitemporal satellite data

Wular Lake, one of the largest freshwater lakes of Jhelum River Basin, is showing signs of deterioration due to the anthropogenic impact and changes in the land use/land cover (LULC) and hydrometeorological climate of the region. The present study investigated the impacts of temporal changes in LULC and meteorological and hydrological parameters to evaluate the current status of Wular Lake environs using multisensor, multitemporal satellite and observatory data. Satellite images acquired for the years 1992, 2001, 2005, and 2008 were used for determining changes in the LULC in a buffer area of 5 km² around the Wular Lake. LULC mapping and change analysis using the visual interpretation technique indicated significant changes around the Wular Lake during the last two decades. Reduction in lake area from 24 km² in 1992 to 9 km² in 2008 (?62.5 %) affected marshy lands, the habitat of migratory birds, which also exhibited drastic reduction from 85 km² in 1992 to 5 km² in 2008 (?94.117 %). Marked development of settlements (642.85 %) in the peripheral area of the Wular Lake adversely affected its varied aquatic flora and fauna. Change in climatic conditions, to a certain extent, is also responsible for the decrease in water level and water spread of the lake as witnessed by decreased discharge in major tributaries (Erin and Madhumati) draining into the Wular Lake.     

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.     

Assessment of the mutual impact between climate and vegetation cover using NOAA-AVHRR and Landsat data in Egypt

The objective of the current study is to use satellite data to assess the mutual influence between vegetation and climate. The Ismailia Governorate was selected as a case study to investigate the impact of vegetation cover expansion on both land surface and air temperature from 1983 to 2010 and vice versa. This observation site was carefully selected as a clear example of the high rate of the reclamation and vegetation expansion process in Egypt. Land surface temperature (LST) was estimated through the Advanced Very High Resolution Radiometer (a space-borne sensor embarked on the National Oceanic and Atmospheric Administration) data while air temperature (T _air) was collected from ground meteorological stations in the study area. Irrigated agriculture is the largest consumer of freshwater resources. However, consistent information on irrigation water use is still lacking. Relative humidity, wind speed, solar radiation, and T _air data were inserted in the Penman–Monteith equation to calculate potential evapotranspiration (ET_o), while both LST and T _air were used to observe the relative water status of the study area as a result of the water deficit index (WDI). Then, both WDI and ET_o were used to calculate actual evepotranspiration (ET_C.). The results showed that LST decreased by about 2.3 °C while T _air decreased by about 1.6 °C during the study period. The results showed also that the vegetation cover expanded from 25,529.85 ha in 1985 to 63,140.49 ha in 2009 with about 147 % increase. This decrease in LST and air temperature was according to the expansion of the cultivated land that was proved through the processing of three Landsat TM and Landsat ETM+ imageries acquired in June 19, 1985, June 7, 1998, and June 29, 2009. The vegetation water consumption was affected by the decreasing surface and air temperature. The results showed that the water deficit index decreased by about 0.35, and actual evapotranspiration increased by about 2.5 mm during the study period.