Destruction Of Vegetation Research Articles

Plausible causes of temporal variation in suspended sediment concentration in the upper Changjiang River and major tributaries during the second half of the 20th century

In the second half of the 20th century, suspended sediment concentration (SSC) varied in different ways in the upper Changjiang River and major tributaries due to the changing human activity and precipitation. The variation in annual precipitation ( P m) can explained only 16%–37% of the variation in suspended sediment concentration, and thus variation in precipitation is not the main cause for the variation in suspended concentration. Using the analysis of double-mass curve, the effect of human activities on the variation in suspended concentration has been studied. The suspended concentration of the lower Jinshajiang River increased from 1983 due to large-scale mining and road and urban construction. The double-mass curve for the Minjiang shows three periods where the relationship between SSC and P m changes because of reservoir construction and reforestation. The SSC of the Jialingjiang River decreased from 1984 because marked sediment-reduction effect has been achieved by soil and water conservation measures. The SSC of the Wujiang River increased from 1968 and then decreased from 1983, the former can be related to the vegetation destruction that enhanced soil erosion and the latter to the construction of reservoirs that trapped sediment. Compared to the 4 tributaries, the suspended sediment of the main stem of the upper Changjiang River shows smaller variation in SSC. The results of a multiple regression analysis show that the contribution percentages of SSC of the Jinshajiang, Minjiang, Jialingjiang and Wujiang Rivers to that of the upper Changjiang are 28%, 13%, 44% and 15%, respectively.

The habitat preference of four kingfisher species along a branch of the Kilombero River, southern Tanzania

Several factors have been found to influence kingfisher habitat use, including perch height (Monadjem, OwenSmith & Kemp, 1994), diet (Woodall, 1991; Libois & Laudelout, 2004), water quality (Douthwaite, 1982), river depth (Monadjem, 1996), river width and river speed (Peris & Rodriguez, 1996). Comparisons of the habitat preferences of different African kingfisher species have in the past mainly concerned the influence of single habitat variables on kingfisher presence [for example Monadjem et al. (1994) compared perch height preferences between Giant kingfisher (Ceryle maxima), Half-collared kingfisher (Alcedo semitorquata) and Pied kingfisher (Ceryle rudis)]. In this study, by regarding multiple habitat variables we compare the habitat preferences of four African species of kingfisher: Giant, Half-collared, Pied and Malachite (Alcedo cristata), along the Kilombero River, southern Tanzania. Riverine habitat of the Kilombero River is cleared for purposes such as agriculture and livestock grazing and this may negatively affect the resident bird community (Baker & Baker, 2002). We aim to highlight those habitat variables that influence kingfisher habitat use, in an area experiencing moderate levels of anthropogenic pressure. Materials and methods

Destruction and Recovery of Vegetation Caused by the 2000-Year Eruption on Miyake-Jima Island, Japan

The active Mt. Oyama volcano on Miyake-jima Island in the Izu Islands, Japan, erupted in 2000 followed by large amounts of volcanic gas containing high concentrations of SO2has been emitted. The island ecosystem has been heavily damaged by the volcanic ash and gas. We detail the destruction and recovery of vegetation found in a 7-year study of 11 permanent plots from 2001 to 2007. Damage to vegetation by ash was worst near the crater in 2001. Trees began dying in 2001, apparently due to direct and/or indirect effects of volcanic gas emission. In contrast to the tree decline, two grass species,Miscanthus condensatusandCarex oshimensis, increased notably following the eruption, suggesting their high SO2and acidic soil tolerance.Miscanthus condensatusandC. oshimensiswere not dominant species in early stage of primary succession before the 2000-year eruption. In the vegetation recovery after the eruption, the tolerances to SO2and acidic soils are necessary for plant species to colonize on devastated sites.

Effects of harvest intensity and aspect on a boreal transition tolerant hardwood forest. I. Initial postharvest understory composition

Disturbance effects on plant communities largely reflect the degree of overstory removal, soil disturbance, and attendant vegetation destruction. We examined initial harvest-related impacts of partial and complete canopy removal, with and without soil disturbance, on north- and south-facing aspects of an older, relatively undisturbed, boreal transition tolerant hardwood forest at Turkey Lakes, Ontario. We recorded vascular plant cover in 180 25 m2plots in the 3rd postharvest year and analyzed community response using unconstrained (nonmetric multidimensional scaling) and constrained (distance-based (partial) redundancy analysis) ordination, multivariate ANOVA, indicator species analysis and diversity measures. Community composition and diversity measures were related primarily to gradients in soil disturbance and, particularly for herbaceous species, aspect-related radiative exposure. Canopy opening generally played a lesser role. There were, however, notable canopy opening – soil disturbance × aspect interaction effects on both woody and herbaceous composition. In contrast with herbs, proportionately more woody species had indicator value for south- than for north-facing aspects and for disturbed than for undisturbed soils. Understory community response and diversity measures were affected more by logging-related soil disturbance than by the amount of canopy opening associated with the silvicultural system used. Aspect-related effects, however, suggest silvicultural impacts will be both site- and species (functional group) specific.

The effects of vegetative ash on infiltration capacity, sediment transport, and the generation of progressively bulked debris flows

Through the alteration of the physical characteristics of a landscape, such as the destruction of vegetation and the formation of a hydrophobic layer, a fire can dramatically amplify erosion rates. On the basis of field observations, it has been proposed that the deposition of a layer of ash on the ground surface can enhance the erosion of mountainous terrain by surface runoff and might even be a necessary condition for the generation of progressively bulked debris flows. In this study, a flume was constructed to investigate the role of ash in increasing both the volume and the transport capacity of runoff. The experiments demonstrated that the presence of ash on the soil surface reduces the ability of flowing water to infiltrate; this effect is even greater when the ash has been pre-wetted. In addition, the ability of ash slurries to infiltrate decreases with increasing ash concentration. The results also indicate that the transport capacity of runoff is enhanced by the incorporation of ash into the flow because of the increased fluid density. However, the addition of ash reduces the boundary Reynolds number such that, at high ash concentrations and with fine-grained sediment, sediment transport declines as the flow becomes hydraulically smooth. The experimental results were also used to evaluate the ability of steep flow fronts, a common characteristic of debris flows and flash floods, to increase sediment transport rates. Finally, it is proposed that ash slurries may evolve into progressively bulked debris flows through a positive feedback between fluid density, transport capacity, and erosivity.

Changes in suspended sediments associated with 2004 Indian Ocean tsunami

The Sumatra tsunami on 26 December, 2004 in the Indian Ocean was generated by one of the largest earthquakes of the past 100 years. The present study investigated spatial and temporal changes of suspended sediment concentration (SSC) in North-East Indian Ocean (NEIO) after the Sumatra tsunami used satellite remote sensing data. The nLw551 products of MODIS-aqua data (using as indexing SSC) were analyzed for 5 years (2002–2006). Result shows SSC notably increased (55.6–200%) in large river estuaries along coast of the Bay of Bengal (BOB) in a short time (4 weeks) after the tsunami, especially the northwest coast of Indonesia, southeast coast of Myanmar, as well as the north offshore of BOB. Those increases were mainly caused by the re-suspension function induced by the initial surge of the tsunami. Monthly analysis indicates increases (4.26%) of SSC of the entire North-East Indian Ocean area in 2005; especially in November 2005 when increase of SSC increased by about 6.19% compared with other years; those may mainly be caused by the destruction of coastal vegetation and modifying of estuaries or wetlands by the 2004 tsunami. The increases of SSC have different mechanism in different region and period after the tsunami.

Land cover dynamic changes in northern China: 1989–2003

The 13 provinces (autonomous regions and municipalities) in northern China are located in latitude 31°–54°N and longitude 73°–136°E including Beijing, Tianjin, Hebei, Shanxi, Inner Mongolia, Jilin, Liaoning, Heilongjiang, Shaanxi, Gansu, Ningxia, Qinghai, and Xinjiang, where environments are fragile. In recent years, the eco-environmental problems such as vegetation destruction, desertification and soil erosion etc. become serious because of climate change and unreasonable human activities. In this paper, landscape pattern and its evolution in northern China from 1989 to 2003 was investigated by the combined use of RS and GIS based on the basic theory and method of landscape ecology. Land use/cover maps of the study area in 1989, 1999 and 2003 were produced by using 1 km monthly NOAA Advanced Very High Resolution Radiometer (AVHRR) and SPOT/VGT Normalized Difference Vegetation Index (NDVI) dataset from national climate bureau of China which were geo-registered to Lambert azimuthal equal-area map projection and were used in the paper. Landscape evolution in the area over the study period was investigated by two methods: (a) the changes of various landscape metrics were analyzed using the landscape structure analysis program FRAGSTATS; (b) the transition matrix of landscape patch types was calculated with the help of the RS and GIS software. The results showed that from 1989 to 2003, the landscape within the study area had undertaken a complicated evolution in landscape structure and composition. The diversity index and evenness index increased during the period, which means that the landscape pattern tended to be diversified and even. The fragmentation index of grassland, forestland and water areas also increased significantly. This showed that the distribution and structure of forestland, grassland and water areas had been changed greatly during the period, especially grassland which became more and more fragmentized, and its fragmentation index increased from 19.23% to 88.72%. The transitions of the landscape types were mainly shown by the changes among forestland, grassland and farmland, and grassland changing into unable land. Over the study period, grassland and water areas had decreased remarkably, accounting for 15% and 37% from 1989 to 1999 and 24.79% and 49.25% from 1999 to 2003 respectively. The grassland and water resources play an important role in the eco-environment and economic development of the region. So, they must be protected carefully. According to the analysis, we can conclude that the eco-environment in the study area is obviously degenerated due to unreasonable human activities and climate changes and some measures should be taken to combat the environ-mental degradation.

Building Houses and Planting Vineyards: The Early Inner-Biblical Discourse on an Ancient Israelite Wartime Curse

(ProQuest: ... denotes non-USASCII text omitted.) Notions of building and planting have profound significance in the discourse of biblical literature. One important indication of this is the inner-biblical discourse of a wartime curse, which threatens Israel in the following words, "You will build a house, but you will not live in it. You will plant a vineyard, but you will not harvest its fruit" (Deut 28:30). A survey of biblical literature reveals that this particular curse held an especially prominent place in the discourse of ancient Israel and early Judaism.1 Over a dozen biblical texts contain formulations of, or allusions to, this particular curse and its imagery (Amos 5:11; 9:14; Isa 5:1-17; Zeph 1:13; Jer 6:9-15; 29:5,28; 31:4; Deut 20:5-6; 28:30; Isa 62:6-9; 65:21; Ezek 28:26; 36:36). The following study traces the origins and early inner-biblical discourse of the curse in the eighth and seventh centuries E.C.E.2 Placement of the early biblical occurrences of the curse against certain historical moments allows one to see the ways in which various historical processes influenced its different biblical formulations. A study of the historical motivations behind the curse's literary history also points to its attractiveness as a persistent motif in biblical literature. I. NEO-ASSYRIAN MILITARY TACTICS, SIEGE WARFARE, AND THE BACKGROUND OF THE CURSE IN BIBLICAL DISCOURSE Scholars have long noted that the threat of war forms the background of the present curse. It is during wartime that the fulfillment of one's labors, such as the harvesting of a vineyard, is thwarted. Assyrian textual and iconographie sources, however, suggest that a more specific, and interrelated, aspect of Assyrian siege warfare stands behind the curse's imagery. One of the major developments that accompanied the increasing Assyrian presence in the southern Levant during the eighth century was the rise of siege warfare as the dominant mode of battle.3 Assyrian sources indicate that siege warfare increasingly displaced open-field battles beginning in the eighth century. Assyrian iconography of this period increasingly depicts the Assyrians laying siege to a well-fortified city, as opposed to meeting an enemy in an open field. The advent of siege warfare brought with it new military tactics and battle techniques, many of which are alluded to in Assyrian and biblical sources. One of the most devastating military tactics that the Assyrians employed during a siege was the destruction of the agricultural support systems.4 Several Assyrian iconographie sources depict Assyrian soldiers chopping down trees, orchards, and other vegetation surrounding an enemy city. Such imagery is paralleled in the Assyrian textual sources, which often describe the king or the military destroying the vegetation of their enemies. For instance, in the Suhu annals of Shalmaneser III, the king boasts, "We will go and attack the houses of the land of Suhu; we will seize his cities of the steppe; and we will cut down their fruit trees."5 In the Nimrud Monolith, Shalmaneser also boasts, "Ahuni, son of Adini... I shut up in his city, carried off the crops of his (fields), cut down his orchards."6 Such descriptions of the destruction of orchards and other types of vegetation are found in many other Assyrian inscriptions. Scholars have long sought to understand the exact purpose behind the Assyrian destruction of agricultural support systems. Several studies have claimed that the destruction of trees and other vegetation enabled the Assyrians to build additional equipment during a prolonged siege.7 Other scholars have argued that the destruction of vegetation was a "face saving device employed in a report about an uncompleted siege."8 More recent studies, however, argue that a close examination of the order of events in the iconographie sources suggests an alternative explanation. These studies emphasize that the destruction of agricultural support systems in the iconographie sources always occurs during or directly after the successful destruction and looting of a city. …

Effects of Volcanic Eruptions on Environment and Health

Volcanoes pose a threat to almost half a billion people; today there are approximately 500 active volcanoes on Earth, and every year there are 10 to 40 volcanic eruptions. Volcanic eruptions produce hazardous effects for the environment, climate, and the health of the exposed persons, and are associated with the deterioration of social and economic conditions. Along with magma and steam (H2O), the following gases surface in the environment: carbon dioxide (CO2) and sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide (H2S), carbon sulphide (CS), carbon disulfide (CS2), hydrogen chloride (HCl), hydrogen (H2), methane (CH4), hydrogen fluoride (HF), hydrogen bromide (HBr) and various organic compounds, as well as heavy metals (mercury, lead, gold).Their unfavourable effects depend on the distance from a volcano, on magma viscosity, and on gas concentrations. The hazards closer to the volcano include pyroclastic flows, flows of mud, gases and steam, earthquakes, blasts of air, and tsunamis. Among the hazards in distant areas are the effects of toxic volcanic ashes and problems of the respiratory system, eyes and skin, as well as psychological effects, injuries, transport and communication problems, waste disposal and water supplies issues, collapse of buildings and power outage. Further effects are the deterioration of water quality, fewer periods of rain, crop damages, and the destruction of vegetation. During volcanic eruptions and their immediate aftermath, increased respiratory system morbidity has been observed as well as mortality among those affected by volcanic eruptions. Unfavourable health effects could partly be prevented by timely application of safety measures.

Performance of management strategies in the protection of riparian vegetation in three oregon cities

The destruction of riparian vegetation in urban areas signals the loss of valuable ecosystem services. This paper documents the extent of riparian vegetation loss during a period of rapid development (1990 – 2002) in three Oregon cities with distinctive, local management strategies. Findings show that loss has occurred in all three cities, but this loss has been curtailed by implementation of protective policies. Moreover, more than half the losses in each city were due to a few large development projects, rather than a large number of smaller ones. The paper concludes that management strategies do limit destructive actions by small projects and that large losses are potentially avoidable with targeted attention to large-scale projects.

Original and secondary high‐frequency sandstorm zones in the loess plateau region, china

.A study of sandstorms in the Loess Plateau and neighbouring areas is based on observations of sandstorms and precipitation. Through analysis of the relationship between the mean annual number of sandstorms and the mean annual precipitation, an original sandstorm zone and a secondary high‐frequency zone of sandstorms have been defined. The latter is mainly formed as a result of human activities, such as vegetation destruction and waste‐land cultivation, and not because of climatic change. The secondary sandstorm zone is located 350–500 km away from the original sandstorm zone, reflecting the fact that the sandstorm zone in the Loess Plateau area has shifted 350–500 km to the southeast, in response to human impact. Some abrupt change has been found in the area where the mean annual precipitation is 270 mm, where the original sandstorm zone ends and a secondary zone of high‐frequency sandstorms begins. This transition area can be regarded as an abnormally unstable area. This study shows that destruction of the vegetation can cause changes in the environment similar to those attributed to climatic change.

Degradation of an arid coastal landscape in relation to land use changes in Southern Tenerife (Canary Islands)

The results of the first study of land use changes between 1964 and 1992 in Southern Tenerife (Canary Islands) are presented and discussed in relation to the general socio-economic processes and the current nature conservation policy. The analysis of five main land use types with a geographic information system (GIS) revealed that the arid coastal landscape has been dramatically transformed during the past decades due to the increase of mass tourism and the intensification of agriculture, resulting in a large-scale destruction of the coastal scrub, the natural, endemic-rich vegetation. Between 1964 and 1992, the area occupied by irrigated crops increased strongly due to the transition from tomato to banana production. During the same period of time, the amount of abandoned farmland as well as the area used for housing and infrastructure increased markedly, the latter by more than 20 times. In nature reserves, most of the natural vegetation has survived but only in a degraded state, mainly due to recreation activities and illegal waste dumping. In unprotected areas, by contrast, 60% of the natural vegetation was lost between 1964 and 1992, and 86% of the native vegatation of recent lava flows. The results show that the current practice of protecting comparatively small natural areas is not sufficient to stop the massive destruction of natural vegetation. Surprisingly and disturbingly, there is evidence, that a substantial part (40%) of these losses could easily have been avoided by better environmental planning.

Stream Temperature Surges Under Urbanization and Climate Change: Data, Models, and Responses1

ABSTRACT: Multiple anthropogenic stressors, including increased watershed imperviousness, destruction of the riparian vegetation, increased siltation, and changes in climate, will impact streams over the coming century. These stressors will alter water temperature, thus influencing ecological processes and stream biota. Quantitative tools are needed to predict the magnitude and direction of altered thermal regimes. Here, empirical relationships were derived to complement a simple model of in‐stream temperature [developed by Caissie et al. Canadian Journal of Civil Engineering25 (1998) 250; Journal of Hydrology251 (2001) 14], including seasonal temperature shifts linked to land use, and temperature surges linked to localized rainstorms; surges in temperature averaged about 3.5°C and dissipated over about 3 h. These temperature surges occurred frequently at the most urbanized sites (up to 10% of summer days) and could briefly increase maximum temperature by >7°C. The combination of empirical relationships and model show that headwater streams may be more pervasively impacted by urbanization than by climate change, although the two stressors reinforce each other. A profound community shift, from common cold and coolwater species to some of the many warmwater species currently present in smaller numbers, may be expected, as shown by a count of days on which temperature exceeds the “good growth” range for coldwater species.

Muskrats ( Ondatra zibethicus) in treatment wetlands

Muskrat grazing can change treatment wetlands from being densely vegetated to a patchwork of open and emergent areas. Muskrats consume a portion of the annual net primary productivity, primarily rhizomes, but their mounds represent a greater share of this production. Densities of 20 or more animals per ha have been found, which can destroy the majority of the macrophyte standing crop in a given year. At such an exacerbated scale, muskrat herbivory may be termed as an “eatout,” and is evidenced by the removal of essentially all emergent plant parts. Destruction of the wetland vegetative infrastructure may create an attendant loss of some water quality functions, but may not harm others. The integrity of berms may be threatened by burrowing. Impacts on wetland hydraulics are also possible. In all cases, loss of the emergent vegetation has been viewed with dismay by owners, wetland practitioners, regulators and the general public. Several case histories are reviewed to illustrate the breadth and severity of muskrat damage. Muskrat control is given scant attention in existing treatment wetland literature, which provides very limited information on potential muskrat problems, or on the means to control them. Controls include trapping, shooting, poisoning, hazing, and exclusion in order to protect the wetland from excessive vegetation destruction by these rodents. This paper summarizes available muskrat controls, as well as their effectiveness. While many of these approaches have had a limited effect on deterring these industrious creatures, there are some methods that have proven to be effective over the long run, and should be considered in wetland design.

Bighorn Sheep Selection of Landscape Features in an Active Copper Mine

Bighorn sheep (Ovis canadensis) and Dall's sheep (O. dalli) use mining areas despite high human activity. We studied bighorn sheep selection of landscape features within a mine in a desert environment to determine those important for bighorn sheep and to enhance reclamation efforts of mines in desert environments. We collared and observed 8 male and 6 female bighorn sheep from December 2003 to January 2005 in the Silver Bell Mountains, Arizona, USA. We classified 13 unique features within a mine landscape based on topography, hydrology, and vegetation. Subadult male, adult male, and female bighorn sheep used desert islands (54, 76, and 54%, respectively) followed by highwalls (14, <10, and 11%, respectively). Subadult male, adult male, and female bighorn sheep selected for desert islands, and subadult males and females also selected for highwalls, whereas adult males did not. We did not observe bighorn sheep using leach ponds, pit bottoms, or tailings dumps. Bighorn sheep behavior while on desert islands was similar to behavior recorded when outside the mine perimeter. Subadult male and female bighorn sheep fed and were alert less and socially interacted more on highwalls than they did while outside the mine perimeter. Bighorn sheep in mines select areas similar to conspecifics outside of mined areas. In areas where mining and bighorn sheep are in proximity, mining engineers and wildlife biologists should work together to design reclamation plans that benefit bighorn sheep. In places where revegetation is difficult (i.e., deserts), mine engineers should design infrastructure (i.e., roadways, waste dumps, buildings) to minimize the unnecessary destruction of native slopes and vegetation.

Small mammals in a mosaic of forest remnants and anthropogenic habitats—evaluating matrix quality in an Atlantic forest landscape

The matrix of altered habitats that surrounds remnants in human dominated landscapes has been considered homogeneous and inhospitable. Recent studies, however, have shown the crucial role of the matrix in maintaining diversity in fragmented landscapes, acting as a mosaic of units with varying permeability to different species. Inclusion of matrix quality parameters is especially urgent in managing fragmented landscapes in the tropics where agriculture frontiers are still expanding. Using standardized surveys in 23 sites in an Atlantic forest landscape, we evaluated matrix use by small mammals, the most diverse ecological group of mammals in the Neotropics, and tested the hypothesis that endemic species are the most affected by the conversion of original forest into anthropogenic habitats. By comparing species distribution among forest remnants and the predominant adjacent habitats (native vegetation in initial stages of regeneration, eucalyptus plantations, areas of agriculture and rural areas with buildings), we found a strong dissimilarity in small mammal assemblages between native vegetation (including initial stages) and anthropogenic habitats, with only two species being able to use all habitats. Endemic small mammals tended to occupy native vegetation, whereas invading species from other countries or open biomes tended to occupy areas of non-native vegetation. Our results highlight that future destruction of native vegetation will favor invading or generalist species which could dominate highly disturbed landscapes, and that some matrix habitats, such as regenerating native vegetation, should be managed to increase connectivity among populations of endemic species.

Population recovery and spatial dynamics of colony recruitment in a harvester ant: a case study in a park

AbstractThe recovery process of Messor aciculatus (Fr. Smith) harvester ant colonies from habitat disturbance by construction work in an urban park was investigated from 1989 to 1994. Colonies located in 1989 were considered to be survivors of the disturbance, and colonies located for the first time after 1990 were considered to be recruits. The colonies continuously increased in number after the disturbance, and the population size more than doubled just after the disturbance. Analyses of the nest site distribution of colonies in 1989 and 1994 suggest that landform modification destroyed some of them, and that the changed nest site distribution in 1989 affected the distribution in 1994, or, in other words, the disturbance indirectly affected the nest distribution 5 years later. Analyses of the nearest neighbor to each colony suggested that established colonies would obstruct newly recruited colonies around their nests. Construction may open up space for recruitment colonization by removing established colonies, and may also create suitable conditions by destruction of original vegetation, or returning vegetation to the early stages of plant community succession. As a result, the disturbance may facilitate the subsequent recruitment of new colonies and rejuvenate the population.

Effect of Vegetation Changes on Soil Erosion on the Loess Plateau

Vegetation is one of the key factors affecting soil erosion on the Loess Plateau. The effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from long-term field runoff plots established on the eastern slope of the Ziwuling secondary forest region, China and a field survey. The results showed that before the secondary vegetation restoration period (before about 1866-1872), soil erosion in the Ziwuling region of the Loess Plateau was similar to the current erosion conditions in neighboring regions, where the soil erosion rate now is 8 000 to 10 000 t km(-2) year(-1). After the secondary vegetation restoration, soil erosion was very low; influences of rainfall and slope gradient on soil erosion were small; the vegetation effect on soil erosion was predominant; shallow gully and gully erosion ceased; and sediment deposition occurred in shallow gully and gully channels. In modern times when human activities destroyed secondary forests, soil erosion increased markedly, and erosion rates in the deforested lands reached 10 000 to 24 000 t km(-2) year(-1), which was 797 to 1682 times greater than those in the forested land prior to deforestation. Rainfall intensity and landform. greatly affected the soil erosion process after deforestation. These results showed that accelerated erosion caused by vegetation destruction played a key role in soil degradation and eco-environmental deterioration in deforested regions.

GIS and Remote Sensing Applications in the Assessment of Change within a Coastal Environment in the Niger Delta Region of Nigeria

In the last decades, the Niger Delta region has experienced rapid growth in population and economic activity with enormous benefits to the adjacent states and the entire Nigerian society. As the region embarks upon an unprecedented phase of economic expansion in the 21st century, it faces several environmental challenges fuelled partly by the pressures caused by human activities such as oil and gas exploration, housing development, and road construction for transportation, economic development and demographic changes. This continued growth has resulted in environmental problems such as coastal wetland loss, habitat degradation, and water pollution, gas flaring, destruction of forest vegetation as well as a host of other issues. This underscores the urgent need to design new approaches for managing remote costal resources in sensitive tropical environments effectively in order to maintain a balance between coastal resource conservation and rapid economic development in developing countries for sustainability. Notwithstanding previous initiatives, there have not been any major efforts in the literature to undertake a remote sensing and GIS based assessment of the growing incidence of environmental change within coastal zone environments of the study area. This project is an attempt to fill that void in the literature by exploring the applications of GIS and remote sensing in a tropical coastal zone environment with emphasis on the environmental impacts of development in the Niger Delta region of Southern Nigeria. To deal with some of the aforementioned issues, several research questions that are of great relevance to the paper have been posed. The questions include, Have there been any changes in the coastal environment of the study area? What are the impacts of the changes? What forces are responsible for the changes? Has there been any major framework in place to deal with the changes? The prime objective of the paper is to provide a novel approach for assessing the state of coastal environments while the second objective seeks a contribution to the literature. The third objective is to provide a decision support tool for coastal resource managers in the assessment of environmental impacts of development in tropical areas. The fourth objective is to assess the extent of change in a tropical ecosystem with the latest advances in geo-spatial information technologies and methods. In terms of methodology, the paper draws from primary and census data sources analyzed with descriptive statistics, GIS techniques and remote sensing. The sections in the paper consist of a review of the major environmental effects and factors associated with the problem: initiatives and mitigation measures. The project offers some recommendations as part of the conservation strategies. In spite of concerted efforts by managers to address the problems, results revel that the study area experienced some significant changes in its coastal environments. These changes are attributed to socio-economic and environmental variables.

The land reclamation and its influence on environment in West Liaohe Basin from 1902 to 1990

West Liaohe Basin is one of the key regions in the West development strategies implemented by the Chinese Government,and its eco-environment is vulnerable.Study on land reclamation and its influence on environment is the only way to explore the cause of land desertification and seek for the proper pattern of land use. (1)This paper examines changes of the land reclamation in West Liaohe Basin in about 100 years(1902-1990).At the end of the Qing Dynasty,it had no land to open up in the south of West Liaohe,but areas of plowland got increased in counties and Qis(banners) in the north of West Liaohe.In the period of Republic of China,much plowland was turned into wasteland in the south of West Liaohe,but in the north of West Liaohe,a great amount of grassland was developed into arable land.After liberation(1949),because of unreasonable land policies,all grassland was almost opened up completely. (2)Above all,natural environment in West Liaohe Basin has been greatly influenced.First,vegetation was destroyed,so the virgin forest of the Qing Dynasty now becomes the secondary forest dominately composed of mountain polar and white pirch,and the thick forest gets the thin one.Secondly,wild animals lost their natural living environment owing to vegetation destruction,so small animals such as rabbits,pheasants,crows,pied magpies and so on,now become rarer and rarer besides of macro-animals being extinct. (3)Soil erosion happened in the Qing Dynasty,lately reclamation took place at a large scale at the end of the Qing Dynasty,much plowland changed into wasteland in Republic of China,and extensive reclamation after liberation makes it on the rise.