Wildfire seasonality and land use: when do wildfires prefer to burn?

Because of the increasing anthropogenic fire activity, understanding the role of land-use in shaping wildfire regimes has become a major concern. In the last decade, an increasing number of studies have been carried out on the relationship between land-use and wildfire patterns, in order to identify land-use types where fire behaves selectively, showing a marked preference (or avoidance) in terms of fire incidence. By contrast, the temporal aspects of the relationship between landuse types and wildfire occurrence have received far less attention. The aim of this paper is, thus, to analyze the temporal patterns of fire occurrence in Sardinia (Italy) during the period 2000–2006 to identify land-use types where wildfires occur earlier or later than expected from a random null model. The study highlighted a close relationship between the timing of fire occurrence and land-cover that is primarily governed by two complementary processes: climatic factors that act indirectly on the timing of wildfires determining the spatial distribution of land-use types, and human population and human pressure that directly influence fire ignition. From a practical viewpoint, understanding the temporal trends of wildfires within the different land-use classes can be an effective decision-support tool for fire agencies in managing fire risk and for producing provisional models of fire behavior under changing climatic scenarios and evolving landscapes.     

Impact of urbanization on natural ecosystem service values: a comparative study

With rapid population growth and rural to-urban migration in many Chinese cities, a large amount of natural lands have been converted to urban and agricultural lands recently. During this process of land conversion, economic development and quality of life improvement are considered as major goals, and their influences on ecological systems have often been neglected. The degradation of natural ecological systems due to land use change, however, has become severe,and may require immediate attentions from urban planners and local governments. Taking HaDaQi industrial corridor, Heilongjiang Province, China,as a case study area, this paper examined the trend of land use changes during 1990–2005, and quantified their influences on natural eco system service values. In particular, this study applied two major valuation methods, and examined whether different valuation methods generate significantly different results. Analysis of results suggests that human dominated land uses (e.g., urban and agriculture)have expanded rapidly at the cost of natural lands (e.g., wetlands and forest). Due to these land use changes, the total ecosystem service value decreased 29% (2.26% annually) from 1990 to 2005 when the first method was applied, and this rate is estimated to be 15.7% (1.13% annually)with the second approach. Moreover, the annual rate of ecosystem service value decline during 2000–2005 is about four times higher than that in 1990–2000 with both methods, suggesting much more severe ecosystem degradation during 2000–2005.     

Variations of measured and simulated soil-loss amounts in a semiarid area in Turkey

The main goal of this research was soil-loss determination and comparison of the plot measurement results with simulation model (universal soil loss equation (USLE)) results in different land use and slope classes. The research took place in three different land-use types (Scotch pine forest, pasture land, and agricultural land) and in two different slope classes (15–20%, 35–40%). Within six measurement stations (for each land-use type and slope class-one station), totally 18 measurement plots have been constituted, and soil-loss amount measurements have been investigated during the research period (3 years along). USLE simulation model is used in these measurement plots for calculation the soil-loss amounts. The results pointed out that measured (in plots) and simulated (with USLE) soil-loss amounts differ significantly in each land-use type and slope class.     

阿图什市"十五"期间土地利用变化及分析

利用2001-2005年的遥感影像数据(覆盖范围主要是克孜勒苏柯尔克孜自治州行政辖区内的阿图什市),通过统计2001-2005 年土地利用数据,分析了该市近五年土地利用/覆盖的时空变化规律,并进而探究了导致该变化发生的自然、人文驱动因素.结果表明:在2001-2005年,该区域林地和草地面积增加,耕地面积减少,土地沙化和盐碱化现象得到遏制.探其原因主要是由社会、经济等人文因素造成,而包括气候波动在内的自然条件只是土地利用变化的背景条件.     

Evaluating climate change effects on water and salt resources in Salt Lake, Turkey using multitemporal SPOT imagery

The main goal of this study is to investigate the dimension of climate change effects in Salt Lake and its vicinity in Turkey using satellite remote sensing data. The first stage of the study includes evaluation of the multitemporal climatic data on the Salt Lake Basin Area, Turkey for a period of 35 years (1970–2005). The changes in mean temperature and precipitation are evaluated for the study area by comparing two periods, 1970–1992 and 1993–2005. In the second stage, the effects of climate changes in the Salt Lake are investigated by evaluating water and salt reserve changes through seasonal and multitemporal SPOT imagery collected in 1987 and 2005. The climatic data and remotely sensed and treated satellite images show that water and salt reserve in Salt Lake has decreased between 1987 and 2005 due to drought and uncontrolled water usage. It is suggested that the use of water supplies, especially underground waters, around the Salt Lake should be controlled and the lake should regularly be monitored by current remote sensing data for an effective management of water and salt resources in the region.     

How Do River Nitrate Concentrations Respond to Changes in Land-use? A Modelling Case Study of Headwaters in the River Derwent Catchment,North Yorkshire,UK

A combined semi-distributed hydrological model (CASCADE/QUESTOR) is used to evaluate the steady-state that may be achieved after changes in land-use or management and to explore what additional factors need to be considered in representing catchment processes. Two rural headwater catchments of the River Derwent (North Yorkshire, UK) were studied where significant change in land-use occurred in the 1990s and the early 2000s. Much larger increases in mean nitrate concentration (55%) were observed in the catchment with significant groundwater influence (Pickering Beck) compared with the surface water-dominated catchment (13% increase). The increases in Pickering Beck were considerably greater than could be explained by the model in terms of land-use change. Consequently, the study serves to focus attention on the long-term increases in nitrate concentration reported in major UK aquifers and the ongoing and chronic impact this trend is likely to be having on surface water concentrations. For river environments, where groundwater is a source, such trends will mask the impact of measures proposed to reduce the risk of nitrate leaching from agricultural land. Model estimates of within-channel losses account for 15–40% of nitrate entering rivers.     

Dynamics of the lakes in the middle and lower reaches of the Yangtze River basin, China, since late nineteenth century

The middle and lower reaches of the Yangtze River basin have the most representative and largest concentration of freshwater lakes in China. However, the size and number of these lakes have changed considerably over the past century due to the natural and anthropogenic impact. The lakes, larger than 10 km² in size, were chosen from relief maps and remotely sensed images in 1875, 1950, 1970, 1990, 2000, and 2008 to study the dynamics of lakes in the middle and lower reaches of the Yangtze River basin and to examine the causes and consequences of these changes. Results indicated that there was a dramatic reduction in lake areas, which decreased by 7,841.2 km² (42.64 %) during the study period (1875–2008), and the number of lakes in this region changed moderately. Meanwhile, a large number of lakes in the middle and lower reaches of the Yangtze River basin were directly converted into paddy fields, ponds, building lands, or other land-use types over the study period. Therefore, all kinds of lake reclamation should be identified as the major driving factors for the loss of lake in this region. Furthermore, flooding, soil erosion, and sedimentation were also the main factors which triggered lake changes in different periods. Some wetland conservation and restoration projects have been implemented since the 1970s, but they have not reversed the lake degradation. These findings were of great importance to managers involved in making policy for the conservation of lake ecosystems and the utilization of lake resources.     

Land use and land cover (LULC) of the Republic of the Maldives: first national map and LULC change analysis using remote-sensing data

The Maldives islands in recent decades have experienced dramatic land-use change. Uninhabited islands were turned into new resort islands; evergreen tropical forests were cut, to be replaced by fields and new built-up areas. All these changes happened without a proper monitoring and urban planning strategy from the Maldivian government due to the lack of national land-use and land-cover (LULC) data. This study aimed to realize the first land-use map of the entire Maldives archipelago and to detect land-use and land-cover change (LULCC) using high-resolution satellite images and socioeconomic data. Due to the peculiar geographic and environmental features of the archipelago, the land-use map was obtained by visual interpretation and manual digitization of land-use patches. The images used, dated 2011, were obtained from Digital Globe’s WorldView 1 and WorldView 2 satellites. Nine land-use classes and 18 subclasses were identified and mapped. During a field survey, ground control points were collected to test the geographic and thematic accuracy of the land-use map. The final product’s overall accuracy was 85%. Once the accuracy of the map had been checked, LULCC maps were created using images from the early 2000s derived from Google Earth historical imagery. Post-classification comparison of the classified maps showed that growth of built-up and agricultural areas resulted in decreases in forest land and shrubland. The LULCC maps also revealed an increase in land reclamation inside lagoons near inhabited islands, resulting in environmental impacts on fragile reef habitat. The LULC map of the Republic of the Maldives produced in this study can be used by government authorities to make sustainable land-use planning decisions and to provide better management of land use and land cover.     

Using exploratory regression to identify optimal driving factors for cellular automaton modeling of land use change

Defining transition rules is an important issue in cellular automaton (CA)-based land use modeling because these models incorporate highly correlated driving factors. Multicollinearity among correlated driving factors may produce negative effects that must be eliminated from the modeling. Using exploratory regression under pre-defined criteria, we identified all possible combinations of factors from the candidate factors affecting land use change. Three combinations that incorporate five driving factors meeting pre-defined criteria were assessed. With the selected combinations of factors, three logistic regression-based CA models were built to simulate dynamic land use change in Shanghai, China, from 2000 to 2015. For comparative purposes, a CA model with all candidate factors was also applied to simulate the land use change. Simulations using three CA models with multicollinearity eliminated performed better (with accuracy improvements about 3.6%) than the model incorporating all candidate factors. Our results showed that not all candidate factors are necessary for accurate CA modeling and the simulations were not sensitive to changes in statistically non-significant driving factors. We conclude that exploratory regression is an effective method to search for the optimal combinations of driving factors, leading to better land use change models that are devoid of multicollinearity. We suggest identification of dominant factors and elimination of multicollinearity before building land change models, making it possible to simulate more realistic outcomes.     

Oasis land-use change and its effects on the eco-environment in Yanqi Basin, Xinjiang, China

Satellite data and the published coefficients about the world's and China's ecosystem were used to analyze the effects of land-use changes on the ecosystem service in the Yanqi Basin. Both economic developments and arid, fragile ecosystems have strongly affected the land use. A sensitivity analysis determined the effect of manipulating the coefficients on the estimated values. Results indicated that (1) the total value of ecosystem services in the Yanqi Basin were 9,374.66, 10,450.52, 9,964.20, and 9,8707.77 million Yuan in 1990, 2000, 2005, and 2011, respectively. The net increase in ecosystem service values were about 496.11 million Yuan within 1990–2011; (2) The aggregated ecosystem service values of water body, wetlands, grasslands, and croplands were about 99.25 % of the total value; (3) Waste treatment and soil formation were the top two ecological functions with high service values and contributing about 61.70 % of the total service values; and (4) Ecosystem service values estimated in this study were inelastic with respect to the value coefficients; therefore, the estimation was robust in spite of uncertainties on the value coefficients. A reasonable land-use plan should be based on rigorous environmental impact analyses for maintaining stability and sustainable development of the Yanqi Basin.     

Development and Application of Urban High Temporal-Spatial Resolution Vehicle Emission Inventory Model and Decision Support System

This paper reports on the development and application of an urban high temporal-spatial resolution vehicle emission inventory model and decision support system based on the current situation in China and actual vehicle emission control requirements. The system incorporates a user-friendly modular architecture that integrates a vehicle emission model and a decision support platform and includes scenario analysis and visualisation capabilities. A bottom-up approach based on localised emission factors and actual on-road driving condition has been adopted to develop the system. As a case study of application and evaluation, an emission reduction effect analysis of the supposed low-emission zone (LEZ) policy in Beijing (2012) was conducted. According to the simulated results in the forms of tables, histograms and grid maps, the establishment of this LEZ had a definite effect on the emission reduction of various types of air pollutants, especially carbon monoxide and hydrocarbon. In the system, the simulation methodology for identifying environmental benefits brought by the LEZ policy could be used to assess other similar environmental policies. Through flexible modification of configuration values or input data variables, the efficacy of separate or joint policies could be quantifiably evaluated and graphically displayed.     

Use of a non-planning driving background change methodology to assess the land-use planning impact on the environment

The implementation of land-use planning (LUP) impacts on the environment and may degrade regional environmental quality due to the changes in land-use patterns. To minimize the environmental impact of non-LUP driven (NPD) land-use background changes (LUBC), we propose an NPD land-use background change (NPD-LUBC) methodology to improve the LUP environmental impact assessment (LUPEA) process. With the application of the state-impact-state (SIS) framework and spatial information technologies including remote sensing and geographic information system (GIS), the methodology was tested on the eastern Chinese city of Lianyungang. The results indicate that (1) our proposed methodology is capable of distinguishing the environmental impact in implementing a target LUP, i.e. a LUP scheme to be assessed, from those driven by NPD-LUBC; (2) the prediction of NPD Land-use pattern simulated through the discrimination of NPD forces provides the basic data to support the LUPEA using our proposed methodology; (3) SO₂, PM₁₀, and COD emitted into the atmosphere and water are the major pollutants considered in the LUPEA of the city; and (4) despite the positive impacts of the comprehensive land-use change under the direction of target LUP, the implementation of LUP would have negative impacts on the regional environment in the entire study area and in individual counties/districts respectively in 2020. Our proposed methodology provides a new and operable way for the areas with data to simulate NPD land-use pattern and predict the individual indicator values for the assessment.     

2001-2005年新疆植被覆盖动态变化及原因分析

利用2001-2005年新疆归一化植被指数NDVI,得出该时间段新疆植被覆盖整体呈增加趋势,但局部有退化现象.对2001 - 2005年植被覆盖变化原因进行了分析,阐明降水是新疆植被覆盖变化的主要驱动因子之一.     

Estimation of late twentieth century land-cover change in California

We present the first comprehensive multi-temporal analysis of land-cover change for California across its major ecological regions and primary land-cover types. Recently completed satellite-based estimates of land-cover and land-use change information for large portions of the United States allow for consistent measurement and comparison across heterogeneous landscapes. Landsat data were employed within a pure-panel stratified one-stage cluster sample to estimate and characterize land-cover change for 1973?C2000. Results indicate anthropogenic and natural disturbances, such as forest cutting and fire, were the dominant changes, followed by large fluctuations between agriculture and rangelands. Contrary to common perception, agriculture remained relatively stable over the 27-year period with an estimated loss of 1.0% of agricultural land. The largest net declines occurred in the grasslands/shrubs class at 5,131 km² and forest class at 4,722 km². Developed lands increased by 37.6%, composing an estimated 4.2% of the state??s land cover by 2000.     

新安江水库透明度与叶绿素a浓度反演模式初步研究

新安江水库有完整监测数据记录开始于1985年,但2001年后才有浮游植物密度和叶绿素a数据。文章利用2001—2009年透明度和叶绿素a监测数据,采用SPSS统计软件拟合回归方程,再根据2001年以前的透明度数据,反演相对应的新安江水库浮游植物叶绿素a浓度。结果表明,新安江水库1988、1990年浮游植物生物量较低,而1993、1996、2009年浮游植物生物量分别出现峰值,2000年以前浮游植物生物量波动剧烈,2000年以后基本呈上升趋势,特别是2005年以后上升趋势非常明显。     

Did the ecological engineering have a great impact on the land use change?

Overuse of land resources has increasingly contributed to environmental crises in China. To mitigate widespread land degradation, actions have been taken to maintain and restore the ecological environment through efforts such as ecological engineering. By analyzing trends in land use, the impact and effectiveness of ecological engineering can be determined. In this study, such changes in Huanjiang County in China were considered. In the early 1990s, an eco-immigration policy and “returning farmland to forest program” were implemented in the county, drastically impacting land use. Land use/land cover changes were detected and analyzed using remote sensing data recorded over 4 years (1995, 2000, 2005, and 2010). Land transfer flow and the rate of land use change elucidated the extent of changes, while nuclear density analysis indicated spatial agglomeration. The results indicate that, over a period of 15 years, farmland area increased, while forest area decreased initially before subsequently increasing. From 1995 to 2000, the highest transfer flow was observed in the grassland to farmland conversion (79.34%). From 2000 to 2005, the transfer flow of conversions was the highest for forest to farmland (56.79%). Land use changes were not prominent from 2005 to 2010. Direct drivers of land use change exert obvious impacts on land use, and indirect drivers impact direct drivers that are then channeled through direct anthropogenic drivers (e.g., land use policies). We found that ecological engineering has a very significant impact on land use change, and that impact varies from region to region.     

新疆伊犁州2000～2005年生态环境质量变化评价与分析

利用Landsat-5 TM遥感影像解译的土地利用数据分析了新疆伊犁州(州直辖)2000～2005年的土地利用变化,同时根据<生态环境状况评价技术规范>(试行)(HJ/T192-2006),对该区域生态环境质量状况进行综合评价,对生态环境指标变化情况进行对比分析.结果表明,2000～2005年伊犁州的生态环境质量均为一般,生态环境质量指数(E1)减少0.71.主要原因为草地面积明显减少,耕地面积明显增加.     

Comparison of fecal coliform bacteria before and after wastewater treatment plant in the Izmir Bay (Eastern Aegean Sea)

The distribution of fecal coliforms was investigated and determined in Izmir Bay from 1996 to 2005. Izmir Bay severely was polluted from industrial and domestic discharges during decades. In early 2000, a wastewater treatment plant began to treat domestic and industrial wastes. This plant treats the wastes about 80% capacity after 2001. The sampling periods cover before and after treatment plant. Assessment method for determining the number of fecal coliform has evolved membrane filtrations. Maximum surface fecal coliform concentration was 4.9 × 10⁵ cfu 100 ml^???1 in 1996–2000 period. Following the opening treatment system, fecal coliform density decreased 2.1 × 10⁴ cfu 100 ml^???1 during 2001–2005. A continuous improvement can be sustained in the water quality if direct inflow of untreated wastewater is prevented.     

Assessing the impact of alternative land-use zoning policies on future ecosystem services

Land use conversions rank among the most significant drivers of change in ecosystem services worldwide, affecting human wellbeing and threatening the survival of other species. Hence, predicting the effects of land use decisions on ecosystem services has emerged as a crucial need in spatial planning, and in the associated Strategic Environmental Assessment (SEA) practice. The paper presents a case-study research aimed at empirically exploring how the implementation of different land-use zoning policies affect the future provision of a set of ecosystem services (water purification, soil conservation, habitat for species, carbon sequestration and timber production). The study area is located in The Araucanía, one of Chile's Administrative Regions. The first part of the methods consisted in the construction of land-use scenarios associated to different policies. Subsequently, the effects of the land-use scenarios on the provision of the selected ecosystem services were assessed in a spatially explicit way, by using modeling tools. Finally, a set of metrics was developed to compare scenarios, and trade-offs in the provision of different ecosystem services were made explicit through trade-off curves. The results indicate that, for this case study, spatial configuration of land uses is as an important factor as their size. This suggests that the analysis of land-use patterns deserves attention, and that this information should be included in scenario exercises aimed to support spatial planning. The paper concludes by discussing the potential contribution of the approach to support SEA of spatial plans.     

Spatio-temporal pattern and rationality of land reclamation and cropland abandonment in mid-eastern Inner Mongolia of China in 1990�C2005

The Mid-eastern Inner Mongolia of China, a typical agro-pastoral transitional zone, has undergone rapid agricultural land use changes including land reclamation and cropland abandonment in past decades due to growing population and food demand, climatic variability, and land use policy such as the "Grain for Green" Project (GFG Project). It is significant to the regional ecology and sustainability to examine the pattern and its rationality of land use change. The processes of land reclamation and cropland abandonment were accessed by using land use change dataset for four periods of 1990, 1995, 2000, and 2005, derived from the interpretation of Landsat TM images. And then the rationality of land reclamation and cropland abandonment was analyzed based on the habitat suitability for cultivation. The results indicated that: (1) land reclamation was the dominant form of agricultural land use change from 1990 to 2005, the total cropland area increased from 64,954.64 km(2) in 1990 to 76,258.51 km(2) in 2005; However, the speed of land reclamation decreased while cropland abandonment increased around 2000. The Land Reclamation Degree decreased from 1995-2000 to 2000-2005, meanwhile, Cropland Abandonment Degree increased. (2) As for the habitat suitability levels, moderately and marginally suitable levels had largest areas where cropland was widespread. Pattern of agricultural land use trended to become more rational due to the decrease of land reclamation area in low suitable levels and the increase of cropland abandonment in unsuitable area after 2000. (3) The habitat suitability-based rationality analysis of agricultural land use implicated that the GFG Project should take cultivation habitat suitability assessment into account.