Effects Of Land Cover Types Research Articles

Evaluation of GPM IMERG Early, Late, and Final Run in Representing Extreme Rainfall Indices in Southwestern Iran

The growing concerns about floods have highlighted the need for accurate and detailed precipitation data as extreme precipitation occurrences can lead to catastrophic floods, resulting in significant economic losses and casualties. Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM IMERG) is a commonly used high-resolution gridded precipitation dataset and is recognized as trustworthy alternative sources of precipitation data. The aim of this study is to comprehensively evaluate the performance of GPM IMERG Early (IMERG-E), Late (IMERG-L), and Final Run (IMERG-F) in precipitation estimation and their capability in detecting extreme rainfall indices over southwestern Iran during 2001–2020. The Asfezari gridded precipitation data, which are developed using a dense of ground-based observation, were utilized as the reference dataset. The findings indicate that IMERG-F performs reasonably well in capturing many extreme precipitation events (defined by various indices). All three products showed a better performance in capturing fixed and non-threshold precipitation indices across the study region. The findings also revealed that both IMERG-E and IMERG-L have problems in rainfall estimation over elevated areas showing values of overestimations. Examining the effect of land cover type on the accuracy of the precipitation products suggests that both IMERG-E and IMERG-L show large and highly unrealistic overestimations over inland water bodies and permanent wetlands. The results of the current study highlight the potential of IMERG-F as a valuable source of data for precipitation monitoring in the region.

Estimation of PM2.5 concentrations in North China with high spatiotemporal resolution using the ERA5 dataset and machine learning models

Previous studies have predominantly focused on developing high spatiotemporal resolution PM2.5 models utilizing moderate-resolution imaging spectroradiometer (MODIS) aerosol optical depth (AOD) products alongside certain meteorological factors. However, MODIS AOD is not continuous, and there is a problem of missing data, which is not conducive to the study of PM2.5 in areas without AOD. This study proposes a new method for estimating PM2.5 concentration in North China, which not only simplifies the complex process associated with the use of AOD, but also partially solves the issue of missing AOD data. This study proposes a machine learning (random forest, RF; back propagation neural network, BPNN) based method for estimating PM2.5 using meteorological parameters obtained from the fifth-generation reanalysis (ERA5) dataset released by the European Centre for Medium-Range Weather Forecasts and considering the effects of land cover type, digital elevation model, vegetation index and population data. The model performed well, with 10-fold cross-validation (coefficient of determination) R2 and (root-mean-square error) RMSE of 0.79/0.95 and 26.10/13.22 µg/m3, respectively, for BPNN and RF. The estimated hourly performance of the RF model in winter (00:00 to 23:00 BST) with an R2 ranging from 0.92 to 0.96, an RMSE of 11.45 to 16.70 µg/m3. RF model with the best performance and ERA5 were selected to build a high-resolution (0.25°×0.25°) hourly PM2.5 map (PMM), and the PMM was compared with CHAP, with R2 and RMSE of 0.75 and 20.62 µg/m3, respectively. This study further investigates the impacts of land cover types, digital elevation model, and land surface characteristics on the spatial distribution of PM2.5 in North China.

Microclimate Impacts of Land Cover Types in Halu Oleo University Botanical Garden and Its Surroundings

Halu Oleo University (UHO) Botanical Garden is one of the green open spaces that contribute to maintaining climate stability and environmental comfort in Kendari City, along with the high land use change due to increased population and city progress. The study aimed to determine the effect of land cover types on microclimate in UHO Botanical Garden and its surroundings. The research was conducted from June 2021 to January 2022. The research was conducted on three types of vegetation land cover. The variables measured were microclimate, including light intensity, temperature, relative humidity, and temperature humidity index. Measurements were conducted in the morning, afternoon, and evening. The method used was descriptive quantitative and statistical analysis using the analysis of variance and the least significant difference (LSD) test. The results showed that the microclimatic conditions of UHO Botanical Garden in tree-dominant land cover are more comfortable and significantly different from grass-dominant and settlement-dominant, but they are not significantly different between grass-dominant and settlement-dominant. This fact indicates the importance of the conservation of tree vegetation and the need for supervision so that there is no diversion of functions into settlements to maintain the preservation and sustainability of UHO Botanical Garden as one of the green open spaces that control climate stability and environmental comfort in Kendari City. Keywords: botanical garden, microclimate, settlement, temperature humidity index, vegetation

Effects of Land Cover on the Taxonomic and Functional Diversity of the Bird Communities on an Urban Subtropical Mountain

Mountain ecosystems are crucial for global biodiversity conservation. However, their landscape features are constantly changing owing to urban expansion. Understanding the relationships between biotic communities and landscape features is essential for biodiversity conservation. This study aimed to examine the effect of land cover type on avian communities in Lishui, a mountainous urban area in eastern China. Avian surveys were conducted using 168 line transects in total across different land cover types once per season from December 2019 to January 2021. We assessed the diversity of bird communities by calculating various metrics at both taxonomic and functional levels. Among the land cover types measured, woodland, built-up land, cultivated land, and water bodies significantly influenced bird community diversity and composition. Species richness, species abundance, and functional richness were negatively correlated with the proportion of woodland but were positively correlated with the proportion of non-natural land cover, such as built-up and cultivated land. In contrast, functional evenness was positively correlated with the proportion of woodland and grassland but negatively correlated with the proportion of non-natural land cover. Land cover type also exhibited significant correlations with avian functional characteristics such as diet, foraging strata, and body mass, thereby influencing the overall community structure. Our results indicated that mountainous landscape patterns substantially affect avian communities. Different land cover types possess varying resource endowments that affect the distribution of avian species. Therefore, urban landscape planning in mountainous areas should carefully consider the various functions provided to organisms by different types of land cover to promote biodiversity.

Estimated effects of clear-cuts and burns associated with habitat use by female Newfoundland Caribou (<i>Rangifer tarandus</i>)

The decline of Caribou (Rangifer tarandus) is mainly attributed to anthropogenic disturbance from resource development (i.e., logging, oil and gas extraction), which causes habitat loss and increased predation risk. Natural landscape disturbance, particularly from fire, can have similar effects, and cumulative effects from disturbance have been associated with lower neonate recruitment. Our objective was to evaluate the potential effects of land cover types on resource selection by females, with an emphasis on clear-cuts and fire, during the calving season (May–June) in three neighbouring herds (Middle Ridge, Gaff Topsails, and Pot Hill) on insular Newfoundland, Canada, and compare results with pre-existing information on calf recruitment. We applied a resource selection framework to analyze location data collected from global positioning system collars between 2007–2010 and estimate relative probability of use for different cover types. Recruitment was lowest in Pot Hill, where ≤10-year old clear-cuts were favoured, whereas recruitment was highest in Middle Ridge and Gaff Topsails, where females favoured burns, suggesting that burns could be more beneficial to Caribou fitness. Further investigation will be needed to more closely examine how anthropogenic versus natural disturbance affects Caribou fitness in Newfoundland and improve our understanding of important habitat for calving females.

Landscape characteristics and predation risk influence spatial variation in auditory courtship of an upland game bird

ContextNumerous wildlife species use a polygynous mating system, where males use auditory courtship behaviors to secure breeding opportunities. The acoustic adaptation hypothesis, risk reward, and landscape of fear theories suggest spatial variation in male auditory courtship will be influenced by areas in landscapes where sound transmission is increased, and predation risk is reduced. However, it is often unclear what landscape features drive spatial variation in courtship behaviors.ObjectivesWe quantified the influence of predation risk, land cover type, and resource selection on spatial trends in the auditory courtship behavior (gobbling activity) of Eastern wild turkeys (Meleagris gallopavo silvestris).MethodsWe used 53,025 gobbles coupled with GPS locations from 111 turkeys and 36 coyotes (Canis latrans), and distance metrics associated with hunter activity and land cover type, to investigate influences of predation risk, resource selection, and land cover type on spatial variation in gobbling activity in Georgia, USA.ResultsDistance to public access during hunting was the most influential predictor of gobbling activity, wherein the expected number of daily gobbles increased by 40% for every 500 m farther from public access. Daily gobbles decreased by 22% for every 500 m farther away from private property during hunting. We failed to find significant effects of land cover type and coyote use but found limited evidence that areas with increased predicted probability of turkey use was associated with increased gobbling.ConclusionsPredation risk associated with increased anthropogenic disturbance had the greatest influence on gobbling activity. Our findings suggest that altering hunter access by closing roads to vehicle use, reducing hunter activity, or creating refuge areas on the landscape could positively influence gobbling activity.

Amphibian richness along modified riparian areas of central Mexico: conservation priorities

BackgroundLand-use change frequently affects faunistic populations and communities. To achieve successful conservation strategies, we need suitable information about species distribution and the causes of extinction risk. Many amphibian species depend on riparian vegetation to complete their life cycles. About 41% of amphibian species are globally threatened, and accurate estimations of population size, species richness and the identification of critical habitats are urgently needed worldwide. To evaluate the magnitude of changes in species richness and demography, estimations that include detection probability are necessary. In this study, we employed multi-species occupancy models to estimate detection probability and the effect of land cover type (i.e., cropland, artificial pasture, secondary and mature forest) in a 500-m radius on the occupancy probability and richness of diurnal amphibians in 60 riparian zones in the state of Michoacán in central Mexico. Furthermore, we evaluated the potential of the endemic salamander Ambystoma ordinarium as a flagship species for the conservation of other native amphibian species.ResultsWe registered a total of 20 amphibian species in the diurnal assemblage, of which 10 species are considered at risk of extinction. We found that cropland was the most important land-use type for explaining amphibian distribution in riparian zones, with negative effects on most amphibian species. We found no differences in species richness between zones with and without A. ordinarium. In riparian zones occupied by A. ordinarium, however, we found a higher number of species at risk of extinction.ConclusionsOur findings showed negative effects of croplands on the distribution of most amphibian species. The riparian zones are important for the maintenance of native diurnal amphibian communities and A. ordinarium can act as a flagship species for the conservation of threatened amphibian species.

The Response of Land Surface Temperature Changes to the Vegetation Dynamics in the Yangtze River Basin

Land surface temperature (LST) is a key parameter in the study of surface energy balance and climate change from local through to global scales. Vegetation has inevitably influenced the LST by changing the surface properties. However, the thermal environment pattern in the Yangtze River Basin (YRB) still remains unclear after the implementation of large-scale ecological restoration projects. In this study, the temporal and spatial variation characteristics of LST were analyzed based on the Theil–Sen estimator, Mann–Kendall trend analysis and Hurst exponent from 2003 to 2021. The relationships between vegetation and LST were further revealed by using correlation analysis and trajectory-based analysis. The results showed that the interannual LST was in a state of fluctuation and rise, and the increasing rate at night time (0.035 °C·yr−1) was faster than that at day time (0.007 °C·yr−1). An obvious cooling trend could be identified from 2007 to 2012, followed by a rapid warming. Seasonally, the warming speed was the fastest in summer and the slowest in autumn. Additionally, it was found that autumn LST had a downward trend of 0.073 °C·yr−1 after 2015. Spatially, the Yangtze River Delta, Hubei province, and central Sichuan province had a significant warming trend in all seasons, except autumn. The northern Guizhou province and Chongqing showed a remarkable cooling trend only in autumn. The Hurst exponent results indicated that the spring LST change was more consistent than the other three seasons. It was found by studying the effect of land cover types on LST changes that sparse vegetation had a more significant effect than dense vegetation. Vegetation greening contributed 0.0187 °C·yr−1 to the increase in LST in winter, which was spatially concentrated in the central region of the YRB. For the other three seasons, vegetation greening slowed the LST increase, and the degree of the effect decreased sequentially in autumn, summer, spring and winter. These results improve the understanding of past and future variations in LST and highlight the importance of vegetation for temperature change mitigation.

Climate, habitat interactions, and mule deer resource selection on winter landscapes

AbstractMule deer (Odocoileus hemionus) are a valued game species across their range in North America. At higher latitudes mule deer inhabit the Northern Forests ecoregion, where the winter season poses challenging conditions. We studied resource selection during winter by mule deer in northwest Montana, USA, focused on the effects of snow and canopy cover on deer behavior. Specifically, we assessed the effects of land cover type, terrain characteristics, snow accumulation, percent canopy cover, solar radiation, and forage biomass on resource selection by 126 mule deer captured during 2017–2019 in 3 partially migratory subpopulations. We collected pellet samples and conducted diet analyses to assess forage species by individual and study area. Deer displayed a shift from nitrogen‐rich forbs and shrubs in summer to nutrient‐poor evergreens like conifers in winter. Deer avoided areas with deeper snow and sought more closed canopy forests for their snow‐intercept advantages. Weather and vegetative variation among and within study areas resulted in disparities in selection for attributes such as land cover. Similarly, mule deer diets varied spatiotemporally as a function of snow, with some deer favoring coniferous species in deep snow, whereas others less constrained by snow had more diverse diets with more shrub species. Additional analyses revealed annual individual survival correlated with changes in snow depth, suggesting fitness consequences as snow accumulated. These differences suggest locally adapted behaviors as mule deer reflect energetic constraints of winter landscapes.

Retrieval of Fractional Snow Cover over High Mountain Asia Using 1 km and 5 km AVHRR/2 with Simulated Mid-Infrared Reflective Band

Accurate long-term snow-covered-area mapping is essential for climate change studies and water resource management. The NOAA AVHRR/2 provides a unique data source for long-term, large-spatial-scale monitoring of snow-covered areas at a daily scale. However, the value of AVHRR/2 in mapping snow-covered areas is limited, due to its lack of a shortwave infrared band for snow/cloud discrimination. We simulated the reflectance in the 3.75 µm mid-infrared band with a radiative transfer model and then developed three fractional-snow-cover retrieval algorithms for AVHRR/2 imagery at 1 km and 5 km resolutions. These algorithms are based on the multiple endmember spectral mixture analysis algorithm (MESMA), snow index (SI) algorithm, and non-snow/snow two endmember model (TEM) algorithm. Evaluation and comparison of these algorithms were performed using 313 scenarios that referenced snow-cover maps from Landsat-5/TM imagery at 30 m resolution. For all the evaluation data, the MESMA algorithm outperformed the other two algorithms, with an overall accuracy of 0.84 (0.85) and an RMSE of 0.23 (0.21) at the 1 km (5 km) scale. Regarding the effect of land cover type, we found that the three AVHRR/2 fractional-snow-cover retrieval algorithms have good accuracy in bare land, grassland, and Himalayan areas; however, the accuracy decreases in forest areas due to the shading of snow by the canopy. Regarding the topographic effect, the accuracy evaluation indices showed a decreasing and then increasing trend as the elevation increased. The accuracy was worst in the 4000–5000 m range, which was due to the severe snow fragmentation in the High Mountain Asia region; the early AVHRR/2 sensors could not effectively monitor the snow cover in this region. In this study, by increasing the number of bands of AVHRR/2 1 km data for fractional-snow-cover retrieval, a good foundation for subsequent long time series kilometre- resolution snow-cover monitoring has been laid.

Effect of Land Cover on Tsunami Overland Flow Propagation: A Case Study of Painan, West Sumatra, Indonesia

Tsunami overland flow may cause severe destruction to the affected coastal area. Several tsunamis had hit Indonesia. Studies have shown that there is a high probability of a massive earthquake in the Mentawai fault, Sumatra, Indonesia. A massive earthquake with a magnitude of over 8 Mw might occur in the next 50 years. The nearshore tsunami propagation and inundation in Painan City, West Sumatra, Indonesia, is assessed using HEC-RAS. Various land cover types are simulated to investigate their effects on the tsunami overland flow. The model showed satisfactory results. The model can show the known behaviors of tsunami propagation in urban areas and in rivers. It was found that there is a significant effect of land cover types on the inundation at the coast. Inundation depth increases with roughness along the coast. On the other hand, high roughness decreases the inundated area. Furthermore, the land cover has a significant effect on the velocity. The velocity is much lower in higher Manning’s value. Simulation with a high surface roughness shows a significant reduction in both inundation area and velocity. The high roughness causes a blockage effect for tsunami propagation. Thus, the Tsunami cannot penetrate further inland. The information can be used for land use control suggestions. These provide significant information for future mitigation plans, e.g., placement of evacuation buildings and evacuation routes.

The impact of land covers on carbon stock potential Rantau Research Forest in South Kalimantan

Changes in land cover determine the decrease or increase in carbon storage in a landscape. This study aimed to determine the amount of carbon storage in each type of land cover and determine the effect of land cover type on the carbon storage amount in each carbon pool. This research was conducted in Rantau research forest with three main land coverage, they were: plantation forest, secondary forest, and grassland. The survey was carried out by measuring five carbon pools, namely vegetation, litter, understorey, necromass, and soil carbon, carried out on the land cover types of grassland, plantation forests, and secondary forest. The effect of land coverage to carbon storage was determined by using analysis of variance. The results showed that carbon storage was mostly deposited in vegetation carbon and soil carbon. The secondary forest has the largest carbon storage, namely 135.1 Mg/Ha, followed by plantation forest at 107.4 Mg/Ha, and Grassland at 83.3 Mg/ha. Changes in land cover from secondary forest to cogon grass caused the largest carbon storage reduction by 34%. This change decreased in the cover of the plantation forest to grassland by 20.5%. The implication is that an increase in carbon storage can be achieved by planting in grassland so that the cover becomes secondary forest or plants.

Urban climate and registration of thermal anomalies of territories using satellite imagery

This paper describes a simplified method of mapping of the ur-ban environment surface to obtain a map of the thermal anomalies distribu-tion and study the structure of the urban heat island. Those maps allow evaluating or planning the urban microclimate optimization methods and studying the effect of land cover type on the site temperature. The article discusses the processing of five satellite images for the summer and winter from 2002 to 2019. We propose a simpler and more automated processing of thermal images for Landsat 7 and Landsat 8. The stages of automatic atmospheric correction according to the DOS1 method and calculation of the emissivity with surface classification are considered. Image processing was carried out in the QGIS software package using the Semiautomatic Classification Plugin extension. As a result, thermal anomalies in Chelya-binsk were localized and a comparison of the thermal map for the specific region before and after urbanization was made.

Assessment of the Impact of Land Cover Type on the Water Quality in Lake Tondano Using a SWAT Model

Lake Tondano is the largest natural lake in North Sulawesi, Indonesia, which functions as a provider of clean water, hydroelectric power, rice field irrigation, inland fisheries, and tourism. This research aims to determine the effect of land cover types from the Tondano watershed on the lake water quality. The Soil and Water Assessment Tool (SWAT) model was used to evaluate the rate of soil erosion and the pollutant load of various land types in the watershed during the last ten years. Rainfall data is obtained from two rainfall stations, namely Paleloan Station and Noonan Station. The model is calibrated and validated before being used for analysis. We use climatological data from 2014 to 2019. The process of the SWAT model calibration and validation was carried out with the statistical formulas of the coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). The results show that the potential for pollution load from the Tondao watershed is organic N of 0.039 kg/ha and organic P of 0.006 kg/ha coming from the agricultural land. The results of this study conclude that the fertility conditions of Lake Tondano are at the eutrophic level, where the pollutant inflow is collected in the lake waters, especially for the parameters of total N (1503697.44kg/year) and total P (144831.36kg/year). The SWAT simulation results show deviation between the modeling and field data collected with the value of R2 = 0.9303, and the significant level ≤ 10.

Effect of working forest conservation easements on surrounding property values

The hedonic pricing method was applied to examine the effect of working forest conservation easements (WFCEs) on the value of surrounding land parcels in state of Georgia. Data were collected on attributes of WFCEs in 62 counties and 46,580 property sales occurring from 2001 to 2018. Results suggested that one size did not fill all and that the type of property (agricultural, commercial or residential) near a WFCE played a large role in determining potential price effects of land cover types and other attributes. Additionally, an increase in the age of the nearest WFCE had a negative price effect on surrounding properties. This research could be used in strategic management decisions to maximize both conservation and economic outcomes.

Effects of land cover type on carabid beetles (Coleoptera: Carabidae) of the Canterbury foothills, New Zealand

Background: Land cover changes during the recent history of New Zealand have had a major impact on its largely endemic and iconic biodiversity. As in many other countries, large areas of native forest have been replaced by other land cover and are now in exotic pasture grassland or plantation forest. Ground beetles (Carabidae) are often used as ecological indicators, they provide ecosystem services such as pest control, and some species are endangered. However, few studies in New Zealand have assessed the habitat value for carabid beetles of natural forest, managed regenerating natural forest, pine plantation forest and pasture.
 Methods: We compared the carabid beetle assemblages of natural forest of Nothofagus solandri var solandri (also known as Fuscospora solandri or black beech), regenerating N. solandri forest managed for timber production, exotic pine plantation forest and exotic pasture, using pitfall traps. The study was conducted at Woodside Forest in the foothills of the Southern Alps, North Canterbury, New Zealand, close to an area where the critically endangered carabid Holcaspis brevicula was found.
 Results: A total of 1192 carabid individuals from 23 species were caught during the study. All but two species were native to New Zealand, with the exotic species present only in low numbers and one of these only in the pasture habitat. Carabid relative abundance and the number of species was highest in the pine plantation, where a total of 15 species were caught; however, rarefied species richness did not differ significantly between habitats. The sampled carabid beetle assemblages were similar across the three forested habitat types but differed significantly from the pasture assemblages based on unconstrained and canonical analyses of principal coordinates. Holcaspis brevicula was not detected in this area.
 Conclusions: Our results show that managed or exotic habitats may provide habitat to species-rich carabid assemblages although some native species occur only in natural, undisturbed vegetation. Nevertheless, it is important to acknowledge the potential contribution of these land uses and land cover types to the conservation of native biodiversity and to consider how these can be managed to maximise conservation opportunities.

Effects of land cover type on community structure and functional traits of alpine stream benthic macroinvertebrates

Abstract In the European Alps, due to the current changes in land use driven by different social and economic factors, grasslands and pastures are being increasingly replaced by forests. Whereas many studies have focused on the impacts of urbanisation and intensive agricultural activities, no study has evaluated the effects of changes among types of natural to semi‐natural land cover in the Alps with a focus on lotic environments. Here, combining taxonomic and functional approaches, we show the effects of four different alpine land cover types (rocks, grasslands, coniferous forests, valley bottom pastures) on stream benthic macroinvertebrate communities. Irrespective of elevation, grasslands and pastures exhibited unpredicted similarity in terms of the composition of the macroinvertebrate assemblages and hosted the highest diversity of benthic organisms, whereas in each of the other land cover types, the density and diversity of the faunal assemblages showed distinct and characteristic values. When analysing the functional diversity decomposed to richness, evenness, and divergence components, grasslands and pastures again showed a similar trend, being characterised by high levels of resource exploitation and niche differentiation, with the potential to host additional organisms. However, as expected, differences driven by land cover type and elevation emerged when examining the single functional traits, since elevation played a major role in terms of the distribution of traits conferring resistance and resilience. Our results demonstrate that land cover type is a prominent factor influencing the taxonomic and functional variety of stream benthic macroinvertebrate communities. Moreover, alpine grasslands contained an unexpected diversity of aquatic insects, as previously assessed for other organisms (e.g. plants and snails). Overall, our study highlights the importance of the preservation of the diversity of habitats in the alpine region, with a special focus needed for valuable semi‐natural landscapes, such as grasslands and pastures, particularly in a time of increasing intensification and abandonment of lands in the alpine context.

Spatial variability of soil organic carbon density under different land covers and soil types in a sub-humid terrestrial ecosystem

T he main objectives of the current study are i) to estimate SOC in different soil depths and to generate their spatial distribution maps, ii) to assess relationship between variation of different soil types and SOC density, iii) to determine effects of land cover types on SOC in Inebolu Watershed located in sub-humid terrestrial ecosystem. In order to determine land cover types of the study area, aster satellite image was used and five main land cover types that are bare land, sparsely vegetated area, broadleaved forest area, mixed forest area and needleleaved forest area were classified. Results indicated that soil types and land cover were two crucial influencing factors for spatial variation of SOC density. It was determined that SOC density of soil types, Vertic Haplustept ( 12.93 kg.m -2 ) was significantly higher than other soil subgroups. In this case, it can be said that main reasons of this result are indicated as soil profile depth and pedological development. In addition, when comparing the two main factors, land cover explained more of the SOC density variability and was the main controlling factor in the surface; in the subsurface, not only land cover types but also some properties of soil types such as texture, genetic horizons, soil depth have an important role on SOC density. On the other hand, it can be conclude that the combination of the soil type and land cover was a dramatically better predictor of SOC density.

西北干旱区河西走廊荒漠绿洲土地覆盖类型与蒸散的关系研究——基于Landsat 8和ZY3数据融合

PDF HTML阅读 XML下载 导出引用 引用提醒 西北干旱区河西走廊荒漠绿洲土地覆盖类型与蒸散的关系研究——基于Landsat 8和ZY3数据融合 DOI: 10.5846/stxb201807161532 作者: 作者单位: 中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室/中国科学院大学。,中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室。,中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室。,中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室。,中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室/中国科学院大学。,中国科学院西北生态环境资源研究院临泽内陆河流域研究站/中国科学院生态水文与流域科学重点实验室/中国科学院大学。 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFC0504303）；国家自然科学基金项目（41771041，41501044，41701035） Relationship between land cover type and evapotranspiration on the basis of Landsat 8 and ZY3 data fusion approach for a desert oasis in the middle Hexi corridor area of the arid regions of northwestern China Author: Affiliation: Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, University of Chinese Academy of Sciences.,Linze Inland River Basin Research Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences.,Linze Inland River Basin Research Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences.,Linze Inland River Basin Research Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences.,Linze Inland River Basin Research Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, University of Chinese Academy of Sciences.,Linze Inland River Basin Research Station; CERN/Key Laboratory of Ecohydrology and Watershed Science, Chinese Academy of Sciences/Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, University of Chinese Academy of Sciences. Fund Project: National Key Research and Development Plan（2017YFC0504303）；The National Natural Science Foundation of China （41771041；41501044；41701035） 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:蒸散是地表水热平衡的重要分量，也是陆地生态过程与水文过程之间的重要纽带，尤其在干旱区地-气相互作用、碳循环、水循环等过程所包含的物质与能量交换中占有极其重要的地位。基于Landsat 8遥感影像和资源三号影像（ZY3）的高分辨率植被信息，利用SEBS模型对西北干旱区河西走廊中段临泽绿洲北部区域地表蒸散量进行了估算，并用绿洲内部和绿洲-荒漠过渡带两个通量塔涡动相关数据对模型进行评估，分析了不同土地覆盖类型对蒸散量空间分布的影响。结果表明：（1） SEBS模型模拟值与实测日蒸散值之间拟合效果较好，且在均一地表时（绿洲农田区）估算精度更高（R2=0.96，P < 0.001），RMSE、MAE分别为0.84 mm/d、0.56 mm/d；（2）从季节变化来看蒸散量与作物生长密切相关，夏季灌溉和降雨使得研究区水分充足，植被覆盖度高，蒸散量相应增加，在绿洲地区可达5.95 mm/d，而冬季最小仅为0.52 mm/d；（3）从蒸散量的空间变化来看，水体蒸散值最大，其余依次为农田、防护林、裸地和灌木丛，说明除水体外，随着植被覆盖的增大，蒸散量也逐渐增加。通过ZY3影像的高分辨率植被信息与Landsat 8影像热红外数据融合，提高了SEBS模型对该区域蒸散量的模拟效果，增进了我们对绿洲下垫面与大气间水热交换规律、水文过程、生态-水文相互作用的深入理解。 Abstract:Evapotranspiration is a major component of water and heat exchange in terrestrial ecosystems, as it acts as a critical link between ecological and hydrological processes, particularly for the exchange of mass and energy involved in land surface-air interaction, carbon cycle, and hydrological cycle in arid regions. In this study, we used Landsat 8 remote-sensing images and resources NO.3 (ZY3) images, with high-resolution vegetation information, and surface energy balance system (SEBS) model to estimate surface evapotranspiration (ET) in a desert oasis in the middle Hexi corridor area of the arid regions of northwestern China. We compared the estimated ET values with the measured values by using the eddy covariance method. We also spatially analyzed the effects of land cover types on ET. The main results of this study indicated that (1) the estimated daily ET was consistent with the corresponding measured values, especially for homogeneous underlying surface such as oasis (R2=0.96, P < 0.001) with low values of RMSE (0.84 mm/d) and MAE (0.56 mm/d). (2) In terms of seasonal changes, ET is closely related to phonological period, highest in summer, followed by spring, autumn, and winter (e.g., daily ET was 5.95 mm/d for cropland within the oasis, as opposed to 0.52 mm/d in winter), because of the peaked plant cover and summer rainfall in this study area. (3) With respect to spatial variations in ET, the surface ET for water body was the highest, followed by those for cropland, shelterbelt, bare land, and shrubland; this suggested that evapotranspiration also increases gradually with the increase in plant cover, except for water body. In addition, performance of the SEBS model for estimating ET in this region was fairly good when applying the data fusion of high-resolution vegetation information of ZY3 and thermal infrared data of the Landsat 8 remote-sensing images was performed. All these results have enhanced our understanding of the patterns of water and heat exchange between the underlying surface and atmosphere, which play a key role in hydrological and ecological processes or interaction between ecological and hydrological processes locally in arid desert oasis area. Our findings may provide some scientific insights into the decision-making for rational water utilization by the local government. 参考文献 相似文献 引证文献

Seasonal effect of land use type on soil absolute and specific enzyme activities in a Brazilian semi-arid region

Tropical environments are considerable contributors to overall soil carbon loss to the atmosphere. Land use effects on soil chemical attributes have been well documented mainly in humid environments; however, less attention has been paid to the changes in soil enzymatic activities in dry ecosystems that is a sensitive indicator in ecological processes, due to its importance in soil dynamics and microbial activity. The present study is part of interdisciplinary project that investigated the effect of land cover type and seasonal variation on absolute and specific enzymatic activities per unit of soil organic carbon (SOC) and per microbial biomass carbon (MBC). We assessed five different land use type (Tropical dry forest-TDF, protected area with Angico –ANA, protected area with Ipê-TAB, Scrub area-SCR and agricultural area with maize-M) and five areas of each land use in three layers: 0–0.05, 0.05–0.10 and 0.10–0.20 m. The samples were collected at rainy season 1 in April 2014 (RS1), dry season October 2015 (DS) and rainy season 1 April 2016 (RS2). The conversion of the preserved area provided a reduction in absolute enzymatic activities, especially in the SCR and M. The reductions were of 76% for β-glucosidase, 95% for urease and 72% for acid phosphatase. The specific enzymatic activities per unit of MBC increased with the change of soil use, except in M. The enzymatic activity per unit of SOC in the TDF area was higher in relation to the other areas evaluated, except for specific activity of acid phosphatase. The land use type influenced the absolute and specific soil enzyme activities, but not show a clear trend of seasonal effect.