基于高分遥感的广州市登革热蚊媒适生区识别

利用高分遥感卫星影像提取广州市蚊虫生境要素(林地、居住地、水域、植被覆盖、公园、道路),并结合人口密度,依据蚊虫生境评价指标和评价模型来识别登革热蚊媒适生区。

基于高分遥感的疾病监测评估系统的设计与应用

通过介绍基于高分遥感技术的疾病监测评估系统设计过程,探讨空间信息技术、计算机技术等在疾病预防控制领域中的应用。从系统技术路线、系统架构设计、功能模块设计、核心框架设计、数据管理设计等诸方面对系统进行详细介绍,分析系统的优点与局限性。

基于高分辨遥感的矿区周边居民健康风险评估系统关键技术研究

研究了基于空间信息技术的矿区周边居民健康风险评估方法。基于该方法能够对遥感影像数据中与致病因子相关的环境要素进行关联和提取,并结合人口分布、疾病信息等数据进行空间分析,实现对矿区周边居民健康风险的快速评估,旨在为我国矿区周边居民健康风险快速评估提供全新的思路和途径。

东西伯利亚苔原-泰加林过渡带植被遥感物候时空特征及其对气温变化的响应

Phenology is an important indicator of climate change.Studying spatiotemporal variations in remote sensing phenology of vegetation can provide a basis for further analysis of global climate change.Based on time series data of MODIS-NDVI from 2000 to 2017,we extracted and analyzed four remote sensing phenological parameters of vegetation,including the Start of Season(SOS),the End of Season(EOS),the Middle of Season(MOS)and the Length of Season(LOS),in tundra-taiga transitional zone in the East Siberia,using asymmetric Gaussian function and dynamic threshold methods.Meanwhile,we analyzed the responses of the four phenological parameters to the temperature change based on the temperature change data from Climate Research Unit(CRU).The results show that:in regions south of 64°N,with the rise of temperature in April and May,the SOS in the corresponding area was 5-15 days ahead of schedule;in the area between 64°N and 72°N,with the rise of temperature in May and June,the SOS in the corresponding area was 10-25 days ahead of schedule;in the northernmost of the study area on the coast of the Arctic Ocean,with the drop of temperature in May and June,the SOS in the corresponding area was 15-25 days behind schedule;in the northwest of the study area in August and the southwest in September,with the drop of temperature,the EOS in the corresponding areas was 15-30 days ahead of schedule;in regions south of 67°N,with the rise of temperature in September and October,the EOS in the corresponding area was 5-30 days behind schedule;the change of the EOS in autumn was more sensitive to the change of the SOS in spring,because the smaller temperature fluctuation can cause the larger change of the EOS;the growth season of vegetation in the study area was generally moving forward,and the LOS in the northwest was shortened,while the LOS in the middle and south of the study area was prolonged.

中国东北森林物候期遥感监测数据集

物候是气候和自然环境变化的综合指示器。森林是全球生态系统的重要组成部分,森林物候期是反映气候变化对森林生长阶段影响的综合性生物指标。以2000-2010年MODIS 500 m空间分辨率8天合成的MOD09A1产品为数据基础,计算和重建增强型植被指数(EVI)时间序列数据,采用动态阈值法获得中国东北地区森林植被物候期数据(生长始期、生长末期和生长期长度)。通过与该地区相关研究文献和地面观测数据的比较,表明基于MODIS数据获取的森林物候期与调查数据具有可比性。该数据集包括2000-2010年中国东北森林生长始期、生长末期和生长期长度的遥感监测数据。该数据集有效反映了气候和自然环境变化背景下中国东北森林物候期的时空差异,对于区域植物物候监测和气候变化研究具有参考价值,可以作为中国东北地区和世界中高纬度地区植物物候研究的参考数据。

东西伯利亚苔原—泰加林过渡带植被遥感物候时空特征及其对气温变化的响应

物候变化是气候变化的重要指示器,通过对植被物候时空变化的研究可以为进一步分析全球气候变化提供依据。基于2000—2017年MODIS-NDVI时间序列数据,利用不对称高斯函数和动态阈值法,提取、分析了东西伯利亚苔原—泰加林过渡带植被生长季起始期(SOS)、结束期(EOS)、中期(MOS)和长度(LOS)4种植被遥感物候参数的时空变化格局。同时结合同期CRU(Climate Research Unit)气温观测数据,分析了4种物候参数对气温变化的响应关系。结果表明:遥感物候参数可以直接、有效地反映气温的变化:研究区64°N以南区域4—5月气温升高,对应区域SOS提前5~15 d;64°N~72°N之间5—6月气温升高,对应区域SOS提前10~25 d;最北端北冰洋沿岸6月气温升高幅度较小且7月气温降低,对应区域SOS推后15~25 d;西北部8月、西南部9月气温降低,对应地区EOS提前15~30 d;67°N以南区域9—10月气温升高,对应区域EOS推后5~30 d;EOS的变化对气温变化较SOS更为敏感,较小的气温波动即引起EOS较大的变动;研究区内植被生长季整体呈前移趋势,且西北部LOS缩短,中部、南部LOS延长。

Mapping wetland changes in China between 1978 and 2008

Four wetland maps for all China have been produced,based on Landsat and CBERS-02B remote sensing data between 1978 and 2008 (1978,1990,2000 and 2008).These maps were mainly developed by manual interpretation and validated by substantial field investigation in 2009.Based on these maps,we analyzed the 2008 wetland distribution in China and discussed wetland changes and their drivers over the past 30 years.(i) There were about 324097 km 2 of wetlands in 2008,for which inland marshes or swamps were the most common wetland type (35%),with lakes (26%) second.Most of the wetlands were in Heilongjiang,Inner Mongolia,Qinghai and Tibet,occupying about 55% of the national wetland area.(ii) From 1978 to 2008,China's wetland area continually and significantly decreased,by about 33% based on changes in the wetland map.This was in sharp contrast to the increase in artificial wetlands,which increased by about 122%.Inland marshes accounted for the main loss of total wetlands from 1978 to 2000.From 2000 through 2008,riverine and lacustrine wetlands constituted the main wetland loss.Fortunately however,the rate of wetland loss decreased from 5523 to 831 km 2 /a.(iii) The change ratio of lost natural wetlands (including inland and coastal wetlands) to non-wetlands has decreased slightly over the past 30 years.From 1978 to 1990,nearly all natural wetlands (98%) lost were transformed into non-wetlands.However,the ratio declined to 86% from 1990 to 2000,and to 77% from 2000 to 2008.(iv) All Chinese provinces were divided into three groups according to patterns of wetland changes,which could relate to the driving forces of such changes.Tibet was completely different from other provinces,as it was one representative example in which there was a net wetland increase,because of global warming and decreased human activity since 1990.Increased economic development caused considerable wetland loss in most eastern provinces,and artificial wetlands increased.

Assessing the relative role of climate change and human activities in sandy desertification of Ordos region, China

Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches. A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China. Potential NPP and the difference between potential and actual NPP were selected as indicators to assess the relative role of climate change and human activities in sandy desertification, respectively. Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000. The results showed that although some local places experienced an expansion of sandy desertification, the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend. The relative role of climate change and human activities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes. In the reversion of sandy desertification, climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate deciduous scrubs in north east of Ordos region; however, human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region. In the expansion of sandy desertification, human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around common boundary of Hanggin, Dalad Banners and Dongsheng City; however, climate change dominated the expansion of sandy desertification from 1991 to 2000, the expanded areas equably distributed in the whole of Ordos region except the south east of Otog Qian, Uxin and Jungar Banners.

Assessment of the relative role of climate change and human activities in desertification：

Climate change and human activities are the two kinds of driving forces in desertification,and assessing their relative role in desertification is of great significance to deeply understanding the driving mechanisms and preventing desertification expansion.This paper has systematically reviewed the progress of the researches on assessing the relative role of climate change and human activities in desertification from qualitative,semi-quantitative and quantitative aspects respectively.The authors found that there were still some problems in the previous researches.For example,the subjectivity in assessment was obvious,the assessment cannot be easily repeated,and the assessment and its results were always based on administrative regions and less taken and expressed in a continuous space.According to the progress of previous researches and the works conducted by the authors recently,we put forward a quantitative approach by selecting NPP as a common indicator to measure the relative role of climate change and human activities in desertification and dividing the ecological process of ＂driving force effect-dynamic response of desertified land＂ into several scenarios.Meanwhile,validation and scale of assessment should be taken into account when quantitative assessment of the relative role of climate change and human activities in desertification are carried out.

Estimation of wind erosion rates by using ^(137)Cs tracing technique:A case study in Tariat-Xilin Gol transect, Mongolian Plateau

Wind erosion is one of the major environmental problems in semi-arid and arid regions. Here we es- tablished the Tariat-Xilin Gol transect from northwest to southeast across the Mongolian Plateau, and selected seven sampling sites along the transect. We then estimated the soil wind erosion rates by using the ^(137)Cs tracing technique and examined their spatial dynamics. Our results showed that the ^(137)Cs inventories of sampling sites ranged from 265.63±44.91 to 1279.54±166.53 Bq·m^(-2), and the wind erosion rates varied from 64.58 to 419.63 t·km^(-2)·a^(-1) accordingly. In the Mongolia section of the transect (from Tariat to Sainshand), the wind erosion rate increased gradually with vegetation type and climatic regimes; the wind erosion process was controlled by physical factors such as annual precipitation and vegetation coverage, etc., and the impact of human activities was negligible. While in the China section of the transect (Inner Mongolia), the wind erosion rates of Xilin Hot and Zhengxiangbai Banner were thrice as much as those of Bayannur of Mongolia, although these three sites were all dominated by typical steppe. Besides the physical factors, higher population density and livestock carrying level should be responsible for the higher wind erosion rates in these two regions of Inner Mongolia.

Using ^(137)Cs tracing technique to estimate wind erosion rates in the typical steppe region, northern Mongolian Plateau

Wind erosion is one of the major factors of land degradation in the typical steppe region, northern Mongolian Plateau. Using 137Cs tracing technique, we estimated the wind erosion rates of different pastures and abandoned farmland at Bayannur and Karakorum in Mongolia. The pastures and cutting grassland at Bayannur were slightly eroded by wind, with the rates of 64.58-169.07 t·km?2·a?1. The abandoned farmland in Karakorum, however, was strongly eroded by wind, with annual surface soil loss of 4.05 mm·a?1, and wind erosion rates up to 6723.06 t·km?2·a?1. The total loss of surface soil due to wind erosion has been 17.4 cm since the cultivation of the steppe land in the 1960s. The wind ero- sion rate at the abandoned farmland was much higher than that at the typical steppe sites, showing that the cultivation led to serious wind erosion in the typical steppe region, northern Mongolian Plateau. By contrast, traditional livestock grazing resulted in less disturbance to the surface soil, and did not in- duce to devastating wind erosion, which plays an important role in maintaining the stability of the steppe ecosystem in the northern Mongolian Plateau.

Esophageal cancer spatial and correlation analyses： Water pollution, mortality rates, and safe buffer distances in China

Esophageal cancer exhibits one of the highest incidence and mortality rates in China. Malignant tumors caused by esophageal cancer, and the relationship to environmental factors has been the focus of many public health studies. This study applied spatial analysis to ascertain the relationship between water pollution and esophageal cancer mortality rates nationwide. We employed two datasets, including a national investigation of esophageal cancer rates and distribution, and national water quality grades in China＇s primary rivers and lakes. Esophageal cancer data were grouped based on different water quality grades, which included a scaled buffer distance from rivers and lakes. Non-parametric correlation analyses were performed to examine the presence or absence of the following correlations： （i） eso- phageal cancer mortality and buffer distance from rivers and lakes; and （ii） esophageal can- cer mortality and water quality grade values. The present study revealed a significant positive correlation between widespread water pollution and esophageal cancer mortality nationwide; and a significant negative correlation between esophageal cancer mortality, and buffer dis- tance from rivers and lakes.

Urban surface heat fluxes infrared remote sensing inversion and their relationship with land use types

Using ASTER （Advanced Spaceborne Thermal Emission and Reflection Radiometer） infrared remote sensing data we inversed the parameters of urban surface heat fluxes applying the PCACA model and theoretical position algorithm, and then we analyzed the influence of different land use types on the surface heat fluxes and energy balance. In this study Kumagaya, a city in Saitama Prefecture, Japan, was selected as the experimental area. The result shows that the PCACA model is feasible for the surface heat fluxes estimation in urban areas because this model requires less parameters in the procedure of heat fluxes estimation in urban areas with complicated surface structure and can decrease the uncertainty. And we found that different land-use types have indicated the height heterogeneity on the surface heat fluxes significantly. The magnitudes of Bowen ratio in descending order are industrial, residential, transportation, institutional, dry farmland, green space, and water body. Under the same meteorological condition, there are distinct characteristics and regional differences in Bowen ratios among different surface covers, indicating higher sensible heat flux and lower latent heat flux in the urban construction land, while lower sensible heat flux and higher latent heat flux in the vegetation-covered area, the outskirt of the urban area. The increase of urban impervious surface area caused by the urban sprawl can enlarge the sensible heat flux and the Bowen ratio, so that it causes the increasing of urban surface temperature and air tem- perature, which is the mechanism of the so-called heat island effect.