ETAS Model Analysis on the Chang Island Earthquake Swarm in Shandong Province,China

Influenced by the layout of seismic network and the location of earthquakes,earthquake catalogs are often incomplete;such incompleteness of earthquake catalogue directly affects the analysis of sequence activity characteristics.In this paper,the GPU-acceleration-based g template matching method is used to scan the continuous waveforms of Chang Island earthquake swarm in Shandong Province from February 9 to August 20,2017.In total,15,286 earthquakes events were detected,which was more than 6 times compared with those in network catalogue and thus reduced the magnitude of completeness from 1.0 to 0.5.Based on the intergrated catalogue of earthquakes,the characteristics of Chang Island earthquake swarm were then analyzed using the Epidemic Type Aftershock Sequences(ETAS)model.The stochastic components in the ETAS model are used as a proxy for possible earthquake triggered by external forces(fluids).The results show that the proportion of earthquakes triggered by external forces of Chang Island swarm increases gradually(from 31.9%to 63.5%)and then decreases.The latter stage of swarm development is mainly affected by the self-excitation of earthquakes,suggesting that the fluids play an important role in the development of the Chang Island swarm.However,the triggering intensity of fluids to microseismicity is divergent in different periods,which may be related to the process of fluid permeation.

The Effective Ecological Factors and Vegetation at Koh Chang Island, Trat Province, Thailand

This study aims to characterize the tropical rain forest present in the Chang Island, Trat Province, Thailand, and to analyze the environmental factors to determine its composition and structure. Thirty one plots were sampled, plant cover was measured in 20 × 40 m2 plots, and the importance value index was calculated. A total of 78 species belonging to 32 families were identified.Twenty soil samples were analyzed, and cluster analysis was employed to classify the vegetation communities. Floristic and environmental data were evaluated and ordered using canonical correspondence analysis. The results showed that the vegetation communities could be divided into 4 types and were significantly (p Calophyllum thorelii Pierrecommunity (Type 2). The Dipterocarpus (Hopea pierrei Heim) community (Type 3) was more likely to occur in regions with moderate to high levels of TWI, but the result from cluster analysis showed that some of the plot samples from the Dipterocarpus community were separated by characteristic importance value index (IVI) values. There was also evidence that the area was impacted by an old disturbance created by a rubber plantation. This impact was referred to as a secondary succession community (Type 4).

Assessing the vulnerability of changing coasts,Hainan Island,China

Knowledge of coastline changes and vulnerability is of great importance to local government departments that are responsible for the management and development of coastal zones.To study the nature of change and vulnerability along the coasts of the Hainan Island,we collected a large number of sediment samples through the last few years,and reconstructed the changes of the coastline by combining the data of sediment grain-size analysis and the nautical charts/TM RS imaginary.Contrary to being almost free from erosion（as expected from the findings that the coastlines are in a relatively stable state）,four major cities in Hainan（i.e.,Haikou,Wenchang,Sanya and Changjiang） turned out to be suffered from a moderate coastal vulnerability primarily because of the large populations that impose considerable pressure on the coastlines.Thus,the assessment methodology utilized in this study,including both anthropogenic and natural factors,serves as a useful tool to obtain a comprehensive understanding of coastline vulnerability for local government,in terms of coastal management and adaptation.

Impacts of land cover change on plant and bird species diversity in Hainan Island,China

Hainan Island, located at the southern end of China, has less than 0.4% of land area but contains 13% of plant and animal species in China. During the last four decades many primary forests have been converted to shrub land, grassland, and tree planation (e.g., eucalyptus forest). As a result, area of primary tropical forest has been reduced from 25.8% in the 1950s to 4% in the 1990s. To assess impacts of land conversion on plant and bird species diversity, a series of samples in primary forest and four types of converted lands were took. The land conversion had tremendously reduced both plant and bird species diversity. Specifically, plant species richness per site was 83.7 in primary forest, 28.3 in shrub land, 12.5 in grassland, 14.4 in eucalyptus forest, and 21.4 in Acacia forest. Bird species richness showed a similar trend: 22.0 in primary forest, 14.5 in shrub land, 2.5 in grassland, 4.9 in eucalyptus forest, and 9.0 in Acacia forest. The Shannon species diversity indices for plants in the five types of land cover were 3.69, 1.99, 0.97, 1.47 and 2.07, respectively. Similarly, the Shannon indices for bird species diversity were the highest in primary forest, and lowest in grassland, and intermediate in shrub land and eucalyptus forest.

Monitoring Intra-annual Spatiotemporal Changes in Urban Heat Islands in 1449 Cities in China Based on Remote Sensing

This study aimed to accurately study the intra-annual spatiotemporal variation in the surface urban heat island intensities(SUHIIs) in 1449 cities in China.First, China was divided into five environmental regions.Then, the SUHIIs were accurately calculated based on the modified definitions of the city extents and their corresponding nearby rural areas.Finally, we explored the spatiotemporal variation of the mean, maximum, and minimum values, and ranges of SUHIIs from several aspects.The results showed that larger annual mean daytime SUHIIs occurred in hot-humid South China and cold-humid northeastern China, and the smallest occurred in arid and semiarid west China.The seasonal order of the SUHIIs was summer > spring > autumn > winter in all the temperate regions except west China.The SUHIIs were obviously larger during the rainy season than the dry season in the tropical region.Nevertheless, significant differences were not observed between the two seasons within the rainy or dry periods.During the daytime, the maximum SUHIIs mostly occurred in summer in each region, while the minimum occurred in winter.A few cold island phenomena existed during the nighttime.The maximum SUHIIs were generally significantly positively correlated with the minimum SUHIIs during the daytime, nighttime and all-day in all environmental regions throughout the year and the four seasons.Moreover, significant correlation scarcely existed between the daytime and nighttime ranges of the SUHIIs.In addition, the daytime SUHIIs were also insignificantly correlated with the nighttime SUHIIs in half of the cases.

Study on ecosytem service function change of island based on remote sensing

Based on the interpretation of the remote sensing data presented by the resource satellite, this paper states the fact that the land-use area in Donghai Island, which is located in the south of Zhanjiang, Guangdong Province, had expanded by 576.71 hm2 in the 25 years from 1986 to 2010 because of human activities such as land reclamation; in the meantime, great changes in types of land cover on the island have occurred. The definite change in land use leads to the remarkable transition in its ecosystem service value. Therefore, by applying the Costanza method in this paper to quantificationally analyze the changes in its ecosystem services on this island; the Costanza method is a calculation technique that shows the service value per unit area of island. It is found that from 1986 to 2010, especially in the recent years, due to the rapid development in the petrifaction, steel and port industries, the areas of cultivated land, woodland, grassland and desert have decreased in different degrees, while the lands for residence, industry and traffic construction and the areas of water and wetlands have increased. Consequently, compared with the number of RMB 547.57x10^6 yuan per year in 1986, the ecosystem service value of Donghai Island was greatly reduced to RMB 493.94x10^6 yuan per year in 2010. As for the spatial distribution, it presents a feature that it is higher in the west and low in the east. The results manifest that it is of great significance to analyze the changes in the ecosystem service function on the basis of the service value of the island presented by the remote sensing data in a quantificational way, which will contribute to the promotion of ecological compensation.

Characteristics of the Heat Island Effect in Shanghai and Its Possible Mechanism

The characteristics of the urban heat island effect and the climate change in Shanghai and its possible mechanism are analyzed based on monthly meteorological data from 1961 to 1997 at 16 stations in Shanghai and its adjacent areas. The results indicate that Shanghai City has the characteristics of a heat island of air temperature and maximum and minimum air temperature, a cold island of surface soil temperature, a weak rainy island of precipitation, and a turbid island of minimum visibility and aerosols, with centers at or near Longhua station (the urban station of Shanghai). Besides theses, the characteristics of a cloudy island and sunshine duration island are also obvious, but their centers are located in the southern part of the urban area and in the southern suburbs. A linear trend analysis suggests that all of the above urban effects intensified from 1961 to 1997. So far as the heat island effect is concerned, the heat island index (difference of annual temperature between Longhua and Songjiang stations) strengthens (weakens) as the economic development increases (decreases). The authors suggest that the heating increase caused by increasing energy consumption due to economic development is a main factor in controlling the climate change of Shanghai besides natural factors. On the other hand, increasing pollution aerosols contribute to the enhancement of the turbid island and cooling. On the whole, the heating effect caused by increasing energy consumption is stronger than the cooling effect caused by the turbid island and pollution aerosols.

A 2200-year Record of Seabird Population on Ganquan Island,South China Sea

Geochemical characteristics of a 107 cm long sediment profile,collected from Ganquan Island,South China Sea,were analyzed.Based on concentrations of bio-elements（Cu,Zn,Cd,Ba,As, Se,P）,^（210）Pb and AMS^（14）C dating,we reconstructed seabird population of Ganquan Island over the past 2200 years.Seabirds inhabited this island more than 2200 years ago,and their population displayed remarkable fluctuations with two peaks around 2100-1850 yr BP and 900-300 yr BP,respectively.The seabird population change profile on Ganquan Island is similar to that on Dongdao Island over the past 1800 years.We examined the relationship between the seabird population and climate,and found it quite complicated.The seabird population did not reach the maximum during the Medical Warm Period（MWP）with relatively high average temperature;however,it remained near the peak value for about 600 years during the climatic transition period and the Little Ice Age（LIA）,indicating that a relatively cool climate is favorable for seabirds on Ganquan Island.

Temperature Trends on Gran Canaria (Canary Islands). An Example of Global Warming over the Subtropical Northeastern Atlantic

The variation in temperature on the island of Gran Canaria is studied using the method applied to the nearby island of Tenerife [1]. An upward warming trend of 0.09°C ± 0.05°C (α = 0.01) was seen from 1946 to date, which has accelerated since the seventies to 0.17°C ± 0.10°C (α = 0.01). The increase was higher at night (0.11°C ± 0.05°C) than by day (0.08°C ± 0.06°C), so the temperature range decreased slightly. These values are similar to those of Tenerife and the time series of anomalies for the two islands are highly correlated. On the coast the same relationship to the sea surface temperature was found as in Tenerife, but in the mid-altitude areas to windward, some differences were detected that are hypothetically attributable to the different relief of the two islands.

Analysis of Urban Change in Shenzhen City Based on Landsat Archived Data

With the ongoing development of economy and urbanization in China, the change of land use types has attracted more and more attention. In this study we focused on the urban development of Shenzhen City, Guangdong Province, analyzing Landsat 5 TM and Landsat 8 OLI data. We used an SVM based classification, a land transfer matrix approach, a directional growth analysis method and we calculated the inversion of land surface temperature to derive information of land cover changes that occurred in the time period between 1987 and 2017. The results are combined with Shenzhen’s economy, transportation policy and other aspects to find the driving forces of the urban development. The results show that during the observed 30 years, the area of construction land has increased significantly. Most of it is converted from other lands, and some of them are reclaimed. Most rapidly developing are areas west and northwest of the Bao’an, Nanshan and Longhua. The vegetated areas decreased slightly. Caused by the continuous increase of the construction land, the so-called heat island effect emerges slightly but continuously.

Air Temperature Changes and Urbanization Contribution Ratio in Kunming City in Recent 50 Years

[Objective] The aim was to study air temperature changes and urbanization contribution ration in Kunming City in recent 50 years. [ Method] The observation data of air temperature series from Kunming station and other four surrounding meteorological stations were used to in- vestigate air temperature variation in Kunming station affected by urbanization during 1960 -2009. [ Result] The trend slope of mean annual temper- ature was 0.402 ~（3/10 a in Kunming station and 0. 103 ~C/10 a in other four surrounding meteorological stations, and the increasing magnitude of air temperature in Kunming station was more than 3 times that of average global warming in the past 50 year. The effect of urbanization on mean an- nual temperature in Kunming station started from 1990. During 1990 -1994, the increasing contribution rate of urbanization to air temperature in Kunming station was less than 40%. From 1995 to 2009, the contribution ratio was more than 50%, up to about 60% in all seasons. Urban heat is- land effect in Kunming station was intensified with the development of urbanization. In addition, the warming rate caused by urban heat island effect in Kunming station was the greatest in dry season, followed by mean annual temperature, and it was the weakest in rainy season. [ Conclusion] The study provided theoretical foundation for future research.

Observed Changes in Long-Term Climatic Conditions and Inner-Regional Differences in Urban Regions of the Baltic Sea Coast

This paper presents research outcomes from an investigation into climate change and urban impacts on climate development in urban regions of the Baltic Sea coast. The cities considered were Rostock and Stockholm, and their surrounding regions. The objectives were: 1) to determine whether significant changes in temperature and precipitation have occurred and, if so, to what extent;and 2) to establish whether there is a noticeable urban heat island effect in Stockholm and the medium-sized city of Rostock. Climatic trends were detected by linear regression and the Mann- Kendall test. Different precipitation trends were detected over the whole period of observation. Average annual temperatures increased significantly in both case studies, particularly from the 1970s with highest trends in winter and lowest in autumn (Rostock) and summer (Stockholm). Although changes in temperature extremes were detected for both regions, no overall long-term trend for precipitation extremes was observed. The average temperature in the city of Rostock (Stockholm) was approximately 0.3°C to 0.6°C (1.2°C) higher than in the surrounding rural areas had seasonal variations, with maxima in the warm season. The main outcomes were that significant changes in climatic conditions, particularly temperature patterns, have been occurring in the case study regions since the 1980s, and that there is a considerable urban heat island effect in both Stockholm and Rostock. This could encourage urban planners to consider specific climatic conditions and small-scale climatic influences also in relatively small coastal urban conglomerates in mid latitudes which can follow from land use changes.

末次冰期东海嵊山岛黄土粒度端元分析及其环境意义

【目的】东海岛屿晚更新世风尘黄土堆积是我国黄土在东部长三角及外延海域重要的拓展,深化这一区域风尘黄土沉积的物源特征和后期演化问题研究,对于认识晚更新世区域古环境变化尤为重要。【方法】在OSL测年和磁化率测试基础上,基于东海岛屿典型风尘黄土剖面(嵊山岛黄土)的粒度分析,开展了粒度组成的端元分析,探讨了其蕴含的古环境信息。【结果与结论】嵊山岛黄土沉积可提取出3个粒度端元(EM1~EM3),进一步分析发现EM1可能代表通过高空西风气流传输的远源黏粒组分,EM2可能代表以浮尘形式远距离悬浮搬运并随风力减弱而沉降堆积的细粉砂组分,EM3可能代表冬季风驱动下的近地表短距离搬运堆积的粗粉砂组分。粒度端元分析结果表明,高空西风输送的黏粒端元组分和远距离悬浮运移的浮尘端元组分可能是沉积剖面主要粉尘来源;综合年代学结果、百分频率磁化率和颗粒中值粒径等参数分析,认为东海嵊山岛黄土沉积过程在MIS3阶段先后经历暖湿—冷干—暖湿的旋回波动;并且,所记录的MIS3阶段气候波动以及MIS2阶段末次冰盛期和冰消期的古环境变化同深海氧同位素和古海平面变化趋势相对应,说明东海陆架区域该时期环境演变与全球性气候波动相协同。

Study on the Dry Island Effect in Xiamen City

Using relative humidity data from two meteorological stations in Xiamen and absolute humidity calculated from temperature and water vapor,the annual,seasonal and monthly change characteristic of relative humidity and absolute humidity were comprehensive analyzed.Then the dry island effect of Xiamen city was studied.The result demonstrated that because of unique geographical features,the air humidity showed different change rules between urban and suburb.There was no obvious dry island effect in urban and suburb at last century.The change trend of average air humidity was unapparent before 90th of last century.From early 90th of last century,the air humidity in suburb began to decrease obviously.There was dry mutation for these two stations in 1993 and 2004 respectively.From the beginning of early of this century,both areas became dry obviously.The seasonal average relative humidity of Tongan station decreased each season,but what in Xiamen station changed unapparent.The seasonal average absolute humidity of Tongan station decreased apparently in spring and summer,but what did not change obviously in autumn and winter.The seasonal average absolute humidity of Xiamen station decreased apparently in summer,but what did not change apparently in other seasons.As respect from climate change of air humidity of each time,it decreased obviously at all four times at Tongan station.Relative humidity diminished most apparently at 8 and 20 o'clock.Absolute humidity diminished most apparently at 14 o'clock.For Xiamen station,relative humidity diminished most apparently at 14 o'clock.Absolute humidity diminished most apparently at 2 and 20 o'clock.

Analysis of Characteristics of Spatio-temporal Evolution of Land Use in Inhabited Islands of Pearl River Estuary

Under the support of the remote sensing and geographical information system(GIS) techniques,we acquire the land use data in 1990 and 2008 regarding 6 inhabited islands,namely Longxue Island,Hengmen Island,Weiyuan Island,Qi'ao Island,Hengqin Island and Gaolan Island in Pearl River Estuary.By using dynamic degree of land use,land use change intensity,relative change rate and other indicators,we conduct quantitative description,and thus quantitatively and qualitatively analyse characteristics of temporal evolution and law of spatial pattern change concerning land use of each island.The study indicates that in the period 1990-2008,the area of construction land and water in 6 islands increased,while the area of agricultural land and unused land increased in some islands and decreased in others.The land use change shows spatial disparity;the holistic land use change degree in Hengmen Island is higher than that of other islands;the dynamic degree of land use,intensity of land use,and relative change rate differ in different islands.

中国人对西沙群岛历史认知与风力、潮流、海浪作用下的变迁研究

通过研究西沙群岛的历史认识和地理环境演变,强调了地理特征和稳定性的重要性,以及风力、潮流和海浪对其造成的影响。研究表明:1)中国人至迟在汉代对“岛”和“沙洲”就有了较为理性的认知,岛屿的形成具有悠久的历史,形成于4000年以上,地势相对较高,不易被海水淹没。相反,沙洲是相对年轻的地貌,其地势较低,容易受到自然因素的影响。2)风力、潮流和巨浪对西沙群岛地貌的变化有重要影响。风力和巨浪堆积沙洲,但同时也能导致其消失在海平面以下。潮流的周期性变化也对这些岛屿和沙洲的稳定性产生重要影响。这些变迁不仅是地貌的动态展现,也与海洋生物数量下降趋势密切相关。综合分析表明,岛和沙洲在地理特征和稳定性上存在明显差异。西沙群岛地貌的变迁是自然因素与人类活动交互作用的结果。文章有助于更好地了解西沙群岛的演化过程,以及保护和改善这一地区的生态环境方面的实际需求。

海南岛土地覆盖变化对海风锋结构演变影响的数值模拟

本文利用WRF-Noah陆气耦合中尺度模式,针对海南岛一次典型的海风锋事件进行了高分辨率的数值模拟,研究了海南岛土地覆盖(下垫面)变化对海风锋结构演变的影响及其机制。结果表明,海南岛土地覆盖变化对海风锋的作用是通过多种地表和植被属性的综合影响决定的。森林化试验中动力和热力作用分别抑制和促进海风锋的发展,对海风锋的影响是两者共同作用的结果;反照率的减小引起净辐射的增大,从而使感热通量小幅增加,使低层大气增温而增加海陆温度梯度,这在一定程度上增强了海风驱动力,但地表粗糙度的增大减弱了海风风速,进一步减弱了海风锋传播距离和上升速度。然而,由于海南岛森林覆盖面积较大,导致森林化试验与控制试验中海风锋的整体差异较小。相比之下,荒漠化试验中热力和动力作用均有利于海风锋的发展;反照率的增大和叶面积指数的降低,改变了地表能量分配,造成潜热通量显著减小,感热通量先减少后增大,对低层大气的增温效应非常明显,从而加大了海陆温度梯度。另一方面,地表粗糙度显著减小,下垫面对海风的阻挡作用减弱,海风风速增大。因此,荒漠化试验海风锋传播距离、上升速度以及海风厚度都显著增大。

海南岛沿海城镇化对海风锋推进影响的数值模拟

本文利用中尺度模式WRF-ARW(Weather Research and Forecasting Model-Advanced Research WRF)(Version 4.0)对海南岛不同天气条件下的典型海风锋个例进行了高分辨率数值模拟,通过设计局地城镇化的敏感性试验,重点分析了海南岛沿海城镇化对海风锋推进的影响及其可能机制。研究结果表明:海南岛沿海城镇化造成的海风锋结构差异是热力作用和动力作用共同影响的结果;城镇下垫面的摩擦效应与城市热岛的增强阻碍海风向内陆推进,减弱了海风锋途经地区的降温增湿效应,造成海风锋位置相对滞后;而城镇化所引起的高海陆热力差异增强了海风风速及海风辐合,同时导致海风锋前的垂直上升气流和海风环流厚度也明显增强。海风锋发展不同时期,城镇化对海风锋的推进影响有所不同。海风锋发展初期,海陆热力差异引起的推动作用与摩擦效应的阻碍作用相抵消,导致海风锋的推进无明显影响;海风锋发展强盛阶段,城镇化条件下内陆城市与非城市之间的热力差异有所增强,阻碍了海风锋向内陆推进,导致海风锋内陆渗透距离减小。不同天气条件下城市化对海风锋推进的影响有所不同,相比于晴空天气,多云天气下城市与非城市的热力差异稍强,加强了城市热岛效应对海风推进的阻碍作用,导致海风锋滞后距离稍远。此外,当土地利用类型更换为城镇后,净辐射与陆气间交换能量减少,导致其潜热通量显著减小,感热通量值变大,从而升高了下垫面温度,增强了海风的垂直上升运动,进而造成边界层高度的升高。

渤海湾海面变化

【研究目的】海面上升,是渤海湾泥质海岸带地区全新世海陆变化最主要的影响因素。通过重建海面变化历史,有助于预测今后的变化趋势。【研究方法】全球基于实际调查的建模研究,恢复了过去数万年来较高分辨率的海面变化历史、分析了导致这种变化的各类分量的贡献。我们通过地区性相对海面变化研究,着重对地区性和区域性分量或做了定量评估、或进行了半定量推理分析,并做了具体的案例研究。【研究结果】这些研究表明,距今10~7 ka时全球海面平均上升速率是~9 mm/a,同期渤海湾西岸相对海面平均上升速率是~5.6 mm/a。这一较快的上升造成了包括渤海湾在内全球沿海平原海岸线后退(以及渤海海盆-渤海湾可能的数道沿岸堤被淹没)。但是,7 ka至今,全球与冰融水等效海面(ice-equivalent sea level,ESL)的平均上升速率降至~0.64 mm/a;5 ka以来,甚至不再上升。7 ka以来,渤海湾西岸相对上升速率是~0.46 mm/a;5.5 ka之后,进一步减弱到~0.18 mm/a。上述全球和渤海湾西岸海面变化,显示出明显的“二段式”上升特点。以~7 ka为转折点:之前与之后的上升速率相差一个数量级。对于渤海湾西岸而言,叠加在这个长达~7000年的明显减速但仍缓慢上升背景上的,是均衡掀升分量与下沉(新构造下沉+沉积自压实下沉)分量的相互抵消。于是,全球性海面的缓慢上升、区域性均衡调整造成的掀升与局地下沉,这三者的复杂博弈,形成了长达~7000年的、经常受高潮水影响的渤海湾西岸障壁岛型贝壳堤-潟湖盐沼洼地周期性交替的沿海地形地貌格局。1870 CE至今的150余年间,全球海面平均上升速率~1.7 mm/a,近10余年来更加速至3.7 mm/a,渤海湾同时期I堤海岸线向海侧的前凸岸段平均蚀退1~3 km。【结论】我们推断1870CE以来的全球气温上升-海面上升与渤海湾同时期海岸线蚀退可能具因果关系。21世纪全球变暖及因此引起海面~6~8 mm/a上升的预测,是1870 CE至今全球加速升温-海面加速上升的必然延续。从地质学角度,这将导致渤海湾今后的“可容空间”逐步增加,为海岸线-潮间带蚀退、盐沼湿地退化提供条件,从而将可能导致持续了~7000年的贝壳堤障壁岛-潟湖盐沼地貌过程的终止,转入与7 ka之前相似的海面上升加速时的沿岸堤-沿海低地模式。以上基于全球研究及渤海湾实际调查结果做出的推断,将对渤海湾泥质海岸带的中长期发展产生影响。

多套降水产品在海南岛的适用性评估

使用卫星遥感技术进行全球范围的降水观测已成为当前热点。然而,热带海岛地区因其气候特殊和地形复杂,遥感降水数据的精度评估尚未充分研究。文章以海南岛为研究区,利用小时尺度的站点数据对CMORPH、CHIRPS、GsMAP、GPM、MSWEP、ERA5-Land和PERSIANN进行多尺度系统评估,分析各类产品在该区域的降水探测能力。结果表明:1)相比于其他5种降水产品,GsMAP和GPM在不同时间尺度上均具有更优表现,相关性强,误差小,对各级降水的探测成功率较高。在3 h尺度上,GPM和GsMAP的相关系数分别为0.53和0.52;在日尺度上,GPM和GsMAP的相关系数分别为0.73和0.74。2)在年降水量对比中,过去20年海南岛的年平均降水量呈现波动中变化趋势,平均值为1776.4 mm/a。CMORPH的年平均值为1765.1 mm/a,与CHM-PRE数据集最为接近,误差较小。3)在空间分布格局研究中,GsMAP的降水量范围为1337.9~2287.0 mm,与站点观测数据(996.9~2368.9 mm)最为接近,呈现东部多于西部,西南山区多于东北平原的环状分布格局,尤其在海南岛东南部的高值中心区域,二者较吻合。4)在降水趋势分析中,CMORPH、ERA5-Land、GPM、MSWEP、CHIRPS和PERSIANN在海南岛部分地区呈现增加趋势,而GsMAP呈现较为强烈的增加趋势。5)在极端降水事件分析中,GPM能较好地模拟海南岛台风降水事件的时空演变特征。因此,在开展海南岛降水研究工作时,GsMAP和GPM是比较合适的选择。