Ecological environmental quality evaluation and driving factor analysis of the Lijiang River Basin,based on Google Earth Engine

For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region.

Landscape Impact Assessment of Regulation Project in Lion Mountain of Lijiang City

The research advances of the technology of landscape impact assessment in China and other countries are introduced at first.And then aiming at the characters of the environmental regulation project,the assessment principles and research methods are proposed.Two typical viewpoints and a representative protection area in the project area are selected to respectively make a landscape impact assessment.Meanwhile,this research describes in details how to apply Map Overlays,Compared Evaluation and Visual Factors Evaluation in the process.

Empirical Research on Tourism Authenticity of Ancient Cultural City——A Case Study of Lijiang Ancient City in China

On the basis of tourism authenticity theory and field investigation and analysis of Lijiang ancient city, the paper had explored tourists' tourism authenticity, and further revealed the inner relation between tourism authenticity and tourism motivation of ancient cultural cities. It was found that ancient cultural cities generally had the highest objective authenticity, followed by existential, constructive and post-modern authenticity. As for tourism motivation, motivation of knowledge function, of reward maximization, of punishment minimization, of self-esteem and of self-fulfillment presented to diminish progressively. Relationships between four types of tourism authenticity and five types of tourism motivations also varied from each other. It had enriched empirical quantitative research results of domestic tourism authenticity in theory, and provided application value for the research on realistic tourism market and planning activity based on tourists in practice.

Research on Development of High-quality Tobacco Leaves in Lijiang Jinsha River Region

The importance of high-quality tobacco leaves with specific characteristics in Lijiang to the development of key cigarette brands was analyzed.The meaning,formation basis and condition of high-quality tobacco leaves in Lijiang Jinsha river region was put forward in this study and the strategies on developing quality tobacco leaves were provided.

Lijiang to Cooperate With Alipay "Internet+" to Build "Blue Lijiang" Smart Travel

On September 20,Lijiang municipal government and Ant Financial signed a strategic cooperation agreement to fully connect the entire Lijiang Town into Alipay,which aims to build a 'blue Lijiang' and enable Lijiang to become the fourth Alipay 'future airport' after Beiing,Shanghai,Hangzhou and Chongqing.In Lijiang Town,tourists

Lijiang 2.4-meter Telescope and its instruments

The Lijiang 2.4-meter Telescope(LJT), the largest common-purpose optical telescope in China,has been available to the worldwide astronomical community since 2008. It is located at the Gaomeigu site,Lijiang Observatory(LJO), in the southwest of China. The site has very good observational conditions.During its 10-year operation, several instruments have been equipped on the LJT. Astronomers can perform both photometric and spectral observations. The main scientific goals of LJT include recording photometric and spectral evolution of supernovae, reverberation mapping of active galactic nuclei, investigating the physical properties of binary stars and near-earth objects(comets and asteroids), and identification of exoplanets and all kinds of transients. Until now, the masses of 41 high accretion rate black holes have been measured, and more than 168 supernovae have been identified by the LJT. More than 190 papers related to the LJT have been published. In this paper, the general observation conditions of the Gaomeigu site is introduced at first. Then, the structure of the LJT is described in detail, including the optical, mechanical, motion and control system. The specification of all the instruments and some detailed parameters of the YFOSC is also presented. Finally, some important scientific results and future expectations are summarized.

Rapid instrument exchanging system for the Cassegrain focus of the Lijiang 2.4-m Telescope

As a facility used for astronomical research, the Lijiang 2.4-m telescope of Yunnan Astronomical Observatories, requires the ability to change one auxiliary instrument with another in as short a time as possible. This arises from the need to quickly respond to scientific programs （e.g. transient observation, time domain studies） and changes in observation conditions （e.g. seeing and weather conditions）. In this paper, we describe the design, construction and test of hardware and software in the rapid instrument exchange system （RIES） for the Cassegrain focal station of this telescope, which enables instruments to be quickly changed at night without much loss of observing time. Tests in the laboratory and at the telescope show that the image quality and pointing accuracy of RIES are satisfactory. With RIES, we observed the same Landolt standard stars almost at the same time with the Princeton Instruments VersArray 1300B Camera （PICCD） and the Yunnan Faint Object Spectrograph and Camera （YFOSC）, while both were mounted at the Cassegrain focus. A quasi-simultaneous comparison shows that the image quality of the optical system inside the YFOSC is comparable with that provided by the PICCD.

Seismotectonic environment of occurring the February 3, 1996 Lijiang M=7.0 earthquake, Yunnan Province

Lijiang-Daju fault, the seismogenic fault of the 1996 Lijiang M=7.0 earthquake, can be divided into Lijiang-Yuhu segment in the south and Yuhu-Daju segment in the north. The two segments show clear difference in geological tectonics, but have the similar dynamic features. Both normal dip-slip and sinistral strike-slip coexist on the fault plane. This kind of movement started at the beginning of the Quaternary (2.4~2.5 Ma B.P.). As to the tectonic types, the detachment fault with low angle was developed in the Early Pleistocene and the normal fault with high angle only after the Mid-Pleistocene (0.8 Ma B.P.). Based on the horizontal displacements of gullies and the vertical variance of planation surfaces cross the Lijiang-Daju fault at east piedmont of Yulong-Haba range, the average horizontal and vertical slip rates are calculated. They are 0.84 mm/a and 0.70 mm/a since the Quaternary and 1.56 mm/a and 1.69 mm/a since the Mid-Pleistocene. The movements of the nearly N-S-trending Lijiang-Daju fault are controlled not only by the regional stress field, but also by the variant movement between the Yulong-Haba range and Lijiang basin. The two kinds of dynamic processes form the characteristics of seismotectonic environment of occurring the 1996 Lijiang earthquake.

Impacts of Yulong Mountain Glacier on Tourism in Lijiang

The glacier on the Yulong Mountain is one of the most important attractions in Lijiang, Yunnan, China. But it keeps retreating these years due to global warming, which is bound to influence regional tourism significantly in Lijiang. This study estimates the effects of the glacier retreat of the Yulong Mountains on tourism there. Primary data were collected through a visitor survey including demographics, motives, lengths of stay, and opinions about each tourism resource from tourists to Lijiang, as well as questions about which scenic spot（s） they had visited or would visit, how much they expended per day during their visit and how their visiting behavior would be changed upon the hypothesis that the glacier would disappear. These data were used to analyze the proportion of the contribution of glacier to the tourism in Lijiang and estimate the impact of glacier on the regional tourism quantitatively. According to the survey, it could be concluded that three quarters of the tourists to Lijiang were interested in the Yulong Mountain glacier, indicating that the glacier possesses notable appeal for sightseeing tourists. The results of our analysis showed that about 689,013-1,508,247 tourists, accounting for 19.63-42.97 % of the total 3,510,000 domestic tourists to Lijiang in 2004, would not come to Lijiang in the absence of the glacier, resulting in a possible direct economic loss of 84,382,508-184,713,011 USD （viz. 700,374,824-1,533,117,993 RMB） and a markedly decrease in the attraction radius.

Astronomical Site Monitoring System at Lijiang Observatory

We installed two sets of Astronomical Site Monitoring Systems(ASMSs)at Lijiang Observatory(GMG),for the running of the 2.4-meter Lijiang optical telescope(LJT)and the 1.6-meter Multi-channel Photometric Survey Telescope(Mephisto).The Mephisto is under construction.The ASMS has been running on robotic mode since 2017.The core instruments:Cloud Sensor,All-Sky Camera and AutonomousDIMM that are developed by our group,together with the commercial Meteorological Station and Sky Quality Meter,are combined into the astronomical optical site monitoring system.The new Cloud Sensor's Cloud-Clear Relationship is presented for the first time,which is used to calculate the All-Sky cloud cover.We designed the Autonomous-DIMM located on a tower,with the same height as LJT.The seeing data have been observed for a full year.ASMS's data for the year 2019 are also analysed in detail,which are valuable to observers.

Study on a gravity precursor mode of the M_S=7.0 Lijiang earthquake

To study the seismogeny process or the precursory behavior of the 1976 MS=7.0 Lijiang earthquake, we analyze the repeat gravity data with high precision from the Western Yunnan Earthquake Prediction Experiment Area (WYEPEA) and the related results of geology and geophysics survey in this paper. Considering the gross errors caused by observation data and model difference, we have firstly inverted the slip distribution of the main active faults with time based on the robust Bayesian least squares estimation and multi-fault dislocation model. The re-sults show that the slip changes of the faults with time from 1990 to 1997 obviously reflect the preparation process of the Lijiang earthquake. The images of main precursor mode have the characteristic of main shock-after shock type, which is agreement to the model of coupling movement between crust density and crust deformation (DD mode of coupling movement).

Preliminary estimation for the focal mechanisms of 1996 Lijiang main shock in Yunnan Province and studies of related problems

The mechanisms of the February 3, 1996 Lijiang main shock, Yunnan Province, are estimated by using the principle to inverse the mechanisms of two point sources simultaneously. The results are that the main shock of Lijiang consists of two large ruptures, the time difference and the distance between the two ruptures are about 12 s (by the inversion) and about 26 km respectively. An extensional normal with strike-slip fault in about the north-south direction was formed by the first rupture, the mechanism of the second rupture is to be further studied. The method to inverse mechanisms of two point sources at the same time and the results obtained by directly analyzing P waveform records of the main shock are introduced, some related problems are also discussed. The Wuding earthquakes of October, 1995 and the Lijiang earthquake are considered to be the manifestation of the same dynamic process at different temporal and spatial points and the occurrence order of the two earthquakes is related to the direction of dynamics transmission.

Analyses on gravity variation before and after the Lijiang earthquake based on a finite rectangular dislocation model

The methods were discussed to calculate the gravity variation due to crustal deformation based on a model of dis-location on a finite rectangular plane. Taking the Lijiang MS=7.0 earthquake as an example the calculating princi-ple of fault parameters were determined, and the results were given. Of particular interests were the characteristics of the gravity variations in different dislocation types. With comparison between the calculated results and the practical measurements, it was found that the model could to some extent account for the observations. But it failed to give explanations to the more far spatial gravity variation.

The middle-long term prediction of the February 3,1996 Lijiang earthquake(M_S=7) by the "criterion of activity in quiescence

Earthquake activities in history are characterized by active and quiet periods. In the quiet period, the place where earthquake M_≥6 occurred means more elastic energy store and speedy energy accumulation there. When an active period of big earthquake activity appeared in wide region, in the place where earthquake (M_≥6) occurred in the past quiet period, the big earthquake with magnitude of 7 or more often occur there. We call the above-mentioned judgement for predicting big earthquake the 'criterion of activity in quiescence'. The criterion is relatively effective for predicting location of big earthquake. In general, error of predicting epicenter is no more than 100 km. According to the criterion, we made successfully a middle-term prediction on the 1996 Lijiang earthquake in Yunnan Province, the error of predicted location is about 50 km. Besides, the 1994 Taiwan strait earthquake (M_s=7.3), the 1995 Yunnan-Myanmar boundary earthquake (M_s=7.2) and the Mani earthquake (M_s=7.9) in north Tibet are accordant with the retrospective predictions by the 'criterion of activity in quiescence'. The windows of 'activity in quiescence' identified statistically by us are 1940-1945, 1958-1961 and 1979-1986. Using the 'criterion of activity in quiescence' to predict big earthquake in the mainland of China,the earthquake defined by 'activity in quiescence' has magnitude of 6 or more; For the Himalayas seismic belt, the Pacific seismic belt and the north-west boundary seismic belt of Xinjiang, the earthquake defined by 'activity in quiescence' has magnitude of 7, which is corresponding to earthquake with magnitude of much more than 7 in future. For the regions where there are not tectonically and historically a possibility of occurring big earthquake (M_s=7), the criterion of activity in quiescence is not effective.

Site amplification in the Lijiang Valley,Yunnan Province

The site amplifications for three stations, Libin (LIBI), Baisha (BASH) and Yulong (YULG) situated respectivelyin the southern, middle and northern parts of Lijiang Valley, are obtained by analyzing the S-wave soil/bedrockand microtremor horizontal/vertical spectral ratios. The data are digital recordings for the aftershocks of the Lijiang Ms=7.0 earthquake on February 3, 1996. In the frequency range of 1-4 Hi, the S-wave soil/bedrock spectralratio of E-W component for LIBI is the largest and amounts to 4.5. The microtremor soil N-S/vertical (V) spectralratio is approximate to l, E-W/V is about 4.5 and the same with above soil/bedrock spectral ratio. It is shown thatthe vertical and N-S components of microtremor have not been amplified by the soil and the Nakamura's method isapplicable. With this method, the microtremor spectral ratios for BASH and YULG are further evaluated. Theyhave similar characteristics with that of LIBI. In above frequency range, both N-S/V ratios are approximate to 1,while the E-W/V ratio is about 6 for BASH, 4.5 for YULG. Ljiang Valley is characterized by the trans-valleydirectional site response.

Variation Law of Organic Contaminant in Lijiang River

Water environmental capacity of Lijiang River within Guilin city is researched. The relationship among concentration of pollutants and flow rate as well as water environmental capacity of Lijiang River is discussed. The changes of pollutant concentration in past years is analyzed. The results show that there exists a certain value of flow rate corresponding to a certain average concentration of pollutants on the upper and lower sections of the research area. If flow rate is greater than that value, the concentration of pollutants will decrease with the increase of flow. While the result will be the contrary when river flow is smaller than that value, that is to say, the concentration will increase with the increase of flow. To be aware of this regularity is of vital significance in water resource protection and comprehensive utilization[1].

Analysis on the Flood Rainstorm in the Lijiang River of Guilin

[Objective] The research aimed to study the flood rainstorm in the Lijiang River of Guilin. [Method] By using the observation data of flood rainstorm and water level in the Lijiang River, the flood rainstorm standard in the Lijiang River was delimited. Via the analysis on the spatial and temporal distribution, weather situation of flood rainstorm in South China, the flood rainstorm in the Lijiang River was systematically studied. [Result] The flood in the Lijiang River closely related to the duration and intensity of torrential rain in the upstream. When the daily rainfall in the upstream ≥100 mm, or the daily rainfall in above continuous 2 d ≥ 50 mm, the flood was easy to happen in the Lijiang River. During April-July in every year, the flood was possible to happen in the flood season in the Lijiang River but mainly happened during May-June. The period of flood water level variation in the Lijiang River was ten-year. When the highest water level was lower than the warning stage (145.00 m) in the year, most of highest water level in the next year surpassed the warning stage and reached above 146.00 m. The weather type which caused the flood rainstorm could be divided into the frontal zone type (frontal zone southward movement type, stationary front northward movement type) and the low pressure vortex type. The upstream in the Lijiang River was the rainstorm center in Guilin area and the key zone of flood rainstorm in the Lijiang River. The special terrain provided the favorable condition for the multi-occurrence of rainstorm. [Conclusion] The research provided the basis for the forecast of flood rainstorm in the Lijiang River.

Impression Remolding: On Design of Lijiang Railway Station

This paper takes "impression remolding" as the hint of design concept, analyzes uniqueness and correlation of Lijiang Train Station, and also multiple design techniques of integrating regional cultural elements, such as roofi ng cluster.

How to Improve Tea Farmers' Livelihoods in the Sightseeing Place along Lijiang River Valley?

The unbalance of tourism development and comparative superiority of the tea industry brings new opportunities to the poor groups along Lijiang River Valley for improving their livelihoods. From the perspective of sustainable livelihoods,we analyze the problems in tea farmers' livelihoods,such as lack of fund,low capacity in price negotiation,and high cost of resisting various risks. Recommendations are put forward for tea farmers to improve their livelihoods through ways of enterprise cooperation,innovative marketing,brand cultivation,industrial integration and so on.

Lijiang Tourism Prediction Based on the Gray Dynamic GM Model and Computer Simulation

[Objective] Taken the Linjiang tourism as an example, tourism forecast system was established, difficulties related to the work of tourist area were solved. [Method] Dynamic predicted response model of Lijiang tourism market was established, through the gray correlation model GM (1, 1) and time-series method, using a computer simulation program for the actual model of operation, Lijiang tourism prospects were predicted and predicting results were evaluated. [Result] Total revenue of model gray parameter of Lijiang tourism a= 0.572 3 from 2009 to 2011, internal control parameters u=0.393 7, x(t+1) =-0.563 3exp(-0.572 3t)+0.688 0; total reception numbers of model gray parameter of Lijiang tourism a = 0.125 6, internal control parameters u = 344. 326 0, x(t+1)=3 102.483 5 exp(0.125 6 t)-2 741.283 5. Test results of two models showed that fitting degrees were good, and at the same time predicted that total revenue of Lijiang tourism reached 13 000 000 000, and total reception numbers reached 8 800 000. [Conclusion] This predicted system can carry out precision forecast for other tourist areas when cannot get all the information.