Using autologistic spatial models to simulate the distribution of land-use patterns in Zhangjiajie, Hunan Province

Nowadays, spatial simulation on land use patterns is one of the key contents of LUCC. Modeling is an important tool for simulating land use patterns due to its ability to integrate measurements of changes in land cover and the associated drivers. The conventional regression model can only analyze the correlation between land use types and driving factors but cannot depict the spatial autocorrelation characteristics. Land uses in Yongding County, which is located in the typical karst mountain areas in northwestern Hunan province, were investigated by means of modeling the spatial autocorrelation of land use types with the purpose of deriving better spatial land use patterns on the basis of terrain characteristics and infrastructural conditions. Through incorporating components describing the spatial autocorrelation into a conventional logistic model, we constructed a regression model （Autologistic model）, and used this model to simulate and analyze the spatial land use patterns in Yongding County. According to the comparison with the conventional logistic model without considering the spatial autocorrelation, this model showed better goodness and higher accuracy of fitting. The distribution of arable land, wood land, built-up land and unused land yielded areas under the ROC curves （AUC） was improved to 0.893, 0.940, 0.907 and 0.863 respectively with the autologistic model. It is argued that the improved model based on autologistic method was reasonable to a certain extent. Meanwhile, these analysis results could provide valuable information for modeling future land use change scenarios with actual conditions of local and regional land use, and the probability maps of land use types obtained from this study could also support government decision-making on land use management for Yongding County and other similar areas.

Relationship between Sex Ratio at Age 0 to 4 and Geographical Environment in China

The Relationship between sex ratio at age 0 to 4 and altitude in China is quantitatively investigated by using Geographical Information System(GIS)technology in this paper.The results show that the counties with high sex ratio at age 0 to 4 in 1990 and 2000 are mainly distributed on the east of the well-known Chinese population division,Anhui-Tengchong line,and there is high negative correlation between sex ratio at age 0 to 4 and altitude in Chinese counties. There are highest sex ratio at age 0 to 4 in the regions under 100 meters,but this ratio over 3200 meters falls into the normal range.And the sex ratio at age 0 to 4 continues to fall down when the altitude rises. So the geographical environment evidently affects the sex ratio at birth.There is higher sex ratio at birth in lower-altitude regions.The effect with altitude may be associated with the ambient tempeture.

Indexing habitat suitability and human-elephant conflicts using GIS-MCDA in a human-dominated landscape

Concerns for biodiversity loss, wildlife conservation, and habitat destruction have dominated the policy agenda worldwide for decades. Unsustainable human-induced development and negative interaction between humans and wildlife have emerged as predominant issues globally. The present study deals with human and elephant conflicts (HEC) in the Polpitigama Divisional Secretariat, Sri Lanka, which is located in the Kahalla-Pallekele elephant corridor and connects Wilpattu and Kaudulla wildlife sanctuaries. The research objectives are identifying spatial patterns of elephant habitat suitability and probable risk zones for HEC. The elephant habitat suitability and HEC risk zones were identified on spatial and temporal scales using Geographic Information System integrating Multi-Criteria Decision Analysis. Different factors, including habitat suitability, distance to roads, distance to croplands, distance to forests and protected areas, settlements, and population density, were considered to determine HEC risk zones in the area. Topography, water, and vegetation criteria are considered when determining elephant habitat suitability. The results of the Analytic Hierarchy Process run the spatially explicit model. The results revealed that of the total area, 15.3% is very highly suitable for elephant habitats, while the least suitable areas contribute only 4%. About 33.8% of the area is moderately suitable for elephants. The risk map indicates that 23.7% of the total area is under very high risk for HEC, and the least risk areas only account for 5.4%. About 26.2% of the area falls under the moderate risk zone for HEC. Since the model considered three aspects of HEC, it will help policymakers in wildlife conservation to avoid and minimize the HEC.

Monitoring lake changes of Qinghai-Tibetan Plateau over the past 30 years using satellite remote sensing data

During the years 2006–2009,lakes in the Qinghai-Tibetan Plateau(QTP)were investigated using satellite remote sensing strategies.We report the results of this investigation as well as follow-up research and expanded work.For the investigation,we mainly focused on lakes whose areas are more than 1 km2.The remote sensing data that we used included 408 scenes of CBERS CCD images and 5 scenes of Landsat ETM?images in Qinghai Province and Tibet Autonomous Region.All these data were acquired around years 2005–2006.Besides remote sensing images,we also collected 1,259 topographic maps.Numbers and areas of lakes were analyzed statistically,which were then compared with those coming from the first lake investigation(implemented between the1960s and 1980s).According to our investigation,up to and around year 2005–2006,the total number of lakes in the QTP was 1,055(222 in Qinghai and 833 in Tibet),accounting for more than 30%of that of China.Thirty newborn lakes with area[1 km2were found,and 5 dead lakes with initial area[1 km2were also found.Among those 13 big lakes([500 km2),Yamzhog Yumco had seriously shrunk,and it has continued to shrink in recent years;Qinghai Lake had shrunk during the period,but some new researches indicated that it has been expanding since the year 2004;Siling Co,Nam Co,and Chibuzhang Co had expanded in the period.We divided the newborn lakes into six categories according to their forming reasons,including river expansion,wetland conversion,etc.The changes of natural conditions led to the death of four lakes,and human exploitation was the main reason for the death of Dalianhai Lake in Qinghai.We picked out three regions which were sensitive to the change of climate and ecological environment:Nagqu Region,Kekexili Region,and the source area of the Yellow River(SAYR).Lakes in both Nagqu and Kekexili have been expanded;meanwhile,most lakes in the SAYR have obviously been shrunk.These regional patterns of lake changes were highly related to variations of temperature,glacier,precipitation,and evaporation.Our investigation and analysis will provide references for researches related to lake changes in the QTP and the response to climate fluctuations.