Liu Gaohuan

Characteristics of landscape information Tupu of the Yellow River swings and its subdeltas during 1855-2000

Based on the theories and methods of cartography on spatial pattern and temporal evolution in Geo-information Tupu (Carto-methodology in Geo-information, CMGI) and the quantitative measurements of pattern and process in landscape ecology, the methodology of landscape information Tupu in studying the swing process of the Yellow River (YR) over the Yellow River Delta (YRD) during 1855–2000 has been demonstrated. The main content includes: (1) methodology of landscape information Tupu; (2) evolution process Tupu of YR rump channels; (3) evolution process Tupu of the 7 pieces of subdeltas in YRD during 1855–2000; (4) landscape information Tupu of the modern YRD and the current YRD; (5) landscape information Tupu of YR rump channels on the 7 pieces of subdeltas during 1855–2000; and (6) corridor-matrix landscape information Tupu by YR swings. The methodology of landscape information Tupu here is still primary but we hope that it could provide a new tool for exploring an integrated research on spatiotemporal approaches for landscape “pattern and process”.

Remote Sensing Monitoring of Surface Characteristics in the Badain Jaran, Tengger, and Ulan Buh Deserts of China

Deserts and sandy land in northern China are very susceptible to sandy desertification and are the main source of sand-dust storms of Asian dust. However, because of the complex factors involved, descriptions of the relationship between sandy desertification and surface characteristics in these regions are lacking. We monitored the surface characteristics and their changes in time using information about soil, vegetation, and landforms in the Badain Jaran Desert (BJD), Tengger Desert (TD), and Ulan Buh Desert (UBD) in the northern China. The monitoring was done using tasseled cap angle (TCA), disturbance index (DI), and topsoil grain size index (TGSI) from Moderate Resolution Imaging Spectroradiometer (MODIS) images combined with a decision tree classification. Results showed that the TD had higher topsoil fine sand content, and the ratio of non-vegetated to vegetated areas was similar with that in the UBD. Northeast-southwest coarse sand dunes with thin interdune (NECTI) dominated the BD, fine sand dunes (FSD) dominated the TD, and a combination of northeast-southwest coarse sand dunes with wide interdune (NECWI) and northwest-southeast coarse sand dunes with wide interdune (NWCWI) dominated the UBD. From 2000 to 2015, in the BJD the area of the NECTI, non-sand dune (Non) and potential sand sources (PSS) increased, whereas the area of the NECWI, FSD and NWCWI decreased, indicating a improve process in the BJD. In the TD, the area covered by Non increased, whereas the area covered by PSS, NECWI, NECTI, FSD, and NWCWI decreased from 2000 to 2015. The area covered by the various surface characteristic types fluctuated annually in the UBD from 2000 to 2015. Changes in surface characteristics reflect the combined effects of natural conditions and human activity. The findings of our study will assist scientists and policy makers in proposing different management techniques to combat sandy desertification for the different surface characteristics of these regions.