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Preparation of landslide susceptibility map is the first step for landslide hazard mitigation and risk assessment. The main aim of this study is to explore potential applications of two new models such as two-class Kernel Logistic Regression (KLR) and Alternating Decision Tree (ADT) for landslide susceptibility mapping at the Yihuang area (China). The ADT has not been used in landslide susceptibility modeling and this paper attempts a novel application of this technique. For the purpose of comparison, a conventional method of Support Vector Machines (SVM) which has been widely used in the literature was included and their results were assessed. At first, a landslide inventory map with 187 landslide locations for the study area was constructed from various sources. Landslide locations were then spatially randomly split in a ratio of 70/30 for building landslide models and for the model validation. Then a spatial database with a total of fourteen landslide conditioning factors was prepared, including slope, aspect, altitude, topographic wetness index (TWI), stream power index (SPI), sediment transport index (STI), plan curvature, landuse, normalized difference vegetation index (NDVI), lithology, distance to faults, distance to rivers, distance to roads, and rainfall. Using the KLR, the SVM, and the ADT, three landslide susceptibility models were constructed using the training dataset. The three resulting models were validated and compared using the receive operating characteristic (ROC), Kappa index, and five statistical evaluation measures. In addition, pairwise comparisons of the area under the ROC curve were carried out to assess if there are significant differences on the overall performance of the three models. The goodness-of-fits are 92.5% (the KLR model), 88.8% (the SVM model), and 95.7% (the ADT model). The prediction capabilities are 81.1%, 84.2%, and 93.3% for the KLR, the SVM, and the ADT models, respectively. The result shows that the ADT model yielded better overall performance and accurate results than the KLR and SVM models. The KLR model considered slightly better than SVM model in terms of the positive prediction values. The ADT and KLR are the two promising data mining techniques which might be considered to use in landslide susceptibility mapping. The results from this study may be useful for landuse planning and decision making in landslide prone areas. [ABSTRACT FROM AUTHOR]

• Pedodiversity was higher in southern China than northern China. • Analysis unit sizes had little effect on spatial pattern analysis of pedodiversity. • Overall, parent material and topography were major driving factors of pedodiversity. Knowledge of pedodiversity is essential for the protection and management of soil resources. The analysis of regional pedodiversity is typically based on analysis units of different sizes. However, the effect of analysis unit size on regional pedodiversity studies remains unclear. In this paper, the effects of analysis unit size on the studies of spatial distribution characteristics of pedodiversity and its major driving factor in China were studied based on two levels of geomorphological regions. A combined method encompassing the moving window, soil richness, and Shannon index was used to analyze the spatial distribution pattern of pedodiversity in China. A geographical detector was used to determine a major driving factor of pedodiversity in each geomorphological region. The spatial distribution pattern of pedodiversity based on two levels of geomorphological regions both showed that pedodiversity was highest in southern China, followed by northern China, and lowest in the Qinghai-Tibet Plateau, which indicated that analysis unit sizes had little effect on the study on spatial distribution pattern of pedodiversity. The major driving factor analysis of pedodiversity based on first-order geomorphological regions showed that the major driving factor in China, except for the Qinghai-Tibet Plateau, was parent material. However, the results based on second-order geomorphological regions showed that the major driving factors of pedodiversity, except for the Qinghai-Tibet Plateau, were parent material and topography in hilly regions, topography in mountainous regions, and parent material in regions occupied by alluvial landforms, aeolian landforms, or karst landforms. The driving factor analysis of pedodiversity based on the two levels of geomorphological regions suggested that the effect of the analysis unit sizes on the major driving factor study was significant. The results of this study are an important supplement for pedodiversity studies. [ABSTRACT FROM AUTHOR]

• Distinct slope features of China's cropland conversion were detected. • Cropland conversion in flat areas and steep areas triggered diverse risks. • "Grain for Green project" should be adjusted based on slope features of sub-regions. • Upslope reclamation and downslope loss of cropland indicated develop conflicts. Cropland conversion is a significant theme of the influence of human activities on ecological systems and global food security. Conventionally, cropland conversion in China has been deemed to match the dynamic balance of cropland resources well and to ensure food security for the whole country. However, local studies have presented some conflicting signs that call for an integrated analysis from a national viewpoint. In this paper, by considering the significance of slope in cropland-related natural and socioeconomic issues, we explore the slope features of China's cropland conversion during 2000–2015 and endeavor to identify some potential risks hidden in the process. High-resolution remotely sensed images, digital elevation model and spatial analytical methods are adopted to conduct the analysis. The results show that, the features of cropland conversion in diverse slope division areas are all distinct. Some risks indicated by these conversion features can be identified as follows: (1) unsuitable reclamation of cropland in flat areas causes ecological damage, (2) the invasion of sparsely populated construction land on cropland in steep areas has a dramatic impact on the local area, (3) excessive greening in Northwest and Northeast China, and insufficient greening in Southwest China are not healthy for regional sustainability, (4) cropland's upslope reclamation and downslope loss pose potential risks for food security. In the context of dynamic balance management and other related national policies, cropland conversion in China is not as optimistic as former surveys have indicated, and promoted measures should be elaborately adjusted based on local conditions. [ABSTRACT FROM AUTHOR]

• Contour tillage reduced runoff and sediment yield compared to traditional tillage. • Topography and management practices affected the effectiveness of contour tillage. • Climate affected the capacity of contour tillage in reducing runoff. • Soil properties affected the benefits of contour tillage in reducing sediment yield. Contour tillage is a widely practiced conservation tillage in China. The beneficial effects of contour tillage in controlling water erosion have been recognized, further researches are needed to quantify the effectiveness of contour tillage in reducing water erosion and identify the influencing factors in China. We conducted a nationwide meta-analysis based on 229 runoff and 290 sediment paired observations from 47 published papers from national and international literatures. The results showed that compared to traditional tillage, the benefits of contour tillage in China with respect to runoff and sediment reduction were 35.86% and 49.02%, respectively. Sediment yield reduction by contour tillage was greater under simulated rainfall than under natural rainfall. Runoff reduction by contour tillage decreased with the increasing mean annual precipitation and temperature, while sediment yield reduction was not affected by climate factors. Contour tillage in loamy soils and soils with organic carbon content > 1% showed the greatest benefits in reducing sediment yield (64.26% and 52.52%, respectively). The greatest runoff and sediment yield reduction (61.04% and 67.24%, respectively) occurred at slope length > 20 m. The greatest runoff reduction by contour tillage was found for tillage duration > 10 years (44.08%), while the greatest sediment yield reduction occurred at tillage duration ≤ 5 years (52.89%). The effectiveness of contour tillage under cereals was better for runoff and sediment yield reduction compared to legumes and rotation as consequence of the high biomass quantity and lower mineralization rate of cereal straw. Our results conclude that contour tillage is an effective measure for controlling water erosion, and its benefits in reducing runoff and sediment yield are different according to the climate, soil properties, topography and management practices. [ABSTRACT FROM AUTHOR]