The enhancement of the park cooling effect (PCE) is one method used to alleviate the urban heat island (UHI). The cooling effect is affected by park factors; however, the importance of these factors in the case of the PCE is still unclear. Optimizing or planning urban parks according to the importance of the influencing factors can effectively enhance the PCE. Herein, we selected 502 urban parks in 29 cities in China with three different climatic regions and quantified the PCE based on the park cooling intensity (PCI) and park cooling area (PCA). Subsequently, the relative importance of the influencing factors for the PCE was compared to identify the main factors. Consequently, certain park planning suggestions were proposed to enhance the cooling effect. The results show that: (1) the PCE increased in the order of arid/semi-arid, semi-humid, and humid regions. (2) The main factors of the PCI differed significantly in different climatic regions; however, the waterbody within a park significantly affected the PCI in all three climates. However, for the PCA, park patch characteristics were the dominant factor, contributing approximately 80% in the three climates regions. (3) In arid/semi-arid and semi-humid regions, the optimal area proportion of waterbody and vegetation within the park were approximately 1:2 and 1:1, respectively, and the threshold value of the park area was 16 ha. In contrast, in the humid region, the addition of a waterbody area within the park, to the best extent possible, enhanced the PCI, and the threshold value of the park area was 19 ha. The unique results of this study are expected to function as a guide to future urban park planning on a regional scale to maximize ecological benefits while mitigating the UHI.

China’s rapid urbanization has been attracting widespread interests of the economists, sociologists, and geographers all over the world in recent years. This study was conducted to analyze the network tendency of the urban system in China based on quantitative methods. In the theoretical analysis part, this paper reveals the transformation from a size-based to a network-based urban system in the urban system research and planning concept in China. Then, this paper established the network economy model and the linear model for quantitative analysis about network tendency of the urban system. The results were established based on the employment data for 18 major industry categories data and flow data of 35 cities from statistics on Chinese cities over the period 1999–2010. This paper reveals that urban networks have begun to affect the urban system increasingly more significantly, even more so than the size-based hierarchy. Further analysis shows that there will be a transition from size-based contr...

Accurate satellite precipitation estimates are vital for understanding global and largescale regional water cycles. Among the many factors influencing satellite precipitation data quality, the detection and accuracy of precipitation products at different atmospheric aerosol concentrations are not well studied. In this study, we investigated the impact of atmospheric aerosols on the accuracy of satellite precipitation products (IMERG) over North China by comparing performance metrics such as Bias, Normalized Root Mean Squared Error, probability of detection and false alarm ratio under different atmospheric aerosol conditions. The results revealed that: (1) IMERG generally exhibits poorer detectability and quantification under pollution condition. (2) Based on the error decomposition, the estimated errors in autumn and winter were dominated by false biases, which are mainly affected by atmospheric aerosols. (3) At the sensor level, the false alarm ratios (FARs) of both infrared (IR) and passive microwave (PMW) sensors show escalating trends as pollutant concentrations increase. The probability of detection (POD) of IR sensors is affected by pollution. Pollution has a significant impact on IR detection capability. Our findings suggest that atmospheric aerosols may impact the accuracy of IMERG precipitation estimates over Northern China and need to be taken into consideration in the IMERG retrieval process and data utilization.