s u m m a r y Sensitivity analysis (SA) aims to identify the key parameters that affect model performance and it plays important roles in model parameterization, calibration, optimization, and uncertainty quantification. However, the increasing complexity of hydrological models means that a large number of parameters need to be estimated. To better understand how these complex models work, efficient SA methods should be applied before the application of hydrological modeling. This study provides a comprehensive review of global SA methods in the field of hydrological modeling. The common definitions of SA and the typical categories of SA methods are described. A wide variety of global SA methods have been introduced to provide a more efficient evaluation framework for hydrological modeling. We review, analyze, and categorize research into global SA methods and their applications, with an emphasis on the research accomplished in the hydrological modeling field. The advantages and disadvantages are also discussed and summarized. An application framework and the typical practical steps involved in SA for hydrological modeling are outlined. Further discussions cover several important and often overlooked topics, including the relationship between parameter identification, uncertainty analysis, and optimization in hydrological modeling, how to deal with correlated parameters, and time-varying SA. Finally, some conclusions and guidance recommendations on SA in hydrological modeling are provided, as well as a list of important future research directions that may facilitate more robust analyses when assessing hydrological modeling performance.

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The incidence of stroke in rural China increased rapidly, particularly among middle-aged adults, along with a concurrent increase in risk factor prevalence. These findings suggest that without controlling these risk factors, stroke incidence will continue to increase over future decades in China.

The study population was recruited to the Tianjin Brain Study (TBS), a population-based study on stroke incidence and mortality from a township of Ji County in Tianjin, China, since 1985, which is ≈100 km from Beijing. The total population was 15 438 people distributed within 18 administrative villages, and 95% of residents were low-income farmers. The primary source of income was grain production; annual per capita income was <100 USD in 1991 and <1000 USD in 2010. 7 The illiteracy rate in this population was 30% in menBackground and Purpose-Sex differences in secular trends of stroke incidence are rarely reported. We aimed to explore sex differences in incidence and mortality of stroke in rural China from 1992 to 2012. Methods-In 1992, 14 920 residents were recruited to participate in the Tianjin Brain Study, a population-based study on stroke surveillance. Stroke events and all deaths were annually registered. Results-We observed 908 incident strokes (366 in women) from 1992 to 2012. Women were significantly younger than men (64±12 versus 68±11 years) in 1992 to 1998 (P=0.024). The incidence of first-ever stroke per 100 000 person-years for men was 166 in 1992 to 1998, 227 in 1999 to 2005, and 376 in 2006 to 2012; for women, the rates were 86 (1992-1998), 148 (1999-2005), and 264 (2006-2012). From 1992 to 2012, the incidence grew annually by 5.8% in men and 8.0% in women. The male/female incidence ratio declined significantly: 1.9 in 1992 to 1998, 1.5 in 1999 to 2005, and 1.4 in 2006 to 2012. There were no significant sex differences in mortality. The prevalence of obesity and diabetes mellitus, the levels of total cholesterol and triglycerides, and the age of menopause and reproductive years in women concurrently increased in 2011. Conclusions-There was a significant increase in the incidence of first-ever stroke in women annually and a declining trend in the male/female rate ratio in rural China during the past 21 years. These results suggest that stroke will become one of the major diseases affecting women in future decades in China. (Stroke. 2014;45:1626-1631.)

Background and Purpose-We investigated secular trends in the age of stroke onset and stroke incidence in a low-income population in rural China. Methods-The study population was recruited from a population-based stroke surveillance study conducted in a township in Tianjin, China, from 1992 to 2014. The trends in mean age and incidence of first-ever stroke were assessed by sex and stroke subtype. Risk factor surveys were conducted in the same population in both 1991 and 2011. Results-A total of 1053 patients experienced first-ever stroke from 1992 to 2014. The mean age of stroke onset in men significantly decreased by 0.28 years annually overall, by 0.56 years for intracerebral hemorrhage, and by 0.22 years for ischemic stroke (P<0.05). However, a similar trend was not observed in women. The age-standardized first-ever stroke incidence in the same population significantly increased across sex and stroke subtypes, increased by 6.3% overall, 5.5% for men, 7.9% for women, 4.6% for intracerebral hemorrhage, and 7.3% for ischemic stroke (P<0.05) during 1992 to 2014. Concurrently, the prevalence of hypertension, diabetes mellitus, obesity, current smoking, and alcohol consumption increased significantly in young and middle-aged adults from 1991 to 2011. Conclusions-The age of stroke onset tends to be younger among low-income population in China after the dramatic increased incidence of stroke during the gradual extension of life expectancy of population in China. These findings suggested that stroke burden will continue to increase in the long time, unless the risk factors in low-income populations are effectively controlled. (Stroke. 2016;47:929-935.

Abstract. Surface runoff from the Wei River basin, the largest tributary of the Yellow River in China, has dramatically decreased over last 51 years from 1958 to 2008. Climate change and human activities have been identified as the two main reasons for the decrease in runoff. The study period is split into two sub-periods (1958-1989 and 1990-2008) using the Mann-Kendall jump test. This study develops an improved climate elasticity method based on the original climate elasticity method, and conducts a quantitative assessment of the impact of climate change and human activities on the runoff decrease in the Wei River basin. The results from the original climate elasticity method show that climatic impacts contribute 37-40 % to the decrease in runoff, while human impacts contribute 60-63 %. In contrast, the results from the improved climate elasticity method yield a climatic contribution to runoff decrease of 22-29 % and a human contribution of 71-78 %. A discussion of the simulation reliability and uncertainty concludes that the improved climate elasticity method has a better mechanism and can provide more reasonable results.

Regional sustainable development is an important focus on natural resources management, and also is a critical requirement for socio-economic system's sustainability. Water resource is one of the most important supports for the sustainable development of society and economy. The study proposed the concept of water resources carrying capacity (WRCC) to assess the scale of economy and population that the local water resources can support. And the study took Tianjin city of China for an example, and its population size and economic scale were chosen as two main indices. Based on the historical statistical datum, the carrying index (CI) and index of water supply-demand balance (IWSD) were evaluated, and then the current WRCC in Tianjin city and its dynamic tendency were evaluated by means of the method of carrying capacity of relative resources (CCRR). The results showed that the utilization of water resources in Tianjin is inefficient for now, the dynamic trend would be partly rational after the protection policy of water resource was put into practice in 2010 and 2020, and the WRCC of Tianjin city went beyond the average WRCC of China and was roughly equal to that of Beijing city. This paper showed that the rational policies and measures should be established and implemented to make sure utilize water resources efficiently in Tianjin city.Keywords Water resources carrying capacity · Carrying capacity of relative water resources · Carrying index · Index of water supply-demand balance · Tianjin City of China

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