Post-change Period Research Articles

Analysis of an overlapping surgery policy change on costs in a high-volume neurosurgical department.

Overlapping surgery remains a controversial topic in the medical community. Although numerous studies have examined the safety profile of overlapping operations, there are few data on its financial impact. The authors assessed direct hospital costs associated with neurosurgical operations during periods before and after a more stringent overlapping surgery policy was implemented. The authors retrospectively reviewed the records of nonemergency neurosurgical operations that took place during the periods from June 1, 2014, to October 31, 2014 (pre-policy change), and from June 1, 2016, to October 31, 2016 (post-policy change), by any of the 4 senior neurosurgeons authorized to perform overlapping cases during both periods. Cost data as well as demographic, surgical, and hospitalization-related variables were obtained from an institutional tool, the Value-Driven Outcomes database. A total of 625 hospitalizations met inclusion criteria for cost analysis; of these, 362 occurred prior to the policy change and 263 occurred after the change. All costs were reported as a proportion of the average total hospitalization cost for the entire cohort. There was no significant difference in mean total hospital costs between the prechange and postchange period (0.994 ± 1.237 vs 1.009 ± 0.994, p = 0.873). On multivariate linear regression analysis, neither the policy change (p = 0.582) nor the use of overlapping surgery (p = 0.273) was significantly associated with higher total hospital costs. A more restrictive overlapping surgery policy was not associated with a reduction in the direct costs of hospitalization for neurosurgical procedures.

Attributing Changes in Streamflow to Land Use and Climate Change for 472 Catchments in Australia and the United States

A data-based method to distinguish climate and land use change impacts on streamflow has been previously developed and needs further evaluation through a large sample study. This study aims to apply the method to a large sample set of 472 catchments in the United States and Australia. The method calculates the water and energy budget of a catchment which can be translated to climate and land use induced changes in streamflow between two periods: a pre-change and post-change period. Several geographical characteristics (e.g., aridity index, average catchment slope, historical land use) were considered for the interpretation of the results. The results show that in general as expected, an increase of the annual discharge is caused by deforestation and a wetter climate, and a decrease of the annual discharge is caused by afforestation and a drier climate. In addition, changes in streamflow of American catchments are likely caused by a wetter climate, while changes in streamflow of Australian catchments are caused by a wetter or drier climate. It can be concluded that the method performs reasonably well and that the results are best explained by the location of the catchment, the aridity index and historical land use.

Quantifying the relative contribution of climate and human impacts on seasonal streamflow

Climate change and human activities have induced alterations to hydrological processes. The quantification of their impacts on streamflow is a challenge, especially at the seasonal scale due to seasonality of climate variables and human activities. In this study, the decomposition method based on Budyko equation is extended to the seasonal scale for quantifying the climate and direct human impacts on annual and seasonal streamflow changes in Huifa River basin by defining prechange period (1953–1974) and postchange period (1975–2005). The results are further verified by the monthly abcd model. Both climate change and direct human activities are found to induce a decrease in streamflow at the annual scale, with 68% of the change contributed by direct human activities. At the seasonal scale, the direct human-induced declines in streamflow account for 67% and 39% of the total changes for energy-limited and water-limited seasons, respectively; whereas, the impact of direct human activities is more pronounced during the irrigation season due to water withdrawal for irrigation. In addition, the decomposition results are analyzed for each month in the energy-limited season to reveal the effects of precipitation and operation rules of ponds and reservoirs during the flood season.

Development of a New Integrated Framework for Improved Rainfall-Runoff Modeling under Climate Variability and Human Activities

The relationship between rainfall and runoff is a complex phenomenon and understanding the physical processes, hydrological components and their impacts on response of watershed to precipitation is one of the challenging issues in watershed hydrology and planning. There is still a need to improve conceptual hydrological models in water scarce regions, such as Iran mainly because in many cases there is not enough data to fully describe this phenomenon. In this research, we aimed to present an improved and parsimonious framework that increases the performance of a conceptual model in water balance and discharge modeling for Delichay watershed located in Hablehroud basin, Iran as one of the main source of water supply for downstream fertile agricultural areas that produce a considerable amount of cereals and play a major role for food and water security of the region. In areas where data for water cycle components are not available or limited, it is recommended to use parsimonious approach in order to have an acceptable level of understanding of the system with minimum possible predictor variables. The Salas model used in current research to model water balance over the period 1983–2012 and evaluation of the results indicated an unsatisfactory performance when the entire period was modeled altogether (NSE = 0.35, d = 0.70, R2 = 0.63, RSR = 0.80, PBIAS = 4.96 and RMSE = 41.87). A key reason is that this watershed is intensively impacted by human activities and homogeneity analysis confirmed a sudden shift in runoff data during 1998–1999. Such a sudden shift reveals the role of human activities impacts on the watershed with a total reduction of 58 mm of runoff per year while the climate variability has not occurred in the region. Thus, the entire period (i.e. 1983–2012) was divided into two homogenous sub-periods of before and after the change point (i.e., pre-change and post-change periods). The results indicated that modeling performance in the sub-periods improved (e.g. the NSE was 0.77 and 0.66 for pre-change and post-change, respectively, vs. 0.35 for entire period). Meanwhile, it is revealed that water balance affected by human activities over the time and application of historical data for water balance modeling cannot be reliable without considering the homogeneous data. Since, many watersheds in the world have been affected by human activities or climate variability, it is recommended to consider the homogeneity of observed data before any application.

Impact of Climate Variabilities and Human Activities on Surface Water Extents in Reservoirs of Yongding River Basin, China, from 1985 to 2016 Based on Landsat Observations and Time Series Analysis

Yongding River is the largest river flowing through Beijing, the capital city of China. In recent years, Yongding River Basin (YDRB) has witnessed increasing human impacts on water resources, posing serious challenges in hydrological and ecological health. In this study, remote sensing techniques and statistical time series approaches for hydrological studies were combined to characterize the dynamics and driving factors of reservoir water extents in YDRB during 1985–2016. First, 107 Landsat 4, 5, 7 and 8 images were used to extract surface water extents in YDRB during 1985–2016 using a combination of water indices and Otsu threshold algorithm. Significant positive correlation was found between water extents and the annual inflow for the two biggest reservoirs, the downstream Guanting and upstream Cetian reservoirs, proving their representativeness of surface water availability in this basin. Then, statistical time series approaches including trend-free pre-whitening Mann-Kendall trend test, Pettit change-point test and double mass curve method, which are frequently used in hydrological studies, were adopted to quantify the trend of reservoir water extents dynamics and the relative contributions of climate variability and human activities. Results showed that the water extents in both reservoirs exhibited significant downward trend with change point occurring in 2001 and 2005 for Guanting and Cetian, respectively. About 74%~75% of the shrinkage during the post-change period can be attributed to human activities, among which GDP, population, electricity power production, raw coal production, steel and crude iron production, value of agriculture output, and urban area were the major human drivers. Hydrological connectivity between the upstream Cetian and downstream Guanting reservoirs declined during the post-change period. Since 2012, water extents in both reservoirs recovered as a result of various governmental water management policies including the South-to-North Water Diversion Project. The methodology presented in this study can be used for analyzing the dynamics and driving mechanism of surface water resources, especially for un-gauged or poorly-gauged watersheds.

Attribution Analysis for Runoff Change on Multiple Scales in a Humid Subtropical Basin Dominated by Forest, East China

Attributing runoff change to different drivers is vital in order to better understand how and why runoff varies, and to further support decision makers on water resources planning and management. Most previous works attributed runoff change in the arid or semi-arid areas to climate variability and human activity on an annual scale. However, attribution results may differ greatly according to different climatic zones, decades, temporal scales, and different contributors. This study aims to quantitatively attribute runoff change in a humid subtropical basin (the Qingliu River basin, East China) to climate variability, land-use change, and human activity on multiple scales over different periods by using the Soil and Water Assessment Tool (SWAT) model. The results show that runoff increased during 1960–2012 with an abrupt change occurring in 1984. Annual runoff in the post-change period (1985–2012) increased by 16.05% (38.05 mm) relative to the pre-change period (1960–1984), most of which occurred in the winter and early spring (March). On the annual scale, climate variability, human activity, and land-use change (mainly for forest cover decrease) contributed 95.36%, 4.64%, and 12.23% to runoff increase during 1985–2012, respectively. On the seasonal scale, human activity dominated runoff change (accounting for 72.11%) in the dry season during 1985–2012, while climate variability contributed the most to runoff change in the wet season. On the monthly scale, human activity was the dominant contributor to runoff variation in all of the months except for January, May, July, and August during 1985–2012. Impacts of climate variability and human activity on runoff during 2001–2012 both became stronger than those during 1985–2000, but counteracted each other. The findings should help understandings of runoff behavior in the Qingliu River and provide scientific support for local water resources management.

Understanding the hydropower exploitation’s hydrological impacts through a len of change in flow-sediment relationship: A case study in the Han River Basin, China

The water and sediment yields of rivers are changing substantially under the impacts of climate variability and anthropogenic activities, which are increasingly becoming an important research topic in the field of hydro-environmental science. This study presents a comprehensive investigation of the changes in runoff depth (h), specific sediment yield (SSY), and flow-sediment relationship at multi-temporal scales in the Han River Basin (HRB). The effects of climate variability and anthropogenic activities on SSY were quantified by employing double cumulative curve analysis. The results are as follows: (1) The annual and flood season h and SSY in the midstream (Huangzhuang Station) during the past six decades presented declining trends. The detected change points (i.e., 1968 and 1984) in SSY were linked to the reservoir and dam construction and soil and water conservation programs. The Danjiangkou (DJK) Reservoir impounded water in the flood season and supplied water in the non-flood season, which made the intra-annual distributions of h and SSY more even and the intra-annual variations more moderate in the comparisons between the pre- and post-change periods. (2) The annual and flood-season flow-sediment relationships were fitted with the power function and the sediment productive ability of runoff in the flood season was much greater than that in the non-flood season. The construction and operation of the DJK Reservoir intercepted a significant quantity of sediment; thus, the sediment transported by unit runoff largely declined. (3) The estimated relative contributions of climate variability and anthropogenic activities to the changes in SSY suggested that the anthropogenic activities played a more substantial role in the SSY decline after the transition years. Sustainable development of the HRB will face many challenges as the water and sediment discharges decrease further from the Han River into the Yangtze River. These results will provide a reference for better soil and water resource conservation and draw more attention to strengthen the river basin management.

Analysis of return periods and return levels of Yearly July–September extreme droughts in the West African Sahel

This paper aims to model the occurrence of Yearly July–September (YJAS) extreme droughts in the West African Sahel (WAS) and to estimate return periods and return levels of these events through stationary peaks-over-threshold model. For this purpose, the historical gridded monthly rainfall data from Climatic Research Unit for the period 1901–2009 were used. The results show that return levels of YJAS dry extremes have increased since 1970, implying that YJAS extreme droughts are consistently more severe after 1970 than they were before. Approximately $$62\%$$ of the WAS area in the postchange period of 1971–2009 was dominated by dry spells not longer than 1 year. The dynamics of the YJAS extremes drying trend indicate that the changes at the tails of YJAS dry extreme distribution have contributed to the dry trend in mean YJAS rainfall in the WAS. The estimated 40-year return level of these events based on 1971–2009 period was less than the average of dry extremes of the same period, suggesting that droughts could intensify in the future even though with some amelioration. Such a finding could prove helpful in anticipation of climate risks in this region where adaptive capacities are very low.

Return times and return levels of July–September extreme rainfall over the major climatic sub-regions in Sahel

Return times (RTs) and return levels (RLs) of July–September (JAS) extreme rainfall are estimated using stationary peaks-over-threshold approach through generalized pareto distribution (GPD) over the three climatic sub-regions in Sahel. Monthly rainfall data from the Climatic Research Unit were used. The period of analysis goes from 1901 to 2009. Results computed for both accumulated JAS rainfall and fractional area of extreme rainfall, indicate that JAS extreme rainfall in semiarid and sub-humid sub-regions were more frequent in the postchange period of 1971–2009 than in the prechange period of 1901–1970. The RLs of these extremes have greatly decreased after 1970. The changes at JAS extreme tails of the distribution have significantly contributed to the decrease in mean of JAS rainfall after 1970. Predicted 40-year RL shows that over each sub-region, JAS extreme rainfall are expected to be more severe after the postchange period. For the postchange period, 1999 has been detected as the most extreme year in arid and semiarid sub-regions, and 2008 in sub-humid sub-region. These events were found occurred during the manifestation of moderate La Niña. The spatial distributions of accumulated JAS rainfall associated with these years show that highest values were concentrated along the coastline of semiarid and sub-humid sub-regions, and the lowest values in the northern part of the arid sub-region. Using the GPD, the JAS extreme rainfall (fractional area) associated with 1999 and 2008 are expected at least once every 144 (40), 99 (17) and 197 (67) yr in arid, semi-arid and sub-humid sub-regions, respectively. These results highlight the importance of an analysis of extreme rainfall in Sahel based on climatic sub-regions.

Effect of Dial-Out Prefix Change on 9-1-1 Calls at a Large State University

Background: Accessing the emergency medical services system via 9–1-1 operators is an effective way for patients to seek urgent health care; however, technological advances and telecommunication practices inundate the 9–1-1 and emergency services infrastructure with unintentional calls that delay response efforts to legitimate medical emergencies. Objective: To determine whether the change in university-wide dial-out prefix from “9” to “7” reduced unnecessary calls to a 9–1-1 call center. Methods: This is a retrospective study conducted utilizing information obtained from the University of North Carolina at Chapel Hill (UNC) Department of Public Safety (DPS) call center. Call center calls received during pre-change, intervening, and post-change periods were included in the study. The cost savings, defined in time and money, resulting from the prefix change were also examined. Results: A total of 33,646 calls were made during the study period (January 11, 2010 through December 31, 2012) and included in the analysis. The prefix change was found to reduce the rate of invalid calls to the call center by 319 calls per month, resulting in a 43% reduction in total calls to the call center while preserving the rate of valid calls. The largest decrease occurred in hang-up calls (a decrease of 232 calls per month), especially those originating from the university. The prefix change was found to save the UNC DPS telecommunications division approximately $798.82 per month and the police officer division approximately $3,874.95 per month. Conclusion: A prefix change was not only beneficial to the UNC community but it also has potentially wide-reaching effects. A reduction of invalid 9–1-1 calls translates to telecommunicators having more time available to handle true emergencies, phone lines remaining available for true emergencies, and police officers dedicating more time and effort to matters that necessitate officer assistance. Based on the call decrease seen with the prefix change, this study may be used as evidence to advocate for a change of dial-out codes beginning with “9.”

Quantitative impact of precipitation and human activity on runoff in the upper and middle Taoer River basin

Abstract Improved analysis and usage of water resources in the Taoer River basin requires an evaluation of the contributions of precipitation and human activities to runoff. In this study, we apply an integrated method combining the non-parametric Mann–Kendall trend test and the double-mass curve to analyze runoff data from 1961 to 2010. The major findings are as follows. (1) Annual runoff showed a statistically significant decrease, while precipitation showed no significant trend. (2) An abrupt change point was identified in 1998 at four representative stations, resulting in the study period being divided into pre-change and post-change periods for subsequent analysis. The double-mass curves were approximately linear in the pre-change periods, indicating that the dominant factor was probably climate change. Annual precipitation–runoff curves showed a decreasing trend from 1998, probably because of human activity. (3) The contributions of human activity to runoff in the post-change period for the four selected stations were 58.31%, 17.81%, 37.17%, and 47.66%, and the influence of human activity increased after the abrupt change point.

Improvement of diagnostic performance of pathologists by reducing the number of pathologists responsible for thyroid fine needle aspiration cytology: An institutional experience.

Various efforts have been made to improve the diagnostic accuracy of thyroid fine needle aspiration (FNA) cytology. We changed the diagnostic system by reducing the number of pathologists responsible for the thyroid FNA cytology in the routine work, and analyzed the effect on the pathologist's diagnostic performance. Since March 1, 2015, 3 pathologists have been responsible for diagnostic thyroid FNA, previously undertaken by 9 equally. We compared the prechange period (three months, 319 nodules) and the postchange period (12 months, 1194 nodules). The turnaround time was shortened from 1.4 ± 0.7 days to 0.9 ± 0.5 days (P < .001). The utilization rate of the Bethesda system for Reporting Thyroid Cytopathology (TBSRTC) increased from 92.5% to 99.8%. Diagnostic rates of categories that are confirmative [II (benign) and VI (malignant)] increased, while the inadequate (I) or indeterminate (III) categories decreased. With category IV (follicular neoplasm), a challenging category in our country, an elevated malignancy rate was found at follow-up. Overall, the diagnostic performance was improved in terms of sensitivity (from 98.5% to 99.2%) and specificity (from 94.4% to 98.4%), with reduced false-negative rates (from 1.5% to 0.8%) and false-positive rates (from 2.9% to 1.1%). The area under the receiver operating characteristic curve increased from 0.861 to 0.958. Reducing the number of pathologists responsible for diagnostic thyroid FNA cytology resulted in a higher utilization rate of TBSRTC, and more rapid and accurate diagnosis.

Increased Precipitation as the Main Driver of Increased Streamflow in Tile-Drained Watersheds of the Upper Midwestern U.S.

Abstract. Recent increased streamflow (Q) and its associated impacts on water quality have frequently been linked to land use and land cover (LULC) changes such as increased tile drainage, cultivation of prairies, and adoption of soybean () in modern-day cropping systems. However, many previous studies have assumed minimal to no change in precipitation during their study period. A recent analysis of streamflow records from 29 HUC 8 (Hydrologic Unit Code 008) watersheds in Iowa and Minnesota showed that increased precipitation instead of LULC change was the main driver of increased streamflow. The analysis was done through hierarchical regression of annual streamflow as a function of annual precipitation for the periods prior to 1975 (pre-change period) and after 1976 (post-change period). A statistical shift in annual relationship from the pre- to post-change period was assumed to be an indication of LULC changes, whereas a lack of statistical shift suggested no change in the relationship and higher flows were mainly driven by increased precipitation. In this article, we further show that annual streamflow and annual baseflow were influenced not only by the current year’s precipitation but also by precipitation in the preceding one to two years, and this effect was manifested through increased or decreased stored soil water. The present analysis was done using backward stepwise hierarchical regression with the natural log of annual streamflow as the predictor variable and three to five years of precipitation, the area under soybean production, a group variable simulating pre- and post-change periods, and its interaction terms with precipitation and soybean area as the explanatory variables. This analysis also showed that precipitation was the main driver of annual streamflow or baseflow; however, for some rivers, the area under soybean production and group differences were also significant variables, although at a much smaller confidence level. Annual streamflow testing was done for the Blue Earth River, Redwood River, Cottonwood River, and Whetstone River watersheds in Minnesota and the Maquoketa River and Raccoon River watersheds in Iowa. Annual baseflow testing was done only on the Redwood River and Raccoon River watersheds. Using similar backward stepwise regressions, the analysis showed that changes in Ln(monthly streamflow) were linked to stored soil water through the preceding months’ and years’ precipitation. On a daily scale, comparison of slopes of the hydrograph’s rising limb for two large precipitation events in 1957 (pre-change period) and 1993 (post-change period) showed less watershed connectivity due to LULC changes such as drainage, a finding that is contrary to what has been suggested in the literature. A similar comparison of the falling limb slopes for a given streamflow condition showed similar slope values in pre-change (1947) and post-change (1991) periods, thus suggesting no changes in storage capacity of the watershed as a result of LULC changes. Further comparisons of high-level streamflows (Q &amp;gt; 100 m3 s-1) as a function of average daily storm precipitation showed no effect of drainage between the pre- and post-change periods. A statistical analysis of the relationship between the falling limb slopes as a function of streamflow for low (dQ/dt &amp;lt; -5 m3 s-1 d-1) and medium (dQ/dt varying from -2 to -5 m3 s-1 d-1) slopes also showed no discernable change in the retentive capacity of the Redwood River watershed between the pre- and post-change periods. The above evaluations at three temporal scales further supported our previous conclusion that increased precipitation in recent years is the main driver of the increased streamflow in tile-drained watersheds of the upper Midwestern U.S., and the impacts of LULC change on streamflow characteristics were minimal. We conclude that any comparison of daily, monthly, or annual streamflow and baseflow to evaluate LULC change impacts must be done at comparable stored soil water conditions or with accounting of precipitation from previous days, months, and years. Keywords: Baseflow, Hydrograph, Land use land cover, Precipitation, Streamflow, Tile drainage.

Understanding the impacts of climate change and human activities on streamflow: a case study of the Soan River basin, Pakistan

Climate change and land use change are the two main factors that can alter the catchment hydrological process. The objective of this study is to evaluate the relative contribution of climate change and land use change to runoff change of the Soan River basin. The Mann-Kendal and the Pettit tests are used to find out the trends and change point in hydroclimatic variables during the period 1983–2012. Two different approaches including the abcd hydrological model and the Budyko framework are then used to quantify the impact of climate change and land use change on streamflow. The results from both methods are consistent and show that annual runoff has significantly decreased with a change point around 1997. The decrease in precipitation and increases in potential evapotranspiration contribute 68% of the detected change while the rest of the detected change is due to land use change. The land use change acquired from Landsat shows that during post-change period, the agriculture has increased in the Soan basin, which is in line with the positive contribution of land use change to runoff decrease. This study concludes that aforementioned methods performed well in quantifying the relative contribution of land use change and climate change to runoff change.

Identification of impacts of climate change and direct human activities on streamflow in Weihe River Basin in Northwest China

Climate change and human activities make major influences on hydrology, which are known to have important impacts on streamflow variation. Therefore, it is critically important to identify how climate change and human activities will impact streamflow variation. Thus, the goal of this study is to identify the impacts of climate change and direct human activities on annual streamflow at four hydrologic stations in the Weihe River basin of China, with the estimation of evaporation based on the Budyko hypothesis. The Mann-Kendall test was employed to detect the break points of the four stations. According to the occurrence time of break points, the data series were divided into two periods: pre-change period (1960-1984) and post-change (1985-2010) period. The parameter of one-parameter Budyko-type model was calibrated with observed data during the pre-change period, with the R2 values ranged from 0.95 to 0.97 and the NSE values ranged from 0.80 to 0.94, and the high R2 and Nash-Sutcliffe Efficiency coefficient shows the model has good performance. The contribution ratios of climate change impacts on decreasing streamflow were 37%, 23%, 57% and 43%, and those of the impacts of direct human activities were 63%, 77%, 43% and 57% for the Linjiacun, Xianyang, Lintong and Huaxian station, respectively. Both the climate change and direct human activities have positive impacts on streamflow decrease at all of the four stations, and the direct human activities are the main factor causing the decrease of annual streamflow. Keywords: streamflow, climate change; human activities; evaporation, hydrological cycle, watershed, Budyko hypothesis, Weihe River basin DOI: 10.25165/j.ijabe.20171004.2313 Citation: Fan J J, Huang Q, Liu D F. Identification of impacts of climate change and direct human activities on streamflow in Weihe River Basin in Northwest China. Int J Agric & Biol Eng, 2017; 10(4): 119–129.

Weight Gain in Psychiatric Inpatients: Are Interventions Making a Positive Impact?

The negative impact of weight gain is a common problem facing all patients, but it is especially concerning in the seriously mentally ill population. The literature is replete with interventions to mitigate weight gain in this population; however, most focus on outpatient settings. This study was undertaken to quantify weight gain in an inpatient setting and to assess whether instituted interventions to reduce weight gain were effective. This retrospective study analyzed weight changes in adult psychiatric inpatients with length of stay of 30 days or more. Data regarding weight changes were collected from records before (July 2005 to June 2006) a hospital-wide policy change to combat weight gain and after (July 2013 to June 2014) the changes were instituted. A total of 537 charts were reviewed. Male inpatients gained a mean of 7.61 lb and females gained 6.02 lb. The mean weight change increased for the pre and post policy change periods: 6.08 lb and 7.85 lb, respectively, a 29% increase in mean weight. This study demonstrates that weight in psychiatric inpatients hospitalized for 30 days or longer increased despite widespread changes in the hospital setting implemented to limit weight gain.

Reporting accounting changes and their multi-period effects

U.S. GAAP and IFRS require full disclosure of the effects of an accounting change in the year the change is made, but not in future years. However, some accounting changes have multi-period effects. We conduct an experiment to examine whether investors forget to adjust for an accounting change in periods subsequent to the change, and examine the effectiveness of interventions designed to mitigate that tendency. In the experiment, a company changed how it accounts for pension gains and losses, and investors value the company over three consecutive reporting periods. Results indicate that investors gradually forget to adjust for the accounting change over time under the current approach used to disclose accounting changes. These effects are mitigated in post-change periods when investors receive full disclosure of the current effect of the prior accounting change, and to a lesser extent when investors receive a disclosure that includes a simple non-quantitative disclosure that the accounting change occurred. Supplemental analyses indicate that investors rely more on memory-aiding disclosures as the time delay between valuation judgments increases.

Detecting a Suddenly Arriving Dynamic Profile of Finite Duration

This paper addresses the detection of a suddenly arriving dynamic profile of a finite duration often called a transient change. In contrast to the traditional abrupt change detection, where the post-change period is assumed to be infinitely long, the detection of a suddenly arriving transient change should be done before it disappears. The detection of transient changes after their disappearance is considered as missed. Hence, the traditional quickest change detection criterion, minimizing the average detection delays provided a prescribed false alarm rate, is compromised. The proposed optimality criterion minimizes the worst case probability of missed detection provided that the worst case probability of false alarm during a certain period is upper bounded. A suboptimal CUSUM-type transient change detection algorithm, based on a subclass of truncated Sequential Probability Ratio Tests, is proposed. The optimization of the proposed algorithm in this subclass leads to a specially designed Finite Moving Average Test. The proposed method is analyzed theoretically and by simulation. A special attention is paid to the case of Gaussian observations with a dynamic profile.

Responses of Streamflow to Climate Change and Human Activities in a River Basin, Northeast China

It is now common knowledge that many water resources stresses relate to access to water within a basin. Yi River Basin, a typical river basin characterized by intensive agricultural processes, significant population growth, and water management, has been undergoing grave water problems. In this paper, the long-term trend of precipitation and streamflow in Yi River Basin, from 1964 to 2010, was investigated via Mann-Kendall test. The change point occurred in the year 1965 dividing the long-term series into two periods. Climate elasticity method and linear regression method were implemented to quantify the impact of precipitation and human activities on runoff and presented basically consistent results of the percentage change in an annual runoff for the postchange period. The results reveal that the decline of annual runoff in postchange period is mainly attributed to precipitation variability of 53.66–58.25% and human activities of 46.34–41.74%, as estimated by climate elasticity method and linear regression method, respectively. This study detected the changes in the precipitation-streamflow relationship and investigated the possible causes in the Yi River, which will be helpful for providing a reference for the management of regional water resources.

Reply to comment by Belmont et al. on “Climate and agricultural land use change impacts on streamflow in the upper midwestern United States”

AbstractThe reply addresses concerns raised by Belmont et al. (2016) on Gupta et al. (2015) through additional analysis of streamflow versus precipitation relationships for the Whetstone and the Redwood Rivers and with data on available soil moisture in prechange and postchange periods in the Cottonwood River watershed.