Subsurface mechanisms control hydrologic response to a multi-year drought in a mountainous watershed with a Mediterranean climate

2021 ◽  
Author(s):  
Adam Schreiner-McGraw ◽  
Hoori Ajami
Keyword(s):  
Hydrologic Model ◽  
Subsurface Water ◽  
Groundwater Depletion ◽  
Hydrologic Response ◽  
Primary Input ◽  
Groundwater System ◽  
Drought Period ◽  
Mountainous Watershed ◽  
The Future ◽  
The Impact

<p>Mountain watersheds often act as water towers that supply water to large human populations in valley aquifers. Therefore, their susceptibility and resilience to droughts are of outsize importance particularly, as global climate change projections suggest more frequent droughts in the future. Previous studies have examined the impact of climate warming on mountain hydrology, but they have not explicitly linked impacts of multi-year droughts to subsurface water storage. In this study, we use the 2012-2015 California drought to examine the mechanisms via which subsurface flow paths and storage affect the hydrologic response to drought in the Kaweah River watershed in the Sierra Nevada mountains. We build and test an integrated hydrologic model using the coupled land surface-groundwater model ParFlow.CLM. The model is able to simulate the observed hydrology with a high degree of accuracy. Results reveal that mountain aquifer recharge sourced from snowmelt (<em>MAR</em><sub><em>snow</em></sub>) is the primary input to the groundwater system, and much of the simulated streamflow. We find that increases in air temperature and decreases in precipitation during the drought reduces snow water equivalent (<em>SWE</em>), and causes a 73% reduction in <em>MAR</em><sub><em>snow</em></sub> compared to the pre-drought period. Reduction in <em>MAR</em><sub><em>snow</em></sub> initially results in subsurface storage losses along the ridgelines and areas of low topographic convergence. Topography induced draining of the regolith storage causes groundwater depletion and provides supplemental water to maintain streamflow and riparian evapotranspiration (<em>ET</em>). As the drought develops, drying of the subsurface alters lateral connectivity of the shallow groundwater system, and reduces streamflow and riparian <em>ET</em>. We apply machine learning models to examine the spatial patterns in groundwater storage depletion and recovery. These models reveal that topography induced draining and filling of subsurface storage in response to drought and precipitation recovery, respectively, is the key control on the streamflow response in this mountainous watershed. Warmer conditions and more frequent droughts that reduce <em>SWE</em> in the future are likely to amplify this cycle.</p>

scholarly journals Impact Assessment of Climate Change on the Near and the Far Future Streamflow in the Bocheongcheon Basin of Geumgang River, South Korea

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2516
Author(s):  
Yoonji Kim ◽  
Jieun Yu ◽  
Kyungil Lee ◽  
Hye In Chung ◽  
Hyun Chan Sung ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Resources Management ◽  
Model Performance ◽  
Hydrologic Model ◽  
Management Policy ◽  
Resources Management ◽  
The Future ◽  
Management Plans ◽  
The Impact

Highly concentrated precipitation during the rainy season poses challenges to the South Korean water resources management in efficiently storing and redistributing water resources. Under the new climate regime, water resources management is likely to become more challenging with regards to water-related disaster risk and deterioration of water quality. To alleviate such issues by adjusting management plans, this study examined the impact of climate change on the streamflow in the Bocheongcheon basin of the Geumgang river. A globally accepted hydrologic model, the HEC-HMS model, was chosen for the simulation. By the calibration and the validation processes, the model performance was evaluated to range between “satisfactory” and “very good”. The calibrated model was then used to simulate the future streamflow over six decades from 2041 to 2100 under RCP4.5 and RCP8.5. The results indicated significant increase in the future streamflow of the study site in all months and seasons over the simulation period. Intensification of seasonal differences and fluctuations was projected under RCP 8.5, implying a challenge for water resources managers to secure stable sources of clean water and to prevent water-related disasters. The analysis of the simulation results was applied to suggest possible local adaptive water resources management policy.

scholarly journals Combined Impacts of Uncertainty in Precipitation and Air Temperature on Simulated Mountain System Recharge from an Integrated Hydrologic Model

2021 ◽  
Author(s):  
Adam P. Schreiner-McGraw ◽  
Hoori Ajami
Keyword(s):  
Groundwater Recharge ◽  
Air Temperature ◽  
Water Budget ◽  
Hydrologic Model ◽  
Meteorological Forcing ◽  
Mountainous Regions ◽  
Mountainous Watershed ◽  
Mountain System ◽  
Mountain Front ◽  
The Impact

Abstract. Mountainous regions act as the water towers of the world by producing streamflow and groundwater recharge, a function that is particularly important in semiarid regions. Quantifying rates of mountain system recharge is difficult, and hydrologic models offer a method to estimate recharge over large scales. These recharge estimates are prone to uncertainty from various sources including model structure and parameters. The quality of meteorological forcing datasets, particularly in mountainous regions, is a large source of uncertainty that is often neglected in groundwater investigations. In this contribution, we quantify the impact of uncertainty in both precipitation and air temperature forcing datasets on the simulated groundwater recharge in the mountainous watershed of the Kaweah River in California, USA. We make use of the integrated surface water – groundwater model, ParFlow.CLM and several gridded datasets commonly used in hydrologic studies, downscaled NLDAS-2, PRISM, Daymet, Gridmet, and TopoWx. Simulations indicate that across all forcing datasets, mountain front recharge is an important component of the water budget in the mountainous watershed accounting for 25–46 % of the annual precipitation, and ~90 % of the total mountain system recharge to the adjacent Central Valley aquifer. The uncertainty in gridded air temperature or precipitation datasets, when assessed individually, results in similar ranges of uncertainty in the simulated water budget. Variations in simulated recharge to changes in precipitation (elasticities) and air temperature (sensitivities) are larger than 1 % change in recharge per 1 % change in precipitation or 1-degree C change in temperature. The total volume of snowmelt is the primary factor creating the high water budget sensitivity; and snowmelt volume is influenced by both precipitation and air temperature forcings. The combined effect of uncertainty in air temperature and precipitation on recharge is additive, and results in uncertainty levels roughly equal to the sum of the individual uncertainties. Mountain system recharge pathways including mountain block recharge, mountain aquifer recharge, and mountain front recharge are less sensitive to changes in air temperature than changes in precipitation. Mountain front and mountain block recharge are more sensitive to changes in precipitation than other recharge pathways. The magnitude of uncertainty in the simulated water budget reflects the importance of developing high qualify meteorological forcing datasets in mountainous regions.

scholarly journals Climate elasticity of evapotranspiration shifts the water balance of Mediterranean climates during multi-year droughts

2020 ◽  
Vol 24 (9) ◽  
pp. 4317-4337
Author(s):  
Francesco Avanzi ◽  
Joseph Rungee ◽  
Tessa Maurer ◽  
Roger Bales ◽  
Qin Ma ◽  
...  
Keyword(s):  
Water Balance ◽  
Precipitation Amount ◽  
Hydrologic Model ◽  
Data Driven ◽  
Subsurface Water ◽  
Drought Period ◽  
Climate Elasticity ◽  
Predictive Skill ◽  
General Improvement ◽  
Time Required

Abstract. Multi-year droughts in Mediterranean climates may shift the water balance, that is, the partitioning rule of precipitation across runoff, evapotranspiration, and sub-surface storage. Mechanisms causing these shifts remain largely unknown and are not well represented in hydrologic models. Focusing on measurements from the headwaters of California's Feather River, we found that also in these mixed rain–snow Mediterranean basins a lower fraction of precipitation was partitioned to runoff during multi-year droughts compared to non-drought years. This shift in the precipitation–runoff relationship was larger in the surface-runoff-dominated than subsurface-flow-dominated headwaters (−39 % vs. −18 % decline of runoff, respectively, for a representative precipitation amount). The predictive skill of the Precipitation Runoff Modeling System (PRMS) hydrologic model in these basins decreased during droughts, with evapotranspiration (ET) being the only water-balance component besides runoff for which the drop in predictive skill during drought vs. non-drought years was statistically significant. In particular, the model underestimated the response time required by ET to adjust to interannual climate variability, which we define as climate elasticity of ET. Differences between simulated and data-driven estimates of ET were well correlated with accompanying data-driven estimates of changes in sub-surface storage (ΔS, r=0.78). This correlation points to shifts in precipitation–runoff relationships being evidence of a hysteretic response of the water budget to climate elasticity of ET during and after multi-year droughts. This hysteresis is caused by carryover storage offsetting precipitation deficit during the initial drought period, followed by vegetation mortality when storage is depleted and subsequent post-drought vegetation expansion. Our results point to a general improvement in hydrologic predictions across drought and recovery cycles by including the climate elasticity of ET and better accounting for actual subsurface water storage in not only soil, but also deeper regolith that stores water accessible to roots. This can be done by explicitly parametrizing carryover storage and feedback mechanisms capturing vegetation response to atmospheric demand for moisture.

Pengaruh Budaya Terhadap Akuntansi, Auditing Dan Praktik Akuntansi Internasional

2016 ◽  
Vol 3 (1) ◽  
pp. 78-95
Author(s):  
Priyastiwi Priyastiwi
Keyword(s):  
Cultural Values ◽  
Leadership Style ◽  
Financial Reporting ◽  
National Level ◽  
Deep Understanding ◽  
Cultural Dimensions ◽  
Financial Disclosure ◽  
Cross Cultural Differences ◽  
The Future ◽  
The Impact

The purpose of this article is to provide the basic model of Hofstede and Grays’ cultural values that relates the Hofstede’s cultural dimensions and Gray‘s accounting value. This article reviews some studies that prove the model and develop the research in the future. There are some evidences that link the Hofstede’s cultural values studies with the auditor’s judgment and decisions by developing a framework that categorizes the auditor’s judgments and decisions are most likely influenced by cross-cultural differences. The categories include risk assessment, risk decisions and ethical judgments. Understanding the impact of cultural factors on the practice of accounting and financial disclosure is important to achieve the harmonization of international accounting. Deep understanding about how the local values may affect the accounting practices and their impacts on the financial disclosure are important to ensure the international comparability of financial reporting. Gray’s framework (1988) expects how the culture may affect accounting practices at the national level. One area of the future studies will examine the impact of cultural dimensions to the values of accounting, auditing and decision making. Key word : Motivation, leadership style, job satisfaction, performance

A Study on the Impact of Family-friendly Certification on Financial Performance of SMEs: Focusing on the Manufacturing Industry

2019 ◽  
Vol 118 (2) ◽  
pp. 7-12
Author(s):  
Ok-Hee Park ◽  
Kwan-sik Na ◽  
Seok-Kee Lee
Keyword(s):  
Financial Performance ◽  
Family Life ◽  
Manufacturing Industry ◽  
Work And Family ◽  
Family Friendly ◽  
The Future ◽  
The Impact

Background/Objectives: The purpose of the paper is to examine how family-friendly certificates introduced to pursue the compatibility of work and family life affect the financial performance of small and medium-sized manufacturers, and to provide useful information to companies considering the introduction of this system in the future.

TSUNAMI ACEH 2004 SEBAGAI DASAR PENATAAN RUANG KOTA MEULABOH

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Wisyanto Wisyanto
Keyword(s):  
Coastal Area ◽  
Building Damage ◽  
Tsunami Hazard ◽  
The Road ◽  
Tsunami Disaster ◽  
Landuse Planning ◽  
The Future ◽  
Tsunami Mitigation ◽  
Potential Losses ◽  
The Impact

Tsunami which was generated by the 2004 Aceh eartquake has beenhaunting our life. The building damage due to the tsunami could be seenthroughout Meulaboh Coastal Area. Appearing of the physical loss wasclose to our fault. It was caused by the use dan plan of the land withoutconsidering a tsunami disaster threat. Learning from that event, we haveconducted a research on the pattern of damage that caused by the 2004tsunami. Based on the analysis of tsunami hazard intensity and thepattern of building damage, it has been made a landuse planning whichbased on tsunami mitigation for Meulaboh. Tsunami mitigation-based ofMeulaboh landuse planning was made by intergrating some aspects, suchas tsunami protection using pandanus greenbelt, embankment along withhigh plants and also arranging the direction of roads and setting of building forming a rhombus-shaped. The rhombus-shaped of setting of the road and building would reduce the impact of tsunamic wave. It is expected that these all comprehensive landuse planning will minimize potential losses in the future .

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