Test of a distributed modelling approach to predict flood flows in the karst Suoimuoi catchment in Vietnam

The major obstacles for modelling flood processes in karst areas are a lack of understanding and model representations of the distinctive features and processes associated with runoff generation and often a paucity of field data. In this study, a distributed flood-modelling approach, WetSpa, is modified and applied to simulate the hydrological features and processes in the karst Suoimuoi catchment in northwest Vietnam. With input of topography, land use and soil types in a GIS format, the model is calibrated based on 15 months of hourly meteorological and hydrological data, and is used to simulate both fast surface and conduit flows, and groundwater discharges from karst and non-karst aquifers. Considerable variability in the simulation accuracy is found among storm events and within the catchment. The simulation results show that the model is able to represent reasonably well the stormflows generated by rainfall events in the study catchment.     

Changes in heat wave characteristics over Extremadura (SW Spain)

Theoretical and Applied Climatology - Heat wave (HW) events are becoming more frequent, and they have important consequences because of the negative effects they can have not only on the human...     

A distinction between summer rainy season and summer monsoon season over the Central Highlands of Vietnam

Theoretical and Applied Climatology - The daily rainfall data at 13 stations over the Central Highlands (CH) Vietnam were collected for the period 1981–2014. Two different sets of criteria...     

Integration of ecosystem-based adaptation to climate change policies in Viet Nam

There is growing recognition of the importance of ecosystem-based approaches for adaptation to climate change—it is a cost-effective measure that has multiple benefits and can overcome many of the drawbacks of more common engineering adaptation options. Viet Nam has a rich biodiversity and is also one of the most vulnerable countries impacted by climate change. Climate change policies have been adopted at national and local levels as well as by sector, making Viet Nam one of the nations to most systematically fulfill their obligation under the United Nations Framework Convention on Climate Change. Consequently, we have used Viet Nam as a case study, to assess the integration of ecosystem-based approach to adaptation to climate change. We found that ecosystem-based adaptation is being implemented in some projects but, overall, is inadequately considered by Viet Nam’s climate change policies. Instead, policies predominantly rename infrastructure projects as climate change adaptation and focus on hard solutions for disaster reduction, rather than responding to long-term climate change through ecosystem-based adaptation. Moreover, ecosystem-based adaptation projects have focused on only a few relevant types of ecosystems. Viet Nam should revise its existing climate change policies and sectoral strategies to integrate ecosystem-based adaptation across different scales of governance. As other nations develop adaptation policies at different scales, the lesson from Viet Nam is that engineering measures need to be balanced with ecosystem-based adaptation for more affordable and effective responses to climate change.     

Modelling infiltration enhancement in a tropical urban catchment for improved stormwater management

To mitigate the impacts of impervious surfaces in urban areas, structures such as bioretention systems and permeable pavements have been installed to enhance infiltration in many countries. However, relatively little knowledge is available regarding the performance of such infiltration‐based structures in humid tropical and highly urbanized areas. This study investigates the feasibility of enhancing the infiltration of stormwater in tropical urbanized areas using Singapore as a case study. It first shows that the rainfall depth and intensity are both high, but the time interval between consecutive rainfall event is long in Singapore. It then numerically simulates single‐event local infiltration and finds that the fraction of infiltrated rainfall is actually high. It finally performs catchment‐scale simulations and finds that bioretention systems can enhance infiltration and groundwater recharge particularly during wet periods. However, local mounding of groundwater can be significant and can hinder the performance of those structures. Furthermore, with 5% of catchment area being converted to such structures, the infiltration of the entire catchment is enhanced but still not yet up to the natural level. To increase the overall effectiveness, future studies can look into bioretention systems with underdrain systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Topography of the Moho and earth crust structure beneath the East Vietnam Sea from 3D inversion of gravity field data

The Moho depth, crustal thickness and fault systems of the East Vietnam Sea (EVS) are determined by 3D interpretation of satellite gravity. The Moho depth is calculated by 3D Parker inversion from residual gravity anomaly that is obtained by removing the gravity effects of seafloor and Pre-Cenozoic sediment basement topographies from the free air anomaly. The 3D inversion solution is constrained by power density spectrum of gravity anomaly and seismic data. The calculated Moho depths in the EVS vary from 30–31 km near the coast to 9 km in the Central Basin. A map of the lithosphere extension factor in the Cenozoic is constructed from Moho and Pre-Cenozoic sediment basement depths. The fault systems constructed by the maximum horizontal gradient approach include NE-SW, NW-SE, and N-S oriented faults. Based on the interpretation results, the EVS is sub-divided into five structural zones which demonstrated the different characteristics of the crustal structure.     

An empirical method for approximating canopy throughfall

Rainfall replenishes surface and subsurface water but is partially intercepted by a canopy. However, it is challenging to quantify the rainfall passing through the canopy (i.e. throughfall). This study derives simple‐to‐use empirical equations relating throughfall to canopy and rainfall characteristics. Monthly throughfall is calculated by applying a mass balance model on weather data from Singapore; Vancouver, Canada; and Stanford, USA. Regression analysis is then performed on the calculated throughfall with three dependent variables (i.e. maximum canopy storage, average rainfall depth and time interval between two consecutive rainfall in a month) to derive the empirical equations. One local equation is derived for each location using data from that particular location, and one global equation is derived using data from all three locations. The equations are further verified with calculated monthly throughfall from other weather data and actual throughfall field measurements, giving an accuracy of about 80–90%. The global equation is relatively less accurate but is applicable worldwide. Overall, this study provides a global equation through which one can quickly estimate throughfall with only information on the three variables. When additional weather data are available, one can follow the proposed methodology to derive their own equations for better estimates. Copyright © 2012 John Wiley & Sons, Ltd.     

An anisotropic model for estimating of hourly sums of solar radiation on vertical south-facing surfaces

Summary An empirical study was performed to obtain a new anisotropic model for estimating of individual hourly sums of solar radiation on vertical south-facing surfaces. The procedure consists of correcting statistically the isotropic model by taking into account the anisotropic character of both sky diffuse and ground reflected solar radiation. Based on the data measured at Budapest-Lörinc station a simple correction function was obtained.

---

Ein anisotropes Modell zur Bestimmung der Sonnenstrahlung auf vertikale Südwände

Zusammenfassung Es wurde eine empirische Studie zur Entwicklung eines neuen anisotropen Modells zur Bestimmung der individuellen Stundensummen der Sonnenstrahlung auf vertikale Südwände durchgeführt. Das Verfahren besteht in einer statistischen Korrektur des isotropen Modells durch Berücksichtigung des anisotropen Charakters der diffusen Himmelsstrahlung und der vom Boden reflektierten Sonnenstrahlung. Mit in Budapest-Lörinc gemessenen Beobachtungsdaten wurde eine einfache Korrektionsfunktion erhalten.

---

---

1 Visiting scientist from the Socialist Republic of Vietnam.     

Predicting Blast-Induced Ground Vibration in Open-Pit Mines Using Different Nature-Inspired Optimization Algorithms and Deep Neural Network

Natural Resources Research - Blast-induced ground vibration (GV) is a hazardous phenomenon in open-pit mines, and it has unquestionable effects, such as slope instability, deformation of...