Evaluation of 2018 drought and effectiveness of adaptation measures in the Netherlands

Author(s):  
Marjolein H.J. van Huijgevoort ◽  
Janine A. de Wit ◽  
Ruud P. Bartholomeus

<p>Extreme dry conditions occurred over the summer of 2018 in the Netherlands. This severe drought event led to very low groundwater  and surface water levels. These impacted several sectors like navigation, agriculture, nature and drinking water supply. Especially in the Pleistocene uplands of the Netherlands, the low groundwater levels had a large impact on crop yields and biodiversity in nature areas. Projections show that droughts with this severity will occur more often in the future due to changes in climate. To mitigate the impact of these drought events, water management needs to be altered.</p><p>In this study, we evaluated the 2018 drought event in the sandy regions of the Netherlands and studied which measures could be most effective to mitigate drought impact. We have included meteorological, soil moisture and hydrological drought and the propagation of the drought through these types. Droughts were determined with standardized indices (e.g. Standardized Precipitation Index) and the variable threshold level method. Investigated measures were, for example, higher water levels in ditches, reduced irrigation from groundwater, and increased water conservation in winter. We also studied the timing of these measures to determine the potential for mitigating effects during a drought versus the effectiveness of long term adaptation. The measures were simulated with the agro-hydrological Soil–Water–Atmosphere–Plant (SWAP) model for several areas across the Netherlands for both agricultural fields and nature sites.</p><p>As expected, decreasing irrigation from groundwater reduced the severity of the hydrological drought in the region. Severity of the soil moisture drought also decreased in fields that were never irrigated due to the effects of capillary rise from the groundwater, but, as expected, increased in currently irrigated fields. Increasing the level of a weir in ditches had a relatively small effect on the hydrological drought, provided water was available to sustain higher water levels. This measure is, therefore, better suited as a long term change than as ad hoc measure during a drought. The effectiveness of the measures depended on the characteristics of the regions; for some regions small changes led to increases in groundwater levels for several months, whereas in other regions effects were lost after a few weeks. This study gives insight into the most effective measures to mitigate drought impacts in low-lying sandy regions like the Netherlands.</p>

Author(s):  
Frouke Hoogland ◽  
Arjen S. Roelandse ◽  
Beatriz de La Loma González ◽  
Maarten J. Waterloo ◽  
Perry W. Mooij ◽  
...  

Abstract. In the Province of Flevoland, the Netherlands, land subsidence poses a problem to agriculture and water management. The peat layers in the soil are susceptible to compression and oxidation causing further subsidence. Applying subirrigation through the tile drain system to maintain saturation of the peat may be a measure to slow down subsidence. A study was therefore carried out at two sites, Nagele and Zeewolde, to assess the impact of subirrigation in the peat on the seasonal variation in soil moisture content, and corresponding redox conditions. Bacterial community analysis was carried out to verify the hydrochemical observations. Subirrigation proved to be an efficient measure to maintain a high water level in the peat soil as long as the permeability in the upper part of the peat was sufficient to allow transmission of water into the inter-drain area and when the peat layer extended enough below the minimum regional water level to prevent drainage to the sand layer underneath. The peat showed dual porosity and water levels could well be maintained by subirrigation at the Nagele site. At the Zeewolde site, the variability in the thin peat layer allowed drainage to occur in the sand layer, preventing subirrigation to maintain high water levels. However, at both sites the peat layer remained close to saturation throughout the summer, which may be caused by the fine-grained mineral layer isolating the peat from water extraction via evapotranspiration. Nitrate concentrations of up to 100 mg L−1 were observed were high (>50 mg L−1) in the oxic mineral top layer but were low in the peat (0.3 mg L−1) at both Nagele and Zeewolde sites. Sulphate concentrations also showed a decrease with depth in the peat at Nagele, indicating a transition from sub-oxic above 1.5 m depth to anoxic conditions at 3.5 m depth. The hydrochemical observations in the soil moisture in the peat at Nagele confirmed that conditions were sub-oxic in the upper part of the peat (0.7 m below soil surface) to anoxic at greater depth (3.5 m). Soil microbe analyses showed few nitrification bacteria in the peat, whereas communities specialised in denitrification and ammonification were present, as well as sulphate reducing bacteria and methanogenic species. This confirmed the sub-oxic to anoxic conditions in the peat deduced from the hydrochemical observations. At Zeewolde, conditions remained sub-oxic throughout the profile.


Author(s):  

The effect of climatic changes on surface and underground runoff cannot be explained without studying such changes on such processes of moisture transfer in soils as infiltration, evaporation, migration of moisture to the frost front. These processes are components of moisture exchange in soils and almost completely determine the mechanisms of runoff formation and its climatic interconformity. The paper discloses the main links of vertical moisture exchange in soils with environmental factors such as temperature, precipitation, wind speed and water vapor pressure. On the example of the Volga basin, changes in moisture flows in soils over the past decades are considered. Methods. To reveal the patterns of moisture exchange, a physically sound mathematical model of vertical heat-moisture transfer in soils and snow cover was used. Numerical experiments were carried out to assess the impact of all the main weather factors that cause long-term changes in vertical moisture flows in soils for the period 1952-2019. Results. Calculations showed that in the 1970s there were significant changes in soil moisture flows. There was a preferential increase in downstream flows and a decrease in upstream flows, which under certain weather conditions led to an increase in the level of groundwater. In recent decades, the growth of descending soil moisture flows in the river basin. Volga and, accordingly, groundwater levels have slowed down.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 629-629
Author(s):  
Silke Metzelthin ◽  
Sandra Zwakhalen ◽  
Barbara Resnick

Abstract Functional decline in older adults often lead towards acute or long-term care. In practice, caregivers often focus on completion of care tasks and of prevention of injuries from falls. This task based, safety approach inadvertently results in fewer opportunities for older adults to be actively involved in activities. Further deconditioning and functional decline are common consequences of this inactivity. To prevent or postpone these consequences Function Focused Care (FFC) was developed meaning that caregivers adapt their level of assistance to the capabilities of older adults and stimulate them to do as much as possible by themselves. FFC was first implemented in institutionalized long-term care in the US, but has spread rapidly to other settings (e.g. acute care), target groups (e.g. people with dementia) and countries (e.g. the Netherlands). During this symposium, four presenters from the US and the Netherlands talk about the impact of FFC. The first presentation is about the results of a stepped wedge cluster trial showing a tendency to improve activities of daily living and mobility. The second presentation is about a FFC training program. FFC was feasible to implement in home care and professionals experienced positive changes in knowledge, attitude, skills and support. The next presenter reports about significant improvements regarding time spent in physical activity and a decrease in resistiveness to care in a cluster randomized controlled trial among nursing home residents with dementia. The fourth speaker presents the content and first results of a training program to implement FFC in nursing homes. Nursing Care of Older Adults Interest Group Sponsored Symposium


Climate ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 82 ◽  
Author(s):  
Haitham Aladaileh ◽  
Mohammed Al Qinna ◽  
Barta Karoly ◽  
Emad Al-Karablieh ◽  
János Rakonczai

Following the impact of droughts witnessed during the last decade there is an urgent need to develop a drought management strategy, policy framework, and action plan for Jordan. This study aims to provide a historical baseline using the standardized precipitation index (SPI) and meteorological drought maps, and to investigate the spatial and temporal trends using long-term historical precipitation records. Specifically, this study is based on the statistical analysis of 38 years of monthly rainfall data, gathered from all 29 meteorological stations that cover Jordan. The Mann–Kendall test and linear regression analysis were used to uncover evidence of long-term trends in precipitation. Drought indices were used for calculating the meteorological SPI on an annual (SPI12), 6-months (SPI6), and 3-months basis (SPI3). At each level, every drought event was characterized according to its duration, interval, and intensity. Then, drought maps were generated using interpolation kriging to investigate the spatial extent of drought events, while drought patterns were temporally characterized using multilinear regression and spatial grouped using the hierarchical clustering technique. Both annual and monthly trend analyses and the Mann–Kendall test indicated significant reduction of precipitation in time for all weather stations except for Madaba. The rate of decrease is estimated at approximately 1.8 mm/year for the whole country. The spatial SPI krig maps that were generated suggest the presence of two drought types in the spatial dimension: Local and national. Local droughts reveal no actual observed trends or repeatable patterns of occurrence. However, looking at meteorological droughts across all time scales indicated that Jordan is facing an increasing number of local droughts. With a probability of occurrence of once every two years to three years. On the other hand, extreme national droughts occur once every 15 to 20 years and last for two or more consecutive years. Linear trends indicated significant increase in drought magnitude by time with a rate of 0.02 (p < 0.0001). Regression analysis indicated that draught in Jordan is time dependent (p < 0.001) rather than being spatially dependent (p > 0.99). Hierarchical clustering was able to group national draughts into three zones, namely the northern zone, the eastern zone, and the southern zone. This study highlights the urgent need for a monitoring program to investigate local and national drought impacts on all sectors, as well as the development of a set of proactive risk management measures and preparedness plans for various physiographic regions.


1999 ◽  
Vol 3 (3) ◽  
pp. 353-361 ◽  
Author(s):  
J. A. Butterworth ◽  
R. E. Schulze ◽  
L. P. Simmonds ◽  
P. Moriarty ◽  
F. Mugabe

Abstract. To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU) simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.


2019 ◽  
Vol 11 (8) ◽  
pp. 2450 ◽  
Author(s):  
Noora Veijalainen ◽  
Lauri Ahopelto ◽  
Mika Marttunen ◽  
Jaakko Jääskeläinen ◽  
Ritva Britschgi ◽  
...  

Severe droughts cause substantial damage to different socio-economic sectors, and even Finland, which has abundant water resources, is not immune to their impacts. To assess the implications of a severe drought in Finland, we carried out a national scale drought impact analysis. Firstly, we simulated water levels and discharges during the severe drought of 1939–1942 (the reference drought) in present-day Finland with a hydrological model. Secondly, we estimated how climate change would alter droughts. Thirdly, we assessed the impact of drought on key water use sectors, with a focus on hydropower and water supply. The results indicate that the long-lasting reference drought caused the discharges to decrease at most by 80% compared to the average annual minimum discharges. The water levels generally fell to the lowest levels in the largest lakes in Central and South-Eastern Finland. Climate change scenarios project on average a small decrease in the lowest water levels during droughts. Severe drought would have a significant impact on water-related sectors, reducing water supply and hydropower production. In this way drought is a risk multiplier for the water–energy–food security nexus. We suggest that the resilience to droughts could be improved with region-specific drought management plans and by including droughts in existing regional preparedness exercises.


2018 ◽  
Author(s):  
Tiaofeng Zhang ◽  
Lin Li ◽  
Hongbin Xiao ◽  
Hongmei Li

Abstract. Pasture is vital to livestock husbandry development in Qinghai and even in North China. Drought is the primary meteorological disaster that affects pasture, but insufficient soil moisture is the most prominent cause of pasture drought. Timely and accurate determination of the soil moisture threshold of pasture is important for objective recognition and monitoring of the occurrence and development of pasture drought. This study aims at investigating pasture responses to soil drought as well as quantitative expression of soil drought degree and drought threshold. Test plots were selected from the pasture test station. Five testing groups were set according to coverage rate (0–100 %) at the initiation the pasture growth period. The impacts of profile moisture characteristics, drought threshold, and precipitation on duration of pasture drought were studied. Research results have demonstrated that moisture in the soil profile below 20 cm decreases slightly throughout drought events in alpine grassland. Changes of soil moisture in the 0–20 cm layer can generally reflect drought stress of the pasture. In the process of a drought event, the relationship between soil water storage and cumulative relative water loss can be expressed via a logarithmic linear equation. Quantitative expression of drought degree in grasslands can be realized by transforming the slope of this equation into the index D with an interval of [0, 1]. The occurrence rates of mild drought,moderate drought, and severe drought were 0.36, 0.45, and 0.70, respectively. The duration of severe drought was closely related with initial soil moisture. The relationship between duration of drought and the necessary minimum precipitation can be expressed by an exponential equation. Values of the D index can express soil drought intensity and pasture drought intensity. The durations for different grades of drought events were correlated with both initial soil moisture and previous precipitation. The conclusions of this study can provide scientific references for the objective understanding onoccurrence, development, monitoring, and early warning of pasture drought.


2020 ◽  
Author(s):  
Ruijing Sun ◽  
Yeping Zhang ◽  
Shengli Wu

&lt;p&gt;FY-3(Feng Yun 3) satellites series are the China&amp;#8217;s second-generation polar-orbiting meteorological satellites. FY-3B is the second satellite of FY3 series which was launched on November 5, 2010. One of the eleven instruments on board the FY-3B satellite is the Microwave Radiation Imager (MWRI) which is a highly sensitive microwave radiometer. It is China&amp;#8217;s first space-borne microwave radiometer. It has 5 different frequencies from 10.65GHz to 89GHz with dual polarization. The MWRI instrument provides measurements of terrestrial, oceanic, and atmospheric parameters, including precipitation rate, sea ice concentration, snow water equivalent, soil moisture, atmospheric cloud water, and water vapor. Soil moisture, as a key parameter in the drought monitoring, becomes especially concerned. The FY-3B/MWRI soil moisture product provides global observations of land surface soil moisture. The current soil moisture retrieval algorithm of FY-3B/MWRI uses the brightness temperature with both v and h polarizations of 10.65GHz to eliminate the effects of surface roughness and vegetation simultaneously. For the bare surface soil estimation part, the algorithm is based on a parameterized surface emission model (the Qp model) which uses a physically based soil moisture inversion technique for application with passive microwave measurements. For the vegetation correction part, the algorithm uses the empirical relationship between the NDVI and the vegetation water content to estimate the vegetation optical depth. The spatial resolution of FY-3B/MWRI soil moisture product is 0.25&amp;#176;&amp;#215;0.25&amp;#176;. In recent years, drought occurs frequently worldwide. As the only microwave sensor which operationally provides global soil moisture products currently in china, the FY-3B/MWRI soil moisture product plays an important part in drought monitoring during the meteorological service. In the summer of 2014, Henan Province which is located in the middle area of China suffered severe drought. The soil moisture of this area remained a very low level all along until significant precipitation finally came in last September. In the year of 2018, there was a severe drought occurred in Afghan, we used a long-time data series to analyze this drought event. The result showed that the FY-3B/MWRI soil moisture can objectively reflect the spatial distribution and development process of drought. This paper will give an introduction of the applications of FY-3B/MWRI soil moisture product during these drought event.&lt;/p&gt;


2020 ◽  
Author(s):  
Sigrid Jørgensen Bakke ◽  
Monica Ionita ◽  
Lena Merete Tallaksen

&lt;p&gt;An extreme meteorological and hydrological drought occurred in Northern Europe in 2018, with widespread impacts including vast amounts of forests destroyed by wildfires, major crop losses, hydropower shortage, freshwater ecosystem stress, and water usage restrictions. Drought impacts are commonly felt on the ground and many are related to freshwater rather than solely to the atmosphere. A better understanding of the hydrological aspect of drought propagation is therefore vital in order to mitigate drought impacts. This study aims at assessing the drought propagation in 2018 in the (continental) Nordic countries at a monthly resolution, with a special emphasis on the streamflow and groundwater aspect. We used the E-OBS gridded observational datasets for temperature and precipitation, as well as high quality near-natural streamflow and groundwater data from the Nordic countries provided by national agencies. The extremeness for each variable was assessed by ranking each month of 2018 relative to that month in a 60-year record of data (30-year for groundwater due to data limitations). Whereas record-breaking high temperatures and precipitation deficits emerged over the Nordic region in May (Bakke et al., in prep.), streamflow stations did not experience extreme conditions before June in Norway, Sweden and Finland. This delay reflects the effect of various catchment properties and in particular the contribution of catchment water storages (mainly snowmelt) that dampens and delays streamflow response to meteorological conditions. The extent of record low streamflow maximized in July. In mid-August, high precipitation replenished the rivers in western and northern parts of the Nordic region. In the southeastern region, however, extremely low streamflow persisted throughout 2018 despite the return to more normal temperature and precipitation conditions after July. Catchments in western Denmark did not experience extremely low streamflow conditions during the summer of 2018, likely due to large groundwater reservoirs feeding the rivers. The response in groundwater levels was also delayed, with unusually low levels emerging in June and expanding in July. However, there was no clear spatial pattern of extremely low groundwater levels, even wells located very close together showed different results, reflecting the various hydrogeological properties and depths of the wells. Nevertheless, extremeness in groundwater are seen in about half of the wells throughout 2018. The response delay (estimated by the precipitation moving average window best correlated with the groundwater time series), depth and soil type help explain part of the variability in the results amongst the wells. In addition to assessing the uniqueness of the 2018 northern European drought, this study emphasises the added complexity of drought propagation, and the need of incorporating more variables than weather alone to understand hydrological drought development.&lt;/p&gt;&lt;p&gt;Reference: Bakke, S.J., Ionita, M., Tallaksen, L.M. (in prep.). The 2018 Northern Europe Hydrological Drought and its Drivers in a Historical Perspective.&lt;/p&gt;


Sign in / Sign up

Export Citation Format

Share Document