Influence of Various Soil and Water Conservation Methods on the Moisture Balance at Coffee Plant Root Zone

Background: The study of the moisture balance can be used to suppose the plants water requirement and the plants water use efficiency. The moisture balance influenced by climate factor, therefore climate change can affect the moisture balance especially in rainfed. Therefore, an effort is needed to manage soil moisture in rainfed as a climate change mitigation measure: soil and water conservation. This study aimed to determine the influence of soil and water conservation on the moisture balance in the coffee root zone. Methods: This study was conducted at people’s coffee plantation of Argotirto village, Sumbermanjing Wetan District, Malang Regency, located between 8.2411-8.1443 S and 112.4031-112.4634 E. Observation were made on February to November 2020, divided into observations in the wet season, dry seasons and flowering period. The observation plots consisted of terraced plot (P0), terraced + straight silt pit (P1), terraced + L-shaped silt pit (P2) and terrace + biopore (P3). The observation variables were: soil physical characteristics and moisture balance components there were precipitation, percolation, runoff, evapotranspiration and soil moisture storage. Result: At P1, the runoff depth was 80.89% lower and the percolation was 44.22% higher than P0. The total soil moisture storage at P1 was 20.06% higher than P0 in the dry season, indicating that P1 could increase the period of surplus moisture in the dry season.

Using NDII patterns to constrain semi-distributed rainfall-runoff models in tropical nested catchments

A parsimonious semi-distributed rainfall-runoff model has been developed for flow prediction. In distribution, attention is paid to both timing of runoff and heterogeneity of moisture storage capacities within sub-catchments. This model is based on the lumped FLEXL model structure, which has proven its value in a wide range of catchments. To test the value of distribution, the gauged Upper Ping catchment in Thailand has been divided into 32 sub-catchments, which can be grouped into 5 gauged sub-catchments where internal performance is evaluated. To test the effect of timing, firstly excess rainfall was calculated for each sub-catchment, using the model structure of FLEXL. The excess rainfall was then routed to its outlet using the lag time from storm to peak flow (TlagF) and the lag time of recharge from the root zone to the groundwater (TlagS), as a function of catchment size. Subsequently, the Muskingum equation was used to route sub-catchment runoff to the downstream sub-catchment, with the delay time parameter of the Muskingum equation being a function of channel length. Other model parameters of this semi-distributed FLEX-SD model were kept the same as in the calibrated FLEXL model of the entire Upper Ping basin, controlled by station P.1 located at the centre of Chiang Mai Province. The outcome of FLEX-SD was compared to: 1) observations at the internal stations; 2) the calibrated FLEXL model; and 3) the semi-distributed URBS model - another established semi-distributed rainfall-runoff model. FLEX-SD showed better or similar performance both during calibration and especially in validation. Subsequently, we tried to distribute the moisture storage capacity by constraining FLEX-SD on patterns of the NDII (normalized difference infrared index). The readily available NDII appears to be a good proxy for moisture stress in the root zone during dry periods. The maximum moisture holding capacity in the root zone is assumed to be a function of the maximum seasonal range of NDII values, and the annual average NDII values to construct 2 alternative models: FLEX-SD-NDIIMax-Min and FLEX-SD-NDIIAvg, respectively. The additional constraint on the moisture holding capacity by the NDII improved both model performance and the realism of the distribution. Distribution of Sumax using annual average NDII values was found to be well correlated with the percentage of evergreen forest in 31 sub-catchments. Spatial average NDII values were proved to be highly corresponded with the root zone soil moisture of the river basin, not only in the dry season but also in the water limited ecosystem. To check how well the model represents root zone soil moisture, the performance of the FLEX-SD-NDII model was compared to time series of the soil wetness index (SWI). The correlation between the root zone storage and the daily SWI appeared to be very good, even better than the correlation with the NDII, because NDII does not provide good estimates during wet periods. The SWI, which is partly model-based, was not used for calibration, but appeared to be an appropriate index for validation.

Functional Properties of SAP-Based Humidity Control Plasters

The application of materials with high moisture storage capacity close to the interior surface presents a prospective passive method for improving indoor relative humidity conditions. In this paper, lime-cement plasters containing three different types of superabsorbent polymers (SAPs) in varying dosages are introduced and their mechanical, hygric, and thermal characteristics are analyzed in a relation to microstructure. The experimental results show a significant effect of both SAP amount and chemical composition on all functional properties of studied plasters. The incorporation of 1.5% of SAP may induce up to 2.5 better moisture buffering, thus significantly improving the passive humidity control capability. Considering overall functional parameters of SAP-modified plasters, the dosage of 1 wt.% can thus be viewed as a rational compromise between the moisture storage capability and mechanical properties. The obtained wide sets of parameters can be utilized directly as input data of computational models suitable for the assessment of the interior microclimate of residential and administrative buildings.

Effect of Vegetation Restoration on Soil Hydrology in Karst Area of Southwest China: Inspiration from Barrel Planting Experiments

The purpose of this study was to explore the effects of different vegetation restoration types on soil hydrology characteristics in the Karst Plateau Gorge and to clarify the soil moisture (θ) use characteristics. A barrel experiment was conducted to monitor θ and the water potential (Ψ) of three vegetation types (Zanthoxylum bungeanum (ZB), Zea mays L. (ZM), and Sophora tonkinensis (ST), Abandoned land (AL)) was used as a control to explore θ use conditions of each vegetation type. A larger surface permeability led to lower moisture storage. The soil moisture storage showed the law of ZM > ST > AL > ZB. The soil moisture storage also had obvious characteristics in dry-wet seasons. As a typical drought-tolerant crop, ZB responded more obviously to rainfall and had the highest effective replenishment amount and efficiency. Two processes were clearly involved in decreasing soil moisture, which could be divided into three stages of changes: a consumption period (CP), a moisture supplying period (SP), and a relatively stable period (RSP). CP occurred primarily in November to April, when θ was prone to water stress and required proper artificial replenishment. SP was characterized by limited rainfall replenishment in January and May, which significantly increased θ. During the rainy season, corresponding with RSP, θ fluctuated within a relatively stable range. At the end of the CP, the water shortage was more severe. In actual agricultural production, attention should be given to reasonable artificial recharge. This research aims to provide a theoretical basis for karst θ management.

Characterization of the Hygrothermal Properties of Wood Fibre Insulaton Board

High thermal resistance building envelopes comprising wood fibre insulation board (WFIB) contribute to a reduction in building energy consumption associated with unwanted heat losses and gains. The longterm performance and durability of the WFIB material may perform differently than expected due to the temperature and moisture dependent material characteristics, including moisture sorption, vapour permeance, and thermal conductivity. This research investigated the characterization of hygrothermal properties of WFIB at temperatures and relative humidities expected for a Canadian climate. The hygrothermal characteristics of WFIB were determined to have a range of values as a result of the variable nature of wood fibre materials with temperature and moisture, and the variability of WFIB materials amongst manufactured products. The variabilities of these hygrothermal properties are expected to impact the materials overall moisture storage at various in-situ temperature and relative humidity conditions, and the materials ability to transport moisture at various in-situ temperature and relative humidity conditions. Additionally, the thermal performance of WFIB is expected to vary with in-situ temperature and relative humidity conditions, with increased thermal losses/gains with increasing temperature and increasing relative humidities.

Characterization of the Hygrothermal Properties of Wood Fibre Insulaton Board

High thermal resistance building envelopes comprising wood fibre insulation board (WFIB) contribute to a reduction in building energy consumption associated with unwanted heat losses and gains. The longterm performance and durability of the WFIB material may perform differently than expected due to the temperature and moisture dependent material characteristics, including moisture sorption, vapour permeance, and thermal conductivity. This research investigated the characterization of hygrothermal properties of WFIB at temperatures and relative humidities expected for a Canadian climate. The hygrothermal characteristics of WFIB were determined to have a range of values as a result of the variable nature of wood fibre materials with temperature and moisture, and the variability of WFIB materials amongst manufactured products. The variabilities of these hygrothermal properties are expected to impact the materials overall moisture storage at various in-situ temperature and relative humidity conditions, and the materials ability to transport moisture at various in-situ temperature and relative humidity conditions. Additionally, the thermal performance of WFIB is expected to vary with in-situ temperature and relative humidity conditions, with increased thermal losses/gains with increasing temperature and increasing relative humidities.

Assessment of Soil Moisture Storage In Nigeria Using Climatic Water Budgeting Approach

The estimation of soil moisture storage is fundamental to crop production, hydrological and biological processes. This study assessed soil moisture storage in Nigeria using the Climatic Water Budgeting Approach. Mean monthly air temperature and monthly rainfall data were collected from the archives of the Nigerian Meteorological Agency from 27 weather stations in Nigeria. The data were subjected to Climatic Water Budgeting Approach to compute the monthly soil moisture storage at different locations in Nigeria over two years with contrasting moisture conditions (1983 and 2003). The mean monthly air temperature data were used to estimate the monthly potential evapotranspiration (PE) while the PE in conjunction with the mean monthly rainfall and the soil water holding capacity of 250mm were used to calculate the monthly soil moisture storage. The results showed that most locations north of latitude 9°N recorded low soil moisture storage below 10 mm from April to July especially in 1983. The soil moisture storage was high in all the places in January and February due to low potential evapotranspiration and accumulated potential water loss (APWL). Most Places South of latitude 9°N recorded higher soil moisture storage between 20 mm and 100 mm from January to May compared to their counterparts north of latitude 9°N in both 1983 and 2003. The soil moisture storage attained 250 mm (100%) from July-October across Nigeria. This study concluded that the soil moisture varies spatially and temporally in Nigeria decreasing from South to North. A paired sample test revealed a significant difference between the soil moisture storage of 2003 and 1983 in Nigeria (p=.000).

Effect of different types of soil tillage for sunflower on some soil physical characteristics. Part I: soil moisture

The investigation was carried out during 2014–2016 in the land of General Toshevo town in the South Dobrudzha region on slightly leached chernozem soil type. The effect of the types of soil tillage for sunflower given bellow was followed: ploughing at 24–26 cm, chisel-plough at 24–26 cm, disking with disk harrow at 10–12 cm and direct sowing (no-tillage) on the soil moisture content. Based on bulk density, wilting point and the determined soil moisture content the plant-available water was calculated. The additional soil tilths of the areas subjected to ploughing, chisel-ploughing and disking with disc harrow included double spring pre-sowing cultivation with harrowing. To destroy the emerging weeds in the variant with direct sowing, a total herbicide was applied. The soil moisture content was evaluated during three main stages of sunflower development: emergence, flowering and technical maturity. The investigated parameter was determined for each of the studied layers – 0–10, 10–20, 20–30, 30–40 and 40–60 cm. In years with normal amounts of rainfalls, no significant differences in the soil moisture under the different ways of soil tillage were observed. Conventional ploughing and tillage without turning of the soil layer contributed to accumulation of more moisture and to higher moisture storage down the soil profile under heavy and intensive rainfalls. Tillage without turning of the soil layer, minimal and no tillage maintained more and better soil moisture in years with limited precipitation and in periods of drought.

Using observed soil moisture to constrain the uncertainty of simulated hydrological fluxes

Using data from five long-term field sites measuring soil moisture, we show the limitations of using soil moisture observations alone to constrain modelled hydrological fluxes. We test a land surface model, MESH/CLASS, with two configurations: one where the soil hydraulic properties are determined using a pedotransfer function (the texture-based calibration) and one where they are assigned directly (the hydraulic properties-based calibration). The hydraulic properties-based calibration outperforms the texture-based calibration in terms of reproducing changes in soil moisture storage within a 1.6 m deep profile at each site, but both perform reasonably well, especially in the summer months. When the models are constrained using observations of changes in soil moisture, the predicted hydrological fluxes are subject to very large uncertainties associated with equifinality. The uncertainty is larger for the hydraulic properties-based calibration, even though the performance was better. We argue that since the pedotransfer functions constrain the model parameters in the texture-based calibrations in an unrealistic way, the texture-based calibration underestimates the uncertainty in the fluxes. We recommend that reproducing observed cumulative changes in soil moisture storage should be considered a necessary but insufficient criterion of model success. Additional sources of information are needed to reduce uncertainties, and these could include improved estimation of the soil hydraulic properties and direct observations of fluxes, particularly evapotranspiration.

Assessment of the WRF-Hydro uncoupled hydro-meteorological model on flashy watersheds of the tropical island of New Caledonia (South-West Pacific)

<p>Situated in the South-West Pacific, New Caledonia is a tropical island dominated by a central mountain range and is subject to cyclones, regular intense precipitation events and flash-flooding. Recent fine-scaled projections of climate change in New Caledonia show that the frequency and intensity of extreme precipitation events could be reduced by ~ 20% by 2080-2100 [Dutheil <em>et al.</em>, 2020]. This paper investigates the ability of the WRF-Hydro/Noah-MP modelling framework to represent the hydrological regime of six watersheds in New Caledonia. A nearly 2-year long WRF ideal atmospheric forcing was completed with observed precipitations from 24 rain gauges using two rainfall spatial interpolation methods at 0.2 km-resolution. This study mainly seeks to calibrate the uncoupled WRF-Hydro/Noah-MP system as well as to evaluate its performance upon short and contrasted heavy rainfall events between 2012 and 2014. Particular attention was paid to (i) the sensitivity of calibration processes to rainfall spatial interpolation methods, (ii) the consistency in modelled soil moisture storage and (iii) the reliability of hydrograph separation provided by WRF-Hydro.</p><p>After automatic calibration relying upon the DDS algorithm [Tolson and Shoemaker, 2007], streamflow simulations show overall good performance with Nash–Sutcliffe efficiencies (NSE) greater than 0.6 on a 21-month period for all watersheds. Standard hydrological features of all studied watersheds are well reproduced. The quality of simulation is found to be decreasing with lower values of runoff coefficient. We show on three watersheds that spatial distribution of rainfall can highly condition the calibration process and thus greatly modify modelled soil moisture storage and in result the shape of simulated flash floods. WRF-Hydro’s hydrograph decomposition between surface and underground runoff is presented and compared with known characteristics of watersheds as well as with other quickflow/baseflow separation methods. To our knowledge, this work is the first attempt to use the uncoupled WRF-Hydro hydro-meteorological model for flash flood analysis in New Caledonia and opens a pathway to study multiple hydrological and climatic features in the region in the context of climate change.</p><p><strong>Keywords</strong>: hydro-meteorological modelling, WRF-Hydro, Noah-MP, flash flood, rainfall spatial interpolation, hydrograph separation, baseflow, New-Caledonia</p>