Hillslope soil moisture temporal stability under two contrasting land use types during different time periods

AbstractSoil moisture, stable hydrogen, and oxygen isotopes were sampled and determined in a demonstration area of soil and moisture conservation at the Laocheng Town of Yuanmou County in Chuxiong Prefecture, Yunnan of three land use types: Leucaena Benth artificial forest, Heteropogon contortus grass field, and farmland. The characteristics of stable hydrogen and oxygen isotopes of soil moisture in these different land use types at different soil depths were analyzed to investigate the regularities in the quantitative formation of soil moisture balance. In terms of forest land, we found that the variable coefficient of hydrogen isotopes in the 0-20 cm soil layer was the smallest, but decreased with depth under 20 cm. While in grassland, the variable coefficient in 80-100 cm was the largest, and decreased with depth above 80 cm. As for farmland, the variable coefficient in the top 20 cm was the largest, followed by 40-60 cm, and the medium 20-40 cm was the smallest. The soil moisture hydrogen isotope values of three land use type were different at surface layer, but prone to be consistent in each type. Along the soil depth in forest land, the hydrogen isotope increased first and then decreased, while increased in the end, and the maximum appeared in 80-100 cm. In grassland, the hydrogen isotope increased initially as the forest land but then decreased continuously, so the maximum was found at 20-40 cm. And in grassland, the hydrogen isotope of all depths were higher than which of forest land and farmland. In same land use type, the hydrogen isotope of soil moisture changed significantly at the surface, and the variation of hydrogen isotopes was obviously decreased along the depth. Our findings could provide reference data which would contribute to the assessment of regional groundwater resources in the dry-hot valley of Yuanmou in this study.

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A signature-based approach to quantify soil moisture dynamics under contrasting land-uses

10.22541/au.162435676.61345839/v1 ◽

2021 ◽

Author(s):

Ryoko Araki ◽

Flora Branger ◽

Inge Wiekenkamp ◽

Hilary McMillan

Keyword(s):

Land Use ◽

Time Series ◽

Soil Moisture ◽

Shallow Groundwater ◽

Storm Event ◽

Land Uses ◽

Soil Moisture Dynamics ◽

Land Use Types ◽

Event Based ◽

Moisture Dynamics

Soil moisture signatures provide a promising solution to overcome the difficulty of evaluating soil moisture dynamics in hydrologic models. Soil moisture signatures are metrics that represent catchment dynamics extracted from time series of data and enable process-based model evaluations. To date, soil moisture signatures have been tested only under limited land-use types. In this study, we explore soil moisture signatures’ ability to discriminate different dynamics among contrasting land-uses. We applied a set of nine soil moisture signatures to datasets from six in-situ soil moisture networks worldwide. The dataset covers a range of land-use types, including forested and deforested areas, shallow groundwater areas, wetlands, housing areas, grazed areas, and cropland areas. These signatures characterize soil moisture dynamics at three temporal scales: event, seasonal, and time-series scales. Statistical and visual assessment of extracted signatures showed that (1) storm event-based signatures can distinguish different dynamics for most land-uses, (2) season-based signatures are useful to distinguish different dynamics for some types of land-uses (forested vs. deforested area, greenspace vs. housing area, and deep vs. shallow groundwater area), (3) timeseries-based signatures can distinguish different dynamics for some types of land-uses (forested vs. deforested area, deep vs. shallow groundwater area, non-wetland vs. wetland area, and ungrazed vs. grazed area). We compared signature-based process interpretations against literature knowledge: event-based and time series-based signatures were generally matched well with previous process understandings from literature, but season-based signatures did not. This study demonstrates the best practices of extracting soil moisture signatures under various land-use and climate environments and applying signatures for model evaluations.

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Elucidating soil moisture dynamics in agricultural landscapes under varying weather patterns

10.5194/egusphere-egu21-5876 ◽

2021 ◽

Author(s):

Veronica Fritz ◽

Thakshajini Thaasan ◽

Andrew Williams ◽

Ranjith Udawatta ◽

Sidath Mendis ◽

...

Keyword(s):

Land Use ◽

Soil Moisture ◽

Soil Water ◽

Water Cycle ◽

Water Storage ◽

Soil Water Storage ◽

Storm Events ◽

Weather Patterns ◽

Land Use Types ◽

Moisture Dynamics

<p>Changing weather patterns and anthropogenic land use change significantly alter the terrestrial water cycle. A key variable that modulates the water cycle on the land surface is soil moisture and its variability in time and space. Hydrological models are used to simulate key components of the water cycle including infiltration, soil storage and uptake by plants. However, uncertainties remain in accurately representing soil moisture dynamics in models. Here, with the aid of several sensors installed at a 30-ha experimental research facility, we attempt to quantify differences in soil water storage across multiple land use types &#8211; cropped area, mosaic of turf grass and native plants, and an unkept weeded area as control land use. We will also discuss the accuracy of sensors to correctly measure soil water storage. Our study was conducted at an agricultural experimental station in Columbia, Missouri, USA. We use a variety of instruments to measure weather, evapotranspiration, and soil water. We used boundary layer scintillometers to measure near-surface turbulence, sensors to continuously track soil moisture and temperature, as well as weather stations for precipitation, air temperature, solar radiation and wind speed. &#160;Changes in volumetric water content and soil temperature are measured at 5-minute intervals at 10-, 20-, and 40-cm soil depths to compare soil water storage among the three land use types. We also took soil samples before and after several storm events to calibrate the sensor readings at three sites. We, then, analyzed several storm events over a period of five months and compared the actual soil moisture and soil temperature dynamics at finer time intervals. With additional measurements of weather and boundary layer turbulence, we hope to reveal the landscape and weather control on soil moisture distribution across multiple land uses, and their subsequent impact on plant water uptake. Our preliminary results indicate that continuously disturbed agricultural lands depletes soil moisture at faster rates, which may present challenges in maintaining land productivity in the long term.</p>

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Estimating the Effects of DEM and Land Use Types on Soil Moisture Using HJ-1A CCD/IRS Images: A Case Study in Minhou County

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.4572 ◽

2013 ◽

Vol 726-731 ◽

pp. 4572-4576 ◽

Cited By ~ 1

Author(s):

Yu Qin Liu ◽

Jin Ming Sha ◽

De Sheng Wang

Keyword(s):

Land Use ◽

Soil Moisture ◽

Land Surface ◽

Vegetation Index ◽

Vegetation Indexes ◽

Land Use Types ◽

Research Findings ◽

Soil Moisture Status

Soil moisture is of great significance for regional resources and environments. The combination of land surface temperature (Ts) and vegetation index (VI) is appropriate for monitoring the regional surface soil moisture status. In this study, we employed HJ-1B CCD/IRS images,DEMand land use types to obtain the information about soil moisture for Minhou county in FuZhou. Firstly,TVDIreflected the soil moisture status was analyzed with in-situ soil moisture measurements based on two kinds of different vegetation indexes (NDVI/EVI). Secondly, the relationship betweenTVDIandDEMwas analyzed. Finally, the soil moisture status of each land use type was explored combined with the main land use types of study area. Research findings indicate that: (1)TVDIcan effectively reflect the spatial pattern of soil moisture andTs/EVIhas a higher accuracy thanTs/NDVI; (2) the spatial distribution of soil moisture is obviously affected by the altitude; (3) there exists correlationship between soil moisture and land use types in study area.

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Comparative analysis on spatial variability of soil moisture under different land use types in orchard

Scientia Horticulturae ◽

10.1016/j.scienta.2016.05.017 ◽

2016 ◽

Vol 207 ◽

pp. 65-72 ◽

Cited By ~ 13

Author(s):

Kaikai Fang ◽

Huike Li ◽

Zhikang Wang ◽

Yifei Du ◽

Jing Wang

Keyword(s):

Land Use ◽

Soil Moisture ◽

Comparative Analysis ◽

Spatial Variability ◽

Land Use Types

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Seasonal variations in soil respiration and temperature sensitivity under three land-use types in hilly areas of the Sichuan Basin

Soil Research ◽

10.1071/sr07223 ◽

2008 ◽

Vol 46 (8) ◽

pp. 727 ◽

Cited By ~ 20

Author(s):

XiaoGuo Wang ◽

Bo Zhu ◽

MeiRong Gao ◽

YanQiang Wang ◽

XunHua Zheng

Keyword(s):

Land Use ◽

Soil Moisture ◽

Soil Respiration ◽

Soil Temperature ◽

Co2 Efflux ◽

Forest Plantation ◽

Soil Co2 ◽

Q10 Value ◽

Land Use Types ◽

The Relationship

CO2 emissions from soils were measured under 3 land-use types at the adjacent plots of forest plantation, grassland, and cropland from January 2005 to December 2006. Mean soil CO2 efflux rates measured during the 2-year study varied from 59 to 527 mg CO2/m2.h in forest plantation, 37 to 498 mg CO2/m2.h in grassland, and 32 to 397 mg CO2/m2.h in cropland. Soil respiration in the 3 types of land-use showed a similar seasonal pattern in variation during both years, in which the single-peaked curve occurred in early summer and the minimum in winter. In particular, the date of maximum soil CO2 efflux rate in cropland occurred about 30 days earlier than in forest and grassland in both 2005 and 2006. The relationship of soil respiration rate (R) with soil temperature (T ) and soil moisture (W ) fitted well to the equation R = β0eβ1TW β2 (a, b, c were constants) than other univariate models which consider soil water content or soil temperature alone. Soil temperature and soil moisture together explained 69–92% of the temporal variation in soil respiration in the 3 land-use types. Temperature sensitivity of soil respiration (Q10) was affected positively by soil moisture of top 0.1 m layer and negatively by soil temperature at 0.05 m depth. The relationship between Q10 values and soil temperature (T ) or soil moisture (W ) indicated that a 1°C increase in soil temperature at 0.05 m depth will reduce the Q10 value by 0.07, 0.05, and 0.06 in forest, grassland, and cropland, respectively. Similarly, a 1% decrease in soil moisture of the top 0.1 m layer will reduce the Q10 value by 0.10, 0.09, and 0.11 in forest, grassland, and cropland.

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Spatiotemporal variation of soil moisture under different land use types in a typical karst hill region

Acta Ecologica Sinica ◽

10.5846/stxb201405100939 ◽

2014 ◽

Vol 34 (18) ◽

Author(s):

徐慧芳 XU Huifang ◽

宋同清 SONG Tongqing ◽

黄国勤 HUANG Guoqin ◽

彭晚霞 PENG Wanxia ◽

曾馥平 ZENG Fuping ◽

...

Keyword(s):

Land Use ◽

Soil Moisture ◽

Spatiotemporal Variation ◽

Hill Region ◽

Land Use Types

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Uncertainty in predicting the spatial pattern of soil water temporal stability at the hillslope scale

Soil Research ◽

10.1071/sr15059 ◽

2016 ◽

Vol 54 (6) ◽

pp. 739 ◽

Cited By ~ 1

Author(s):

K. Liao ◽

X. Lai ◽

L. Lv ◽

Q. Zhu

Keyword(s):

Land Use ◽

Soil Moisture ◽

Spatial Pattern ◽

Spatial Variation ◽

Soil Water ◽

Ordinary Kriging ◽

Temporal Stability ◽

Relative Difference ◽

Tea Garden ◽

Hillslope Scale

Soil water temporal stability is subject to spatial variation, which influences the prediction of mean soil water status on a hillslope. However, estimation of the spatial pattern of soil water temporal stability and quantification of the uncertainties associated with the predictions are often ignored. In this study, volumetric soil water contents at 10 and 30cm depths on tea garden and forest hillslopes were monitored across 17 dates from January 2013 to April 2014. Soil moisture maps on these 17 dates were interpolated using ordinary kriging and then the spatial distribution of the relative difference of soil moisture was assessed. Based on these maps, standard deviations of relative difference (SDRD) of soil moisture were calculated to represent the spatial variation of soil water temporal stability. Uncertainties in predicted patterns of SDRD due to the limited number of sampling days used for calculating SDRD (U1) and for spatial interpolation of soil moisture by ordinary kriging (U2) were investigated using bootstrap and sequential Gaussian simulation techniques respectively. Results showed that soil water content on the forest hillslope generally exhibited stronger spatial variability than that on the tea garden hillslope. The SDRD substantially varied in space at the hillslope scale. Temporal stabilities of soil water content at 30cm depth were significantly (P<0.05) stronger than those at 10cm soil depth, regardless of the land use type. However, differences in soil water temporal stabilities on these two land use hillslopes were not significant. In addition, U2 was generally more important than U1 on both hillslopes. This suggests that additional sampling sites and more robust interpolation methods rather than additional sampling days should be developed to reduce SDRD prediction uncertainty on the study hillslopes.

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