TITLE:
Response Relationship between the Seasonal Freezing-Thawing Process of Soil and Spatial Factor Changes in the Dayekou Basin of the Qilian Mountains
AUTHORS:
Yun Niu, Jinling An
KEYWORDS:
Freezing-Thawing, Spatial Factor, Seasonal Frozen Soil, Dayekou Basin of the Qilian Mountains
JOURNAL NAME:
Open Journal of Ecology,
Vol.8 No.8,
August
10,
2018
ABSTRACT: Objective: In this study, the influence and response
relationship between the seasonal freezing-thawing process of soil and the
spatial factor changes in the management and utilization of water resource
processes were explored. Methods: The monitoring equipment in this study
was arranged at different altitudes, gradients, and slope directions, such as
the typical forest sample area in the Dayekou Basin of the Qilian Mountains.
The spatial variation characteristics of the seasonal freezing-thawing process
of the soil were analyzed, and a regression model was established. Results: 1) The results of this study determined that the rate of the soil’s freezing
increased with the altitude in a trend of volatility. However, the rate of the
thawing of the frozen soil was found to have an opposite trend. The variation
degree of the freezing-thawing process increased with the altitude in a trend
of volatility. The end time of the approximate soil freezing with altitude
increased in a volatility trend ahead of schedule. However, the opposite was
observed in the thawing rate of the frozen soil; 2) The rate of the soil’s
freezing under the mosses of the spruce forest at an altitude of 3028 m was
found to be the lowest. However, in the sub-alpine scrub forest at an altitude
of 3300 m, a maximum in the spatial ordering was observed, with an average of
1.9 cm·d-1. The thawing rate of
the frozen soil in scrub-spruce forest at an altitude of 3300 m was found to be
minimal. However, in the sunny slope grassland at an altitude of 2946 m, a
maximum in the spatial ordering was observed, with an average of 1.5 cm·d-1.
In the spatial ordering of the variation degree of the process of
freezing-thawing with an average of 1.2, the scrub-grassland at an altitude of
2518 m was found to be the lowest, and the scrub-spruce
forest at an altitude of 3195 m was also low; 3) The soil freezing began on
approximately October 20th, and the rate of soil freezing gradually
became reduced. The arrival time of the frozen soil of up to 150 cm in depth in
sub-alpine scrub forest was first observed at an altitude of 3028 m. However,
the scrub-spruce forest at an altitude of 3100 m did not become frozen until
approximately January 12th on average. Then, the thawing rate of the
frozen soil increased gradually. The end time of the thawing was earliest
observed in the sunny slope grassland at an altitude of 2946 m. However, the scrub-spruce
forest at an altitude of 3100 m was found to be the last to thaw, and averaged
approximately July 27th. The average durations of the freezing and
thawing of the soil were 77 and 121 days, respectively, and the average
duration of the entire process of freezing-thawing was 199 days; 4) This
study’s established regression models of the duration time of frozen soil’s
thaw, and the rate of frozen soil’s thaw, all passed the R test of goodness of fit, F test
of variance, and t test. Conclusions: The characteristics of the seasonal freezing-thawing process of the soil
with the spatial changes were seasonal. However, the characteristics under the
different spatial factor influences were not the same.