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Kelin Wang

Publications and source records attributed to Kelin Wang.

9 recordsLinked to original sources
PubMed2005

[Water cycling characteristics of grassland and bare land soils on Loess Plateau].

The study under natural and simulated rainfall conditions showed that the variance coefficient of soil water in the grassland and bare land on Loess Plateau decreased with increasing soil depth, and the vertical change of soil water in drought year in the profile could be divided into four layers. In rainy year, the variance coefficient of soil water decreased first, increased later, and decreased lastly with the increase of soil depth, due to the continual rainfall infiltration and intensive evapotranspiration. The variance coefficient at surface soil layer was obviously smaller in rainy year than in drought year. Compared with that in bare land, the soil water cycling in grassland was deeper in depth and greater in intensity, as well as higher in evapotranspiration. The temporal change of soil water mostly depended on rainfall and evapotranspiration, especially in surface soil layer, and the change of soil water lagged behind gradually from low to deep layers in the profile. Soil water storage had a seasonal change, and could be divided into three main periods, i. e., decreasing in spring, alternatively decreasing and increasing in summer and autumn, and relatively stable in winter. In drought year, soil water storage decreased, and infiltrated rainfall was all consumed by intensive evapotranspiration. In rainy year, soil water storage increased, but most infiltrated rainfall (more than 80%) was consumed by intensive evapotranspiration.

China↗
PubMed2004

Hydrological response to a seafloor spreading episode on the Juan de Fuca ridge.

Seafloor hydrothermal systems are known to respond to seismic and magmatic activity along mid-ocean ridges, often resulting in locally positive changes in hydrothermal discharge rate, temperature and microbial activity, and shifts in composition occurring at the time of earthquake swarms and axial crustal dike injections. Corresponding regional effects have also been observed. Here we present observations of a hydrological response to seafloor spreading activity, which resulted in a negative formation-fluid pressure transient during and after an earthquake swarm in the sediment-sealed igneous crust of the Middle Valley rift of the northernmost Juan de Fuca ridge. The observations were made with a borehole seal and hydrologic observatory originally established in 1991 to study the steady-state pressure and temperature conditions in this hydrothermally active area. The magnitude of the co-seismic response is consistent with the elastic strain that would be expected from the associated earthquakes, but the prolonged negative pressure transient after the swarm is surprising and suggests net co-seismic dilatation of the upper, permeable igneous crust. The rift valley was visited four weeks after the onset of the seismic activity, but no signature of increased hydrothermal activity was detected in the water column. It appears that water, not magma, filled the void left by this spreading episode.

Journal Article↗
PubMed2004

Entangling the complexity of protected area management: the case of Wolong Biosphere Reserve, southwestern China.

Protected Area (PA) management is a complex issue that requires the consideration of many factors and relationships. A conceptual framework for the analysis of biodiversity change, local human communities, and PA management was put forward, accordingly. Under the framework, we investigated the economic status, livelihood activities, biodiversity use and perceptions of local communities, and the land use history in Wolong Biosphere Reserve, southwestern China through household survey and document review in order to gain a better understanding of the complexity of PA management. According to the land use history, the preservation of agro-biodiversity, and the raising of productivity, ecological rehabilitation and the regulation of the human pressures are indispensable in the management of the reserve. Livelihood activities and the perceptions of local communities were largely determined by the socioeconomic background, which has important implications in solving the conflicts or incompatibilities in the reserve. In Wolong Biosphere Reserve, it is beneficial to support local farmers in solving their socioeconomic problems such as the overabundance of labor force and the lack of livelihood alternatives. Without this, there will be scarcely any effective biodiversity conservation and successful reserve management in the long term.

Agriculture↗
PubMed2003

[Structure and function of several intercropping ecosystems in newly built orchard].

Sloping wildland is the important potential land resource in China. Structures and functions of five optimized models selected from more than 10 intercropping patterns in the newly built orchards in the uncultivated sloping field were analyzed in this paper. The results showed that organic matter was increased by 5-20%, total N by 7-40%, total P by 8-70%, and total K by 15-80% yearly. Considering its benefit in soil and water conservation, the intercropping model of peanut and autumn soybean was the best, and followed by spring soybean and autumn soybean, tomato and Chinese cabbage, cayenne and tomato, and drought rice and red turnip. Compared with the control, the average soil erosion module and runoff amount of the 5 models were decreased by 44.19%, 38.24%, 39.52%, 37.56%, 37.30%, and 22.40%, 9.28%, 24.11%, 21.60%, 15.93%, respectively. The intercropping model of cayenne and tomato had the highest biomass, and its annual biomass averaged 1,00,267 kg.hm-2. The biomass of intercropping model of peanut and autumn soybean was the second, and the annual value averaged 77,026 kg.hm-2. Intercropping model of peanut and autumn had the highest annual productivity, which averaged 15,619 kg.hm-2, and that of intercropping model of tomato and Chinese cabbage was the second, averaged 15,394 kg.hm-2. The efficiency of energy introjection was in order of cayenne and tomato, tomato and Chinese cabbage, peanut and autumn soybean, spring soybean and autumn soybean, and dry rice and red turnip, and their values were 3.06, 2.16, 2.15, 2.06, and 0.71, respectively.

Crops, Agricultural↗
PubMed2003

[Soil water availability in new-cultivated hillside land].

The dynamics of water content in three soil layers (0-20 cm, 20-40 cm and 40-60 cm) were determined at three geographic locations (mesoslope, downgrade, valley) of new-cultivated sugarcane field and uncultivated hillside land at one day before rain, 4 hours, 2, 4, 6 and 8 days after rain during rainy season and dry season in 1998 at environmental immigrants settlement area of northwest Guangxi. The result showed that the increment of available soil water content in valley sugarcane field after rain was equal to precipitation, but that in mesoslope sugarcane field and uncultivated hillside land was 80% of precipitation. The distribution of available soil water content in 0-60 cm soil horizons was uniform after rain during rainy season; however it was concentrated in surface horizon after rain during dry season. The differences of available soil moisture saturation degree between treatments and between soil horizons were significant during rainy season; nevertheless, those of dry season were not significant. The consumption rate of available soil water content in 0-60 cm soil horizons of uncultivated hillside land was the least among all treatments. Although the consumption rate of available soil water content during dry season was less than that of rainy season, the available soil water content during dry season would be exhausted in 15 days after rain.

Crops, Agricultural↗