Greenhouse gas emissions from the water–air interface of a grassland river: a case study of the Xilin River

Greenhouse gas (GHG) emissions from rivers and lakes have been shown to significantly contribute to global carbon and nitrogen cycling. In spatiotemporal-variable and human-impacted rivers in the grassland region, simultaneous carbon dioxide, methane and nitrous oxide emissions and their relationships under the different land use types are poorly documented. This research estimated greenhouse gas (CO2, CH4, N2O) emissions in the Xilin River of Inner Mongolia of China using direct measurements from 18 field campaigns under seven land use type (such as swamp, sand land, grassland, pond, reservoir, lake, waste water) conducted in 2018. The results showed that CO2 emissions were higher in June and August, mainly affected by pH and DO. Emissions of CH4 and N2O were higher in October, which were influenced by TN and TP. According to global warming potential, CO2 emissions accounted for 63.35% of the three GHG emissions, and CH4 and N2O emissions accounted for 35.98% and 0.66% in the Xilin river, respectively. Under the influence of different degrees of human-impact, the amount of CO2 emissions in the sand land type was very high, however, CH4 emissions and N2O emissions were very high in the artificial pond and the wastewater, respectively. For natural river, the greenhouse gas emissions from the reservoir and sand land were both low. The Xilin river was observed to be a source of carbon dioxide and methane, and the lake was a sink for nitrous oxide.

Optimization of Scanning Scheme for Low-height Vegetation Survey Based on Terrestrial Laser Scanning - A Case Study on the Restored Sand Land, Southern Qinghai-Tibetan Plateau

Background: In recent decades, vegetation surveys based on terrestrial laser scanning (TLS) have developed rapidly, especially on the forest inventory, but few studies have been conducted to the low-height vegetation. Because of the high investigation cost and subjectivity, it is impending to provide a scientific scanning scheme based on the TLS for the low-height vegetation survey (e.g. shrub, grassland, and meadow) in eco-fragile region (e.g. Qinghai-Tibetan Plateau). Method: In this study, we extracted the vegetation parameter i.e., number, height (H), and crown width (CW) of the two sample plots to evaluate the integrity of the data collected by TLS, on the restored sand land in southern Qinghai-Tibetan Plateau. We assessed the difference between the scanning mode of single-scan (SS) and multiple-scan (MS), and evaluated the influence of terrain fluctuation (windward slope, leeward slope, and the peak of slope) on the determination of scanning spots.Results: The results showed that: (1) the accuracy of vegetation parameter extracted by the mode of SS was mainly affected by the occlusion and the distance from central scanning spot, the RMSE of vegetation parameters is the smallest (RMSEH = 0.186 m; RMSECW = 0.208 m) within 20 m from the central scanning spot. (2) For the MS mode, in addition to the central scanning spot, the scanning spot located at the peak of the slope is the most important, which was the connection of combining the data of windward slope and leeward slope.Conclusion: To sum up, the scientific layout of scanning spot is the key to collecting data by TLS efficiently, and topography is the main factor affecting the layout of scanning spot. Since occlusion effect cannot be avoided, it can only be compensated by setting up more scanning points. Secondly, the accuracy of different sensors will has influence on the distance between adjacent scanning spots.

Analysis of Unconfined Compressive Strength in Clay Mixed with Sand

Clay soils are soils that have high shrinkage potential and have good carrying capacity in water unsaturated conditions but poor in water-saturated conditions. Clay soil has a low carrying capacity, so to increase the carrying capacity of the soil it needs to be stabilized by using an added material which is sand. Land used for 100% disturbed soil, 95% disturbed soil + 5% sand, 90% disturbed soil + 10% sand, 85% disturbed soil + 15% sand, with curing time 3,7,14, and 28 days. The mixture was tested using aunconfined compressive strength test instrument with SNI 03-6887-2002 method. The results of the unconfined compressive strength test showed that the increase in maximum soil strength occurred in the addition of 90% disturbed soil + 10% sand at the age of 28 days curing, which reached 1,194 kg/cm2. But the results of unconfined compressive strength increased when the mixture of 85% disturbed soil + 15% of sand reaching 1,348 kg / cm2. Based on testing that the more amount of sand is added, the higher the value of unconfined compressive strength obtained.

Karakteristik Tanah dan Strategi Rehabilitasi Lahan Bekas Tambang Timah di Provinsi Kepulauan Bangka Belitung

<p><strong>Abstrak</strong>. Pasca penambangan timah menyisakan sebagian berupa lahan pasir tailing yang mempunyai tekstur pasir dengan proporsi fraksi pasir &gt;80%, debu dan liat keduanya &lt;20%. Lahan ini merupakan lahan sangat miskin bahan organik dan hara, sukar menyimpan air, sulit merehabilitasinya karena memerlukan input tinggi. Tulisan ini membahas karakteristik dan dinamika hara tanah pada lahan bekas tambang timah serta teknik pendekatan rehabilitasi lahan tepat guna menanggulangi faktor pembatas lahan pasir tailing timah agar mampu menghasilkan produk berupa komoditas pertanian. Sampai saat ini tanah mineral liat dan bahan organik merupakan bahan yang secara ekonomis murah dan secara teknis mudah dilakukan. Memperbaiki kemampuannya menyimpan hara dan air merupakan kunci keberhasilan merehabilitasi lahan pasir tailing timah. Pendekatan inilah yang seharusnya menjadi pedoman umum dalam merehabilitasi lahan pasir tailing timah untuk dijadikan lahan pertanian</p><p><strong>Abstract</strong>. Post tin mining leaves a portion in the form of tailings sand which has a sand texture with a proportion of sand fraction &gt;80%, both silt and clay &lt;20%. This land is a very poor of organic matter and nutrients, it is difficult to store water. Therefore to rehabilitate it is very difficult and high input is needed. This paper examines the characteristic and dynamics of soil nutrients in abandoned tin-mining area and the appropriate land rehabilitation techniques to overcome the limiting factor for tin tailings sand to be ability and can produce agricultural commodity products. Clay soil mineral and organic material is a material that is economically inexpensive and technically easy to do. Improving its ability to store nutrients and water is the key to the success of rehabilitating tin tailings sand fields. This approach should be a general guideline in rehabilitating tin tailings sand land to be used as agricultural land.</p>

Studi Morfologi Pantai Rewata’a Desa Lalampanua

This research is aimed at knowing morphology characteristics and factors which influence landform that is located at Rewata’a Coastal. Geomorphology is a study stressed on landform characteristics with all processes and material at the world surface. The landform is seen as the appearance of landform as the main aspect of the landscape. The method used in this research is a qualitative descriptive method by collecting primary data, such as images or photos of land from that is directly taken from the research location. The phenomenological approach used to explain what, where, how, and why related to landform which based on available theory and prior research. The research result concludes that the Rewata’a Village morphology is cliffed coast, namely the coastal with the vertical cliff. Composed by host rock or hard sediment. Although we can find sand land at bay and north area. The landform found are delta, sea cave, beach, spit, notch, cliff, wave-cut platform, and stack.

Analysis and Prediction of Land Use in Beijing-Tianjin-Hebei Region: A Study Based on the Improved Convolutional Neural Network Model

During the rapid economic development of China, there are certain blind decisions made in the use of land resources, which poses a significant threat to sustainable development. With the help of the improved convolutional neural network model, this paper analyzes the land use of the Beijing-Tianjin-Hebei region of China from 1995 to 2018, and provides a prediction for 2023. The research results show that: (1) There is still much room for improvement in the land use of the Beijing-Tianjin-Hebei region, with dry land taking up the largest proportion of land in these three locations; (2) Beijing’s development has been well protected in terms of land use. It is predicted that by 2023, the proportions of its woodland, grassland, and rivers, lakes, reservoirs and ponds would increase by 0.26%, 0.30%, and 0.61%, respectively, compared with their proportion in 2018; (3) the land use type in Tianjin during the research period was generally stable. In 2018, the proportion of its woodland and grassland had increased by 1.04% and 0.61%, respectively, compared with that of 1995; and (4) many ecological and environmental problems were exposed during the construction of highways in Hebei province. The area of sand land, saline-alkali land, marshland, bare land, and bare rock areas have all increased, and their total proportion is predicted to reach 1.48% by 2023.

Sandy land structural consolidation engineering drive modern agricultural development in China’s Mu Us Sandy Land

&lt;p&gt;Sandification has become a major obstacle to China&amp;#8217;s regional farmland protection, economic development and ecological civilization construction. Sandy land consolidation technologies and sustainable utilization modes will provide farmland for modern agricultural development. We introduced structural consolidation theory to sandy land rehabilitation from the aspects of soil body building, soil layer reconstruction and soil quality improvement. Filed experiments were conducted in Mu Us Sand Land to explore the effects of dry mixtures of guest material (red clay and loess) and sand at four volume ratios (1:1, 1:2, 1:3 and 1:5) on crop yield, soil properties and maize root growth. Red clay treatments had higher sandy land structural consolidation engineering costs and crop yields than loess treatments. Red clay and loess had significant promotion of maize and soybean yields at volume ratios of 1:3. The maximum potato yield is 42501 kg ha&lt;sup&gt;-1&lt;/sup&gt; and 37332 kg ha&lt;sup&gt;-1&lt;/sup&gt; in red clay treatment at volume ratio of 1:5 and in loess treatment at volume ratio of 1:5, respectively. Red clay and loess significantly increased clay and silt ratio and regulated the soil total nitrogen concentration and soil organic matter content during the critical growth stage of maize. Lowest root biomass in surface soil and lowest surface/subsoil root biomass ratio mediated maize growth in red clay treatment at volume ratio of 1:3. Red clay can be used to consolidate sandy land and develop modern agriculture in the long-term according to the engineering costs and crop yields. Enhanced land productivity, increased land transfer rent and extra wage income provide a stainable and stable increase in households&amp;#8217; income for escaping from poverty. Spatial overlap between red clay with sandy land makes red clay as a new available material for sand land consolidation and utilization from China to global scale. China&amp;#8217;s sandy land structural consolidation engineering and sustainable utilization practices will contribute prescriptions to global desertification fighting and rural poverty alleviation. Regional water resource carrying capacity evaluation should be emphasized before sandy land structural consolidation engineering popularization.&lt;/p&gt;

Method for Classifying Behavior of Livestock on Fenced Temperate Rangeland in Northern China

Different livestock behaviors have distinct effects on grassland degradation. However, because direct observation of livestock behavior is time- and labor-intensive, an automated methodology to classify livestock behavior according to animal position and posture is necessary. We applied the Random Forest algorithm to predict livestock behaviors in the Horqin Sand Land by using Global Positioning System (GPS) and tri-axis accelerometer data and then confirmed the results through field observations. The overall accuracy of GPS models was 85% to 90% when the time interval was greater than 300–800 s, which was approximated to the tri-axis model (96%) and GPS-tri models (96%). In the GPS model, the linear backward or forward distance were the most important determinants of behavior classification, and nongrazing was less than 30% when livestock travelled more than 30–50 m over a 5-min interval. For the tri-axis accelerometer model, the anteroposterior acceleration (–3 m/s2) of neck movement was the most accurate determinant of livestock behavior classification. Using instantaneous acceleration of livestock body movement more precisely classified livestock behaviors than did GPS location-based distance metrics. When a tri-axis model is unavailable, GPS models will yield sufficiently reliable classification accuracy when an appropriate time interval is defined.