Inappropriate Human Activities Research Articles

Vegetation restoration strategies in arid or semi-arid regions-From the perspective of optimal control.

Inappropriate human activities contribute to the degradation of ecosystems in arid or semi-arid regions. Therefore, emphasizing the importance of strategies for restoring vegetation in these areas cannot be overstated. However, there has been insufficient research on how to develop effective restoration strategies at minimal cost. This paper addresses this gap by studying how optimizing the spatiotemporal distribution of human activities through local and boundary controls can reduce the level of desertification in vegetation pattern structures, thereby facilitating the recovery of arid land vegetation. The results indicate that vegetation restoration depends on the proportion and number of human activity areas, with a trade-off between them. Furthermore, consistent conclusions were obtained on circular regions, demonstrating the robustness of the approach to boundary shapes. This paper aims to offer new insights into the restoration of arid land vegetation and the prevention of catastrophic ecosystem changes from the perspective of optimal control.

CONTRIBUTION TO THE STUDY OF SOIL VULNERABILITY TO WATER EROSION IN THE THIES PLATEAU

This study was carried out in the watershed located between the municipalities of Tassette and Notto, where soil water erosion is one of the most dangerous threats in the region.This work aims to quantify the degree of soil erodibility in the Thiesplateauand then draw up an erosion risk map using the improved boyoucoss method. Interpretation of the experimental results reveals that the erodibility index varies between 1.62 and 14.10, with an average value of 5.6. This variation in the erodibility index shows areas of high, moderate and very high vulnerability, respectively 59%, 18.2% and 18% of the areas studied. The progressive degradation of soils by water erosion is also amplified by inappropriate human activities, weakening the resilience of ecosystems and communities.

Spatial characteristics of surface-deposited diatoms in Weishan Lake and their relationship with the water environment (Shandong Province, China)

The Weishan Lake serves as a crucial reservoir and regulating lake in the Eastern Route of the South-to-North Water Diversion Project and the ecological health of its lake ecosystem directly impacts the water quality for water diversion. Diatoms are particularly sensitive to changes in water environments, and the composition of diatom communities serves as a significant indicator of the health of aquatic ecosystems. To understand the composition of diatom communities in Weishan Lake and their relationship with environmental factors, thereby providing scientific grounds for the protection of the lake’s ecological environment, surface sediment diatoms, water samples, and sediments were collected and analyzed. The study revealed that there are 64 species from 19 genera of diatoms in Weishan Lake, predominantly comprising epiphytic and planktonic species. Dominant species include Fragilaria brevistriata, Achnanthes minutissima, and Stephanodiscus parvus, indicating an overall meso-eutrophic status. According to the diatom composition and biodiversity index, the diatom community was divided into three combination zones. Redundancy analysis (RDA) results indicated that the water environmental factors influencing the composition and distribution of diatom communities in Weishan Lake are TP, TOC, DO, NO2 −–N, and Ca2+, collectively explaining 35.60% of the variation in diatom community composition. Due to the influence of agricultural and industrial wastewater runoff, domestic sewage discharge, and cage aquaculture, Weishan Lake is in a mesotrophic eutrophication state. Therefore, it is recommended that strict control over inappropriate human activities in the lake area be implemented in the future to ensure the safety of water quality for water diversion.

Optimized ridge-furrow technology with biochar amendment for alfalfa yield enhancement and soil erosion reduction based on a structural equation model on sloping land

Water scarcity and water-related soil erosion are severely exacerbated by inappropriate human activities and global climate change. Hence, to find a suitable technology to mitigate drought and soil erosion, three consecutive field experiments were conducted to explore the impact of ridge-furrow cropping with biochar amendment on soil water storage, runoff, sediment yield, soil nutrient losses, alfalfa (Medicago sativa L) fodder yield, crop water productivity (WPc), and economic benefit from 2019 to 2021. This experiment was conducted in a split-plot design, taking biochar amendment patterns (no biochar amendment and biochar amendment at a rate of 3× 104 kg ha−1) as a main plot and ridge-furrow technologies (traditional planting, open-ridging, and tied-ridging) as a split-plot. The combination of biochar amendment with ridge-furrow technology, especially tied-ridging technology, increased soil water storage, and captured runoff, sediment, and related soil nutrient losses, consequently increasing alfalfa fodder yield, WPc, and income. During this study, compared to traditional planting, open-ridging depicted an increase in soil water storage by a range of 9.8–39.6 mm, an alfalfa fodder yield boost ranging from 9.8% to 38.6%, and a WPc increase ranging from 0.1 to 16.5 kg ha−1 mm−1. On the other hand, tied-ridging showed greater improvements with soil water storage increasing by 29.1–65.1 mm, alfalfa fodder yield growing by 11.6–44.4%, and WPc advancing by 0.9–17.5 kg ha−1 mm−1. The mean decrease in runoff, sediment, and nutrients (total nitrogen, total phosphorus, and organic matter) loss for open-ridging was 17.9%-37.7%, 46.4%-75.5%, and 40.4%-75.3%, respectively, while for tied-ridging, it was 22.3%-55.5%, 62.1%-87.6%, and 49.0%-87.3%, respectively. Compared to no biochar amendment, soil water storage, alfalfa fodder yield, and WPc for biochar amendment increased by 9.1%-20.4%, 5.8%-52.7%, and 4.6–7.8 kg ha−1 mm−1, respectively, while runoff, sediment, and nutrients loss for biochar amendment decreased by 32.2%-40.9%, 25.5%-55.5%, and 35.9%-53.3%, respectively. Structural equation modeling analysis indicated that the significant direct effect of biochar amendment and ridge-furrow technology on WPc was 0.20 and 0.62, respectively, whereas the significant direct effect of runoff and actual crop evapotranspiration on alfalfa fodder yield was −0.40 and 0.94, respectively. Tied-ridge cropping combined with biochar addition was a highly suggested approach for addressing soil erosion and enhancing alfalfa fodder yields in the Loess Plateau in China. This technology could mitigate soil water scarcity and soil erosion, and give farmers the confidence to invest in this technology in dryland regions.

Water Erosion Risk Assessment for Conservation Planning in the East Hararghe Zone, Ethiopia

Water erosion is accelerating soil loss rates in the East Hararghe Zone due to inappropriate human activities and their complex and intertwined interactions with natural factors, particularly in sensitive agroecosystems that lack soil and water conservation (SWC) measures. Although these dynamic processes cause prolonged impacts, a comprehensive assessment of the risk of soil erosion has not yet been undertaken at the zonal level. To bridge this gap, we employed the revised universal soil loss equation (RUSLE) prediction model, along with remote sensing and geographic information systems (GIS), to estimate annual soil erosion rates, analyze the temporal-spatial patterns of erosion risk, and evaluate the potential of standard conservation practices to reduce soil loss in croplands. Total soil erosion (in millions of tonnes/year; Mt yr−1) was estimated to be 9 in 1990, 14 in 2000, 12 in 2010, and 11 in 2020, with average rates of 33, 50, 44, and 39 t ha−1 yr−1, respectively. This suggests an overall 18% increase in soil erosion from 1990 to 2020. Over 75% of the area showed a tolerable soil loss rate (<10 t ha−1 yr−1) and low susceptibility to erosion risk. A mountainous landscape in the northwest presents extremely high erosion (>120 t ha−1 yr−1), which accounts for more than 80% of soil loss, making SWC planning a priority. Analysis of land-use land-cover change (LULCC) confirmed a higher increase in soil loss for LULCC that involved conversion to croplands, with average rates of 36.4 t ha−1 yr−1 (1990–2000), 70 t ha−1 yr−1 (2000–2010), and 36 t ha−1 yr−1 (2010–2020). The results have further revealed that implementing supportive practices such as terracing, stripping, and contouring could reduce average soil erosion by approximately 87%, 65%, and 29%, respectively, compared to the baseline model’s prediction. Therefore, a rigorous cost–benefit analysis is essential to design and implement optimal location-specific practices that maximize investment returns in SWC efforts and ecological restoration. However, we acknowledge the limitations of this study, associated with an empirical model that does not account for all forms of erosion, as well as reliance mainly on secondary data, which may affect the accuracy of the predicted outcomes.

Analisis Kualitas Air pada Jalur Distribusi Air Bersih di Gedung Baru Fakultas Ekonomi dan Manajemen Institut Pertanian Bogor

One of the causes of the decreasing of water quality was the increasing of inappropriate human activities that caused water pollution. Cihideung River was being made as water resource in the campus area which the water have been used for a lot of activities in IPB Dramaga Campus. The purpose of this research were to analyze the clean water quality from the ground water tank (GWT) in Cihideung to the new buildings of the FEM, to compare the result with a national quality standard, to determine the criteria of clean water quality based on STORET method, and to analyze the influence of time and weather to the water quality. The parameters which had concentration below the standard were TDS, turbidity, temperature, iron, fluoride, chloride, manganese, and sulfate, and biological parameters like the total coliform/E.coli. The parameters which exceeded the standard were the value of color of 60 TCU in Cihideung GWT at rainy afternoon and pH of 6.38 in wing 1 sanitary at rainy morning. According to the US-EPA system, the water quality of distribution channels of FEM new building were classified into grade B, that meant light contaminated.Key words: distribution channels, quality standard, water pollution, water quality

Comparison of soil physico-chemical properties under different land-use and cover types in northeastern China's Horqin Sandy Land

The Horqin Sandy Land of northeastern China was originally a grassland with plenty of water and lush vegetation dominated by palatable grass species along with sparsely scattered woody species. However, it has experienced severe desertification in recent decades due to its fragile ecology together with inappropriate human activities. Currently, the landscape of the Horqin Sandy Land is dominated by irrigated croplands and sand dunes with different degrees of vegetation cover, as the region has become the most important part of the semiarid agro-pastoral ecotone of northern China. In this study, we compared soil physical and chemical properties under different land-use and cover types (irrigated cropland, rainfed cropland, sandy grassland, fixed dunes, and mobile dunes) . We found that soil particle size distribution; organic C, total N, and total mineral element, microelement, and available microelement and nutrient contents; pH; CEC; and bulk density differed significantly among the land-use and cover types. In general, soil quality was highest in the cropland, intermediate in the sandy grassland, and lowest in the dunes. The most important soil quality attribute, soil organic carbon (SOC) storage, decreased in the following order: irrigated cropland (5, 699 g/m 2 ) ＞ sandy grassland (3, 390 g/m 2 ) ＞ rainfed cropland (2, 411 g/m 2 ) ＞ fixed dunes (821 g/m 2 ) ＞ mobile dunes (463 g/m 2 ) . SOC was significantly positively correlated with a large proportion of the other soil physico-chemical parameters. Our results suggest that the key issue in restoration of the degraded soils will be to increase SOC storage, which would also create a high potential for sequestering soil C in desertified areas of the Horqin Sandy Land.

Simulation and control of the linked systems of water quantity–water quality–socio-economics in the Huaihe River basin

ABSTRACTSince the 1980s, inappropriate human activities and excessive water-resource exploitation have had a serious impact on the water environment of the Huaihe River basin. Water shortage and water pollution are both important factors restricting local socio-economic development. To demonstrate the interactions between the socio-economic system and the water-resource system, a physically-based hydro-economic model was developed. After division of the basin into sub-regions, a distributed model was developed that describes the combined systems of water quantity–water quality–socio-economics (WQQSE), and simulates ƒthe changing processes of water quantity and water quality from 1991 to 2000. On the basis of this hydro-economic model, an optimal-control model was also developed to research the maximum sustainable socio-economic scale of the river basin by considering hydro-economic interactions, water supply, water quality and socio-economic development constraints. The results demonstrate that the models developed can be used to depict the hydro-economic interaction and to indicate preferable management strategies to meet the development needs of the future.EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR Not assigned

Effect of vegetation types on chemical and biological properties of soils of karst ecosystems

Inappropriate human activities have caused widespread reductions of forests and have produced degradation in karst regions of China. In the past two decades, numerous attempts have been made to promote recovery of the degraded soil using afforestation and natural regeneration approaches. A better understanding of the effects of vegetation types on the chemical and biological properties of the soil is very important for both reforestation approaches. Five vegetation types, namely, natural old-growth forest (>80 years old), grassland (15–25 years old), natural regeneration (20–25 years old), bamboo plantation (23 years old) and pine plantation (22 years old), were investigated in the Maolan karst area of Guizhou Province. The soil quality index (SQI) was evaluated with a cluster analysis and a principal components analysis to compare soil quality classes among the vegetation types. The results indicated that soil organic matter, the MBC/TOC ratio and soil basal respiration were the most important factors reflecting the general chemical and biological properties of the soil. Based on the SQI values, the soil quality under the selected vegetation types could be divided into three groups: low soil quality (pine plantation with SQI = 0.26 and grassland with SQI = 0.29), intermediate soil quality (bamboo plantation with SQI = 0.41 and natural regeneration forest with SQI = 0.46) and high soil quality (natural old–growth forest with SQI = 0.63). The results of this study suggested that the pure plantation of Pinus massoniana had a negative impact on soil quality and that natural restoration may represent a more effective approach to the improvement of soil quality in degraded karst areas. These results also showed a strong interaction between soil quality, nutrient dynamics and vegetation types.

Oasis land-use change and its effects on the oasis eco-environment in Keriya Oasis, China

Land-use change in oases of arid zones play a significant role in the sustainable development and stability of oases. This paper presents a typical case of successful efforts to mitigate land-use change, its drivers and effects on the oasis eco-environment at Keriya Oasis in the western arid zone of China using remotely-sensed data, official statistics, and data collected by field investigation. Mathematical models were developed to quantify important elements related to land-use change, including net change and total change. The results indicate that: (1) approximately 17% of land-use types of Keriya Oasis changed between 1991 and 2002; (2) socioeconomic development, climate change, and economic polices contributed to land-use change in the oasis; (3) inappropriate human activities were the main cause of land-use change and eco-environmental degradation in the oasis; and (4) the stability of the oasis is threatened by land-use change and unexpected eco-environmental changes in the oasis and oasis–desert ecotone. The study suggests irrational human activity in arid zones, and that caution should be exercised to maintain stability and sustainable development of oases.

Eco-Environmental Evolution, Control, and Adjustment for Aibi Lake Catchment

Aibi Lake in north Xinjiang is a typical lake of the arid area, but with a peculiar wetland-arid area ecosystem. Due to the climate becoming drier and the disturbance of human activities, the eco-environment of Aibi Lake catchment has degraded. It was found in our study that there were spatial-temporal changes of vegetation cover, plant species, and soil physical and chemical properties in the catchment. In the upper section of alluvial-fluvial plains, the desertified steppe of Stipa and Artemisia spp. is developed with vegetation cover of some 50%. Haloxylon ammodendron desert occupies the lower section with vegetation cover of some 60%. In these regions with an intensive human disturbance, vegetation has degraded into herb vegetation of annual plant complexes. On the margins of the alluvial-fluvial fans, the lakeshore, and the surrounding regions where the river mouths join the lake, different azonal vegetation-Phragmites communis marsh, Phragmites communis meadow, and Tamarix shrubs-have developed with a vegetation cover of some 80%. On heavier, salinized land, succulent halophyte desert vegetation dominated by Halocnemum strobilaceum has formed with a fractional canopy cover of 10-15%. Haloxylon persicum, Aristida pennata, and other species with a vegetation cover of 30-50% grow in the sand desert zone on the periphery in the lake. In contrast with the 1950s, the vegetation cover around the lakebed and at the river deltas has slightly increased; however, the vegetation cover around the periphery of the lake has decreased and the plant species have still degraded. The surface soils on the windward area and the dried lakebed that have lost vegetation protection have become coarser, whereas the land on the leeward side of the lake has accumulated fine particles. In contrast with the 1980s, soil organic matter has declined markedly. The analyses of climatic data show that the number of days of drifting dust in Jinghe County and Bole City increased in the last 20 years. In the investigation, we found that intensively developed land, the bare lakebed, and abandoned cultivated land provided a great deal of material for drifting dust. In conclusion, we consider the eco-environmental degradation resulting from the inappropriate human activities and put forward recommendations for land-use adjustment and dust control.

Causes of land loss in Tuvalu, a small island nation in the pacific

Studies on land loss in Tuvalu reveal the following findings. Although both sea level rise and coastal erosion can cause land loss in the tropic Pacific oceanic islands, their mechanisms are different. When sea level rises, the low elevation coastal zone submerges and the erosion datum plane rises, the beach process progresses normally as always, resulting in no beach sediment coarsening. When the sea level is stable, coastal erosion removes finer sediment from reef flat, beach and land, resulting in beach sediment coarsening. The human-induced coastal erosion in the tropic Pacific oceanic islands has the following features. 1) Erosion occurs or intensifies immediately after inappropriate human activities. 2) It occurs near the places having human activities and places related to the above places in sediment supply. 3) It often occurs on original prograding or stable coasts (on lagoon coasts for atolls) because there are more coastal engineering projects and other human activities on such coasts. 4) It is chronic, covering a long period of time. The coastal geological events in Tuvalu islands do not accord with the features resulted from sea level rise but do accord with the features resulted from coastal erosion, particularly from human-induced erosion. The land loss in Tuvalu is mainly caused by inappropriate human activities including coastal engineering and aggregate mining, and partly caused by cyclones. Moreover, all recent measurements (satellite altimetry, thermosteric sea level data and tide observations) so far have not been able to verify any sea level rise around Tuvalu islands.