Pond Area Research Articles

Spatial Differentiation of Pond Landscapes across an Urban-Rural Gradient in the Pearl River Delta Region

The impact of ponds by urbanization has been widely discussed on the landscape scale. However, relatively few studies have explored the spatial differentiation of pond landscapes across urban-rural gradients in rapidly urbanising areas. In this study, we applied the DeepLabv3+ network to perform a semantic segmentation on Google Map images to extract ponds in the Pearl River Delta (PRD) region, China; then we employed geographic information systems to analyse the ponds changes in 665 towns along an urban-rural gradient in the PRD. Results indicate that there are clear differences in landscapes between the urban core, urban, peri-urban, agricultural, and forested zone in terms of pond area and size. In total, 57.84% and 31.33% of the ponds are distributed in the peri-urban and agricultural zone, respectively; fewer ponds are present at either end of the urban-rural gradient. Owing to the legacy effects of historical land use and river systems, urban and peri-urban zone in the central and western parts of the PRD are still rich in ponds. We propose that management measures should be implemented according to the characteristics of different pond landscapes.

Using quantitative eDNA analyses to accurately estimate American bullfrog abundance and to evaluate management efficacy

AbstractBiological invasions contribute now more than ever to the global homogenization of fauna and flora. Large‐scale monitoring programs are, therefore, needed to detect incipient invasions and to evaluate management interventions. As conventional monitoring methods are constrained by large costs, environmental DNA (eDNA)‐based methods are increasingly recognized as valuable monitoring tools. However, accurately estimating species abundance from eDNA concentrations in natural systems remains challenging and consequently hinders their integration in management applications. Here, we used droplet digital PCR (ddPCR) in eDNA surveys to estimate the abundance of invasive American bullfrogs (Lithobates catesbeianus). We first introduced bullfrog tadpoles in natural ponds to assess the relationship between abundances and eDNA concentrations under field conditions. Next, we combined eDNA sampling with fyke netting in naturally colonized ponds to investigate whether bullfrog eDNA concentrations can estimate bullfrog capture success and conventional abundance measures obtained via depletion sampling. Finally, we evaluated eradication measures by comparing bullfrog eDNA concentrations before and after fyke netting. We found a strong linear relationship between the numbers of introduced tadpoles and eDNA concentrations (r2 = 0.988). Bullfrog eDNA concentrations were not only linearly related to the catch‐per‐unit‐effort (r2 = 0.739), but also to conventional abundance estimates (r2 = 0.716), particularly when eDNA concentrations were standardized for pond area (r2 = 0.834) and volume (r2 = 0.888). Bullfrog tadpoles were only captured when eDNA concentrations exceeded 1.5 copies µl−1, indicating that quantitative eDNA analyses enable the localization of breeding ponds. We found a significant reduction in eDNA concentrations after fyke netting proportional to the number of captured bullfrogs. These results demonstrate that eDNA quantification is a reliable tool that accurately estimates bullfrog abundance in natural lentic systems. We show that quantitative eDNA analyses can complement the toolbox of natural resource managers and facilitate the coordination of eradication campaigns targeting alien invasive species.

Rapid expansion of coastal aquaculture ponds in Southeast Asia: Patterns, drivers and impacts

Aquaculture pond is one of the most important land use types and a main income source in coastal zones in Southeast Asia. However, the fast expansion of aquaculture ponds threatens coastal ecosystems – an issue that Sustainable Development Goals (SDGs)14 seeks to address. Investigating expansion patterns is essential for exploring the drivers and understanding its impacts, and thus the focus of the sustainable management of aquaculture. This study aims to assess the spatio-temporal expansion patterns of aquaculture ponds with multitemporal remote sensing images and geographic information system in the coastal zone of Southeast Asia over a 25-year period (1990–2015), to understanding how globalization and economic policies may have contributed to such changes. The results show that, in 2015, total area of coastal aquaculture ponds was about 23,245 km2, and 79% of coastal aquaculture ponds distributed within 15 km from the coastline. And the amount has expanded about 2.6 times in the past 25 years. Vietnam has the largest area of aquaculture in 2015 and the highest annual increasing rate, accounting for 40.28% and 298.5 km2/y, followed by Indonesia (31.50% and 156.8 km2/y), Thailand (10.79% and 64.8 km2/y), Myanmar (8.76% and 61.1 km2/y).The expansion pattern of aquaculture ponds in the region altered from outlying to edge-expansion from the year of 2000. The main drivers of rapid expansion lie to the intensified local fisher policies as a result of economic globalization. While development of aquaculture has enhanced family income, it has also led to significant reduction of mangrove and coastal water pollution (eutrophication). With the prevailing antagonism between aquaculture expansion and ecosystem conversion, our research call for the local government's attention to sustainable management of aquaculture. This will be the key to reduce food safety risk and simultaneously prevent inevitable damages to coastal ecosystems, as stipulated by SDGs 2 and 14.

Biodiversitas Makrobentos Sebagai Indikator Kualitas Habitat Pada Ekosistem Mangrove

Macrobenthos is one of the organisms that play an essential role in the decomposition process of mangrove plant litter. Other organisms then use the result of the decomposition process in mangrove forests. Still, the existence of these organisms is susceptible to environmental changes, so it is often interpreted as one of the indicators of habitat quality. This research aims to determine the sustainability and diversity of macrobenthos as an indicator of habitat quality in mangrove forests. Data collection is carried out by the plot cluster method. Sample deflating points using purposive sampling. Cluster plots are placed on three observation stations with different conditions, namely natural mangrove forests (station 1), former pond areas (station 2), and areas adjacent to agricultural land (station 3). Each station has three plots measuring 10 x 10 meters to record tree level mangrove vegetation. Each plot has five subplots measuring 1 x 1 meter to take macrobenthos samples. The total number of plots is nine plots for mangrove vegetation and 45 subplots for macrobenthos. The results showed that macrobenthos ability ranged from 10 individuals / m2 to 15 individuals / m2, with the diversity index ranging from 1.49 to 1.73. This condition illustrates that mangrove habitat is included in the medium classification in other words, based on the state of the structure of the biota Bentos community in the mangrove forest in Siantan District, Mempawah regency is fairly a stable category.

Impact of fish culture value chain development project on production, pond area, employment creation, and technical capability of participating farmers in some areas of Natore district, Bangladesh

This study examines the impact of the fish culture value chain development project of PKSF (Palli Karma Sahayak Foundation) implemented by United Development Initiatives for Program Action (UDDIPAN) on fish farmers in the Natore district. The project period was 20 months. With the views in mind, 600 project participating fish farmers were selected purposively from the study area. It is evident that 15.53% of farmers used lime regularly as a precautionary measure against fish stocks in their ponds but 84.46% of farmers applied lime irregularly. At present, 100% fish, farmers apply a moderate amount of lime during the preparation of fish farming ponds. The final assessment survey found that fish feeding increased by 95% of the farmers used regular and 5% of the farmers applied irregular food. The final fish marketing capabilities increased by 58.58% sold fish from farms, 20.32% from local markets, and 21.12% from national markets. Fry marketing increased by 83.57% sold fry to farmers, 16.27% to potters, and 6.18% to other places. Water change increased by 90% of the farmers change the water regularly and 10% of the farmers change the water irregularly in the pond after participating in the fish culture value chain development project of PKSF implemented by UDDIPAN. Fish production has been 14.77 kg per decimal in the pond. Finally, the study concludes that PKSF on fish culture value chain development project had positively influenced production, pond area, employment generation, and technical capability of participating farmers in the project area.

Minimum Requirement to Improve Quality before Discharging from Hybrid Red Tilapia Intensive Cage-Culture in Earthen Ponds to the Environment

This study determined a practical method to reduce environmental pollution by wastewater from fish ponds. Water quality in three hybrid red tilapia ponds (0.24 ha) was examined before and during harvest at five water depths of 10, 20, 50, 100, and 150 cm, as well as at the water surface and pond bottom. All water samples were analyzed for BOD, TN, TP, TAN, TS, TSS, and SS, with results compared with the Thailand control standard for freshwater aquaculture effluent. All quality parameters of the seven water samples showed statistical significance (p<0.05) that increased with water depth. Degradation was highest in the bottom 50 cm of the fish pond. Limiting drainage to a depth of 50 cm was achieved by tilting the drainage pipe, and the resulting effluent met all water quality parameter standards. At a water depth of 50 cm, the remaining water was drained using a water pump, and all water quality parameters failed to meet the required standards. When this water was allowed to settle for 24 h, BOD, TN, TP, TAN, and TSS reduced to 21.06%, 2.42%, 11.68%, 5.47%, and 43.36% of full pond values, respectively. Results suggested sedimentation as a practical technique requiring a smaller pond area to reduce environmental pollution.

Prairie wetlands as sources or sinks of nitrous oxide: Effects of land use and hydrology

National and global greenhouse gas (GHG) budgets are continually being refined as data become available. Primary sources of the potent GHG nitrous oxide (N2O) include agricultural soil management and burning of fossil fuels, but comprehensive N2O budgets also incorporate less prominent factors such as wetlands. Freshwater wetland GHG flux estimates, however, have high uncertainty, and wetlands have been identified as both sources and sinks. Here, we analyzed a regional database of >26,000 N2O chamber flux measurements sampled across >150 wetlands from the Prairie Pothole Region (PPR) in the Great Plains of North America. Our goal was to identify important land use and hydrologic drivers of N2O flux to help reduce uncertainty in N2O models, and to incorporate these drivers into an upscaled estimate of wetland N2O emissions from the U.S. portion of the PPR. Within individual wetlands, exposed soils with no standing water, such as along wetland edges, were hotspots that accounted for greater than 90% of wetland N2O emissions. In contrast wet (i.e., ponded) areas had minimal or negative N2O flux. N2O flux from wetlands nested within croplands (16.3–17.3 μg N2O m−2 hr−1) was, in some instances, nearly double that from wetlands within grasslands (9.2–14.4 μg N2O m−2 h−1). We estimated that seasonal N2O flux from PPR wetlands equated to roughly 0.2% (1.04 Tg CO2 equivalents) of the U.S. N2O budget (c. 2019). Overall, even though PPR wetlands are a small net source of N2O to the atmosphere, their emissions are negligible relative to agricultural soil management. Policy and management to restore wetland hydrology and surrounding uplands from cropland to grasslands can reduce landscape N2O fluxes. Future activities focused on wetland N2O flux would benefit from inclusion of adjacent land use and hydrologic factors, as well as from incorporation of temporally dynamic ponded wetland areas.

Surface Groundwater Pollution Dynamics Over 2015-2020 in the Salt Drying Pond of Pademawu Subdistrict, Madura, Indonesia

Pamekasan coastal area is the center of salt production concentrated in the Pademawu subdistrict with the ponds area of 740.96 ha. The sufficiently close distance of salt ponds to settlement areas allows several issues, such as shallow groundwater salinization. This study aimed to determine the salt pond’s degradation over five years (2015-2020) and its influence on the salinization issue in Pademawu. We compare groundwater quality parameters (conductivity, TDS, the depth of shallow surface groundwater, and salinity) surveyed in 2015 and 2020, correlated to salt pond area alterations. Over five years of measurement, it was found that conductivity declined, reaching 2779.94 µS/cm. Based on TDS deterioration, groundwater transformed from brackish to freshwater in 2020. By contrast, the depth of shallow groundwater-surface increased by almost one meter. The freshwater area also increased by 22% over five years based on conductivity classification. Groundwater quality dynamics are related to the alteration of the salt pond area. On the other hand, the significant increase in rainfall intensity, which is not beneficial for salt agriculture, results in the salt pond area deterioration, thereby declining surface groundwater salinity in Pademawu due to the less interaction between Cl and groundwater within aquifers. Although the groundwater pollution induced by seawater intrusion and salinization declined in 2020, re-organizing the distance between salt ponds and the settlement area in Pademawu is crucial to minimize further groundwater pollution. 
 Keywords : Dynamics; pollution; groundwater; salt agriculture; Pademawu
 
 Copyright (c) 2022 Geosfera Indonesia and Department of Geography Education, University of Jember
 This work is licensed under a Creative Commons Attribution-Share A like 4.0 International License

Practice of application of fish rotation in KFH “BAM” Astrakhan region

The modern development of pond aquaculture dictates the need to improve biotechnologies to increase productivity, reduce costs and produce highquality fish products. Fish rotation is a system of sequentially growing fish and crops to improve the soil and optimize the natural food supply in ponds in order to increase the productivity of the crops grown. In recent years, this practice has been widely developed in many farms of the country, and in particular, in the BAM peasant farm, which is one of the largest in the Astrakhan region, where up to 400 tons of fish and 700 tons of fish are produced annually on six hundred hectares of pond areas. gourds. On the basis of this farm, in the fish-breeding season of 2021, studies were carried out, according to a comparative assessment, of the fish-breeding indicators of carp and herbivorous fish grown in three ponds before and after melon crops. The temperature and hydrochemical regimes, changes in the weight of the studied individuals and the total biomass of fish in the ponds for the season from March to September, as well as feed costs, fish productivity and melon crops were studied. Carp were fed manually in the ponds with wheat or barley, which were applied to feeding places once a day in the morning, with a volume of 5% of the total fish biomass. This year, one pond was taken out for flying, and melons were grown in it, and in pond No. 4, experimental work was carried out to grow cyprinid fish species after cultivating melons in it. The obtained results indicate that the use of ponds for growing gourds — melons allows for the next year to improve the natural food base, which has a positive effect on fish breeding indicators: survival rate, fish productivity and reduced feed costs. Growing gourds in fish ponds improves the yield of melons by 24.4% compared to normal conditions.

Study on Shrimp Production in Peureulak Coastal National Priority Program, Aceh Timur, Aceh

The potential for shrimp in the Peureulak Coast of East Aceh, Aceh is very large, so that it is part of the increase in the National shrimp with a target of 250%. The purpose of this study was to examine intensive, semi-intensive and extensive shrimp production. This research uses case studies, financial analysis through observation and interviews. To find out the level of shrimp production which has a productive shrimp pond area of 5,072.14 hectares (50,721,400 m2), the existing production data per year reaches 1,078,960 kg so that a study is needed for 1 cycle with Operation Profit, Net Profile, Profile Rate, Benefit Cost Ratio , Rentability, Break Event Point (BEP) and Payback Period (PP). The results of the analysis carried out from intensive, semi-intensive and extensive ponds, the level of net returns from investment, is extensive pond analysis because it is seen from a percentage of 0.48%, with a B / C ratio of 3%, but the longest payback period is 4 years of extensive ponds. Meanwhile, intensive ponds are 3.1 years and semi-intensive ponds are 3 years, while the biggest profit is found in intensive ponds of Rp. 223,135,000 and analysis of existing shrimp production of 10% of the total pond area of 5,072.14 hectares (50,721,400 m2), namely intensive ponds 34,236,945 kg, semi intensive 26,628,735 kg and extensive 1,997,916, then the economic potential of the area is sufficient. large and sustainable.

Conserving wetlands in agroecosystems can sustain aerial insectivore productivity and survival

Agricultural intensification simplifies natural landscapes and frequently results in the loss of biodiversity. Wetlands are highly productive and may offset these losses, but the amount of wetland area needed to support declining avian species on farmland is unknown. Using an avian aerial insectivore, the Tree Swallow ( Tachycineta bicolor (Vieillot, 1808)), we tested whether a gradient of pond area (visible surface water in wetland basins within 500 m of nest boxes; range 0.2%–30% pond area) at cropland and grassland sites was related to aquatic insect biomass, reproductive success, and adult female or nestling body condition. Aquatic insect biomass was ∼2–8 times higher at the cropland sites with intermediate (5.2%) pond areas than at sites with the highest (15.6%) and lowest (0.2%) pond areas. Swallow clutch initiation date was ∼3–4 days earlier, and nestling body condition and model-predicted first-year survival were ∼10% higher among cropland sites with more pond area and were comparable to birds hatched at grassland sites. Loss of ponds due to agricultural drainage can reduce aquatic insect prey during the breeding season with apparent individual and demographic consequences for insectivorous birds. Overall, the results suggest that where wetlands are conserved, intensive croplands can sustain Tree Swallow populations.

Influence of climate on seawater quality and green mussel production

This study aimed to investigate the relationships between atmospheric parameters, seawater quality and green mussel production which were cultured in pond, estuary and coastal areas. Seawater and mussel samples were collected from mussel farms in the inner Gulf of Thailand from January to December 2019. Climate data were obtained from the Thai Meteorological Department. The correlations between selected atmospheric and seawater parameters were developed using linear and non-linear models. The influence of seawater quality on mussel production was evaluated using principal component analysis and stepwise multiple linear regression. The effects of atmospheric variation on green mussel productivity were simulated. The results showed that high air temperature and rainfall caused an increase in seawater temperature and a decrease in salinity, respectively. It was observed that the most influential factors affecting mussel production were nutrients and dissolved oxygen in ponds, temperature and salinity in estuaries, and nutrients and pH in coastal areas. The simulation indicated that mussel production can deteriorate when air temperature reaches 34°C and rainfall is higher than 200 mm per month. Our results suggest that under climate change events, locations with less riverine influence can provide higher mussel productivity. These results can be used as a guideline for farmers during a climate change event.

Where the wild beavers are: Climate and landscape controls on beaver pond area in snow‐dominated rangeland headwaters

AbstractBeavers are of increasing interest as a mechanism for ecosystem restoration. However, the physical watershed characteristics that allow for successful beaver re‐establishment are not consistent across habitat suitability models. We delineated the extent of beaver impounded surface water in the Pole Mountain Area (PMA) of south‐eastern Wyoming with six National Agricultural Imagery Program acquisitions over an 18‐year time period via a random forest classification algorithm. We computed beaver pond area for first‐ and second‐order watersheds within the PMA and related the impounded pond area to climatic metrics such as maximum annual snow water equivalent and snowmelt and rain input into the ground. There was no apparent relationship between annual climate metrics and beaver pond area. Further, we developed a random forest regression model to correlate beaver pond area with topographically derived watershed characteristics (e.g. hillslope size and riparian area size) to explore physical controls on impounded area at the watershed scale. Controls differed for first‐ and second‐order watersheds, with pond area in smaller watersheds largely being controlled by lateral water contributions from the hillslopes and in the larger watersheds by water from upstream and available space in the riparian areas. Interestingly, vegetation height did not emerge as an important predictor for pond area, likely because of generally good availability of forage material in all watersheds. This study improves our understanding of watershed characteristics that contribute to beaver habitat suitability and can be used to guide beaver reintroduction efforts through analysis targeted at identifying watersheds most appropriate to beaver pond construction.

Evaluation of Multi-Function Drainage Channels For Running Water Fish Culture For The Benefit of The Community In Pangururan District

Pangururan Subdistrict in Samosir Regency requires rearranging its open land functions related to the meaning of the environment. From the civil engineering perspective, landslides can occur suddenly during the rainy season without being noticed by the people around the Pangururan sub-district, Samosir Regency. To realize this program, the community can add the function of the drainage channel into a mobile fish pond around the Pangururan Subdistrict, Samosir Regency, which still has a large area of land/settlements to become a running fish pond drainage channel. This can increase residents' income which is beneficial for the community around the drainage canal. In addition, the problem of overflowing water in the rainy season will be minimized. To implement this program, an analysis should be prepared in advance to evaluate the drainage channel that will function as a fish pond around Pangururan District, Samosir Regency. In line with the government's program in promoting and increasing the income of residents, the existing drainage channels should be utilized. Unproductive drainage channels can become productive drainage channels by cultivating freshwater fish along the drainage channel while simultaneously irrigating rice fields. Therefore, a wet section of the plan is made along 1000 meters where the condition of the drainage channel is planned according to the analysis. The depth of the drainage channel for running water fish ponds is 100 to 170 cm and the width of the top side from 100 cm to 150 cm, and the width of the sides below 100 cm. Based on the calculations, the first process that must be done is to first calculate the maximum planned rainfall, calculate the planned discharge, calculate the dimensions of the channel, and flood discharge (designated discharge), where QT = 0.278 x C x I x A = 6.69 m3/s at a speed of plan average flow. The flow velocity of the drainage channel is installed with a sluice so that the average velocity value is = 1/n R2/3 x S1/2 = 3.8 m/s, the cross-sectional area of a fish pond with a wet cross-section A = a x b = 1.904 m2, the cross-sectional area of the wet plan making fish ponds where the channel design discharge for fish ponds is QS = AS x V = 7.23 m3/s and the calculation of sluice gates with a width of 50 cm and a height of 170 cm for fish pond water with Q = (u x b x a ) x 3 of 10.8 m/s.

Allometric Model, Aboveground Biomass and Carbon Sequestration of Natural Regeneration of Avicennia lanata (Ridley). at in-active Pond of Muna Regency, Southeast Sulawesi

This study aimed to establish an allometric model for estimation of aboveground biomass, and carbon sequestration in A. lanata mangrove forest growing in Muna Regency, Southeast Sulawesi. Research methods were done by transect and 5 quadrats with size of 100 m2 each. A total of thirteen individual trees with different sizes were harvested. While DBH and D30 were measured. The samples were separated into stems, branches, and leaves and then weighted. The sample from each fresh organs were taken and brought to the Laboratory and then oven dried at 80°C for 7 days. The allometric equations were established by using independent variables (DBH and D30), and dependent variables (Ws, Wb, Wl). The partial and overall aboveground biomasses were calculated from allometric model, while carbon stock and CO2 sequestration were estimated. The results showed that the independent variable of DBH was more applicable for estimation of Ws, Wb, Wl, and total biomasses (Mg ha-1) of A. lanata forest, which were estimated as 28.28±3.48, 6.40±0.79, 5.00±0.66, and 40.08±4.97 respectively. The carbon stock in stems (13.24±1.63 Mg ha-1) was higher than in branches (3.01±0.37 Mg C ha-1) as well as in leaves (2.35±0.31 Mg C ha-1). The total of carbon stock were estimated at about 18.83±2.33 Mg C ha-1. Meanwhile, the total of CO2 absorption by A. lanata mangrove was 43.95±5.45 Mg CO2 ha-1. Therefore a regenerated A. lanata mangrove in this in-active pond area had potentiality on carbon stock and sequestrations, although these vegetation condition was still in the growth stage.

Optimizing Hydraulic Retention Time and Area of Biological Settling Ponds for Super-Intensive Shrimp Wastewater Treatment Systems

Biological settling ponds are a practicable approach for treating super-intensive shrimp aquaculture wastewater for almost all shrimp producers in the Vietnamese Mekong Delta (VMD). The optimization of the hydraulic retention time (HRT) of biological settling ponds plays a crucial role in establishing the stability of outflow wastewater quality and suitability of the settling pond area (SPA). This study aims to suggest appropriate HRT and SPA for super-intensive shrimp wastewater treatment systems based on the National Standard (QCVN 02-19:2014/BNNPTNT) and the best aquaculture practices (BAP) standards and guidelines. We investigated 20 typical super-intensive shrimp farms in the VMD and collected effluent samples from siphoning process, daily water exchange, and outflow of biological effluent-treatment settling ponds. The results showed that the average of each super-intensive shrimp farm produced wastewater at approximately 218 m3 ha−1 day−1. The contaminant loads of TSS, COD, TKN, and TP were commensurate to 177, 113, 9.86, and 4.19 kg ha−1 day−1, respectively. Based on the relationship between outflow COD, TSS concentrations, and HRT of biological-surveyed settling ponds, a 13.4-day HRT and 1934-m2 SPA were suggested to optimize the super-intensive shrimp wastewater treatment systems. Our recommendation for further work is to continuously optimize the HRT and SPA rates of functional ponds (anaerobic, facultative, and maturation) to ameliorate the engineering configuration of the recommended biological settling pond.

Evaluation of effective use of dredged soil as containment dikes of a disposal pond in Japan

An extra fill on a revetment was constructed by using mechanically dewatered clay (MDC) made from dredged material in the third area of the Shinmoji-Oki disposal pond (S-3), Japan, in 2011. Since MDC is an artificial material, its long-term stability has not been confirmed. To understand the long-term stability of the constructed revetment, mechanical tests, such as box shear tests, were conducted on block samples taken from two designated areas of the extra fill on the revetment over the 10 years since its construction (2011–2020). As a result, it was confirmed that the shear strength under certain overburden effective stress sufficiently satisfied the value assumed at the designing stage and the strength properties did not change much after 10 years, although the strength constants varied.

Exploratory Analysis on the Spatial Distribution and Influencing Factors of Beitang Landscape in the Shangzhuang Basin

Beitang landscape is a production system and land use pattern that ancient people created to adapt to droughts and floods during a long traditional farming culture. It has a critical reference meaning for water resource use and water systems protection in modern cities. Taking the Shangzhuang Basin (China) as an example, this study used multi-source data, such as remote sensing images, Beitang vector dataset, land-use dataset, elevation, slope, river, road, and field survey, to investigate the spatial distribution and influencing factors Beitang landscape. Results showed that in a typical small watershed basin, an area of ponds accounted for 1.0%, about 12 ponds per square kilometer—the average area of ponds is 814 m2, of which the vast majority is less than 1000 m2. The study found that the spatial distribution of Beitang in the Shangzhuang Basin has cluster characteristics, influenced by elevation, slope, aspect, river, roads, villages, farmland, woodland, and other factors, all of which have closely related to the natural environment development and human activities. The upstream, middle, and downstream of three Beitang landscapes were coordinated to support the Beitang landscape system in the small watershed of the basin. Findings provided a model for protecting and utilizing natural water systems in rural areas during the construction of sponge cities.

Economic Analysis of Sustainable Admission Business in Development Area Tanete Riattang East Bone

The results of this study aim to determine the pattern of business activities and application of pond cultivation technology and the level of feasibility per unit of pond land. Starting from January - July, 2020, in Tanete Riattang Timur District. The pond business patterns are grouped into milkfish monoculture (Chanos chanos fork), milkfish polyculture (Chanos chanos fork) and seaweed (Gracillaria verrucosa), milkfish (Chanos chanos fork) and shrimp (Litopenaeus vannamei) polycultures with narrow (< 2 hectares), medium (2-5 hectares) and broad (> 5 hectares) scales. The results of the study show that almost all of the ponds in the Tanete Riattang Timur sub-district have entisol soil types. The soil texture is fine and coarse, the slope of the pond land is 1-9%. The appropriate distance for aquaculture is 50 – 500 meters from the river bank, water pH ranges from 7.5 – 8, salinity ranges from 15 – 29 ppt, water temperature ranges from 29 – 32 0C. GIS analysis of total pond area ±817.015 Ha. Respondents were 59 Fishery Households (RTP). The financial feasibility of monoculture milkfish (Chanos chanos fork) DF 12%, the highest is the NPV of Rp. 57,267,164. Net B/C ratio 1.77; IRR of 29.03%. The financial feasibility of milkfish (Chanos chanos fork)-shrimp polyculture where the highest DF 12% is the NPV of Rp. 88,857,765, Net B/C ratio of 2,099; IRR of 35.48%. The financial feasibility of polyculture of milkfish (Chanos chanos fork) seaweed (Gracillaria verrucosa) where the DF is 12% with the highest value, namely NPVRp. 90,665,055; Net B/C ratio of 2,099; IRR is 33.67%. The conclusion is that the land suitability category in Tanete Riattang Timur District consists of very suitable.

Present status of freshwater prawn (Macrobrachium rosenbergii) farming in Dinajpur District of Bangladesh

A year-long investigation, on the farming status of freshwater prawn in Dinajpur district of Bangladesh, revealed that prawn was cultured in polyculture systems with finfish in ponds (94.64%) and rice fields (5.36%). Average pond areas of 51.78% farmers were less than 0.50 acre and average depth 1.52m. Solely farm made feeds, manufactured with mustard oil cake, rice bran, maize bran, wheat bran, were applied by 41.07% farmers and commercial feeds by 30.36%. Feeds were applied manually twice daily by most of the farmers. Different social, technical and financial problems faced by farmers (91.07%) were unavailability and higher price of prawn seed, electricity, lack of proper knowledge on prawn farming etc. Although prawn culture can contribute to uplift the socio-economic status of the farmers, it was a recent and subsistence practice and not adopted widely by the farmers.